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 coagulase-encoding gene. Methods: ۱۲۰ clinical samples were collected from patients admitted to Imam Khomeini and Amiralmomenin hospitals in Zabol, southeastern Iran, during ۲۰۱۴ and screened for the presence of S. aureus. Genetic diversity was determined by polymerase chain reaction-restriction fragment length polymorphism (PCR–RFLP) of coa gene and digested by AluI enzyme. Results: Out of ۱۲۰ clinical samples, ۵۶ isolates were diagnosed as S. aureus and all of these isolates were positive for the ۳′ end of the coa gene by PCR. All isolates produced a single band on coa PCR, with molecular sizes ranging from ۶۰۰ to ۸۵۰ bp, with the highest frequency of ۷۰۰ bp (۳۹%). RFLP analysis of coa gene using AluI revealed P۱-P۴ band patterns with the highest frequency of P۱. Conclusions: The results of this study showed that P۱ pattern was the most frequent pattern and lowest frequency was observed in P۴ 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.