Evaluation of different methods for detecting methicillin resistance in Staphylococcus aureus isolates in a university hospital located in the Northeast of Brazil

Sousa Júnior, Francisco Canindé deNéri, Gildelane da SilvaSilva, Ana KarineAraújo, Bibiana Priscila Rodrigues Câmara deGuerra, Myrian Júlia de Paiva DouradoFernandes, Maria José de Britto CostaMilan, Eveline PipoloMelo, Maria Celeste Nunes de

Many methods have been described for the detection of methicillin-resistant Staphylococcus aureus (MRSA), but the heterogeneous expression of methicillin resistance affects the reliability of these methods. The aim of the present study was to evaluate some methods for detecting methicillin resistance in Staphylococcus aureus isolates in a university hospital located in the Northeast of Brazil. Among the isolates, 15 were methicillin-susceptible and 45 were methicillin-resistant, including low-level heterogeneous resistance strains. Both the 30 µg-cefoxitin disk and PBP2a test had 100% sensibility/specificity and appear to be good options for the detection of MRSA in the clinical laboratory.

1. PBP2a
2. methicillin resistance
3. cefoxitin
4. heterogeneous resistance
5. MRSA