RESUMEN
We report a case of infective endocarditis (IE) caused by ceftaroline-resistant, daptomycin-tolerant, and heterogeneous vancomycin-intermediate methicillin-resistant S. aureus (MRSA). Resistance to ceftaroline emerged in the absence of drug exposure, and the E447K substitution in the active site of PBP2a previously associated with ceftaroline resistance was identified. Additionally, we present evidence of patient-to-patient transmission of the strain within the same unit. This case illustrates the difficulties in treating MRSA IE in the setting of a multidrug-resistant phenotype.
Asunto(s)
Antibacterianos/uso terapéutico , Proteínas Bacterianas/genética , Daptomicina/uso terapéutico , Farmacorresistencia Bacteriana Múltiple/genética , Endocarditis Bacteriana/tratamiento farmacológico , Proteínas de Unión a las Penicilinas/genética , Infecciones Estafilocócicas/tratamiento farmacológico , Vancomicina/uso terapéutico , Adulto , Sustitución de Aminoácidos , Cefalosporinas/uso terapéutico , Infección Hospitalaria/tratamiento farmacológico , Infección Hospitalaria/microbiología , Infección Hospitalaria/patología , Quimioterapia Combinada , Endocarditis Bacteriana/microbiología , Endocarditis Bacteriana/patología , Expresión Génica , Humanos , Masculino , Meticilina/uso terapéutico , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Staphylococcus aureus Resistente a Meticilina/genética , Staphylococcus aureus Resistente a Meticilina/crecimiento & desarrollo , Pruebas de Sensibilidad Microbiana , Infecciones Estafilocócicas/microbiología , Infecciones Estafilocócicas/patología , CeftarolinaRESUMEN
We performed a nested case-control study (ratio of 1:4) on the emergence of tigecycline-resistant multidrug-resistant Klebsiella pneumoniae (TR-MDRKP) isolates among patients who initially presented with a tigecycline-susceptible MDRKP isolate. Out of 260 patients, 24 (9%) had a subsequent clinical culture positive for a TR-MDRKP isolate within the 90-day follow-up period. On logistic regression analyses, receipt of tigecycline (adjusted odds ratio [OR], 5.06; 95% confidence interval [CI], 1.80 to 14.23; P = 0.002) was the only independent predictor of subsequent isolation of a TR strain.