Mycobacterium tuberculosis fabG1 mutations confer resistance to isoniazid

Accession ARO:3004922
CARD Short NameMtub_fabG1_INH
DefinitionMutations that occur in fabG1 resulting in or contributing to resistance in isoniazid.
AMR Gene Familyisoniazid resistant fabG1
Drug Classisoniazid-like antibiotic
Resistance Mechanismantibiotic target alteration
Classification9 ontology terms | Show
Parent Term(s)2 ontology terms | Show
+ isoniazid resistant fabG1 [AMR Gene Family]
+ confers_resistance_to_antibiotic isoniazid [Antibiotic]

Lavender C, et al. 2005. Antimicrob Agents Chemother 49(10):4068-74 Molecular characterization of isoniazid-resistant Mycobacterium tuberculosis isolates collected in Australia. (PMID 16189082)


Prevalence of Mycobacterium tuberculosis fabG1 mutations confer resistance to isoniazid among the sequenced genomes, plasmids, and whole-genome shotgun assemblies available at NCBI or IslandViewer for 413 important pathogens (see methodological details and complete list of analyzed pathogens). Values reflect percentage of genomes, plasmids, genome islands, or whole-genome shotgun assemblies that have at least one hit to the AMR detection model. Default view includes percentages calculated based on Perfect plus Strict RGI hits. Select the checkbox to view percentages based on only Perfect matches to AMR reference sequences curated in CARD (note: this excludes resistance via mutation as references in protein variant models are often wild-type, sensitive sequences).

Prevalence: protein variant model

SpeciesNCBI ChromosomeNCBI PlasmidNCBI WGSNCBI GI
No prevalence data

Detection Models

Model Type: protein variant model

Model Definition: Protein Variant Models (PVM) perform a similar search as Protein Homolog Models (PHM), i.e. detect protein sequences based on their similarity to a curated reference sequence, but secondarily screen query sequences for curated sets of mutations to differentiate them from antibiotic susceptible wild-type alleles. PVMs are designed to detect AMR acquired via mutation of house-keeping genes or antibiotic targets, e.g. a mutated gyrase resistant to aminocoumarin antibiotics. PVMs include a protein reference sequence (often from antibiotic susceptible wild-type alleles), a curated bit-score cut-off, and mapped resistance variants. Mapped resistance variants may include any or all of single point mutations, insertions, or deletions curated from the scientific literature. A Strict RGI match has a BLASTP bit-score above the curated BLASTP cutoff value and contains at least one curated mutation from amongst the mapped resistance variants, while a Loose RGI match has a bit-score less than the curated BLASTP bit-score cut-off but still contains at least one curated mutation from amongst the mapped resistance variants.

Bit-score Cut-off (blastP): 425


  • discovered in clinical, agricultural, or environmental isolates

  • discovered via laboratory selection experiments

  • ReSeqTB

Published Variants:

PMID in progress (TB): T8A T8C C15T G17T P81A


High ConfidenceC15T G17T T8A T8C
Indeterminate ConfidenceP81A

>gb|CCP44243.1|+|Mycobacterium tuberculosis fabG1 mutations confer resistance to isoniazid [Mycobacterium tuberculosis H37Rv]

>gb|AL123456.3|+|1673440-1674183|Mycobacterium tuberculosis fabG1 mutations confer resistance to isoniazid [Mycobacterium tuberculosis H37Rv]