mec-A-mediated Resistance in Staphylococcus aureus in a Referral Hospital, Tehran, Iran

BACKGROUND: The emerge of rapid and accurate detection of Meticillin-Resistant Staphylococcus aureus (MRSA) has been highlighted. OBJECTIVES: The current study evaluated the prevalence of mec-A gene in biological specimens of various medical wards, in order to determine any possible relationship. PATIENTS AND METHODS: Using traditional culture methods, 250 isolates were detected. The prevalence of mec-A mediated resistance was evaluated by PCR method. RESULTS: Among 98 isolates (39.2%) with resistant inhibition zones, 92 isolates carried mec-A gene and were considered as MRSA. Significantly higher rate of MRSA was observed in the specimens from emergency department and intensive care unit (P value < 0.001). Although, the prevalence of MRSA was higher in patients with history of previous hospital admission within the past three months (P = 0.006), but only one case with the same history was hospitalized in the emergency ward that was among the wards with the highest rate of MRSA. CONCLUSIONS: The study findings show that, although there is higher rate of MRSA infection in patients with history of hospitalization, but even in cases without any history of medical admission, more detailed questions emphasizing on receiving any recent health care should be asked in a referral hospital, in order to determine the true community-acquired MRSA.