The occurrence of vancomycin-resistant enterococci in hematological patients in relation to antibiotic use.

Very important bacterial pathogens found in hematological patients at present are vancomycin-resistant enterococci (VRE). The main goal of this retrospective study was to assess their occurrence in relation to antibiotic use. We isolated 1918 Enterococcus strains, in toto, 138 (7.2%) of which proved to be VRE. The VRE most frequently identified were Enterococcus faecium VanA (77%) and Enterococcusfaecalis VanB (12%), mostly isolated from stools (57%). Comparing the development of the selection pressure of antibiotics and percentage of VRE in each period of observation, an effect of the administration of each antibiotic group on the occurrence of VRE can be presumed. A reduction in the administration of third generation cephalosporins, glycopeptides and fluoroquinolones and its replacement by penicillin antibiotics combined with inhibitors of bacterial beta-lactamases, contributed to the cessation of VRE incidence and succeeding reduced occurrence from 15.1% in the second half of 1998 to 6.1% in the first half of 2000.