Drug Information

Drug (ID: DG00136) and It's Reported Resistant Information

• Name: Isoniazid
• Synonyms: Abdizide; Andrazide; Anidrasona; Antimicina; Antituberkulosum; Armacide; Armazid; Armazide; Atcotibine; Azuren; Bacillen; Bacillin; Cedin; Cemidon; Chemiazid; Chemidon; Continazine; Cortinazine; Cotinazin; Cotinizin; Defonin; Dibutin; Diforin; Dinacrin; Ditubin; Ebidene; Eralon; Ertuban; Eutizon; Evalon; Fetefu; Fimalene; HIA; Hidranizil; Hidrasonil; Hidrulta; Hidrun; Hycozid; Hydra; Hydrazid; Hydrazide; Hyozid; Hyzyd; INH; Idrazil; Inah; Inizid; Iscotin; Isidrina; Ismazide; Isobicina; Isocid; Isocidene; Isocotin; Isohydrazide; Isokin; Isolyn; Isonerit; Isonex; Isoniacid; Isoniazida; Isoniazide; Isoniazidum; Isonicazide; Isonicid; Isonico; Isonicotan; Isonicotil; Isonicotinhydrazid; Isonicotinohydrazide; Isonide; Isonidrin; Isonikazid; Isonilex; Isonin; Isonindon; Isonirit; Isoniton; Isonizida; Isonizide; Isotamine; Isotebe; Isotebezid; Isotinyl; Isozid; Isozide; Isozyd; LANIZID; Laniazid; Laniozid; Mybasan; Neoteben; Neoxin; Neumandin; Nevin; Niadrin; Nicazide; Nicetal; Nicizina; Niconyl; Nicotibina; Nicotibine; Nicotisan; Nicozide; Nidaton; Nidrazid; Nikozid; Niplen; Nitadon; Niteban; Nydrazid; Nyscozid; Pelazid; Percin; Phthisen; Pycazide; Pyreazid; Pyricidin; Pyridicin; Pyrizidin; Raumanon; Razide; Retozide; Rimicid; Rimifon; Rimiphone; Rimitsid; Robiselin; Robisellin; Roxifen; Sanohidrazina; Sauterazid; Sauterzid; Stanozide; Tebecid; Tebemid; Tebenic; Tebexin; Tebilon; Tebos; Teebaconin; Tekazin; Tibazide; Tibemid; Tibiazide; Tibinide; Tibison; Tibivis; Tibizide; Tibusan; Tisin; Tisiodrazida; Tizide; Tubazid; Tubazide; Tubeco; Tubecotubercid; Tubercid; Tuberian; Tubicon; Tubilysin; Tubizid; Tubomel; Tyvid; Unicocyde; Unicozyde; Vazadrine; Vederon; Zidafimia; Zinadon; Zonazide; Hid rasonil; Isoco tin; Isoniazid SA; Isozid e; Nidra zid; Rimif on; BP 5015; Bp 5 015; FSR 3; I0138; INHd20; L 1945; Nitebannsc 9659; Preparation 6424; RP 5015; AZT + Isoniazid; Cedin (Aerosol); Dow-Isoniazid; FRS-3; FSR-3; Ido-tebin; In-73; Inh-Burgthal; Isoniazid & EEP; Isoniazid & Propolis; Laniazid (TN); Neo-Tizide; Nydrazid (TN); RP-5015; TB-Phlogin; TB-Razide; TB-Vis; Usaf cb-2; I.A.I; RU-EF-Tb; RY-EF-Tb; I.A.I.
• Indication:
  In total 1 Indication(s)
  HIV-infected patients with tuberculosis [ICD-11: 1B10-1B14]; Approved; [1]
• Drug Resistance Disease(s):
  Disease(s) with Clinically Reported Resistance for This Drug (4 diseases)
  Pneumoconiosis [ICD-11: CA60]; [2]
  Tuberculosis [ICD-11: 1B10]; [3]
  Tuberculous sclerokeratitis [ICD-11: 1B12]; [4]
  Urinary tuberculosis [ICD-11: 1G80]; [5]
  Disease(s) with Resistance Information Validated by in-vivo Model for This Drug (2 diseases)
  HIV associated with tuberculosis [ICD-11: 1C60]; [6]
  Mycobacterial diseases [ICD-11: 1B2Z ]; [1]
• Target: Bacterial Fatty acid synthetase I (Bact inhA); INHA_MYCTU; [1]
• Formula: C6H7N3O
• IsoSMILES: C1=CN=CC=C1C(=O)NN
• InChI: 1S/C6H7N3O/c7-9-6(10)5-1-3-8-4-2-5/h1-4H,7H2,(H,9,10)
• InChIKey: QRXWMOHMRWLFEY-UHFFFAOYSA-N
• PubChem CID: 3767
• ChEBI ID: CHEBI:6030
• TTD Drug ID: D09XQF
• VARIDT ID: DR00422
• INTEDE ID: DR0886
• DrugBank ID: DB00951

Type(s) of Resistant Mechanism of This Drug

  ADTT: Aberration of the Drug's Therapeutic Target

  DISM: Drug Inactivation by Structure Modification

  UAPP: Unusual Activation of Pro-survival Pathway

Drug Resistance Data Categorized by Their Corresponding Diseases

ICD-01: Infectious/parasitic diseases

Tuberculosis [ICD-11: 1B10]

Drug Resistance Data Categorized by Their Corresponding Mechanisms

Aberration of the Drug's Therapeutic Target (ADTT)

Key Molecule: Enoyl-[acyl-carrier-protein] reductase [NADH] (INHA) [3]

• Molecule Alteration: Mutation; .
• Resistant Disease: Tuberculosis [ICD-11: 1B10.0]
• Experimental Note: Identified from the Human Clinical Data
• In Vitro Model: Mycobacterium tuberculosis H37Rv; 83332
• In Vitro Model: Mycobacterium tuberculosis isolates; 1773
• Experiment for Molecule Alteration: qRT-PCR
• Mechanism Description: Monoresistance to rifampicin and isoniazid was found in 11% (95% CI: 0.077-0.150; p, 0.087) and 8.5% (95% CI: 0.056-0.123; p, 0.692) of all the patients, respectively. Resistance to RIF and INH among newly diagnosed patients was 10.2% and 8.6%, while among previously treated patients, resistance to RIF and INH was 23.5% and 5.9% respectively. Furthermore, 4.9% of the samples from newly diagnosed with INH monoresistance, were found to have mutations in the InhA region while 8.6% had mutations in the katG region, a condition that can lead to phenotypic isoniazid drug resistance.

Unusual Activation of Pro-survival Pathway (UAPP)

Key Molecule: DNA-directed RNA polymerase subunit beta (RPOB) [3]

• Molecule Alteration: Mutation; .
• Resistant Disease: Tuberculosis [ICD-11: 1B10.0]
• Experimental Note: Identified from the Human Clinical Data
• In Vitro Model: Mycobacterium tuberculosis H37Rv; 83332
• In Vitro Model: Mycobacterium tuberculosis isolates; 1773
• Experiment for Molecule Alteration: qRT-PCR
• Mechanism Description: Monoresistance to rifampicin and isoniazid was found in 11% (95% CI: 0.077-0.150; p, 0.087) and 8.5% (95% CI: 0.056-0.123; p, 0.692) of all the patients, respectively. Resistance to RIF and INH among newly diagnosed patients was 10.2% and 8.6%, while among previously treated patients, resistance to RIF and INH was 23.5% and 5.9% respectively. Furthermore, 4.9% of the samples from newly diagnosed with INH monoresistance, were found to have mutations in the InhA region while 8.6% had mutations in the katG region, a condition that can lead to phenotypic isoniazid drug resistance.

Mycobacterial diseases [ICD-11: 1B2Z ]

Drug Resistance Data Categorized by Their Corresponding Mechanisms

Aberration of the Drug's Therapeutic Target (ADTT)

Key Molecule: Enoyl-[acyl-carrier-protein] reductase [NADH] (INHA) [7]

• Molecule Alteration: Missense mutation; p.G141E
• Resistant Disease: Mycolicibacterium smegmatis infection [ICD-11: 1B2Z.6]
• Experimental Note: Discovered Using In-vivo Testing Model
• In Vitro Model: Mycobacterium tuberculosis strain H37Rv ATCC27294 T; 83332
• Experiment for Molecule Alteration: Sequencing analysis
• Experiment for Drug Resistance: In vitro drug susceptibility testing
• Mechanism Description: Notably, isoniazid is activated by the enzyme catalase-peroxidase, KatG, encoded by katG, whereas prothionamide is activated by the flavin monoxygenase, EthA, encoded by ethA. Mutations in katG and ethA are associated with individual isoniazid and prothionamide/ethionamide resistance, respectively. The ndh gene coding for NADH dehydrogenase, Ndh, was first identified as a new mechanism for INHR in Mycobacterium smegmatis. The mutations in ndh gene cause defects in the oxidation of NADH to NAD, which results in NADH accumulation and NAD depletion. The increased level of NADH inhibits the binding of isoniazid-NAD adduct to the active site of the InhA enzyme, which disturbs the regulation of enzyme activity and may cause co-resistance to isoniazid and prothionamide. EthR, a member of the TetR/CamR family, is a repressor of ethA. EthR regulates the transcription of ethA by coordinated octamerization on a 55-bp operator situated in the ethA-R intergenic region. Impeding EthR function leads to enhanced mycobacterial sensitivity to prothionamide, whereas mutations in ethR encoding a negative transcriptional regulator of the expression of EthA lead to prothionamide resistance. Finally, MshA, a member of the glycosyltransferase family, is a key enzyme involved in mycothiol biosynthesis in M. tuberculosis. Mutations in mshA coding MshA have been proposed to create a disturbance in prothionamide/ethionamide activation.

Key Molecule: Enoyl-[acyl-carrier-protein] reductase [NADH] (INHA) [7]

• Molecule Alteration: Missense mutation; p.S94A
• Resistant Disease: Mycolicibacterium smegmatis infection [ICD-11: 1B2Z.6]
• Experimental Note: Discovered Using In-vivo Testing Model
• In Vitro Model: Mycobacterium tuberculosis strain H37Rv ATCC27294 T; 83332
• Experiment for Molecule Alteration: Sequencing analysis
• Experiment for Drug Resistance: In vitro drug susceptibility testing
• Mechanism Description: Notably, isoniazid is activated by the enzyme catalase-peroxidase, KatG, encoded by katG, whereas prothionamide is activated by the flavin monoxygenase, EthA, encoded by ethA. Mutations in katG and ethA are associated with individual isoniazid and prothionamide/ethionamide resistance, respectively. The ndh gene coding for NADH dehydrogenase, Ndh, was first identified as a new mechanism for INHR in Mycobacterium smegmatis. The mutations in ndh gene cause defects in the oxidation of NADH to NAD, which results in NADH accumulation and NAD depletion. The increased level of NADH inhibits the binding of isoniazid-NAD adduct to the active site of the InhA enzyme, which disturbs the regulation of enzyme activity and may cause co-resistance to isoniazid and prothionamide. EthR, a member of the TetR/CamR family, is a repressor of ethA. EthR regulates the transcription of ethA by coordinated octamerization on a 55-bp operator situated in the ethA-R intergenic region. Impeding EthR function leads to enhanced mycobacterial sensitivity to prothionamide, whereas mutations in ethR encoding a negative transcriptional regulator of the expression of EthA lead to prothionamide resistance. Finally, MshA, a member of the glycosyltransferase family, is a key enzyme involved in mycothiol biosynthesis in M. tuberculosis. Mutations in mshA coding MshA have been proposed to create a disturbance in prothionamide/ethionamide activation.

Key Molecule: Enoyl-[acyl-carrier-protein] reductase [NADH] (INHA) [7]

• Molecule Alteration: Missense mutation; p.I194T
• Resistant Disease: Mycolicibacterium smegmatis infection [ICD-11: 1B2Z.6]
• Experimental Note: Discovered Using In-vivo Testing Model
• In Vitro Model: Mycobacterium tuberculosis strain H37Rv ATCC27294 T; 83332
• Experiment for Molecule Alteration: Sequencing analysis
• Experiment for Drug Resistance: In vitro drug susceptibility testing
• Mechanism Description: Notably, isoniazid is activated by the enzyme catalase-peroxidase, KatG, encoded by katG, whereas prothionamide is activated by the flavin monoxygenase, EthA, encoded by ethA. Mutations in katG and ethA are associated with individual isoniazid and prothionamide/ethionamide resistance, respectively. The ndh gene coding for NADH dehydrogenase, Ndh, was first identified as a new mechanism for INHR in Mycobacterium smegmatis. The mutations in ndh gene cause defects in the oxidation of NADH to NAD, which results in NADH accumulation and NAD depletion. The increased level of NADH inhibits the binding of isoniazid-NAD adduct to the active site of the InhA enzyme, which disturbs the regulation of enzyme activity and may cause co-resistance to isoniazid and prothionamide. EthR, a member of the TetR/CamR family, is a repressor of ethA. EthR regulates the transcription of ethA by coordinated octamerization on a 55-bp operator situated in the ethA-R intergenic region. Impeding EthR function leads to enhanced mycobacterial sensitivity to prothionamide, whereas mutations in ethR encoding a negative transcriptional regulator of the expression of EthA lead to prothionamide resistance. Finally, MshA, a member of the glycosyltransferase family, is a key enzyme involved in mycothiol biosynthesis in M. tuberculosis. Mutations in mshA coding MshA have been proposed to create a disturbance in prothionamide/ethionamide activation.

Drug Inactivation by Structure Modification (DISM)

Key Molecule: Catalase-peroxidase (KATG) [7]

• Molecule Alteration: Missense mutation; p.S315T
• Resistant Disease: Mycolicibacterium smegmatis infection [ICD-11: 1B2Z.6]
• Experimental Note: Discovered Using In-vivo Testing Model
• In Vitro Model: Mycobacterium tuberculosis strain H37Rv ATCC27294 T; 83332
• Experiment for Molecule Alteration: Sequencing analysis
• Experiment for Drug Resistance: In vitro drug susceptibility testing
• Mechanism Description: Notably, isoniazid is activated by the enzyme catalase-peroxidase, KatG, encoded by katG, whereas prothionamide is activated by the flavin monoxygenase, EthA, encoded by ethA. Mutations in katG and ethA are associated with individual isoniazid and prothionamide/ethionamide resistance, respectively. The ndh gene coding for NADH dehydrogenase, Ndh, was first identified as a new mechanism for INHR in Mycobacterium smegmatis. The mutations in ndh gene cause defects in the oxidation of NADH to NAD, which results in NADH accumulation and NAD depletion. The increased level of NADH inhibits the binding of isoniazid-NAD adduct to the active site of the InhA enzyme, which disturbs the regulation of enzyme activity and may cause co-resistance to isoniazid and prothionamide. EthR, a member of the TetR/CamR family, is a repressor of ethA. EthR regulates the transcription of ethA by coordinated octamerization on a 55-bp operator situated in the ethA-R intergenic region. Impeding EthR function leads to enhanced mycobacterial sensitivity to prothionamide, whereas mutations in ethR encoding a negative transcriptional regulator of the expression of EthA lead to prothionamide resistance. Finally, MshA, a member of the glycosyltransferase family, is a key enzyme involved in mycothiol biosynthesis in M. tuberculosis. Mutations in mshA coding MshA have been proposed to create a disturbance in prothionamide/ethionamide activation.

Key Molecule: Catalase-peroxidase (KATG) [7]

• Molecule Alteration: Missense mutation; p.S315N
• Resistant Disease: Mycolicibacterium smegmatis infection [ICD-11: 1B2Z.6]
• Experimental Note: Discovered Using In-vivo Testing Model
• In Vitro Model: Mycobacterium tuberculosis strain H37Rv ATCC27294 T; 83332
• Experiment for Molecule Alteration: Sequencing analysis
• Experiment for Drug Resistance: In vitro drug susceptibility testing
• Mechanism Description: Notably, isoniazid is activated by the enzyme catalase-peroxidase, KatG, encoded by katG, whereas prothionamide is activated by the flavin monoxygenase, EthA, encoded by ethA. Mutations in katG and ethA are associated with individual isoniazid and prothionamide/ethionamide resistance, respectively. The ndh gene coding for NADH dehydrogenase, Ndh, was first identified as a new mechanism for INHR in Mycobacterium smegmatis. The mutations in ndh gene cause defects in the oxidation of NADH to NAD, which results in NADH accumulation and NAD depletion. The increased level of NADH inhibits the binding of isoniazid-NAD adduct to the active site of the InhA enzyme, which disturbs the regulation of enzyme activity and may cause co-resistance to isoniazid and prothionamide. EthR, a member of the TetR/CamR family, is a repressor of ethA. EthR regulates the transcription of ethA by coordinated octamerization on a 55-bp operator situated in the ethA-R intergenic region. Impeding EthR function leads to enhanced mycobacterial sensitivity to prothionamide, whereas mutations in ethR encoding a negative transcriptional regulator of the expression of EthA lead to prothionamide resistance. Finally, MshA, a member of the glycosyltransferase family, is a key enzyme involved in mycothiol biosynthesis in M. tuberculosis. Mutations in mshA coding MshA have been proposed to create a disturbance in prothionamide/ethionamide activation.

Key Molecule: Catalase-peroxidase (KATG) [7]

• Molecule Alteration: Missense mutation; p.A312P
• Resistant Disease: Mycolicibacterium smegmatis infection [ICD-11: 1B2Z.6]
• Experimental Note: Discovered Using In-vivo Testing Model
• In Vitro Model: Mycobacterium tuberculosis strain H37Rv ATCC27294 T; 83332
• Experiment for Molecule Alteration: Sequencing analysis
• Experiment for Drug Resistance: In vitro drug susceptibility testing
• Mechanism Description: Notably, isoniazid is activated by the enzyme catalase-peroxidase, KatG, encoded by katG, whereas prothionamide is activated by the flavin monoxygenase, EthA, encoded by ethA. Mutations in katG and ethA are associated with individual isoniazid and prothionamide/ethionamide resistance, respectively. The ndh gene coding for NADH dehydrogenase, Ndh, was first identified as a new mechanism for INHR in Mycobacterium smegmatis. The mutations in ndh gene cause defects in the oxidation of NADH to NAD, which results in NADH accumulation and NAD depletion. The increased level of NADH inhibits the binding of isoniazid-NAD adduct to the active site of the InhA enzyme, which disturbs the regulation of enzyme activity and may cause co-resistance to isoniazid and prothionamide. EthR, a member of the TetR/CamR family, is a repressor of ethA. EthR regulates the transcription of ethA by coordinated octamerization on a 55-bp operator situated in the ethA-R intergenic region. Impeding EthR function leads to enhanced mycobacterial sensitivity to prothionamide, whereas mutations in ethR encoding a negative transcriptional regulator of the expression of EthA lead to prothionamide resistance. Finally, MshA, a member of the glycosyltransferase family, is a key enzyme involved in mycothiol biosynthesis in M. tuberculosis. Mutations in mshA coding MshA have been proposed to create a disturbance in prothionamide/ethionamide activation.

Key Molecule: Catalase-peroxidase (KATG) [7]

• Molecule Alteration: Missense mutation; p.A264V
• Resistant Disease: Mycolicibacterium smegmatis infection [ICD-11: 1B2Z.6]
• Experimental Note: Discovered Using In-vivo Testing Model
• In Vitro Model: Mycobacterium tuberculosis strain H37Rv ATCC27294 T; 83332
• Experiment for Molecule Alteration: Sequencing analysis
• Experiment for Drug Resistance: In vitro drug susceptibility testing
• Mechanism Description: Notably, isoniazid is activated by the enzyme catalase-peroxidase, KatG, encoded by katG, whereas prothionamide is activated by the flavin monoxygenase, EthA, encoded by ethA. Mutations in katG and ethA are associated with individual isoniazid and prothionamide/ethionamide resistance, respectively. The ndh gene coding for NADH dehydrogenase, Ndh, was first identified as a new mechanism for INHR in Mycobacterium smegmatis. The mutations in ndh gene cause defects in the oxidation of NADH to NAD, which results in NADH accumulation and NAD depletion. The increased level of NADH inhibits the binding of isoniazid-NAD adduct to the active site of the InhA enzyme, which disturbs the regulation of enzyme activity and may cause co-resistance to isoniazid and prothionamide. EthR, a member of the TetR/CamR family, is a repressor of ethA. EthR regulates the transcription of ethA by coordinated octamerization on a 55-bp operator situated in the ethA-R intergenic region. Impeding EthR function leads to enhanced mycobacterial sensitivity to prothionamide, whereas mutations in ethR encoding a negative transcriptional regulator of the expression of EthA lead to prothionamide resistance. Finally, MshA, a member of the glycosyltransferase family, is a key enzyme involved in mycothiol biosynthesis in M. tuberculosis. Mutations in mshA coding MshA have been proposed to create a disturbance in prothionamide/ethionamide activation.

Key Molecule: Catalase-peroxidase (KATG) [7]

• Molecule Alteration: Missense mutation; p.N660D
• Resistant Disease: Mycolicibacterium smegmatis infection [ICD-11: 1B2Z.6]
• Experimental Note: Discovered Using In-vivo Testing Model
• In Vitro Model: Mycobacterium tuberculosis strain H37Rv ATCC27294 T; 83332
• Experiment for Molecule Alteration: Sequencing analysis
• Experiment for Drug Resistance: In vitro drug susceptibility testing
• Mechanism Description: Notably, isoniazid is activated by the enzyme catalase-peroxidase, KatG, encoded by katG, whereas prothionamide is activated by the flavin monoxygenase, EthA, encoded by ethA. Mutations in katG and ethA are associated with individual isoniazid and prothionamide/ethionamide resistance, respectively. The ndh gene coding for NADH dehydrogenase, Ndh, was first identified as a new mechanism for INHR in Mycobacterium smegmatis. The mutations in ndh gene cause defects in the oxidation of NADH to NAD, which results in NADH accumulation and NAD depletion. The increased level of NADH inhibits the binding of isoniazid-NAD adduct to the active site of the InhA enzyme, which disturbs the regulation of enzyme activity and may cause co-resistance to isoniazid and prothionamide. EthR, a member of the TetR/CamR family, is a repressor of ethA. EthR regulates the transcription of ethA by coordinated octamerization on a 55-bp operator situated in the ethA-R intergenic region. Impeding EthR function leads to enhanced mycobacterial sensitivity to prothionamide, whereas mutations in ethR encoding a negative transcriptional regulator of the expression of EthA lead to prothionamide resistance. Finally, MshA, a member of the glycosyltransferase family, is a key enzyme involved in mycothiol biosynthesis in M. tuberculosis. Mutations in mshA coding MshA have been proposed to create a disturbance in prothionamide/ethionamide activation.

Key Molecule: Catalase-peroxidase (KATG) [7]

• Molecule Alteration: Missense mutation; p.L147P
• Resistant Disease: Mycolicibacterium smegmatis infection [ICD-11: 1B2Z.6]
• Experimental Note: Discovered Using In-vivo Testing Model
• In Vitro Model: Mycobacterium tuberculosis strain H37Rv ATCC27294 T; 83332
• Experiment for Molecule Alteration: Sequencing analysis
• Experiment for Drug Resistance: In vitro drug susceptibility testing
• Mechanism Description: Notably, isoniazid is activated by the enzyme catalase-peroxidase, KatG, encoded by katG, whereas prothionamide is activated by the flavin monoxygenase, EthA, encoded by ethA. Mutations in katG and ethA are associated with individual isoniazid and prothionamide/ethionamide resistance, respectively. The ndh gene coding for NADH dehydrogenase, Ndh, was first identified as a new mechanism for INHR in Mycobacterium smegmatis. The mutations in ndh gene cause defects in the oxidation of NADH to NAD, which results in NADH accumulation and NAD depletion. The increased level of NADH inhibits the binding of isoniazid-NAD adduct to the active site of the InhA enzyme, which disturbs the regulation of enzyme activity and may cause co-resistance to isoniazid and prothionamide. EthR, a member of the TetR/CamR family, is a repressor of ethA. EthR regulates the transcription of ethA by coordinated octamerization on a 55-bp operator situated in the ethA-R intergenic region. Impeding EthR function leads to enhanced mycobacterial sensitivity to prothionamide, whereas mutations in ethR encoding a negative transcriptional regulator of the expression of EthA lead to prothionamide resistance. Finally, MshA, a member of the glycosyltransferase family, is a key enzyme involved in mycothiol biosynthesis in M. tuberculosis. Mutations in mshA coding MshA have been proposed to create a disturbance in prothionamide/ethionamide activation.

Key Molecule: Catalase-peroxidase (KATG) [7]

• Molecule Alteration: Missense mutation; p.C20R
• Resistant Disease: Mycolicibacterium smegmatis infection [ICD-11: 1B2Z.6]
• Experimental Note: Discovered Using In-vivo Testing Model
• In Vitro Model: Mycobacterium tuberculosis strain H37Rv ATCC27294 T; 83332
• Experiment for Molecule Alteration: Sequencing analysis
• Experiment for Drug Resistance: In vitro drug susceptibility testing
• Mechanism Description: Notably, isoniazid is activated by the enzyme catalase-peroxidase, KatG, encoded by katG, whereas prothionamide is activated by the flavin monoxygenase, EthA, encoded by ethA. Mutations in katG and ethA are associated with individual isoniazid and prothionamide/ethionamide resistance, respectively. The ndh gene coding for NADH dehydrogenase, Ndh, was first identified as a new mechanism for INHR in Mycobacterium smegmatis. The mutations in ndh gene cause defects in the oxidation of NADH to NAD, which results in NADH accumulation and NAD depletion. The increased level of NADH inhibits the binding of isoniazid-NAD adduct to the active site of the InhA enzyme, which disturbs the regulation of enzyme activity and may cause co-resistance to isoniazid and prothionamide. EthR, a member of the TetR/CamR family, is a repressor of ethA. EthR regulates the transcription of ethA by coordinated octamerization on a 55-bp operator situated in the ethA-R intergenic region. Impeding EthR function leads to enhanced mycobacterial sensitivity to prothionamide, whereas mutations in ethR encoding a negative transcriptional regulator of the expression of EthA lead to prothionamide resistance. Finally, MshA, a member of the glycosyltransferase family, is a key enzyme involved in mycothiol biosynthesis in M. tuberculosis. Mutations in mshA coding MshA have been proposed to create a disturbance in prothionamide/ethionamide activation.

Key Molecule: Catalase-peroxidase (KATG) [7]

• Molecule Alteration: Missense mutation; p.S315T
• Resistant Disease: Mycolicibacterium smegmatis infection [ICD-11: 1B2Z.6]
• Experimental Note: Discovered Using In-vivo Testing Model
• In Vitro Model: Mycobacterium tuberculosis strain H37Rv ATCC27294 T; 83332
• Experiment for Molecule Alteration: Sequencing analysis
• Experiment for Drug Resistance: In vitro drug susceptibility testing
• Mechanism Description: Notably, isoniazid is activated by the enzyme catalase-peroxidase, KatG, encoded by katG, whereas prothionamide is activated by the flavin monoxygenase, EthA, encoded by ethA. Mutations in katG and ethA are associated with individual isoniazid and prothionamide/ethionamide resistance, respectively. The ndh gene coding for NADH dehydrogenase, Ndh, was first identified as a new mechanism for INHR in Mycobacterium smegmatis. The mutations in ndh gene cause defects in the oxidation of NADH to NAD, which results in NADH accumulation and NAD depletion. The increased level of NADH inhibits the binding of isoniazid-NAD adduct to the active site of the InhA enzyme, which disturbs the regulation of enzyme activity and may cause co-resistance to isoniazid and prothionamide. EthR, a member of the TetR/CamR family, is a repressor of ethA. EthR regulates the transcription of ethA by coordinated octamerization on a 55-bp operator situated in the ethA-R intergenic region. Impeding EthR function leads to enhanced mycobacterial sensitivity to prothionamide, whereas mutations in ethR encoding a negative transcriptional regulator of the expression of EthA lead to prothionamide resistance. Finally, MshA, a member of the glycosyltransferase family, is a key enzyme involved in mycothiol biosynthesis in M. tuberculosis. Mutations in mshA coding MshA have been proposed to create a disturbance in prothionamide/ethionamide activation.

Key Molecule: Catalase-peroxidase (KATG) [7]

• Molecule Alteration: Missense mutation; p.T308P
• Resistant Disease: Mycolicibacterium smegmatis infection [ICD-11: 1B2Z.6]
• Experimental Note: Discovered Using In-vivo Testing Model
• In Vitro Model: Mycobacterium tuberculosis strain H37Rv ATCC27294 T; 83332
• Experiment for Molecule Alteration: Sequencing analysis
• Experiment for Drug Resistance: In vitro drug susceptibility testing
• Mechanism Description: Notably, isoniazid is activated by the enzyme catalase-peroxidase, KatG, encoded by katG, whereas prothionamide is activated by the flavin monoxygenase, EthA, encoded by ethA. Mutations in katG and ethA are associated with individual isoniazid and prothionamide/ethionamide resistance, respectively. The ndh gene coding for NADH dehydrogenase, Ndh, was first identified as a new mechanism for INHR in Mycobacterium smegmatis. The mutations in ndh gene cause defects in the oxidation of NADH to NAD, which results in NADH accumulation and NAD depletion. The increased level of NADH inhibits the binding of isoniazid-NAD adduct to the active site of the InhA enzyme, which disturbs the regulation of enzyme activity and may cause co-resistance to isoniazid and prothionamide. EthR, a member of the TetR/CamR family, is a repressor of ethA. EthR regulates the transcription of ethA by coordinated octamerization on a 55-bp operator situated in the ethA-R intergenic region. Impeding EthR function leads to enhanced mycobacterial sensitivity to prothionamide, whereas mutations in ethR encoding a negative transcriptional regulator of the expression of EthA lead to prothionamide resistance. Finally, MshA, a member of the glycosyltransferase family, is a key enzyme involved in mycothiol biosynthesis in M. tuberculosis. Mutations in mshA coding MshA have been proposed to create a disturbance in prothionamide/ethionamide activation.

Key Molecule: Catalase-peroxidase (KATG) [7]

• Molecule Alteration: Missense mutation; p.T275A
• Resistant Disease: Mycolicibacterium smegmatis infection [ICD-11: 1B2Z.6]
• Experimental Note: Discovered Using In-vivo Testing Model
• In Vitro Model: Mycobacterium tuberculosis strain H37Rv ATCC27294 T; 83332
• Experiment for Molecule Alteration: Sequencing analysis
• Experiment for Drug Resistance: In vitro drug susceptibility testing
• Mechanism Description: Notably, isoniazid is activated by the enzyme catalase-peroxidase, KatG, encoded by katG, whereas prothionamide is activated by the flavin monoxygenase, EthA, encoded by ethA. Mutations in katG and ethA are associated with individual isoniazid and prothionamide/ethionamide resistance, respectively. The ndh gene coding for NADH dehydrogenase, Ndh, was first identified as a new mechanism for INHR in Mycobacterium smegmatis. The mutations in ndh gene cause defects in the oxidation of NADH to NAD, which results in NADH accumulation and NAD depletion. The increased level of NADH inhibits the binding of isoniazid-NAD adduct to the active site of the InhA enzyme, which disturbs the regulation of enzyme activity and may cause co-resistance to isoniazid and prothionamide. EthR, a member of the TetR/CamR family, is a repressor of ethA. EthR regulates the transcription of ethA by coordinated octamerization on a 55-bp operator situated in the ethA-R intergenic region. Impeding EthR function leads to enhanced mycobacterial sensitivity to prothionamide, whereas mutations in ethR encoding a negative transcriptional regulator of the expression of EthA lead to prothionamide resistance. Finally, MshA, a member of the glycosyltransferase family, is a key enzyme involved in mycothiol biosynthesis in M. tuberculosis. Mutations in mshA coding MshA have been proposed to create a disturbance in prothionamide/ethionamide activation.

Key Molecule: Catalase-peroxidase (KATG) [7]

• Molecule Alteration: Missense mutation; p.S315T
• Resistant Disease: Mycolicibacterium smegmatis infection [ICD-11: 1B2Z.6]
• Experimental Note: Discovered Using In-vivo Testing Model
• In Vitro Model: Mycobacterium tuberculosis strain H37Rv ATCC27294 T; 83332
• Experiment for Molecule Alteration: Sequencing analysis
• Experiment for Drug Resistance: In vitro drug susceptibility testing
• Mechanism Description: Notably, isoniazid is activated by the enzyme catalase-peroxidase, KatG, encoded by katG, whereas prothionamide is activated by the flavin monoxygenase, EthA, encoded by ethA. Mutations in katG and ethA are associated with individual isoniazid and prothionamide/ethionamide resistance, respectively. The ndh gene coding for NADH dehydrogenase, Ndh, was first identified as a new mechanism for INHR in Mycobacterium smegmatis. The mutations in ndh gene cause defects in the oxidation of NADH to NAD, which results in NADH accumulation and NAD depletion. The increased level of NADH inhibits the binding of isoniazid-NAD adduct to the active site of the InhA enzyme, which disturbs the regulation of enzyme activity and may cause co-resistance to isoniazid and prothionamide. EthR, a member of the TetR/CamR family, is a repressor of ethA. EthR regulates the transcription of ethA by coordinated octamerization on a 55-bp operator situated in the ethA-R intergenic region. Impeding EthR function leads to enhanced mycobacterial sensitivity to prothionamide, whereas mutations in ethR encoding a negative transcriptional regulator of the expression of EthA lead to prothionamide resistance. Finally, MshA, a member of the glycosyltransferase family, is a key enzyme involved in mycothiol biosynthesis in M. tuberculosis. Mutations in mshA coding MshA have been proposed to create a disturbance in prothionamide/ethionamide activation.

Key Molecule: Catalase-peroxidase (KATG) [7]

• Molecule Alteration: Missense mutation; p.D142G
• Resistant Disease: Mycolicibacterium smegmatis infection [ICD-11: 1B2Z.6]
• Experimental Note: Discovered Using In-vivo Testing Model
• In Vitro Model: Mycobacterium tuberculosis strain H37Rv ATCC27294 T; 83332
• Experiment for Molecule Alteration: Sequencing analysis
• Experiment for Drug Resistance: In vitro drug susceptibility testing
• Mechanism Description: Notably, isoniazid is activated by the enzyme catalase-peroxidase, KatG, encoded by katG, whereas prothionamide is activated by the flavin monoxygenase, EthA, encoded by ethA. Mutations in katG and ethA are associated with individual isoniazid and prothionamide/ethionamide resistance, respectively. The ndh gene coding for NADH dehydrogenase, Ndh, was first identified as a new mechanism for INHR in Mycobacterium smegmatis. The mutations in ndh gene cause defects in the oxidation of NADH to NAD, which results in NADH accumulation and NAD depletion. The increased level of NADH inhibits the binding of isoniazid-NAD adduct to the active site of the InhA enzyme, which disturbs the regulation of enzyme activity and may cause co-resistance to isoniazid and prothionamide. EthR, a member of the TetR/CamR family, is a repressor of ethA. EthR regulates the transcription of ethA by coordinated octamerization on a 55-bp operator situated in the ethA-R intergenic region. Impeding EthR function leads to enhanced mycobacterial sensitivity to prothionamide, whereas mutations in ethR encoding a negative transcriptional regulator of the expression of EthA lead to prothionamide resistance. Finally, MshA, a member of the glycosyltransferase family, is a key enzyme involved in mycothiol biosynthesis in M. tuberculosis. Mutations in mshA coding MshA have been proposed to create a disturbance in prothionamide/ethionamide activation.

Key Molecule: Catalase-peroxidase (KATG) [7]

• Molecule Alteration: Missense mutation; p.S211G
• Resistant Disease: Mycolicibacterium smegmatis infection [ICD-11: 1B2Z.6]
• Experimental Note: Discovered Using In-vivo Testing Model
• In Vitro Model: Mycobacterium tuberculosis strain H37Rv ATCC27294 T; 83332
• Experiment for Molecule Alteration: Sequencing analysis
• Experiment for Drug Resistance: In vitro drug susceptibility testing
• Mechanism Description: Notably, isoniazid is activated by the enzyme catalase-peroxidase, KatG, encoded by katG, whereas prothionamide is activated by the flavin monoxygenase, EthA, encoded by ethA. Mutations in katG and ethA are associated with individual isoniazid and prothionamide/ethionamide resistance, respectively. The ndh gene coding for NADH dehydrogenase, Ndh, was first identified as a new mechanism for INHR in Mycobacterium smegmatis. The mutations in ndh gene cause defects in the oxidation of NADH to NAD, which results in NADH accumulation and NAD depletion. The increased level of NADH inhibits the binding of isoniazid-NAD adduct to the active site of the InhA enzyme, which disturbs the regulation of enzyme activity and may cause co-resistance to isoniazid and prothionamide. EthR, a member of the TetR/CamR family, is a repressor of ethA. EthR regulates the transcription of ethA by coordinated octamerization on a 55-bp operator situated in the ethA-R intergenic region. Impeding EthR function leads to enhanced mycobacterial sensitivity to prothionamide, whereas mutations in ethR encoding a negative transcriptional regulator of the expression of EthA lead to prothionamide resistance. Finally, MshA, a member of the glycosyltransferase family, is a key enzyme involved in mycothiol biosynthesis in M. tuberculosis. Mutations in mshA coding MshA have been proposed to create a disturbance in prothionamide/ethionamide activation.

Key Molecule: Catalase-peroxidase (KATG) [7]

• Molecule Alteration: Missense mutation; p.S315T
• Resistant Disease: Mycolicibacterium smegmatis infection [ICD-11: 1B2Z.6]
• Experimental Note: Discovered Using In-vivo Testing Model
• In Vitro Model: Mycobacterium tuberculosis strain H37Rv ATCC27294 T; 83332
• Experiment for Molecule Alteration: Sequencing analysis
• Experiment for Drug Resistance: In vitro drug susceptibility testing
• Mechanism Description: Notably, isoniazid is activated by the enzyme catalase-peroxidase, KatG, encoded by katG, whereas prothionamide is activated by the flavin monoxygenase, EthA, encoded by ethA. Mutations in katG and ethA are associated with individual isoniazid and prothionamide/ethionamide resistance, respectively. The ndh gene coding for NADH dehydrogenase, Ndh, was first identified as a new mechanism for INHR in Mycobacterium smegmatis. The mutations in ndh gene cause defects in the oxidation of NADH to NAD, which results in NADH accumulation and NAD depletion. The increased level of NADH inhibits the binding of isoniazid-NAD adduct to the active site of the InhA enzyme, which disturbs the regulation of enzyme activity and may cause co-resistance to isoniazid and prothionamide. EthR, a member of the TetR/CamR family, is a repressor of ethA. EthR regulates the transcription of ethA by coordinated octamerization on a 55-bp operator situated in the ethA-R intergenic region. Impeding EthR function leads to enhanced mycobacterial sensitivity to prothionamide, whereas mutations in ethR encoding a negative transcriptional regulator of the expression of EthA lead to prothionamide resistance. Finally, MshA, a member of the glycosyltransferase family, is a key enzyme involved in mycothiol biosynthesis in M. tuberculosis. Mutations in mshA coding MshA have been proposed to create a disturbance in prothionamide/ethionamide activation.

Key Molecule: Catalase-peroxidase (KATG) [7]

• Molecule Alteration: Missense mutation; p.M126I
• Resistant Disease: Mycolicibacterium smegmatis infection [ICD-11: 1B2Z.6]
• Experimental Note: Discovered Using In-vivo Testing Model
• In Vitro Model: Mycobacterium tuberculosis strain H37Rv ATCC27294 T; 83332
• Experiment for Molecule Alteration: Sequencing analysis
• Experiment for Drug Resistance: In vitro drug susceptibility testing
• Mechanism Description: Notably, isoniazid is activated by the enzyme catalase-peroxidase, KatG, encoded by katG, whereas prothionamide is activated by the flavin monoxygenase, EthA, encoded by ethA. Mutations in katG and ethA are associated with individual isoniazid and prothionamide/ethionamide resistance, respectively. The ndh gene coding for NADH dehydrogenase, Ndh, was first identified as a new mechanism for INHR in Mycobacterium smegmatis. The mutations in ndh gene cause defects in the oxidation of NADH to NAD, which results in NADH accumulation and NAD depletion. The increased level of NADH inhibits the binding of isoniazid-NAD adduct to the active site of the InhA enzyme, which disturbs the regulation of enzyme activity and may cause co-resistance to isoniazid and prothionamide. EthR, a member of the TetR/CamR family, is a repressor of ethA. EthR regulates the transcription of ethA by coordinated octamerization on a 55-bp operator situated in the ethA-R intergenic region. Impeding EthR function leads to enhanced mycobacterial sensitivity to prothionamide, whereas mutations in ethR encoding a negative transcriptional regulator of the expression of EthA lead to prothionamide resistance. Finally, MshA, a member of the glycosyltransferase family, is a key enzyme involved in mycothiol biosynthesis in M. tuberculosis. Mutations in mshA coding MshA have been proposed to create a disturbance in prothionamide/ethionamide activation.

Key Molecule: Catalase-peroxidase (KATG) [7]

• Molecule Alteration: Missense mutation; p.W91R
• Resistant Disease: Mycolicibacterium smegmatis infection [ICD-11: 1B2Z.6]
• Experimental Note: Discovered Using In-vivo Testing Model
• In Vitro Model: Mycobacterium tuberculosis strain H37Rv ATCC27294 T; 83332
• Experiment for Molecule Alteration: Sequencing analysis
• Experiment for Drug Resistance: In vitro drug susceptibility testing
• Mechanism Description: Notably, isoniazid is activated by the enzyme catalase-peroxidase, KatG, encoded by katG, whereas prothionamide is activated by the flavin monoxygenase, EthA, encoded by ethA. Mutations in katG and ethA are associated with individual isoniazid and prothionamide/ethionamide resistance, respectively. The ndh gene coding for NADH dehydrogenase, Ndh, was first identified as a new mechanism for INHR in Mycobacterium smegmatis. The mutations in ndh gene cause defects in the oxidation of NADH to NAD, which results in NADH accumulation and NAD depletion. The increased level of NADH inhibits the binding of isoniazid-NAD adduct to the active site of the InhA enzyme, which disturbs the regulation of enzyme activity and may cause co-resistance to isoniazid and prothionamide. EthR, a member of the TetR/CamR family, is a repressor of ethA. EthR regulates the transcription of ethA by coordinated octamerization on a 55-bp operator situated in the ethA-R intergenic region. Impeding EthR function leads to enhanced mycobacterial sensitivity to prothionamide, whereas mutations in ethR encoding a negative transcriptional regulator of the expression of EthA lead to prothionamide resistance. Finally, MshA, a member of the glycosyltransferase family, is a key enzyme involved in mycothiol biosynthesis in M. tuberculosis. Mutations in mshA coding MshA have been proposed to create a disturbance in prothionamide/ethionamide activation.

Key Molecule: Catalase-peroxidase (KATG) [7]

• Molecule Alteration: Missense mutation; p.S315G
• Resistant Disease: Mycolicibacterium smegmatis infection [ICD-11: 1B2Z.6]
• Experimental Note: Discovered Using In-vivo Testing Model
• In Vitro Model: Mycobacterium tuberculosis strain H37Rv ATCC27294 T; 83332
• Experiment for Molecule Alteration: Sequencing analysis
• Experiment for Drug Resistance: In vitro drug susceptibility testing
• Mechanism Description: Notably, isoniazid is activated by the enzyme catalase-peroxidase, KatG, encoded by katG, whereas prothionamide is activated by the flavin monoxygenase, EthA, encoded by ethA. Mutations in katG and ethA are associated with individual isoniazid and prothionamide/ethionamide resistance, respectively. The ndh gene coding for NADH dehydrogenase, Ndh, was first identified as a new mechanism for INHR in Mycobacterium smegmatis. The mutations in ndh gene cause defects in the oxidation of NADH to NAD, which results in NADH accumulation and NAD depletion. The increased level of NADH inhibits the binding of isoniazid-NAD adduct to the active site of the InhA enzyme, which disturbs the regulation of enzyme activity and may cause co-resistance to isoniazid and prothionamide. EthR, a member of the TetR/CamR family, is a repressor of ethA. EthR regulates the transcription of ethA by coordinated octamerization on a 55-bp operator situated in the ethA-R intergenic region. Impeding EthR function leads to enhanced mycobacterial sensitivity to prothionamide, whereas mutations in ethR encoding a negative transcriptional regulator of the expression of EthA lead to prothionamide resistance. Finally, MshA, a member of the glycosyltransferase family, is a key enzyme involved in mycothiol biosynthesis in M. tuberculosis. Mutations in mshA coding MshA have been proposed to create a disturbance in prothionamide/ethionamide activation.

Key Molecule: Catalase-peroxidase (KATG) [7]

• Molecule Alteration: Missense mutation; p.G490S
• Resistant Disease: Mycolicibacterium smegmatis infection [ICD-11: 1B2Z.6]
• Experimental Note: Discovered Using In-vivo Testing Model
• In Vitro Model: Mycobacterium tuberculosis strain H37Rv ATCC27294 T; 83332
• Experiment for Molecule Alteration: Sequencing analysis
• Experiment for Drug Resistance: In vitro drug susceptibility testing
• Mechanism Description: Notably, isoniazid is activated by the enzyme catalase-peroxidase, KatG, encoded by katG, whereas prothionamide is activated by the flavin monoxygenase, EthA, encoded by ethA. Mutations in katG and ethA are associated with individual isoniazid and prothionamide/ethionamide resistance, respectively. The ndh gene coding for NADH dehydrogenase, Ndh, was first identified as a new mechanism for INHR in Mycobacterium smegmatis. The mutations in ndh gene cause defects in the oxidation of NADH to NAD, which results in NADH accumulation and NAD depletion. The increased level of NADH inhibits the binding of isoniazid-NAD adduct to the active site of the InhA enzyme, which disturbs the regulation of enzyme activity and may cause co-resistance to isoniazid and prothionamide. EthR, a member of the TetR/CamR family, is a repressor of ethA. EthR regulates the transcription of ethA by coordinated octamerization on a 55-bp operator situated in the ethA-R intergenic region. Impeding EthR function leads to enhanced mycobacterial sensitivity to prothionamide, whereas mutations in ethR encoding a negative transcriptional regulator of the expression of EthA lead to prothionamide resistance. Finally, MshA, a member of the glycosyltransferase family, is a key enzyme involved in mycothiol biosynthesis in M. tuberculosis. Mutations in mshA coding MshA have been proposed to create a disturbance in prothionamide/ethionamide activation.

Key Molecule: Catalase-peroxidase (KATG) [7]

• Molecule Alteration: Missense mutation; p.S315T
• Resistant Disease: Mycolicibacterium smegmatis infection [ICD-11: 1B2Z.6]
• Experimental Note: Discovered Using In-vivo Testing Model
• In Vitro Model: Mycobacterium tuberculosis strain H37Rv ATCC27294 T; 83332
• Experiment for Molecule Alteration: Sequencing analysis
• Experiment for Drug Resistance: In vitro drug susceptibility testing
• Mechanism Description: Notably, isoniazid is activated by the enzyme catalase-peroxidase, KatG, encoded by katG, whereas prothionamide is activated by the flavin monoxygenase, EthA, encoded by ethA. Mutations in katG and ethA are associated with individual isoniazid and prothionamide/ethionamide resistance, respectively. The ndh gene coding for NADH dehydrogenase, Ndh, was first identified as a new mechanism for INHR in Mycobacterium smegmatis. The mutations in ndh gene cause defects in the oxidation of NADH to NAD, which results in NADH accumulation and NAD depletion. The increased level of NADH inhibits the binding of isoniazid-NAD adduct to the active site of the InhA enzyme, which disturbs the regulation of enzyme activity and may cause co-resistance to isoniazid and prothionamide. EthR, a member of the TetR/CamR family, is a repressor of ethA. EthR regulates the transcription of ethA by coordinated octamerization on a 55-bp operator situated in the ethA-R intergenic region. Impeding EthR function leads to enhanced mycobacterial sensitivity to prothionamide, whereas mutations in ethR encoding a negative transcriptional regulator of the expression of EthA lead to prothionamide resistance. Finally, MshA, a member of the glycosyltransferase family, is a key enzyme involved in mycothiol biosynthesis in M. tuberculosis. Mutations in mshA coding MshA have been proposed to create a disturbance in prothionamide/ethionamide activation.

Key Molecule: Catalase-peroxidase (KATG) [7]

• Molecule Alteration: Missense mutation; p.V581G
• Resistant Disease: Mycolicibacterium smegmatis infection [ICD-11: 1B2Z.6]
• Experimental Note: Discovered Using In-vivo Testing Model
• In Vitro Model: Mycobacterium tuberculosis strain H37Rv ATCC27294 T; 83332
• Experiment for Molecule Alteration: Sequencing analysis
• Experiment for Drug Resistance: In vitro drug susceptibility testing
• Mechanism Description: Notably, isoniazid is activated by the enzyme catalase-peroxidase, KatG, encoded by katG, whereas prothionamide is activated by the flavin monoxygenase, EthA, encoded by ethA. Mutations in katG and ethA are associated with individual isoniazid and prothionamide/ethionamide resistance, respectively. The ndh gene coding for NADH dehydrogenase, Ndh, was first identified as a new mechanism for INHR in Mycobacterium smegmatis. The mutations in ndh gene cause defects in the oxidation of NADH to NAD, which results in NADH accumulation and NAD depletion. The increased level of NADH inhibits the binding of isoniazid-NAD adduct to the active site of the InhA enzyme, which disturbs the regulation of enzyme activity and may cause co-resistance to isoniazid and prothionamide. EthR, a member of the TetR/CamR family, is a repressor of ethA. EthR regulates the transcription of ethA by coordinated octamerization on a 55-bp operator situated in the ethA-R intergenic region. Impeding EthR function leads to enhanced mycobacterial sensitivity to prothionamide, whereas mutations in ethR encoding a negative transcriptional regulator of the expression of EthA lead to prothionamide resistance. Finally, MshA, a member of the glycosyltransferase family, is a key enzyme involved in mycothiol biosynthesis in M. tuberculosis. Mutations in mshA coding MshA have been proposed to create a disturbance in prothionamide/ethionamide activation.

Key Molecule: Catalase-peroxidase (KATG) [7]

• Molecule Alteration: Missense mutation; p.A110V
• Resistant Disease: Mycolicibacterium smegmatis infection [ICD-11: 1B2Z.6]
• Experimental Note: Discovered Using In-vivo Testing Model
• In Vitro Model: Mycobacterium tuberculosis strain H37Rv ATCC27294 T; 83332
• Experiment for Molecule Alteration: Sequencing analysis
• Experiment for Drug Resistance: In vitro drug susceptibility testing
• Mechanism Description: Notably, isoniazid is activated by the enzyme catalase-peroxidase, KatG, encoded by katG, whereas prothionamide is activated by the flavin monoxygenase, EthA, encoded by ethA. Mutations in katG and ethA are associated with individual isoniazid and prothionamide/ethionamide resistance, respectively. The ndh gene coding for NADH dehydrogenase, Ndh, was first identified as a new mechanism for INHR in Mycobacterium smegmatis. The mutations in ndh gene cause defects in the oxidation of NADH to NAD, which results in NADH accumulation and NAD depletion. The increased level of NADH inhibits the binding of isoniazid-NAD adduct to the active site of the InhA enzyme, which disturbs the regulation of enzyme activity and may cause co-resistance to isoniazid and prothionamide. EthR, a member of the TetR/CamR family, is a repressor of ethA. EthR regulates the transcription of ethA by coordinated octamerization on a 55-bp operator situated in the ethA-R intergenic region. Impeding EthR function leads to enhanced mycobacterial sensitivity to prothionamide, whereas mutations in ethR encoding a negative transcriptional regulator of the expression of EthA lead to prothionamide resistance. Finally, MshA, a member of the glycosyltransferase family, is a key enzyme involved in mycothiol biosynthesis in M. tuberculosis. Mutations in mshA coding MshA have been proposed to create a disturbance in prothionamide/ethionamide activation.

Key Molecule: Catalase-peroxidase (KATG) [7]

• Molecule Alteration: Missense mutation; p.S315T
• Resistant Disease: Mycolicibacterium smegmatis infection [ICD-11: 1B2Z.6]
• Experimental Note: Discovered Using In-vivo Testing Model
• In Vitro Model: Mycobacterium tuberculosis strain H37Rv ATCC27294 T; 83332
• Experiment for Molecule Alteration: Sequencing analysis
• Experiment for Drug Resistance: In vitro drug susceptibility testing
• Mechanism Description: Notably, isoniazid is activated by the enzyme catalase-peroxidase, KatG, encoded by katG, whereas prothionamide is activated by the flavin monoxygenase, EthA, encoded by ethA. Mutations in katG and ethA are associated with individual isoniazid and prothionamide/ethionamide resistance, respectively. The ndh gene coding for NADH dehydrogenase, Ndh, was first identified as a new mechanism for INHR in Mycobacterium smegmatis. The mutations in ndh gene cause defects in the oxidation of NADH to NAD, which results in NADH accumulation and NAD depletion. The increased level of NADH inhibits the binding of isoniazid-NAD adduct to the active site of the InhA enzyme, which disturbs the regulation of enzyme activity and may cause co-resistance to isoniazid and prothionamide. EthR, a member of the TetR/CamR family, is a repressor of ethA. EthR regulates the transcription of ethA by coordinated octamerization on a 55-bp operator situated in the ethA-R intergenic region. Impeding EthR function leads to enhanced mycobacterial sensitivity to prothionamide, whereas mutations in ethR encoding a negative transcriptional regulator of the expression of EthA lead to prothionamide resistance. Finally, MshA, a member of the glycosyltransferase family, is a key enzyme involved in mycothiol biosynthesis in M. tuberculosis. Mutations in mshA coding MshA have been proposed to create a disturbance in prothionamide/ethionamide activation.

Key Molecule: Catalase-peroxidase (KATG) [7]

• Molecule Alteration: Missense mutation; p.G466R
• Resistant Disease: Mycolicibacterium smegmatis infection [ICD-11: 1B2Z.6]
• Experimental Note: Discovered Using In-vivo Testing Model
• In Vitro Model: Mycobacterium tuberculosis strain H37Rv ATCC27294 T; 83332
• Experiment for Molecule Alteration: Sequencing analysis
• Experiment for Drug Resistance: In vitro drug susceptibility testing
• Mechanism Description: Notably, isoniazid is activated by the enzyme catalase-peroxidase, KatG, encoded by katG, whereas prothionamide is activated by the flavin monoxygenase, EthA, encoded by ethA. Mutations in katG and ethA are associated with individual isoniazid and prothionamide/ethionamide resistance, respectively. The ndh gene coding for NADH dehydrogenase, Ndh, was first identified as a new mechanism for INHR in Mycobacterium smegmatis. The mutations in ndh gene cause defects in the oxidation of NADH to NAD, which results in NADH accumulation and NAD depletion. The increased level of NADH inhibits the binding of isoniazid-NAD adduct to the active site of the InhA enzyme, which disturbs the regulation of enzyme activity and may cause co-resistance to isoniazid and prothionamide. EthR, a member of the TetR/CamR family, is a repressor of ethA. EthR regulates the transcription of ethA by coordinated octamerization on a 55-bp operator situated in the ethA-R intergenic region. Impeding EthR function leads to enhanced mycobacterial sensitivity to prothionamide, whereas mutations in ethR encoding a negative transcriptional regulator of the expression of EthA lead to prothionamide resistance. Finally, MshA, a member of the glycosyltransferase family, is a key enzyme involved in mycothiol biosynthesis in M. tuberculosis. Mutations in mshA coding MshA have been proposed to create a disturbance in prothionamide/ethionamide activation.

Key Molecule: Catalase-peroxidase (KATG) [7]

• Molecule Alteration: Missense mutation; p.G279V
• Resistant Disease: Mycolicibacterium smegmatis infection [ICD-11: 1B2Z.6]
• Experimental Note: Discovered Using In-vivo Testing Model
• In Vitro Model: Mycobacterium tuberculosis strain H37Rv ATCC27294 T; 83332
• Experiment for Molecule Alteration: Sequencing analysis
• Experiment for Drug Resistance: In vitro drug susceptibility testing
• Mechanism Description: Notably, isoniazid is activated by the enzyme catalase-peroxidase, KatG, encoded by katG, whereas prothionamide is activated by the flavin monoxygenase, EthA, encoded by ethA. Mutations in katG and ethA are associated with individual isoniazid and prothionamide/ethionamide resistance, respectively. The ndh gene coding for NADH dehydrogenase, Ndh, was first identified as a new mechanism for INHR in Mycobacterium smegmatis. The mutations in ndh gene cause defects in the oxidation of NADH to NAD, which results in NADH accumulation and NAD depletion. The increased level of NADH inhibits the binding of isoniazid-NAD adduct to the active site of the InhA enzyme, which disturbs the regulation of enzyme activity and may cause co-resistance to isoniazid and prothionamide. EthR, a member of the TetR/CamR family, is a repressor of ethA. EthR regulates the transcription of ethA by coordinated octamerization on a 55-bp operator situated in the ethA-R intergenic region. Impeding EthR function leads to enhanced mycobacterial sensitivity to prothionamide, whereas mutations in ethR encoding a negative transcriptional regulator of the expression of EthA lead to prothionamide resistance. Finally, MshA, a member of the glycosyltransferase family, is a key enzyme involved in mycothiol biosynthesis in M. tuberculosis. Mutations in mshA coding MshA have been proposed to create a disturbance in prothionamide/ethionamide activation.

Key Molecule: Catalase-peroxidase (KATG) [7]

• Molecule Alteration: Missense mutation; p.L436P
• Resistant Disease: Mycolicibacterium smegmatis infection [ICD-11: 1B2Z.6]
• Experimental Note: Discovered Using In-vivo Testing Model
• In Vitro Model: Mycobacterium tuberculosis strain H37Rv ATCC27294 T; 83332
• Experiment for Molecule Alteration: Sequencing analysis
• Experiment for Drug Resistance: In vitro drug susceptibility testing
• Mechanism Description: Notably, isoniazid is activated by the enzyme catalase-peroxidase, KatG, encoded by katG, whereas prothionamide is activated by the flavin monoxygenase, EthA, encoded by ethA. Mutations in katG and ethA are associated with individual isoniazid and prothionamide/ethionamide resistance, respectively. The ndh gene coding for NADH dehydrogenase, Ndh, was first identified as a new mechanism for INHR in Mycobacterium smegmatis. The mutations in ndh gene cause defects in the oxidation of NADH to NAD, which results in NADH accumulation and NAD depletion. The increased level of NADH inhibits the binding of isoniazid-NAD adduct to the active site of the InhA enzyme, which disturbs the regulation of enzyme activity and may cause co-resistance to isoniazid and prothionamide. EthR, a member of the TetR/CamR family, is a repressor of ethA. EthR regulates the transcription of ethA by coordinated octamerization on a 55-bp operator situated in the ethA-R intergenic region. Impeding EthR function leads to enhanced mycobacterial sensitivity to prothionamide, whereas mutations in ethR encoding a negative transcriptional regulator of the expression of EthA lead to prothionamide resistance. Finally, MshA, a member of the glycosyltransferase family, is a key enzyme involved in mycothiol biosynthesis in M. tuberculosis. Mutations in mshA coding MshA have been proposed to create a disturbance in prothionamide/ethionamide activation.

Key Molecule: Catalase-peroxidase (KATG) [7]

• Molecule Alteration: Missense mutation; p.N508D
• Resistant Disease: Mycolicibacterium smegmatis infection [ICD-11: 1B2Z.6]
• Experimental Note: Discovered Using In-vivo Testing Model
• In Vitro Model: Mycobacterium tuberculosis strain H37Rv ATCC27294 T; 83332
• Experiment for Molecule Alteration: Sequencing analysis
• Experiment for Drug Resistance: In vitro drug susceptibility testing
• Mechanism Description: Notably, isoniazid is activated by the enzyme catalase-peroxidase, KatG, encoded by katG, whereas prothionamide is activated by the flavin monoxygenase, EthA, encoded by ethA. Mutations in katG and ethA are associated with individual isoniazid and prothionamide/ethionamide resistance, respectively. The ndh gene coding for NADH dehydrogenase, Ndh, was first identified as a new mechanism for INHR in Mycobacterium smegmatis. The mutations in ndh gene cause defects in the oxidation of NADH to NAD, which results in NADH accumulation and NAD depletion. The increased level of NADH inhibits the binding of isoniazid-NAD adduct to the active site of the InhA enzyme, which disturbs the regulation of enzyme activity and may cause co-resistance to isoniazid and prothionamide. EthR, a member of the TetR/CamR family, is a repressor of ethA. EthR regulates the transcription of ethA by coordinated octamerization on a 55-bp operator situated in the ethA-R intergenic region. Impeding EthR function leads to enhanced mycobacterial sensitivity to prothionamide, whereas mutations in ethR encoding a negative transcriptional regulator of the expression of EthA lead to prothionamide resistance. Finally, MshA, a member of the glycosyltransferase family, is a key enzyme involved in mycothiol biosynthesis in M. tuberculosis. Mutations in mshA coding MshA have been proposed to create a disturbance in prothionamide/ethionamide activation.

Key Molecule: Catalase-peroxidase (KATG) [7]

• Molecule Alteration: Missense mutation; p.P92S
• Resistant Disease: Mycolicibacterium smegmatis infection [ICD-11: 1B2Z.6]
• Experimental Note: Discovered Using In-vivo Testing Model
• In Vitro Model: Mycobacterium tuberculosis strain H37Rv ATCC27294 T; 83332
• Experiment for Molecule Alteration: Sequencing analysis
• Experiment for Drug Resistance: In vitro drug susceptibility testing
• Mechanism Description: Notably, isoniazid is activated by the enzyme catalase-peroxidase, KatG, encoded by katG, whereas prothionamide is activated by the flavin monoxygenase, EthA, encoded by ethA. Mutations in katG and ethA are associated with individual isoniazid and prothionamide/ethionamide resistance, respectively. The ndh gene coding for NADH dehydrogenase, Ndh, was first identified as a new mechanism for INHR in Mycobacterium smegmatis. The mutations in ndh gene cause defects in the oxidation of NADH to NAD, which results in NADH accumulation and NAD depletion. The increased level of NADH inhibits the binding of isoniazid-NAD adduct to the active site of the InhA enzyme, which disturbs the regulation of enzyme activity and may cause co-resistance to isoniazid and prothionamide. EthR, a member of the TetR/CamR family, is a repressor of ethA. EthR regulates the transcription of ethA by coordinated octamerization on a 55-bp operator situated in the ethA-R intergenic region. Impeding EthR function leads to enhanced mycobacterial sensitivity to prothionamide, whereas mutations in ethR encoding a negative transcriptional regulator of the expression of EthA lead to prothionamide resistance. Finally, MshA, a member of the glycosyltransferase family, is a key enzyme involved in mycothiol biosynthesis in M. tuberculosis. Mutations in mshA coding MshA have been proposed to create a disturbance in prothionamide/ethionamide activation.

Key Molecule: Catalase-peroxidase (KATG) [7]

• Molecule Alteration: Missense mutation; p.S315T
• Resistant Disease: Mycolicibacterium smegmatis infection [ICD-11: 1B2Z.6]
• Experimental Note: Discovered Using In-vivo Testing Model
• In Vitro Model: Mycobacterium tuberculosis strain H37Rv ATCC27294 T; 83332
• Experiment for Molecule Alteration: Sequencing analysis
• Experiment for Drug Resistance: In vitro drug susceptibility testing
• Mechanism Description: Notably, isoniazid is activated by the enzyme catalase-peroxidase, KatG, encoded by katG, whereas prothionamide is activated by the flavin monoxygenase, EthA, encoded by ethA. Mutations in katG and ethA are associated with individual isoniazid and prothionamide/ethionamide resistance, respectively. The ndh gene coding for NADH dehydrogenase, Ndh, was first identified as a new mechanism for INHR in Mycobacterium smegmatis. The mutations in ndh gene cause defects in the oxidation of NADH to NAD, which results in NADH accumulation and NAD depletion. The increased level of NADH inhibits the binding of isoniazid-NAD adduct to the active site of the InhA enzyme, which disturbs the regulation of enzyme activity and may cause co-resistance to isoniazid and prothionamide. EthR, a member of the TetR/CamR family, is a repressor of ethA. EthR regulates the transcription of ethA by coordinated octamerization on a 55-bp operator situated in the ethA-R intergenic region. Impeding EthR function leads to enhanced mycobacterial sensitivity to prothionamide, whereas mutations in ethR encoding a negative transcriptional regulator of the expression of EthA lead to prothionamide resistance. Finally, MshA, a member of the glycosyltransferase family, is a key enzyme involved in mycothiol biosynthesis in M. tuberculosis. Mutations in mshA coding MshA have been proposed to create a disturbance in prothionamide/ethionamide activation.

Key Molecule: Catalase-peroxidase (KATG) [7]

• Molecule Alteration: Missense mutation; p.G125S
• Resistant Disease: Mycolicibacterium smegmatis infection [ICD-11: 1B2Z.6]
• Experimental Note: Discovered Using In-vivo Testing Model
• In Vitro Model: Mycobacterium tuberculosis strain H37Rv ATCC27294 T; 83332
• Experiment for Molecule Alteration: Sequencing analysis
• Experiment for Drug Resistance: In vitro drug susceptibility testing
• Mechanism Description: Notably, isoniazid is activated by the enzyme catalase-peroxidase, KatG, encoded by katG, whereas prothionamide is activated by the flavin monoxygenase, EthA, encoded by ethA. Mutations in katG and ethA are associated with individual isoniazid and prothionamide/ethionamide resistance, respectively. The ndh gene coding for NADH dehydrogenase, Ndh, was first identified as a new mechanism for INHR in Mycobacterium smegmatis. The mutations in ndh gene cause defects in the oxidation of NADH to NAD, which results in NADH accumulation and NAD depletion. The increased level of NADH inhibits the binding of isoniazid-NAD adduct to the active site of the InhA enzyme, which disturbs the regulation of enzyme activity and may cause co-resistance to isoniazid and prothionamide. EthR, a member of the TetR/CamR family, is a repressor of ethA. EthR regulates the transcription of ethA by coordinated octamerization on a 55-bp operator situated in the ethA-R intergenic region. Impeding EthR function leads to enhanced mycobacterial sensitivity to prothionamide, whereas mutations in ethR encoding a negative transcriptional regulator of the expression of EthA lead to prothionamide resistance. Finally, MshA, a member of the glycosyltransferase family, is a key enzyme involved in mycothiol biosynthesis in M. tuberculosis. Mutations in mshA coding MshA have been proposed to create a disturbance in prothionamide/ethionamide activation.

Key Molecule: Catalase-peroxidase (KATG) [7]

• Molecule Alteration: Missense mutation; p.Q127P
• Resistant Disease: Mycolicibacterium smegmatis infection [ICD-11: 1B2Z.6]
• Experimental Note: Discovered Using In-vivo Testing Model
• In Vitro Model: Mycobacterium tuberculosis strain H37Rv ATCC27294 T; 83332
• Experiment for Molecule Alteration: Sequencing analysis
• Experiment for Drug Resistance: In vitro drug susceptibility testing
• Mechanism Description: Notably, isoniazid is activated by the enzyme catalase-peroxidase, KatG, encoded by katG, whereas prothionamide is activated by the flavin monoxygenase, EthA, encoded by ethA. Mutations in katG and ethA are associated with individual isoniazid and prothionamide/ethionamide resistance, respectively. The ndh gene coding for NADH dehydrogenase, Ndh, was first identified as a new mechanism for INHR in Mycobacterium smegmatis. The mutations in ndh gene cause defects in the oxidation of NADH to NAD, which results in NADH accumulation and NAD depletion. The increased level of NADH inhibits the binding of isoniazid-NAD adduct to the active site of the InhA enzyme, which disturbs the regulation of enzyme activity and may cause co-resistance to isoniazid and prothionamide. EthR, a member of the TetR/CamR family, is a repressor of ethA. EthR regulates the transcription of ethA by coordinated octamerization on a 55-bp operator situated in the ethA-R intergenic region. Impeding EthR function leads to enhanced mycobacterial sensitivity to prothionamide, whereas mutations in ethR encoding a negative transcriptional regulator of the expression of EthA lead to prothionamide resistance. Finally, MshA, a member of the glycosyltransferase family, is a key enzyme involved in mycothiol biosynthesis in M. tuberculosis. Mutations in mshA coding MshA have been proposed to create a disturbance in prothionamide/ethionamide activation.

Key Molecule: Catalase-peroxidase (KATG) [7]

• Molecule Alteration: Missense mutation; p.V431A
• Resistant Disease: Mycolicibacterium smegmatis infection [ICD-11: 1B2Z.6]
• Experimental Note: Discovered Using In-vivo Testing Model
• In Vitro Model: Mycobacterium tuberculosis strain H37Rv ATCC27294 T; 83332
• Experiment for Molecule Alteration: Sequencing analysis
• Experiment for Drug Resistance: In vitro drug susceptibility testing
• Mechanism Description: Notably, isoniazid is activated by the enzyme catalase-peroxidase, KatG, encoded by katG, whereas prothionamide is activated by the flavin monoxygenase, EthA, encoded by ethA. Mutations in katG and ethA are associated with individual isoniazid and prothionamide/ethionamide resistance, respectively. The ndh gene coding for NADH dehydrogenase, Ndh, was first identified as a new mechanism for INHR in Mycobacterium smegmatis. The mutations in ndh gene cause defects in the oxidation of NADH to NAD, which results in NADH accumulation and NAD depletion. The increased level of NADH inhibits the binding of isoniazid-NAD adduct to the active site of the InhA enzyme, which disturbs the regulation of enzyme activity and may cause co-resistance to isoniazid and prothionamide. EthR, a member of the TetR/CamR family, is a repressor of ethA. EthR regulates the transcription of ethA by coordinated octamerization on a 55-bp operator situated in the ethA-R intergenic region. Impeding EthR function leads to enhanced mycobacterial sensitivity to prothionamide, whereas mutations in ethR encoding a negative transcriptional regulator of the expression of EthA lead to prothionamide resistance. Finally, MshA, a member of the glycosyltransferase family, is a key enzyme involved in mycothiol biosynthesis in M. tuberculosis. Mutations in mshA coding MshA have been proposed to create a disturbance in prothionamide/ethionamide activation.

Key Molecule: Catalase-peroxidase (KATG) [7]

• Molecule Alteration: Missense mutation; p.G490S
• Resistant Disease: Mycolicibacterium smegmatis infection [ICD-11: 1B2Z.6]
• Experimental Note: Discovered Using In-vivo Testing Model
• In Vitro Model: Mycobacterium tuberculosis strain H37Rv ATCC27294 T; 83332
• Experiment for Molecule Alteration: Sequencing analysis
• Experiment for Drug Resistance: In vitro drug susceptibility testing
• Mechanism Description: Notably, isoniazid is activated by the enzyme catalase-peroxidase, KatG, encoded by katG, whereas prothionamide is activated by the flavin monoxygenase, EthA, encoded by ethA. Mutations in katG and ethA are associated with individual isoniazid and prothionamide/ethionamide resistance, respectively. The ndh gene coding for NADH dehydrogenase, Ndh, was first identified as a new mechanism for INHR in Mycobacterium smegmatis. The mutations in ndh gene cause defects in the oxidation of NADH to NAD, which results in NADH accumulation and NAD depletion. The increased level of NADH inhibits the binding of isoniazid-NAD adduct to the active site of the InhA enzyme, which disturbs the regulation of enzyme activity and may cause co-resistance to isoniazid and prothionamide. EthR, a member of the TetR/CamR family, is a repressor of ethA. EthR regulates the transcription of ethA by coordinated octamerization on a 55-bp operator situated in the ethA-R intergenic region. Impeding EthR function leads to enhanced mycobacterial sensitivity to prothionamide, whereas mutations in ethR encoding a negative transcriptional regulator of the expression of EthA lead to prothionamide resistance. Finally, MshA, a member of the glycosyltransferase family, is a key enzyme involved in mycothiol biosynthesis in M. tuberculosis. Mutations in mshA coding MshA have been proposed to create a disturbance in prothionamide/ethionamide activation.

Key Molecule: Catalase-peroxidase (KATG) [7]

• Molecule Alteration: Missense mutation; p.Q461P
• Resistant Disease: Mycolicibacterium smegmatis infection [ICD-11: 1B2Z.6]
• Experimental Note: Discovered Using In-vivo Testing Model
• In Vitro Model: Mycobacterium tuberculosis strain H37Rv ATCC27294 T; 83332
• Experiment for Molecule Alteration: Sequencing analysis
• Experiment for Drug Resistance: In vitro drug susceptibility testing
• Mechanism Description: Notably, isoniazid is activated by the enzyme catalase-peroxidase, KatG, encoded by katG, whereas prothionamide is activated by the flavin monoxygenase, EthA, encoded by ethA. Mutations in katG and ethA are associated with individual isoniazid and prothionamide/ethionamide resistance, respectively. The ndh gene coding for NADH dehydrogenase, Ndh, was first identified as a new mechanism for INHR in Mycobacterium smegmatis. The mutations in ndh gene cause defects in the oxidation of NADH to NAD, which results in NADH accumulation and NAD depletion. The increased level of NADH inhibits the binding of isoniazid-NAD adduct to the active site of the InhA enzyme, which disturbs the regulation of enzyme activity and may cause co-resistance to isoniazid and prothionamide. EthR, a member of the TetR/CamR family, is a repressor of ethA. EthR regulates the transcription of ethA by coordinated octamerization on a 55-bp operator situated in the ethA-R intergenic region. Impeding EthR function leads to enhanced mycobacterial sensitivity to prothionamide, whereas mutations in ethR encoding a negative transcriptional regulator of the expression of EthA lead to prothionamide resistance. Finally, MshA, a member of the glycosyltransferase family, is a key enzyme involved in mycothiol biosynthesis in M. tuberculosis. Mutations in mshA coding MshA have been proposed to create a disturbance in prothionamide/ethionamide activation.

Key Molecule: Catalase-peroxidase (KATG) [7]

• Molecule Alteration: Missense mutation; p.E607A
• Resistant Disease: Mycolicibacterium smegmatis infection [ICD-11: 1B2Z.6]
• Experimental Note: Discovered Using In-vivo Testing Model
• In Vitro Model: Mycobacterium tuberculosis strain H37Rv ATCC27294 T; 83332
• Experiment for Molecule Alteration: Sequencing analysis
• Experiment for Drug Resistance: In vitro drug susceptibility testing
• Mechanism Description: Notably, isoniazid is activated by the enzyme catalase-peroxidase, KatG, encoded by katG, whereas prothionamide is activated by the flavin monoxygenase, EthA, encoded by ethA. Mutations in katG and ethA are associated with individual isoniazid and prothionamide/ethionamide resistance, respectively. The ndh gene coding for NADH dehydrogenase, Ndh, was first identified as a new mechanism for INHR in Mycobacterium smegmatis. The mutations in ndh gene cause defects in the oxidation of NADH to NAD, which results in NADH accumulation and NAD depletion. The increased level of NADH inhibits the binding of isoniazid-NAD adduct to the active site of the InhA enzyme, which disturbs the regulation of enzyme activity and may cause co-resistance to isoniazid and prothionamide. EthR, a member of the TetR/CamR family, is a repressor of ethA. EthR regulates the transcription of ethA by coordinated octamerization on a 55-bp operator situated in the ethA-R intergenic region. Impeding EthR function leads to enhanced mycobacterial sensitivity to prothionamide, whereas mutations in ethR encoding a negative transcriptional regulator of the expression of EthA lead to prothionamide resistance. Finally, MshA, a member of the glycosyltransferase family, is a key enzyme involved in mycothiol biosynthesis in M. tuberculosis. Mutations in mshA coding MshA have been proposed to create a disturbance in prothionamide/ethionamide activation.

Key Molecule: Catalase-peroxidase (KATG) [7]

• Molecule Alteration: Missense mutation; p.H417Q
• Resistant Disease: Mycolicibacterium smegmatis infection [ICD-11: 1B2Z.6]
• Experimental Note: Discovered Using In-vivo Testing Model
• In Vitro Model: Mycobacterium tuberculosis strain H37Rv ATCC27294 T; 83332
• Experiment for Molecule Alteration: Sequencing analysis
• Experiment for Drug Resistance: In vitro drug susceptibility testing
• Mechanism Description: Notably, isoniazid is activated by the enzyme catalase-peroxidase, KatG, encoded by katG, whereas prothionamide is activated by the flavin monoxygenase, EthA, encoded by ethA. Mutations in katG and ethA are associated with individual isoniazid and prothionamide/ethionamide resistance, respectively. The ndh gene coding for NADH dehydrogenase, Ndh, was first identified as a new mechanism for INHR in Mycobacterium smegmatis. The mutations in ndh gene cause defects in the oxidation of NADH to NAD, which results in NADH accumulation and NAD depletion. The increased level of NADH inhibits the binding of isoniazid-NAD adduct to the active site of the InhA enzyme, which disturbs the regulation of enzyme activity and may cause co-resistance to isoniazid and prothionamide. EthR, a member of the TetR/CamR family, is a repressor of ethA. EthR regulates the transcription of ethA by coordinated octamerization on a 55-bp operator situated in the ethA-R intergenic region. Impeding EthR function leads to enhanced mycobacterial sensitivity to prothionamide, whereas mutations in ethR encoding a negative transcriptional regulator of the expression of EthA lead to prothionamide resistance. Finally, MshA, a member of the glycosyltransferase family, is a key enzyme involved in mycothiol biosynthesis in M. tuberculosis. Mutations in mshA coding MshA have been proposed to create a disturbance in prothionamide/ethionamide activation.

Key Molecule: Catalase-peroxidase (KATG) [7]

• Molecule Alteration: Missense mutation; p.G111S
• Resistant Disease: Mycolicibacterium smegmatis infection [ICD-11: 1B2Z.6]
• Experimental Note: Discovered Using In-vivo Testing Model
• In Vitro Model: Mycobacterium tuberculosis strain H37Rv ATCC27294 T; 83332
• Experiment for Molecule Alteration: Sequencing analysis
• Experiment for Drug Resistance: In vitro drug susceptibility testing
• Mechanism Description: Notably, isoniazid is activated by the enzyme catalase-peroxidase, KatG, encoded by katG, whereas prothionamide is activated by the flavin monoxygenase, EthA, encoded by ethA. Mutations in katG and ethA are associated with individual isoniazid and prothionamide/ethionamide resistance, respectively. The ndh gene coding for NADH dehydrogenase, Ndh, was first identified as a new mechanism for INHR in Mycobacterium smegmatis. The mutations in ndh gene cause defects in the oxidation of NADH to NAD, which results in NADH accumulation and NAD depletion. The increased level of NADH inhibits the binding of isoniazid-NAD adduct to the active site of the InhA enzyme, which disturbs the regulation of enzyme activity and may cause co-resistance to isoniazid and prothionamide. EthR, a member of the TetR/CamR family, is a repressor of ethA. EthR regulates the transcription of ethA by coordinated octamerization on a 55-bp operator situated in the ethA-R intergenic region. Impeding EthR function leads to enhanced mycobacterial sensitivity to prothionamide, whereas mutations in ethR encoding a negative transcriptional regulator of the expression of EthA lead to prothionamide resistance. Finally, MshA, a member of the glycosyltransferase family, is a key enzyme involved in mycothiol biosynthesis in M. tuberculosis. Mutations in mshA coding MshA have been proposed to create a disturbance in prothionamide/ethionamide activation.

Key Molecule: Catalase-peroxidase (KATG) [7]

• Molecule Alteration: Missense mutation; p.G33V
• Resistant Disease: Mycolicibacterium smegmatis infection [ICD-11: 1B2Z.6]
• Experimental Note: Discovered Using In-vivo Testing Model
• In Vitro Model: Mycobacterium tuberculosis strain H37Rv ATCC27294 T; 83332
• Experiment for Molecule Alteration: Sequencing analysis
• Experiment for Drug Resistance: In vitro drug susceptibility testing
• Mechanism Description: Notably, isoniazid is activated by the enzyme catalase-peroxidase, KatG, encoded by katG, whereas prothionamide is activated by the flavin monoxygenase, EthA, encoded by ethA. Mutations in katG and ethA are associated with individual isoniazid and prothionamide/ethionamide resistance, respectively. The ndh gene coding for NADH dehydrogenase, Ndh, was first identified as a new mechanism for INHR in Mycobacterium smegmatis. The mutations in ndh gene cause defects in the oxidation of NADH to NAD, which results in NADH accumulation and NAD depletion. The increased level of NADH inhibits the binding of isoniazid-NAD adduct to the active site of the InhA enzyme, which disturbs the regulation of enzyme activity and may cause co-resistance to isoniazid and prothionamide. EthR, a member of the TetR/CamR family, is a repressor of ethA. EthR regulates the transcription of ethA by coordinated octamerization on a 55-bp operator situated in the ethA-R intergenic region. Impeding EthR function leads to enhanced mycobacterial sensitivity to prothionamide, whereas mutations in ethR encoding a negative transcriptional regulator of the expression of EthA lead to prothionamide resistance. Finally, MshA, a member of the glycosyltransferase family, is a key enzyme involved in mycothiol biosynthesis in M. tuberculosis. Mutations in mshA coding MshA have been proposed to create a disturbance in prothionamide/ethionamide activation.

Key Molecule: Catalase-peroxidase (KATG) [7]

• Molecule Alteration: Missense mutation; p.W191R
• Resistant Disease: Mycolicibacterium smegmatis infection [ICD-11: 1B2Z.6]
• Experimental Note: Discovered Using In-vivo Testing Model
• In Vitro Model: Mycobacterium tuberculosis strain H37Rv ATCC27294 T; 83332
• Experiment for Molecule Alteration: Sequencing analysis
• Experiment for Drug Resistance: In vitro drug susceptibility testing
• Mechanism Description: Notably, isoniazid is activated by the enzyme catalase-peroxidase, KatG, encoded by katG, whereas prothionamide is activated by the flavin monoxygenase, EthA, encoded by ethA. Mutations in katG and ethA are associated with individual isoniazid and prothionamide/ethionamide resistance, respectively. The ndh gene coding for NADH dehydrogenase, Ndh, was first identified as a new mechanism for INHR in Mycobacterium smegmatis. The mutations in ndh gene cause defects in the oxidation of NADH to NAD, which results in NADH accumulation and NAD depletion. The increased level of NADH inhibits the binding of isoniazid-NAD adduct to the active site of the InhA enzyme, which disturbs the regulation of enzyme activity and may cause co-resistance to isoniazid and prothionamide. EthR, a member of the TetR/CamR family, is a repressor of ethA. EthR regulates the transcription of ethA by coordinated octamerization on a 55-bp operator situated in the ethA-R intergenic region. Impeding EthR function leads to enhanced mycobacterial sensitivity to prothionamide, whereas mutations in ethR encoding a negative transcriptional regulator of the expression of EthA lead to prothionamide resistance. Finally, MshA, a member of the glycosyltransferase family, is a key enzyme involved in mycothiol biosynthesis in M. tuberculosis. Mutations in mshA coding MshA have been proposed to create a disturbance in prothionamide/ethionamide activation.

Unusual Activation of Pro-survival Pathway (UAPP)

Key Molecule: NAD-dependent protein deacylase Sir2 (SIR2) [1]

• Molecule Alteration: Expression; Up-regulation
• Resistant Disease: Mycolicibacterium smegmatis infection [ICD-11: 1B2Z.6]
• Experimental Note: Discovered Using In-vivo Testing Model
• In Vitro Model: Escherichia coli; 668369
• In Vitro Model: Mycobacterium smegmatis mc2155; 246196
• Experiment for Molecule Alteration: Quantitative Real-Time PCR
• Experiment for Drug Resistance: Colony forming units determination assay
• Mechanism Description: MSMEG_5175 regulates diverse cellular processes resulting in an increase in INH resistance in mycobacteria. Overexpression of MSMEG_5175 results in up-regulation of 34 proteins and down-regulation of 72 proteins, which involve in diverse cellular processes including metabolic activation, transcription and translation, antioxidant, and DNA repair. Down-regulation of catalase peroxidase (katG) expression in both mRNA and protein levels were observed in mc(2)155-MS5175 strain, suggesting that a decrease in cellular NAD content and down-regulation of katG expression contribute to the higher resistance to INH in mc(2)155-MS5175.

Key Molecule: D-inositol 3-phosphate glycosyltransferase (MSHA) [7]

• Molecule Alteration: Non-synonymous mutation; p.F355S
• Resistant Disease: Mycolicibacterium smegmatis infection [ICD-11: 1B2Z.6]
• Experimental Note: Discovered Using In-vivo Testing Model
• In Vitro Model: Mycobacterium tuberculosis strain H37Rv ATCC27294 T; 83332
• Experiment for Molecule Alteration: Sequencing analysis
• Experiment for Drug Resistance: In vitro drug susceptibility testing
• Mechanism Description: Notably, isoniazid is activated by the enzyme catalase-peroxidase, KatG, encoded by katG, whereas prothionamide is activated by the flavin monoxygenase, EthA, encoded by ethA. Mutations in katG and ethA are associated with individual isoniazid and prothionamide/ethionamide resistance, respectively. The ndh gene coding for NADH dehydrogenase, Ndh, was first identified as a new mechanism for INHR in Mycobacterium smegmatis. The mutations in ndh gene cause defects in the oxidation of NADH to NAD, which results in NADH accumulation and NAD depletion. The increased level of NADH inhibits the binding of isoniazid-NAD adduct to the active site of the InhA enzyme, which disturbs the regulation of enzyme activity and may cause co-resistance to isoniazid and prothionamide. EthR, a member of the TetR/CamR family, is a repressor of ethA. EthR regulates the transcription of ethA by coordinated octamerization on a 55-bp operator situated in the ethA-R intergenic region. Impeding EthR function leads to enhanced mycobacterial sensitivity to prothionamide, whereas mutations in ethR encoding a negative transcriptional regulator of the expression of EthA lead to prothionamide resistance. Finally, MshA, a member of the glycosyltransferase family, is a key enzyme involved in mycothiol biosynthesis in M. tuberculosis. Mutations in mshA coding MshA have been proposed to create a disturbance in prothionamide/ethionamide activation.

Key Molecule: D-inositol 3-phosphate glycosyltransferase (MSHA) [7]

• Molecule Alteration: Non-synonymous mutation; p.N111S
• Resistant Disease: Mycolicibacterium smegmatis infection [ICD-11: 1B2Z.6]
• Experimental Note: Discovered Using In-vivo Testing Model
• In Vitro Model: Mycobacterium tuberculosis strain H37Rv ATCC27294 T; 83332
• Experiment for Molecule Alteration: Sequencing analysis
• Experiment for Drug Resistance: In vitro drug susceptibility testing
• Mechanism Description: Notably, isoniazid is activated by the enzyme catalase-peroxidase, KatG, encoded by katG, whereas prothionamide is activated by the flavin monoxygenase, EthA, encoded by ethA. Mutations in katG and ethA are associated with individual isoniazid and prothionamide/ethionamide resistance, respectively. The ndh gene coding for NADH dehydrogenase, Ndh, was first identified as a new mechanism for INHR in Mycobacterium smegmatis. The mutations in ndh gene cause defects in the oxidation of NADH to NAD, which results in NADH accumulation and NAD depletion. The increased level of NADH inhibits the binding of isoniazid-NAD adduct to the active site of the InhA enzyme, which disturbs the regulation of enzyme activity and may cause co-resistance to isoniazid and prothionamide. EthR, a member of the TetR/CamR family, is a repressor of ethA. EthR regulates the transcription of ethA by coordinated octamerization on a 55-bp operator situated in the ethA-R intergenic region. Impeding EthR function leads to enhanced mycobacterial sensitivity to prothionamide, whereas mutations in ethR encoding a negative transcriptional regulator of the expression of EthA lead to prothionamide resistance. Finally, MshA, a member of the glycosyltransferase family, is a key enzyme involved in mycothiol biosynthesis in M. tuberculosis. Mutations in mshA coding MshA have been proposed to create a disturbance in prothionamide/ethionamide activation.

HIV associated with tuberculosis [ICD-11: 1C60]

Drug Resistance Data Categorized by Their Corresponding Mechanisms

Drug Inactivation by Structure Modification (DISM)

Key Molecule: Catalase-peroxidase (KATG) [8]

• Molecule Alteration: Expression; Down-regulation
• Resistant Disease: HIV-infected patients with tuberculosis [ICD-11: 1C60.0]
• Experimental Note: Discovered Using In-vivo Testing Model
• Cell Pathway Regulation: Cell growth; Inhibition; hsa05200
• In Vitro Model: Mycobacterium smegmatis mc2155; 246196
• In Vitro Model: Mycobacterium smegmatis mc2155-Cu; 246196
• Experiment for Molecule Alteration: qPCR
• Experiment for Drug Resistance: MIC assay
• Mechanism Description: As a prodrug, INH needs to be activated by katG to execute its antibiotic function. katG is a bifunctional enzyme with both catalase and peroxidase activity and catalyzes the coupling of INH with NAD+ to form the isonicotinic acyl-NAD complex, which binds to the enoyl-acyl carrier protein reductase to inhibit the synthesis of mycolic acid required for the mycobacterial cell wall. In the present study, quantitative proteomic analysis showed that the expression level of katG was down-regulated in mc2155-Cu as compared to mc2155. Down-regulation of katG expression as well as a decrease in cellular NAD level results in the higher resistance to INH in mc2155-Cu.

Key Molecule: Arylamine N-acetyltransferase 1 (NAT1) [9]

• Molecule Alteration: Expression; Up-regulation
• Resistant Disease: HIV-infected patients with tuberculosis [ICD-11: 1C60.0]
• Experimental Note: Discovered Using In-vivo Testing Model
• Cell Pathway Regulation: Cell growth; Activation; hsa05200
• In Vitro Model: Mycobacterium tuberculosis H37Rv; 83332
• Experiment for Molecule Alteration: SDS-PAGE assay
• Experiment for Drug Resistance: Titertek multiskan assay
• Mechanism Description: Arylamine N-acetyltransferase (NAT), a drug-metabolizing enzyme of MTB, can acetylate INH, transferring an acetyl group from acetyl coenzyme A to the terminal nitrogen of the drug, which in its N-acetylated form is therapeutically inactive. The overexpression of NAT in Mycobacterium smegmatis showed increased resistance to INH; in addition, when the gene was knocked-out, the bacteria exhibited increased sensitivity to INH.

Unusual Activation of Pro-survival Pathway (UAPP)

Key Molecule: Isocitrate lyase 1 (ICL1) [6]

• Molecule Alteration: Expression; Up-regulation
• Resistant Disease: HIV-infected patients with tuberculosis [ICD-11: 1C60.0]
• Experimental Note: Discovered Using In-vivo Testing Model
• In Vitro Model: Mycobacterium tuberculosis strains; 1773
• Experiment for Molecule Alteration: qRT-PCR
• Experiment for Drug Resistance: MIC assay
• Mechanism Description: Despite targeting diverse cellular processes, all three drugs trigger activation of Mtb's isocitrate lyases (ICLs), metabolic enzymes commonly assumed to be involved in replenishing of tricarboxylic acid (TCA) cycle intermediates. We further show that ICL-deficient Mtb strains are significantly more susceptible than wild-type Mtb to all three antibiotics, and that this susceptibility can be chemically rescued when Mtb is co-incubated with an antioxidant.

Key Molecule: Isocitrate lyase 2 (ICL2) [6]

• Molecule Alteration: Expression; Up-regulation
• Resistant Disease: HIV-infected patients with tuberculosis [ICD-11: 1C60.0]
• Experimental Note: Discovered Using In-vivo Testing Model
• In Vitro Model: Mycobacterium tuberculosis strains; 1773
• Experiment for Molecule Alteration: qRT-PCR
• Experiment for Drug Resistance: MIC assay
• Mechanism Description: Despite targeting diverse cellular processes, all three drugs trigger activation of Mtb's isocitrate lyases (ICLs), metabolic enzymes commonly assumed to be involved in replenishing of tricarboxylic acid (TCA) cycle intermediates. We further show that ICL-deficient Mtb strains are significantly more susceptible than wild-type Mtb to all three antibiotics, and that this susceptibility can be chemically rescued when Mtb is co-incubated with an antioxidant.

Drug Sensitivity Data Categorized by Their Corresponding Mechanisms

Unusual Activation of Pro-survival Pathway (UAPP)

Key Molecule: Isocitrate lyase 1 (ICL1) [6]

• Molecule Alteration: Expression; Down-regulation
• Sensitive Disease: HIV-infected patients with tuberculosis [ICD-11: 1C60.0]
• Experimental Note: Discovered Using In-vivo Testing Model
• In Vitro Model: Mycobacterium tuberculosis strains; 1773
• Experiment for Molecule Alteration: qRT-PCR
• Experiment for Drug Resistance: MIC assay
• Mechanism Description: Despite targeting diverse cellular processes, all three drugs trigger activation of Mtb's isocitrate lyases (ICLs), metabolic enzymes commonly assumed to be involved in replenishing of tricarboxylic acid (TCA) cycle intermediates. We further show that ICL-deficient Mtb strains are significantly more susceptible than wild-type Mtb to all three antibiotics, and that this susceptibility can be chemically rescued when Mtb is co-incubated with an antioxidant.

Key Molecule: Isocitrate lyase 2 (ICL2) [6]

• Molecule Alteration: Expression; Down-regulation
• Sensitive Disease: HIV-infected patients with tuberculosis [ICD-11: 1C60.0]
• Experimental Note: Discovered Using In-vivo Testing Model
• In Vitro Model: Mycobacterium tuberculosis strains; 1773
• Experiment for Molecule Alteration: qRT-PCR
• Experiment for Drug Resistance: MIC assay
• Mechanism Description: Despite targeting diverse cellular processes, all three drugs trigger activation of Mtb's isocitrate lyases (ICLs), metabolic enzymes commonly assumed to be involved in replenishing of tricarboxylic acid (TCA) cycle intermediates. We further show that ICL-deficient Mtb strains are significantly more susceptible than wild-type Mtb to all three antibiotics, and that this susceptibility can be chemically rescued when Mtb is co-incubated with an antioxidant.

Urinary tuberculosis [ICD-11: 1G80]

Drug Resistance Data Categorized by Their Corresponding Mechanisms

Unusual Activation of Pro-survival Pathway (UAPP)

Key Molecule: Catalase-peroxidase (KATG) [5]

• Molecule Alteration: Missense mutation; p.S531L
• Resistant Disease: Urinary tuberculosis [ICD-11: 1G80.0]
• Experimental Note: Identified from the Human Clinical Data
• In Vitro Model: Mycobacterium tuberculosis isolates; 1773
• Experiment for Molecule Alteration: Gene sequencing assay
• Mechanism Description: Regarding drug-resistance mutation profiles, the most prevalent mutation sites were katG S315T1 and rpoB S531L.

Key Molecule: DNA-directed RNA polymerase subunit beta (RPOB) [5]

• Molecule Alteration: Missense mutation; p.S531L
• Resistant Disease: Urinary tuberculosis [ICD-11: 1G80.0]
• Experimental Note: Identified from the Human Clinical Data
• In Vitro Model: Mycobacterium tuberculosis isolates; 1773
• Experiment for Molecule Alteration: Gene sequencing assay
• Mechanism Description: Regarding drug-resistance mutation profiles, the most prevalent mutation sites were katG S315T1 and rpoB S531L.

Key Molecule: Catalase-peroxidase (KATG) [5]

• Molecule Alteration: Missense mutation; p.S315T1
• Resistant Disease: Urinary tuberculosis [ICD-11: 1G80.0]
• Experimental Note: Identified from the Human Clinical Data
• In Vitro Model: Mycobacterium tuberculosis isolates; 1773
• Experiment for Molecule Alteration: Gene sequencing assay
• Mechanism Description: Regarding drug-resistance mutation profiles, the most prevalent mutation sites were katG S315T1 and rpoB S531L.

Key Molecule: DNA-directed RNA polymerase subunit beta (RPOB) [5]

• Molecule Alteration: Missense mutation; p.S315T1
• Resistant Disease: Urinary tuberculosis [ICD-11: 1G80.0]
• Experimental Note: Identified from the Human Clinical Data
• In Vitro Model: Mycobacterium tuberculosis isolates; 1773
• Experiment for Molecule Alteration: Gene sequencing assay
• Mechanism Description: Regarding drug-resistance mutation profiles, the most prevalent mutation sites were katG S315T1 and rpoB S531L.

ICD-12: Respiratory system diseases

Pneumoconiosis [ICD-11: CA60]

Drug Resistance Data Categorized by Their Corresponding Mechanisms

Drug Inactivation by Structure Modification (DISM)

Key Molecule: Catalase-peroxidase (KATG) [2]

• Molecule Alteration: Missense mutation; p.S315T
• Resistant Disease: Pneumoconiosis complicated with tuberculosis [ICD-11: CA60.Y]
• Experimental Note: Identified from the Human Clinical Data
• In Vitro Model: Mycobacterium tuberculosis isolates; 1773
• In Vitro Model: Mycobacterium tuberculosis H37Rv1; 1773
• Experiment for Molecule Alteration: qRT-PCR
• Mechanism Description: Isoniazid is a hydrazine chemical synthetic drug, which is able to be oxidized to isonicotinic acid by the catalase-peroxidase encoded by the katG gene that participates in the synthesis of coenzyme I (NAD) to inhibit the biosynthesis of mycolic acid of the cell wall in Mycobacterium tuberculosis, so as to damage the MDR-TB's barricade of resisting antioxygen and invasion. Due to deletion or mutation in the katG gene, resistance is able to be generated as the enzymatic activity is lost or degraded, thus, inhibiting the activation of Isoniazid.

Key Molecule: Catalase-peroxidase (KATG) [2]

• Molecule Alteration: Missense mutation; p.S315N
• Resistant Disease: Pneumoconiosis complicated with tuberculosis [ICD-11: CA60.Y]
• Experimental Note: Identified from the Human Clinical Data
• In Vitro Model: Mycobacterium tuberculosis isolates; 1773
• In Vitro Model: Mycobacterium tuberculosis H37Rv1; 1773
• Experiment for Molecule Alteration: qRT-PCR
• Mechanism Description: Isoniazid is a hydrazine chemical synthetic drug, which is able to be oxidized to isonicotinic acid by the catalase-peroxidase encoded by the katG gene that participates in the synthesis of coenzyme I (NAD) to inhibit the biosynthesis of mycolic acid of the cell wall in Mycobacterium tuberculosis, so as to damage the MDR-TB's barricade of resisting antioxygen and invasion. Due to deletion or mutation in the katG gene, resistance is able to be generated as the enzymatic activity is lost or degraded, thus, inhibiting the activation of Isoniazid.

Key Molecule: Catalase-peroxidase (KATG) [2]

• Molecule Alteration: Missense mutation; p.A431V
• Resistant Disease: Pneumoconiosis complicated with tuberculosis [ICD-11: CA60.Y]
• Experimental Note: Identified from the Human Clinical Data
• In Vitro Model: Mycobacterium tuberculosis isolates; 1773
• In Vitro Model: Mycobacterium tuberculosis H37Rv1; 1773
• Experiment for Molecule Alteration: qRT-PCR
• Mechanism Description: Isoniazid is a hydrazine chemical synthetic drug, which is able to be oxidized to isonicotinic acid by the catalase-peroxidase encoded by the katG gene that participates in the synthesis of coenzyme I (NAD) to inhibit the biosynthesis of mycolic acid of the cell wall in Mycobacterium tuberculosis, so as to damage the MDR-TB's barricade of resisting antioxygen and invasion. Due to deletion or mutation in the katG gene, resistance is able to be generated as the enzymatic activity is lost or degraded, thus, inhibiting the activation of Isoniazid.

References

• Ref 1: Functional Characterization of Sirtuin-like Protein in Mycobacterium smegmatis. J Proteome Res. 2015 Nov 6;14(11):4441-9. doi: 10.1021/acs.jproteome.5b00359. Epub 2015 Sep 29.
• Ref 2: Analysis of mutational characteristics of the drug-resistant gene katG in multi-drug resistant Mycobacterium tuberculosis L-form among patients with pneumoconiosis complicated with tuberculosis .Mol Med Rep. 2014 May;9(5):2031-5. doi: 10.3892/mmr.2014.2045. Epub 2014 Mar 13. 10.3892/mmr.2014.2045
• Ref 3: Rifampicin and isoniazid drug resistance among patients diagnosed with pulmonary tuberculosis in southwestern Uganda .PLoS One. 2021 Oct 29;16(10):e0259221. doi: 10.1371/journal.pone.0259221. eCollection 2021. 10.1371/journal.pone.0259221
• Ref 4: Tuberculous Scleritis and Multidrug ResistanceOcul Immunol Inflamm. 2021 Jan 8:1-10. doi: 10.1080/09273948.2020.1853176. Online ahead of print.
• Ref 5: Clinical Features and Drug-Resistance Profile of Urinary Tuberculosis in South-Western China: A Cross-sectional Study .Medicine (Baltimore). 2016 May;95(19):e3537. doi: 10.1097/MD.0000000000003537. 10.1097/MD.0000000000003537
• Ref 6: Isocitrate lyase mediates broad antibiotic tolerance in Mycobacterium tuberculosis. Nat Commun. 2014 Jun 30;5:4306. doi: 10.1038/ncomms5306.
• Ref 7: Detection of novel mutations associated with independent resistance and cross-resistance to isoniazid and prothionamide in Mycobacterium tuberculosis clinical isolates .Clin Microbiol Infect. 2019 Aug;25(8):1041.e1-1041.e7. doi: 10.1016/j.cmi.2018.12.008. Epub 2018 Dec 22. 10.1016/j.cmi.2018.12.008
• Ref 8: Proteomic Analysis of Drug-Resistant Mycobacteria: Co-Evolution of Copper and INH Resistance. PLoS One. 2015 Jun 2;10(6):e0127788. doi: 10.1371/journal.pone.0127788. eCollection 2015.
• Ref 9: Cloning and characterization of arylamine N-acetyltransferase genes from Mycobacterium smegmatis and Mycobacterium tuberculosis: increased expression results in isoniazid resistance. J Bacteriol. 1999 Feb;181(4):1343-7. doi: 10.1128/JB.181.4.1343-1347.1999.