RESUMO
Daptomycin ß-Lactam combination therapy offers "protection" against daptomycin non-susceptibility (DNS) development in Enterococcus faecium. We report failure of this strategy and the importance of source control. Mutations were detected in the LiaF and cls genes in DNS isolates. A single DNS isolate contained an unrecognized mutation, which requires confirmation.
Assuntos
Antibacterianos/uso terapêutico , Daptomicina/uso terapêutico , Enterococcus faecium/efeitos dos fármacos , Infecções por Bactérias Gram-Positivas/tratamento farmacológico , beta-Lactamas/uso terapêutico , Idoso , Antibacterianos/farmacologia , Daptomicina/farmacologia , Farmacorresistência Bacteriana/genética , Quimioterapia Combinada , Enterococcus faecium/genética , Infecções por Bactérias Gram-Positivas/microbiologia , Humanos , Masculino , Testes de Sensibilidade Microbiana , Mutação/genética , beta-Lactamas/farmacologiaRESUMO
OBJECTIVES: To examine the activity of ceftaroline against reduced-vancomycin-susceptible MRSA isolates. METHODS: One-hundred and three MRSA blood culture isolates (predominantly ST239-MRSA-III), with varying vancomycin phenotypes, had their ceftaroline MICs determined by broth microdilution and MIC Evaluator strip (Oxoid-Thermo Fisher). Statistical analyses were performed that examined relationships with vancomycin and daptomycin MICs. Mutations in mecA were also examined. RESULTS: All 103 isolates (including 60 heteroresistant vancomycin-intermediate Staphylococcus aureus/vancomycin-intermediate S. aureus) were susceptible to ceftaroline, with one isolate displaying heteroresistance that may be related to a mecA mutation. Higher ceftaroline MICs were associated with vancomycin-susceptible S. aureus isolates. CONCLUSIONS: This study highlights that ceftaroline fosamil is an option for salvage therapy based on in vitro activity.