OBJECTIVE: To determine the prevalence of vancomycin-resistant enterococci (VRE) bowel colonization in hospitalized patients in Manitoba who had stool specimens collected for Clostridium difficile toxin and/or culture testing.

DESIGN: Two tertiary care and five community hospitals in Winnipeg and three rural Manitoba community hospitals participated in this study. From January 1 to December 31, 1997 stool specimens, one per patient, submitted to hospital microbiology laboratories for C difficile toxin and/or culture testing were screened for VRE on colistin-nalidixic acid-vancomycin (6 g/mL) (CNAV) agar plates. The study was divided into six, eight-week intervals. Stool specimens received in the first two weeks of each eight week interval were screened for VRE.

MAIN RESULTS A total of 1408 stool specimens were submitted over the 48-week study period. Sixty-seven (4.8%) patients with VRE colonization of their lower gastrointestinal tract were identified. Three of the 67 (4.5%) VRE isolates were Enterococcus faecium, with the remaining 64 (95.5%) were Enterococcus gallinarum. The three vancomycin-resistant E faecium (VREF) (from two different Winnipeg hospitals) demonstrated the vanA genotype, and were resistant to vancomycin, teicoplanin and ampicillin. All three VREF isolates also demonstrated high level resistance to both gentamicin and streptomycin but were susceptible to quinuprisitin/dalfopristin and LY333328.

CONCLUSION: VRE colonization in hospitalized patients in Manitoba is infrequent and most commonly due to E gallinarum. The prevalence of VREF colonization in the patients studied was 0.2% (three of 1408).