Accession ARO:3004655
CARD Short NamenimB
DefinitionnimB is a nitroimidazole reductase mainly found in Bacteroides fragilis that is associated with the deactivation of nitroimidazole antibiotics such as metronidazole. Minimum inhibitory concentrations observed in isolates vary greatly depending on species, strain, and nitroimidazole treatment.
AMR Gene Familynitroimidazole reductase
Drug Classnitroimidazole antibiotic
Resistance Mechanismantibiotic inactivation
Resistomes with Perfect MatchesBacteroides fragiliswgs
Resistomes with Sequence VariantsBacteroides fragiliswgs
Classification7 ontology terms | Show
Parent Term(s)2 ontology terms | Show
+ nitroimidazole reductase [AMR Gene Family]
+ confers_resistance_to_antibiotic metronidazole [Antibiotic]

Haggoud A, et al. 1994. Antimicrob. Agents Chemother. 38(5):1047-51 Nucleotide sequence analysis of two 5-nitroimidazole resistance determinants from Bacteroides strains and of a new insertion sequence upstream of the two genes. (PMID 8067736)

Stubbs SL, et al. 2000. J Clin Microbiol 38(9):3209-13 PCR-restriction fragment length polymorphism analysis for identification of Bacteroides spp. and characterization of nitroimidazole resistance genes. (PMID 10970359)


Prevalence of nimB 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 homolog model (view sequences)

SpeciesNCBI ChromosomeNCBI PlasmidNCBI WGSNCBI GI
Bacteroides fragilis0%0%0.53%0%
Show Perfect Only

Detection Models

Model Type: protein homolog model

Model Definition: Protein Homolog Models (PHM) detect protein sequences based on their similarity to a curated reference sequence, using curated BLASTP bitscore cut-offs. Protein Homolog Models apply to all genes that confer resistance through their presence in an organism, such as the presence of a beta-lactamase gene on a plasmid. PHMs include a reference sequence and a bitscore cut-off for detection using BLASTP. A Perfect RGI match is 100% identical to the reference protein sequence along its entire length, a Strict RGI match is not identical but the bit-score of the matched sequence is greater than the curated BLASTP bit-score cutoff, Loose RGI matches have a bit-score less than the curated BLASTP bit-score cut-off.

Bit-score Cut-off (blastP): 150

>gb|CAA50578.1|+|nimB [Bacteroides fragilis]

>gb|X71443.1|+|794-1288|nimB [Bacteroides fragilis]