Clostridioides difficile nimB

Accession ARO:3007671
Synonym(s)C. difficile nimB
CARD Short NameCdnimB
DefinitionClostridioides difficile nimB is a heme-dependent flavin enzyme that degrades nitroimidazoles to amines lacking antimicrobial activity. NimB expression alone is not sufficient for nitroimidazole resistance. Constitutive transcription of nimB, which is driven by a mutation in the promoter PnimBG, is a mechanism of clinically-relevant heme-dependent metronidazole resistance in C. difficile.
AMR Gene Familynitroimidazole reductase
Drug Classnitroimidazole antibiotic
Resistance Mechanismantibiotic inactivation
Classification7 ontology terms | Show
Parent Term(s)2 ontology terms | Show
+ nitroimidazole reductase [AMR Gene Family]
+ confers_resistance_to_antibiotic metronidazole [Antibiotic]

Olaitan AO, et al. 2023. Nat Commun 14(1):4130 Decoding a cryptic mechanism of metronidazole resistance among globally disseminated fluoroquinolone-resistant Clostridioides difficile. (PMID 37438331)


Prevalence of Clostridioides difficile 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

SpeciesNCBI ChromosomeNCBI PlasmidNCBI WGSNCBI GI
No prevalence data

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): 250

>gb|CBE03766.1|-|Clostridioides difficile nimB [Clostridioides difficile R20291]

>gb|FN545816.1|-|1547474-1547941|Clostridioides difficile nimB [Clostridioides difficile R20291]