Isolation of Methicillin-Resistant Staphylococcus aureus Strains Producing Enterotoxins A, K and Q From Chicken Meat in Isfahan, Iran, 2014

Abstract

Background: Methicillin-resistant Staphylococcus aureus (MRSA) strains are known as one of the most common causes of infection in humans and animals can produce a variety of virulence factors such as enterotoxins. Staphylococcal food poisoning is one of the most common food-borne diseases in the world. Objectives: The current experimental study aimed to isolate and determine the clonality of MRSA strains isolated from chicken meat samples, and describe the presence of different prophage types, enterotoxin genes and also the expression of Staphylococcus cassette chromosome mec (SCCmec) gene types. Methods: During six months in 2014, a total of 36 chicken meat samples were collected from Isfahan local markets and analyzed to screen MRSA strains. All isolates were typed using high resolution automated Phene plate (PhP) system and tested for the presence of different enterotoxin genes. Different staphylococcal cassette chromosome mec (SCCmec) and prophage types were determined. Results: All 116 isolated MRSA strains were discriminated into seven PhP types consisting of seven common types (CTs) and were positive for mecA gene. All isolates harbored SCCmec type III and SGF, SGFa and SGFb prophage types. Genes encoding enterotoxins SEA, SEK and SEQ were detected in all MRSA isolates. Conclusions: These findings illustrated the presence and persistence of clonal groups of MRSA strains, in chicken meat in Isfahan, Iran, that serve as reservoirs to disseminate bacteriophage encoded enterotoxin and virulence agents.