| Accession | ARO:3002873 |
| CARD Short Name | FosB3 |
| Definition | A thiol transferase that leads to the resistance of fosfomycin in Enterococcus faecium. Contrasting FosA, FosB is dependent on the cofactor Magnesium (II) and uses either bacillithiol to open up the epoxide ring of fosfomycin. |
| AMR Gene Family | fosfomycin thiol transferase |
| Drug Class | phosphonic acid antibiotic |
| Resistance Mechanism | antibiotic inactivation |
| Resistomes with Perfect Matches | Enterococcus faecalisp+wgs, Enterococcus faeciump+wgs |
| Resistomes with Sequence Variants | Enterococcus faecalisp+wgs, Enterococcus faeciump+wgs, Staphylococcus aureuswgs |
| Classification | 10 ontology terms | Show + process or component of antibiotic biology or chemistry + mechanism of antibiotic resistance + determinant of antibiotic resistance + antibiotic inactivation [Resistance Mechanism] + antibiotic inactivation enzyme + hydrolysis of antibiotic conferring resistance + antibiotic molecule + phosphonic acid antibiotic [Drug Class] + fosfomycin inactivation enzyme + hydrolysis of fosfomycin epoxide ring |
| Parent Term(s) | 2 ontology terms | Show + confers_resistance_to_antibiotic fosfomycin [Antibiotic] + fosfomycin thiol transferase [AMR Gene Family] |
| Publications | Xu X, et al. 2013. PLoS One 8(10): E78106. The fosfomycin resistance gene fosB3 is located on a transferable, extrachromosomal circular intermediate in clinical Enterococcus faecium isolates. (PMID 24205114) |
Prevalence of FosB3 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 |
|---|---|---|---|---|
| Enterococcus faecalis | 0% | 0.74% | 0.08% | 0% |
| Enterococcus faecium | 0% | 0.19% | 0.1% | 0% |
| Staphylococcus aureus | 0% | 0% | 0.01% | 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): 250