brl-28500 and Endocarditis--Bacterial

Stenotrophomonas (Xanthomonas) maltophilia is a rare cause of endocarditis. The extensive resistance of this organism to several antibiotics leaves few options for antimicrobial therapy. In vitro synergism of the combination of trimethoprim-sulfamethoxazole (TMP-SMZ) and ticarcillin/clavulanic acid (TIC/CA) has been demonstrated. To our knowledge, we report the first case of ventriculoatrial cerebrospinal fluid shunt-associated endocarditis due to S. maltophilia. The patient was cured with combination therapy with TMP-SMZ and TIC/CA along with catheter removal. This is also the first report of S. maltophilia endocarditis successfully treated with this antibiotic combination. In a review of the medical literature, only 16 cases of S. maltophilia endocarditis were found. Most patients were intravenous drug users (43.8%) or had either prosthetic heart valves (50%) or an indwelling vascular catheter (18.8%). Although S. maltophilia is usually considered a nosocomial pathogen, about one-half of the cases were community-acquired. Twelve of sixteen patients had left-sided endocarditis. Therapy with a combination of two or more antibiotics was employed in most cases. Seven patients had been given TMP-SMZ therapy, but none had been treated with TIC/CA before. One-half of the patients required cardiac surgery. The overall mortality rate was 33%. Although the optimal antibiotic treatment for S. maltophilia endocarditis remains unknown, the case reported herein reinforces in vitro findings that the combination of TMP-SMZ and TIC/CA may be effective therapy.

Topics: Clavulanic Acids; Drug Therapy, Combination; Endocarditis, Bacterial; Female; Follow-Up Studies; Humans; Microbial Sensitivity Tests; Middle Aged; Ticarcillin; Trimethoprim, Sulfamethoxazole Drug Combination; Ventriculoperitoneal Shunt; Xanthomonas

The efficacy of ticarcillin-clavulanic acid was compared with the efficacies of standard antistaphylococcal agents (flucloxacillin, oxacillin, nafcillin, and vancomycin) and ticarcillin in an experimental model of Staphylococcus aureus endocarditis. Therapy was either initiated soon (8 h) after infection, when numbers of bacteria in aortic valve vegetations were relatively low (approximately 6 to 8 log10 CFU/g), or delayed until 24 h after infection, when the vegetations usually contained greater than 9 log10 CFU/g. Doses of the antibiotic were selected to produce peak concentrations in rat serum similar to those achievable in humans after administration of parenteral therapeutic doses. Ticarcillin-clavulanic acid was more effective overall than ticarcillin alone against endocarditis caused by beta-lactamase-producing strains of S. aureus, illustrating the beta-lactamase-inhibitory activity of clavulanic acid in vivo. Ticarcillin-clavulanic acid was as effective as the standard antistaphylococcal beta-lactam agents flucloxacillin, oxacillin, and nafcillin in these infections, whereas vancomycin was generally less active. These results illustrate the clinical potential of ticarcillin-clavulanic acid in the prophylaxis or therapy of severe staphylococcal infections.

Topics: Animals; beta-Lactamase Inhibitors; beta-Lactamases; Clavulanic Acids; Drug Therapy, Combination; Endocarditis, Bacterial; Male; Microbial Sensitivity Tests; Rats; Staphylococcal Infections; Staphylococcus aureus; Ticarcillin