Evaluation of accuracy and cost of four different methods for detection of methicillin resistance in Staphylococcus aureus isolates from pediatric patients hospitalized in Brazil
Verantwortlicher Herausgeber dieser Rubrik:
25. Juni 2007
10. Dezember 2007
28. Juli 2015 (online)
We studied 70 pediatric clinical isolates of Staphylococcus aureus to perform a comparison of different methods for detection of methicillin-resistant S. aureus (MRSA) using polymerase chain reaction for mecA as the “gold standard” assay. The isolates were tested with oxacillin and cefoxitin discs, oxacillin agar screening plate and E-test. Of the 70 strains, 43 were mecA-positive and 27 mecA-negative. Oxacillin agar screening plate and E-test had 100% sensitivity and specificity for the presence of mecA gene. We found a specificity of 96% for both disc-diffusion methods, and sensitivities of 95% (oxacillin disc) and 93% (cefoxitin disc). However, with the new Clinical and Laboratory Standards Institute 2007 cefoxitin breakpoints the sensitivity of this method would be increased to 100%, without any decrease in specificity. These results show how important is the evaluation of the available microbiological methods by different laboratories in different settings.