Accession ARO:3002863
DefinitiondfrA8 is a transposon-encoded dihydrofolate reductase found in Salmonella enterica
AMR Gene Familytrimethoprim resistant dihydrofolate reductase dfr
Drug Classdiaminopyrimidine antibiotic
Resistance Mechanismantibiotic target replacement
ResistomesCitrobacter amalonaticuswgs, Enterobacter hormaecheiwgs, Escherichia colig+p+wgs, Klebsiella pneumoniaep+wgs, Pseudomonas aeruginosawgs, Salmonella entericawgs, Serratia marcescenswgs, Shigella flexneriwgs, Shigella sonneiwgs
Classification10 ontology terms | Show
Parent Term(s)3 ontology terms | Show
+ confers_resistance_to_antibiotic trimethoprim [Antibiotic]
+ derives_from antibiotic sensitive dihydrofolate reductase
+ trimethoprim resistant dihydrofolate reductase dfr [AMR Gene Family]

Prevalence of dfrA8 among the sequenced genomes, plasmids, and whole-genome shotgun assemblies available at NCBI for 85 important pathogens (see methodological details and complete list of analyzed pathogens). Values reflect percentage of genomes, plasmids, 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 WGS
Citrobacter amalonaticus0%0%11.11%
Enterobacter hormaechei0%0%0.95%
Escherichia coli0.16%0.11%2.08%
Klebsiella pneumoniae0%0.03%0.13%
Pseudomonas aeruginosa0%0%0.05%
Salmonella enterica0%0%0.14%
Serratia marcescens0%0%3.23%
Shigella flexneri0%0%1.04%
Shigella sonnei0%0%2.35%
Show Perfect Only

Detection Models

Model Type: protein homolog model

Model Definition: The protein homolog model is an AMR detection model. Protein homolog models detect a protein sequence based on its similarity to a curated reference sequence. A protein homolog model has only one parameter: a curated BLASTP bitscore cutoff for determining the strength of a match. Protein homolog model matches to reference sequences are categorized on three criteria: perfect, strict and loose. A perfect match is 100% identical to the reference sequence along its entire length; a strict match is not identical but the bitscore of the matched sequence is greater than the curated BLASTP bitscore cutoff. Loose matches are other sequences with a match bitscore less than the curated BLASTP bitscore.

Bit-score Cut-off (blastP): 300

>gb|AHV80711.1|+|dfrA8 [Salmonella enterica subsp. enterica serovar Typhimurium]

>gb|KJ174469|+|711-1220|dfrA8 [Salmonella enterica subsp. enterica serovar Typhimurium]