CLINICAL AND MOLECULAR EPIDEMIOLOGY OF ENTEROCOCCUS-FAECALIS BACTEREMIA, WITH SPECIAL REFERENCE TO STRAINS WITH HIGH-LEVEL RESISTANCE TO GENTAMICIN

The objective of this study was to characterize the clinical and molec ular epidemiology of Enterococcus faecalis bacteremia, specifically th at involving strains with high-level resistance to gentamicin (HLGR). Episodes of E. faecalis bacteremia at the Buffalo Veterans Affairs Med ical Center from January 1986 to September 1989 were retrospectively i dentified. Of 94 episodes, 45 (48%) were due to strains with HLGR. Hem olytic activity was detected with greater frequency (85%) among the la tter strains than among those without HLGR (P<.001). Of the 54 episode s for which medical charts were available for review, 94% were hospita l acquired, and 46% were due to strains with HLGR. An examination of t he plasmid DNA content of isolates revealed restriction-fragment-lengt h polymorphism One plasmid pattern was identified in 15 isolates with HLGR (P<.001), and chromosomal DNA digest patterns suggested a common clonality; there was no direct evidence for patient-to-patient spread of these strains. The use of antibiotics, the presence of invasive dev ices, surgery, and admission to an intensive-care unit were not signif icantly associated with HLGR bacteremia. Mortality during hospitalizat ion was 65%, with no difference between figures for HLGR and non-HLGR infections. This high mortality regardless of gentamicin susceptibilit y status suggests that E. faecalis bacteremia is a marker for severe i llness. In contrast to previous studies, this investigation identified no clinical factors associated with HLGR E. faecalis bacteremia.