Profiling virulence genes in Palestinian strains of community- acquired methicillin-resistant Staphylococcus aureus, exposing those encoding exfoliative toxin

The genes of Staphylococcus aureus encode several toxins causing or strongly suspected of causing specific diseases and adverse symptoms. The distribution of genes encoding superantigens and the gene profiles and genetic background of Palestinian strains of methicillin-resistant Staphylococcus aureus (MRSA) were determined. Strains separated into 12 clonal complexes (CCs) and 41 spa types, and possessed at least one of the studied enterotoxin genes: seo being most prevalent in 69.7% of the strains: followed by seh in 53.3% of the strains. Many (42.6%) of the strains possessed the genes for the classic staphylococcal enterotoxin (SE) sea, seb, sec, sed, and see, whereas 69.2% of the strains possessed the genes of the enterotoxin gene cluster, (egc), seg, seo, seh, sei, sem, seq, sej, sen, sek, sep, seu, sel, ser. Of the strains of S. aureus possessing the genes for Panton-Valentine leucocidin (PVL, n=105) among the strains of CA-MRSA, 16.2% (17/105) belonged to CC8-t008 and 18.1% (19/105) to CC80-t044. All four accessory gene regulator (agr) groups were present with agr group 1 being predominant in 44.1% of the strains. Forty-nine (25%) strains were multidrug resistant (MDR). This study provides information on the molecular markers of strains of S. aureus in clinical samples taken from Palestinian patients, including the characteristics of toxin genes possessed by Palestinian strains of CA-MRSA.