RESUMEN
We report a case of infective endocarditis due to vancomycin-intermediate Staphylococcus aureus (VISA) that did not respond to high doses of vancomycin. Initial vancomycin MIC of the last isolate recovered from blood was 8 micro g/mL, but could be induced up to 32 micro g/mL by consecutive growing with vancomycin. Clinical response was only accomplished when linezolid was included in therapy.
Asunto(s)
Endocarditis/microbiología , Infecciones Estafilocócicas/microbiología , Staphylococcus aureus/aislamiento & purificación , Resistencia a la Vancomicina , Farmacorresistencia Bacteriana Múltiple , Endocarditis/tratamiento farmacológico , Femenino , Humanos , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Oxacilina/farmacología , Infecciones Estafilocócicas/tratamiento farmacológico , Staphylococcus aureus/clasificación , Staphylococcus aureus/efectos de los fármacos , Vancomicina/farmacología , Vancomicina/uso terapéuticoRESUMEN
As part of the Latin American arm of the SENTRY Antimicrobial Surveillance Program, 7,207 bacterial isolates collected consecutively from bloodstream infections (BSI) during the period of January 1997 through December 2000 were analyzed. Ten Latin American laboratories located in six countries participated in the study during each year. Antimicrobial susceptibility testing was performed using the reference NCCLS broth microdilution method. The most frequently isolated species were (n/%): Staphylococcus aureus (1,532/21.3%), Escherichia coli (1,239/17.2%), coagulase-negative Staphylococcus (1,002/13.9%), Klebsiella pneumoniae (664/9.2%), and Pseudomonas aeruginosa (470/6.5%). The prevalence of S. aureus as a cause of BSI increased from 20.5% in 1997 to 23.3% in 2000 (p = 0.011), but oxacillin-resistance rates remained relatively stable during this period (around 30%). Enterococci (216 isolates) showed low rates of resistance to both vancomycin (2.4%) and ampicillin (7.9%) and 72.7% of 289 Streptococcus pneumoniae isolates evaluated were susceptible to penicillin (MIC
