Salud Pública de México
Print version ISSN 0036-3634
ACOSTA-PEREZ, Gabriel; RODRIGUEZ-ABREGO, Gabriela; LONGORIA-REVILLA, Ernesto and CASTRO-MUSSOT, María Eugenia. Evaluation of four methods for detecting methicillin-resistant Staphylococcus aureus isolates from clinical specimens at a regional hospital in Mexico. Salud pública Méx [online]. 2012, vol.54, n.1, pp.1-6. ISSN 0036-3634. http://dx.doi.org/10.1590/S0036-36342012000100001.
OBJETIVE: To estimate the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in clinical isolates and to compare different methods for detection of MRSA in a lab with limited available personnel and resources. MATERIAL AND METHODS: 140 Staphylococcus aureus strains isolated from patients in several departments were assayed for β-lactamase production, MIC-Vitek 2 oxacillin, ChromID MRSA, disk diffusion in agar for cefoxitin 30 μg and PBP2a detection. The results of conventional tests were compared with the "gold standard" PCR test for mecA gene. Cohen´s kappa index was also calculated in order to evaluate the intra assay agreement between the used methods. RESULTS: The found prevalence was 90.7%. Sensitivity and specificity were: disk diffusion for cefoxitin 97 and 92% respectively, MIC Vitek 2-XL 97 and 69%, ChromoID MRSA 97 and 85%, and PBP2a detection 98 and 100%. CONCLUSIONS: All methods are very good for detecting MRSA, choosing a method to use will depend on each laboratory infrastructure.
Keywords : Staphylococcus aureus; prevalence; surveillance; resistance; Mexico.