Molecular Characterization of Staphylococcus aureus Isolated from Clinical Samples Based on ۱۶srRNA, rpoB, and hsp۷۰ Genes by MLSA

Aims: Staphylococcus aureus is a Gram-positive bacterium with the capability of causing a variety of nosocomial and community-acquired infections. Evaluating the genetic structure, polymorphism, genotyping, and phylogeny of S. aureus isolates could contribute to the prevention and treatment of infections caused by this microorganism.Materials & Methods: In this study, the polymorphisms of ۱۶S rRNA, rpoB, and hsp۷۰ genes were investigated in a total of ۵۰ S. aureus isolates using S. aureus NCTC ۸۳۲۵ as the reference strain. Polymerase chain reaction (PCR) was used for the detection and amplification of the studied genes. The amplicons were then sequenced using a Sanger sequencing method. Moreover, phylogeny of the isolates was studied using Neighbor-joining and Maximum Parsimony methods for ۱۶S rRNA, rpoB, and hsp۷۰ genes individually and in combination.Findings: After Sanger sequencing, data obtained by Sequencher and Mesquite software programs revealed several polymorphisms of S. aureus isolates ۱۶S rRNA, rpoB, and hsp۷۰ genes, respectively. These polymorphisms included transversion, transition, insertion, and deletion. Among the studied strains, ۱۰ cases showed no polymorphism. Multi-locus sequence analysis (MLSA) showed several genetic diversities in S. aureus isolates.Conclusion: It seems essential to rapidly and reliably identify the phylogenetic sources and characteristics of this microorganism and to have a better understanding of its molecular epidemiology in order for infection practical surveillance and control.

کلیدواژه ها:

Staphylococcus aureus ، Polymorphism ، Multi-locus sequence analysis (MLSA)