| Accession | ARO:3003751 |
| CARD Short Name | Ecol_nfsA_NIT |
| Definition | nfsA encodes the major oxygen-insesitive nitroreductase in E. coli. The first step of resistance to nitrofurazone is mutation of nfsA. |
| AMR Gene Family | antibiotic resistant nfsA |
| Drug Class | nitrofuran antibiotic |
| Resistance Mechanism | antibiotic target alteration |
| Resistomes with Sequence Variants | Citrobacter freundiig, Enterobacter cloacaewgs, Escherichia colig+wgs, Shigella flexnerig, Shigella sonneiwgs |
| Classification | 8 ontology terms | Show + process or component of antibiotic biology or chemistry + mechanism of antibiotic resistance + antibiotic target alteration [Resistance Mechanism] + mutation conferring antibiotic resistance + determinant of antibiotic resistance + antibiotic molecule + nitrofuran antibiotic [Drug Class] + antibiotic resistant gene variant or mutant |
| Parent Term(s) | 2 ontology terms | Show + confers_resistance_to_antibiotic nitrofurantoin [Antibiotic] + antibiotic resistant nfsA [AMR Gene Family] |
| Publications | Sandegren L, et al. 2008. J. Antimicrob. Chemother. 62(3):495-503 Nitrofurantoin resistance mechanism and fitness cost in Escherichia coli. (PMID 18544599) Race PR, et al. 2005. J. Biol. Chem. 280(14):13256-64 Structural and mechanistic studies of Escherichia coli nitroreductase with the antibiotic nitrofurazone. Reversed binding orientations in different redox states of the enzyme. (PMID 15684426) Ho PL, et al. 2015. Antimicrob. Agents Chemother. 60(1):537-43 Plasmid-Mediated OqxAB Is an Important Mechanism for Nitrofurantoin Resistance in Escherichia coli. (PMID 26552976) |
Prevalence of Escherichia coli nfsA mutations conferring resistance to nitrofurantoin 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).
| Species | NCBI Chromosome | NCBI Plasmid | NCBI WGS | NCBI GI |
|---|---|---|---|---|
| Citrobacter freundii | 1.64% | 0% | 0% | 0% |
| Enterobacter cloacae | 0% | 0% | 1.28% | 0% |
| Escherichia coli | 0.33% | 0% | 0.43% | 0% |
| Shigella flexneri | 1% | 0% | 0% | 0% |
| Shigella sonnei | 0% | 0% | 0.22% | 0% |
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
Legend:
Published Variants:
| PMID: 18544599 | R15C S33R G131D R203L R203C |
| PMID: 26552976 | R133S K141STOP E233STOP Q44STOP -MTPTIELICGHRSIRHFTDEPISEAQ1-26 -QYDEQLA191-197 -nt25:T -nt603:C |