| Accession | ARO:3002863 |
| Synonym(s) | dhfrIIIc |
| CARD Short Name | dfrA8 |
| Definition | dfrA8 is a transposon-encoded dihydrofolate reductase found in Salmonella enterica. |
| AMR Gene Family | trimethoprim resistant dihydrofolate reductase dfr |
| Drug Class | diaminopyrimidine antibiotic |
| Resistance Mechanism | antibiotic target replacement |
| Resistomes with Perfect Matches | Citrobacter amalonaticuswgs, Enterobacter asburiaep, Enterobacter cloacaep, Enterobacter hormaecheiwgs, Escherichia albertiiwgs, Escherichia colig+p+wgs+gi, Klebsiella pneumoniaep+wgs, Providencia rettgeriwgs, Pseudomonas aeruginosawgs, Salmonella entericawgs, Serratia marcescenswgs, Shigella flexneriwgs, Shigella sonneiwgs, Vibrio choleraewgs |
| Resistomes with Sequence Variants | Citrobacter amalonaticuswgs, Enterobacter asburiaep, Enterobacter cloacaep, Enterobacter hormaecheiwgs, Escherichia albertiiwgs, Escherichia colig+p+wgs+gi, Klebsiella pneumoniaep+wgs, Providencia rettgeriwgs, Pseudomonas aeruginosawgs, Salmonella entericawgs, Serratia marcescenswgs, Shigella flexneriwgs, Shigella sonneiwgs, Vibrio choleraewgs |
| Classification | 9 ontology terms | Show + process or component of antibiotic biology or chemistry + mechanism of antibiotic resistance + antibiotic molecule + antibiotic target replacement [Resistance Mechanism] + determinant of antibiotic resistance + diaminopyrimidine antibiotic [Drug Class] + antibiotic target replacement protein + trimethoprim [Antibiotic] + antibiotic resistant dihydrofolate reductase |
| Parent Term(s) | 3 ontology terms | Show + trimethoprim resistant dihydrofolate reductase dfr [AMR Gene Family] + derives_from antibiotic sensitive dihydrofolate reductase + confers_resistance_to_antibiotic trimethoprim [Antibiotic] |
| Publications | Rodrigues GL, et al. 2020. Front Microbiol 11:1864 Frequency of Antimicrobial Resistance Genes in Salmonella From Brazil by in silico Whole-Genome Sequencing Analysis: An Overview of the Last Four Decades. (PMID 32849452) |
Prevalence of dfrA8 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 amalonaticus | 0% | 0% | 1.82% | 0% |
| Enterobacter asburiae | 0% | 0.28% | 0% | 0% |
| Enterobacter cloacae | 0% | 0.56% | 0% | 0% |
| Enterobacter hormaechei | 0% | 0% | 0.26% | 0% |
| Escherichia albertii | 0% | 0% | 1.29% | 0% |
| Escherichia coli | 0.17% | 0.1% | 1.29% | 0.13% |
| Klebsiella pneumoniae | 0% | 0.03% | 0.17% | 0% |
| Providencia rettgeri | 0% | 0% | 0.64% | 0% |
| Pseudomonas aeruginosa | 0% | 0% | 0.01% | 0% |
| Salmonella enterica | 0% | 0% | 0.2% | 0% |
| Serratia marcescens | 0% | 0% | 1.97% | 0% |
| Shigella flexneri | 0% | 0% | 0.62% | 0% |
| Shigella sonnei | 0% | 0% | 2.41% | 0% |
| Vibrio cholerae | 0% | 0% | 0.06% | 0% |
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): 300