Staphylococcus aureus with reduced susceptibility to vancomycin isolated from a patient with fatal bacteremia

A Staphylococcus aureus isolate with reduced susceptibility to vancomycin w as obtained from a dialysis patient with a fatal case of bacteremia. Compar ison of the isolate with two methicillin-resistant S. aureus (MRSA) isolate s obtained from the same patient 4 months earlier suggests that the S. aure us with reduced susceptibility to vancomycin emerged from the MRSA strain w ith which the patient was infected. Atypical phenotypic characteristics, in cluding weak or negative latex-agglutination test results, weak or negative -slide coagulase test results, heterogeneous morphologic features, slow rat e of growth, and vancomycin susceptibility (by disk diffusion test) were ob served.