Evaluation of six methods for detection of methicillin-resistant staphylococcus aureus

【Objective】 To evaluate the reliability and clinical practicability of six methods in detection of methicillin-resistant Staphylococcus aureus(MRSA).【Methods】 A total of 134 strains of clinical isolated staphylococcus aureus were simultaneously assayed by PCR amplification of mecA gene,oxacillin disc diffusion test,cefoxitin disc diffusion test,oxacillin agar dilution test,cefoxitin agar dilution test,and chromogenic media test.【Results】 65.7% of Staphylococcus aureus were confirmed as methicillin-resistant by means of PCR amplification of mecA gene,which was used as a reference method(or gold standard) in the current study.The oxacillin disc diffusion test's sensitivity and specificity for MRSA is 95.5% and 97.8%,respectively,while it was 97.7% and 97.8% for cefoxitin disc diffusion test.The oxacillin agar dilution test's sensitivity and specificity is 100% and 97.8%,respectively,while it was 100% and 91.3% for cefoxitin agar dilution test.The chromogenic media test's sensitivity and specificity is 98.9% and 97.8%,respectively.【Conclusions】 All of the six methods are suitable for clinical laboratories to accurately detecting MRSA.Oxacilin disc diffusion test is cost-effective and easy to processing,which can be a reliable and conventional method for routine detection of MRSA.