EFFECT OF QUINUPRISTIN DALFOPRISTIN ON THE OUTCOME OF VANCOMYCIN-RESISTANT ENTEROCOCCUS-FAECIUM BACTEREMIA - COMPARISON WITH A CONTROL COHORT/

Serious infection with vancomycin-resistant Enterococcus faecium (VREF ) strains has no proven effective antimicrobial therapy. We compared t he clinical and bacteriological outcomes of 20 patients with VREF bact eraemia treated with quinupristin/dalfopristin (RP 59500), an investig ational streptogramin, with a historical cohort of 42 patients with VR EF bacteraemia treated with other agents. Quinupristin/dalfopristin de monstrated in-vitro bacteriostatic activity against all 20 initial VRE F blood isolates (MIG range 0.03-0.50 mg/L) by macrobroth dilution. Th e clinical characteristics of both groups were comparable for major ou tcome-dependent variables. There were five cases of recurrent VREF bac teraemia in the quinupristin/dalfopristin-treated cohort and 21 in the controls (P=0.11); persistence of VREF at the primary site was found in six and 18 of the evaluable patients with follow-up cultures in the se two cohorts (P = 0.06). In-hospital mortality was high in both grou ps: 65% in the quinupristin/dalfopristin group and 52% in the control group; however, VREF-associated mortality was significantly lower in t he quinupristin/dalfopristin group (five and 17 respectively; P = 0.05 ). Follow-up susceptibility testing of five VREF isolates in the quinu pristin/dalfopristin group did not demonstrate resistance to quinupris tin/dalfopristin. Quinupristin/dalfopristin may be a useful agent for the therapy of serious VREF infection. Further clinical investigations are warranted to confirm or refute its clinical efficacy.