Coagulase Gene Polymorphism of Staphylococcus Aureus Isolates Collected From Human Clinical Samples in Southeastern Iran

Background: Staphylococcus aureus is one of the most important pathogens in the development of hospital infections. The production of coagulase is directly related to the pathogenicity of S. aureus. The present study was conducted in order to investigate the polymorphism of the coagulase gene (coa) as a coagulaseencoding gene. Methods: 120 clinical samples were collected from patients admitted to Imam Khomeini and Amiralmomenin hospitals in Zabol, southeastern Iran, during 2014 and screened for the presence of S. aureus. Genetic diversity was determined by polymerase chain reactionrestriction fragment length polymorphism (PCR–RFLP) of coa gene and digested by AluI enzyme. Results: Out of 120 clinical samples, 56 isolates were diagnosed as S. aureus and all of these isolates were positive for the 3′ end of the coa gene by PCR. All isolates produced a single band on coa PCR, with molecular sizes ranging from 600 to 850 bp, with the highest frequency of 700 bp (39%). RFLP analysis of coa gene using AluI revealed P1P4 band patterns with the highest frequency of P1. Conclusions: The results of this study showed that P1 pattern was the most frequent pattern and lowest frequency was observed in P4 pattern. The results of this study suggest that the RFLP of coa gene can be used as a fairly suitable method for determining the genetic differences between S. aureus isolates.