Vancomycin-resistant enterococci (VRE) colonization of high-risk patients in tertiary care Canadian hospitals

We isolated 1487 Enterococcus species from 1200 stool specimens collected from high-risk patients in 12 Canadian tertiary care hospitals between October 1995 and November 1996. The composition of the 1487 isolates teas 601 vancomycin-sensitive Enterococcus faecalis (40.4%), 667 vancomycin-sensitive Enterococcus faecium (44.9%), 18 vancomycin-resistant (nine isolates MIC 8-16 mu g/mL; nine isolates MIC greater than or equal to 32 mu g/mL) E. faecium (VREF) (1.2%), 95 vancomycin-sensitive Enterococcus gallinarum (6.4%), 29 vancomycin-resistant (all MICs 8-16 mu g/mL) E. gallinarum (2.0%), and 77 vancomycin-sensitive Enterococcus casseliflavus (5.2%). Nine of the 18 VREF isolates collected possessed the vanA genotype and were from three patients at one hospital. Two other VREF isolates, of the vanB genotype, were from a single patient at a second hospital, and the remaining seven isolates, also all of the vanB genotype, were from five patients at a third hospital. All VREF were ampicillin resistant (MIC greater than or equal to 16 mu g/mL), streptomycin resistant (MIC >1000 mu g/mL), and ciprofloxacin resistant (MIC greater than or equal to 4 mu g/mL). Ten of the 18 VREF were also resistant to gentamicin (MIC >500 mu g/mL), while all 18 isolates had quinupristin/dalfopristin MICs less than or equal to 0.5 mu g/mL. In conclusion, high-risk patients in tertiary care Canadian hospitals are rarely colonized (9/1200 patients, 0.75%) with VREF in their lower gastrointestinal tract. These findings correlate well with the lack of reported VREF infection in highrisk patients in Canadian hospitals. Quinupristin/dalfopristin demonstrated excellent in vitro activity against VREF and other non-faecalis species of Enterococcus, many of which also possessed high-level ampicillin, and/or high-level aminoglycoside, and/or citprofloxacin I resistance. (C) 1999 Elsevier Science Inc.