Detection of Some Staphylococcal Enterotoxin Genes in MRSA Strains Using PCR Techniques

Abstract

In view of the increasing interest in the Methicillin-resistant Staphylococcus aureus (MRSA). The extracted DNA yield was observed using the phenol-chloroform method, it ranged from (1.6-1.8) and concentration ranged from 100 to 800 ng/µl. Five classical enterotoxin genes were investigated in 20 isolates using multiplex PCR method after it had been molecularly identified into methicillin resistant using mec A (which is the key genetic component of methicillin resistance) and fem A genes in a duplex PCR technique. A multiplex PCR test based on the simultaneous amplification of the five genes genes; sea 102bp, seb 164bp, sec 451bp, sed 278 bp and see 209bp was conducted to directly detect the toxin gene content. Our results had showed that most of MRSA samples harbored at least one enterotoxin gene. Multiple toxin gene combinations were also observed. Using this PCR assay we found that among the MRSA strains obtained (n=20).  The most commonly found gene was the enterotoxin A sea (n: 18, 90%), which was found alone and together with other toxin genes.