Frequency Distribution of Hospital-Acquired MRSA Nasal Carriage Among Hospitalized Patients in West of Iran

Background: Hospital patients who are nasal carriers of methicillin-resistant Staphylococcus aureus (MRSA) are a high-risk potential threat to themselves and other hospitalized patients. The high antibiotic resistance of these isolates renders the treatment of related infections difficult. Objectives: The present study, for the first time investigated the prevalence of MRSA isolates in nasal carriers in Imam Reza Hospital in the western province of Iran. Materials and Methods: Nasal samples from 1269 hospitalized patients were tested for S. aureus. The sensitivity of these isolates to various antibiotics was evaluated by the disk diffusion method and E-test oxacillin strips. After determining the MIC and inducible clindamycin resistance, the mecA gene was investigated by PCR. Results: 17.57% (223) of patients were HA-SA nasal carriers, with 82 isolates (36.8%) being resistant to methicillin (MRSA). The infant ward had the highest rate of carriage (80%). The difference in the sensitivity of MRSA and MSSA isolates to several antibiotics was significant (P < 0.05); furthermore, 80.5% of MRSA isolates and 2.8% of MSSA isolates were multi-drug resistant (MDR). A lower resistance was observed against clindamycin (58.5%), rifampicin (19.5%), and chloramphenicol (7.3%). Conclusions: The high prevalence and antibiotic resistance of HA-MRSA isolates in western Iran indicates the necessity of continuous monitoring of hospital patients in the country for the presence of MRSA, particularly in infant wards.