INFECTIONS BY AMPICILLIN-RESISTANT ENTEROCOCCI - A CASE-CONTROL STUDY

We identified 17 (20%) of 83 consecutive enterococcal isolates from ho spitalized patients with documented infection as high-level ampicillin -resistant enterococci (ARE). Of these, 16 isolates were identified as Enterococcus faecium and 1 isolate as Enterococcus raffinosus. A case -control study found no significant differences with respect to underl ying diseases, central venous catheterization, nosocomial acquisition of the infection and sites of infection. Patients with ARE infection w ere older and had a higher inhospital fatality rate than those with am picillin-susceptible Enterococcus (ASE) infection. Hospitalization in a surgery service (usually for an abdominal procedure), prolonged hosp ital stay, prior treatment with antibiotics (in particular imipenem an d metronidazole), were also more frequent among patients with ARE infe ction. ARE isolates were more frequently resistant to imipenem, ciprof loxacin and streptomycin than ASE isolates.