Abstract

Prevalence and Distribution of Superantigen Toxin Genes in Clinical Community Isolates of Staphylococcus Aureus

Mohamed Elazhari, Driss Elhabchi, Khalid Zerouali, Noureddine Dersi, Abdeloihed Elmalki, Mohammed Hassar, Rachid Saile and Mohammed Timinouni

To investigate the distribution of twelve staphylococcal enterotoxin genes (se) and the toxic shock syndrome toxin-1 gene (tst) in Staphylococcus aureus, 140 community isolates from various origins were investigated. Isolates were collected, from 15 clinical laboratories located at Casablanca, between 2007 and 2008, they were identified by conventional methods, and methicillin resistance was confirmed by amplification of mecA gene by PCR. All isolates were searched using a multiplex PCR for the accessory gene regulator (agr) group, and for thirteen superantigen (SAg) toxin genes: sea, seb, sec, sed, seh, selk, sell, selm, selo, selp, selq, ser and tst. Among all isolates, only two were methicillin-resistant and one hundred seven were shown to be positive for at least one of the tested SAg toxin genes. They were grouped in 43 genotypes. Our work showed that agr group III and agr group I S. aureus isolates, were highly prevalent for the presence of seh, selq, selk and/or tst genes, on one hand, and sec and/or sell genes, on the other hand (P<0.05), respectively. In addition, we found a relationship between pus/ wound S. aureus isolates and the presence of selk + selq genes (P<0.05). Our results suggest that agr group III isolates carried more of SAg toxin genes than agr groups I and II S. aureus strains.