Polymorphism of aroA gene in Staphylococcus aureus isolates from milk and cheese in the city of Tabriz

Abstract

Due to the pathogenicity of Staphylococcus aureus and its presence in dairy products and the importance of transmission of this bacterium through dairy products, the aim of this study was to analyze the aroA gene in Staphylococcus aureus isolated from cow's milk and traditional cheese. For this purpose, number of 40 isolates, including 14 isolates of S.aureus from traditional cheese, 19 isolates from cow's milk and buffalo milk 7 isolates were tested by PCR-RFLP. aroA gene was amplified with specific primers followed by enzymatic digestion using TaqI enzyme was performed. The results of aroA gene was amplified to produce a band with a size of 1153 bp. Digestion of amplified bands produced in the previous step by the enzyme TaqI produced 3 different patterns . The first consists of three bands; patterns with two-band l and the third had four bands. From 40 isolated Staphylococcus aureus in this study, 29 samples, ie the maximum of them had aroA gene with three-band patterns, 9 isolates were 2 bands and two patterns had 4 bands. Most of the bacteria were belonged to the three-band patterns. The frequency of this pattern in the mentioned area is high. However, this method cannot distinguish between strains with different food sources and must be accompanied by complementary methods. Finally, it shows the need to pay more attention to health points in the preparation of dairy foods and also more attention of local veterinarians in dealing with this pathogen and choosing the appropriate treatment approach for it.

Keywords

• dairy products
• taqi enzyme
• staphylococcus aureus
• aroa
• pcr-rflp