Accession ARO:3005354
Synonym(s)trimethoprim-resistance dihydrofolate reductase type 22
CARD Short Namedfr22
DefinitionDfr22 is a dihydrofolate reductase that confers resistant to Trimethoprim. Originally detected by Grape et al., (2005) and isolated from Escherichia coli.
AMR Gene Familytrimethoprim resistant dihydrofolate reductase dfr
Drug Classdiaminopyrimidine antibiotic
Resistance Mechanismantibiotic target replacement
Resistomes with Perfect MatchesAeromonas caviaep, Enterobacter hormaecheiwgs, Escherichia coliwgs, Klebsiella aerogenesp, Klebsiella pneumoniaewgs, Klebsiella quasipneumoniaep+wgs, Pseudomonas aeruginosawgs, Serratia marcescenswgs
Resistomes with Sequence VariantsAeromonas caviaep, Citrobacter koseriwgs, Enterobacter hormaecheiwgs, Escherichia coliwgs, Klebsiella aerogenesp, Klebsiella pneumoniaewgs, Klebsiella quasipneumoniaep+wgs, Pseudomonas aeruginosawgs, Serratia marcescenswgs
Classification9 ontology terms | Show
Parent Term(s)2 ontology terms | Show
+ trimethoprim resistant dihydrofolate reductase dfr [AMR Gene Family]
+ confers_resistance_to_antibiotic trimethoprim [Antibiotic]

Grape M, et al. 2005. Clin Microbiol Infect 11(3):185-92 Integrons and gene cassettes in clinical isolates of co-trimoxazole-resistant Gram-negative bacteria. (PMID 15715715)


Prevalence of dfr22 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
Aeromonas caviae0%1.3%0%0%
Citrobacter koseri0%0%0.9%0%
Enterobacter hormaechei0%0%0.09%0%
Escherichia coli0%0%0.01%0%
Klebsiella aerogenes0%1.09%0%0%
Klebsiella pneumoniae0%0%0.05%0%
Klebsiella quasipneumoniae0%0.21%0.13%0%
Pseudomonas aeruginosa0%0%0.03%0%
Serratia marcescens0%0%0.13%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): 275

>gb|CAF31623.1|+|dfr22 [Escherichia coli]

>gb|AJ628423.2|+|325-822|dfr22 [Escherichia coli]