Linezolid-resistant Enterococcus faecium isolated from a patient without prior exposure to an oxazolidinone: report from the SENTRY Antimicrobial Surveillance Program.
A patient case report describes an Enterococcus faecium strain isolated from a blood culture that was resistant to linezolid (MIC, 8 microg/mL; G2576U mutation of 23S rRNA). Co-resistances were identified for vancomycin, ampicillin, macrolides, fluoroquinolones, chloramphenicol, rifampin, gentamicin (high-level), nitrofurantoin and trimethoprim/sulfamethoxazole. Etest (AB BIODISK, Solna, Sweden) and disk diffusion results also detected the oxazolidinone resistance pattern. Laboratories should be aware of the rare possibility of these strains occurring during linezolid therapy or spontaneously (this case) in contemporary practice, and have in vitro susceptibility methods available capable of detecting oxazolidinone resistance.
Jones
Ronald N
RN
The JONES Group/JMI Laboratories, North Liberty, IA 52317, USA. ronald-jones@jmilabs.com
Della-Latta
Phyllis
P
Lee
Lillian V
LV
Biedenbach
Douglas J
DJ
D000081:Acetamides / Q000494:pharmacology*; D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000627:therapeutic use; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D016984:Enterococcus faecium / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D016908:Gram-Positive Bacterial Infections / Q000382:microbiology; D006801:Humans; D000069349:Linezolid; D008297:Male; D008826:Microbial Sensitivity Tests / Q000379:methods / Q000592:standards; D023303:Oxazolidinones / Q000494:pharmacology* / Q000627:therapeutic use*; D011159:Population Surveillance
D000081:Acetamides; D000900:Anti-Bacterial Agents; D023303:Oxazolidinones; D000069349:Linezolid