Molecular Typing of Staphylococcus aureus by DNA Restriction Fragment Length Polymorphism of coa Gene
Abstract
The aim of this study was to determine the genotypic characteristics of S. aureus isolates by using coagulase gene typing and polymerase chian reaction-restriction fragment length polymorphism (PCR-RFLP) of coagulase gene. One hundred and seventy two wound swab specimens were collected from patients in AL-Kindy Teaching Hospital, Al-Wasity Hospital, Baghdad Al-Taalemey Hospital and Al Shaheed Gazi Hospital in Baghdad during the period from September 2013 to January 2014. All isolates were diagnosed depending on microscopical and biochemical tests. It was found that 47(27.33%) isolates were identified as S.aureus. The amplification of the coa gene of S.aureus strains generated 5 different genotypes: I, II, III, IV, V based on different size of polymorphism raning from 500-900bp. The majority (44.7%) of the strains were of coa gene type II. PCR-RFLP of coa gene exhibited 11patterns which were obtained with AluI digests of PCR products. The number of fragments varied from one to three with sizes of the fragments varied from 80 to 700 bp. Type IX was the most common and accounted for 27.7% of the isolates. PCR-RFLP analysis, showed discriminatory power, reproducibility, easy interpretation and can be considered as a promising alternative for the epidemiological typing of S.aureus isolates.