Coagulase gene polymorphism of Staphylococcus aureus isolated from clinical respiratory system infections in Shahrekord

Background & Respiratory system infections is a common infectious disease and is an acute inflammation of the upper respiratory system caused by several bacterial infections including Staphylococcus aureus. The aim of this study was to investigate the coagulase gene polymorphism of S. aureus isolated from clinical respiratory system infections samples in Shahrekord of Iran.
Material & This study was conducted by a sectional-descriptive study on 200 persons suspected to the upper respiratory system infections who referred to Imam Ali clinic in Shahrekord. After growth of microorganisms on blood agar and manitol salt agar, the suspected colonies were identified by microbiological testing. Next, DNA samples were prepared and the products of PCR reactions were enzymatically digested and genes were genotyped using RFLP.
Overall, 60 patients (30%) were infected to S. aureus. Among them 42 isolates showed a 970 bp fragments and 18 isolates showed a 730bp fragments. After enzymatic digestion with AluI, 42 specimens contained three bands: 320, 490, and 160 bp (genotype I), while 16 specimens contained two bands: 490 and 240 bp (genotype VIII) and 2 specimens contained two bands: 410 and 320 bp (genotype IX).
The results obtained from present study showed that coagulase-positive S. aureus strains isolated from respiratory system infections in Shahrekord belonged mostly to genotype type I, which can be considered as a potential source for the release of the genotypes in the population.