Background: Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most predominant agents that cause nosocomial infections. Objectives: To determine the rate of MRSA and the molecular characteristics of the coagulase encoding gene of these isolates based on polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP).

Methodology: A total of 100 strains of S. aureus were isolated from clinical samples. MRSA was investigated through the antimicrobial susceptibility testing. The coa gene was amplified by PCR and these products were digested by using AluI restriction enzyme.

Results: In total, 100 S. aureus isolates were recovered from clinical samples, of which 59 isolates were MRSA. Three types of coa classes (550, 700, 750) are distinguished into 6 genotypic patterns, which were coded coa 1-6 and coa 2 was the most predominant (42.37%). The 700bp and 750bp amplicons formed two (coa 2 and 3) and three (coa 4, 5 and 6) patterns, respectively, whereas the 550bp fragments generated unique patterns designated coa 1. Only 2 isolates undigested by AluI restriction enzyme.

Conclusion: Our results showed that 59% of MRSA strains are isolated with diverse genotype distributed in many different wards of hospitals by using PCR-RFLP