An enterococcus (E. faecium) was isolated from a urine specimen (100,000 cfu/mL). Treatment of the patient with ampicillin and gentamicin failed. The most clinically appropriate action is
These questions demonstrate commonly occurring clinical infectious diseases and microbiologic problems. Enterococci may be resistant to ampicillin and gentamicin. Vancomycin would be the drug of choice. However, laboratory results do not always correlate well with clinical response. The National Committee on Clinical Laboratory Standards recommends testing enterococci only for ampicillin and vancomycin.
Do no further clinical workup
Suggest to the laboratory that low colony counts may reflect infection
Determine if fluorescent microscopy is available for the diagnosis of actinomycosis
Consider vancomycin as an alternative drug
Bacteria