Screening of Food-borne Staphylococcus aureus and E. coli Pathogens in Artisanal White Soft Cheese in Delta Region, Egypt

Staphylococcus aureus is considered as one of the leading causes of food-intoxication and on the other hand E. coli and particularly, Shiga toxin (ST) producing Escherichia coli (STEC) have emerged as important food-borne enteropathogens frequently associating serious to fatal disorders in humans and both species have shown to be resistant to a wide spectrum of antibiotics. The current study was performed to determine the prevalence of two common food-borne pathogens: Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) in white soft cheese being one of the most popular dairy products in Egypt. A total 150 samples of soft cheese were purchased from the market and were microbiologically tested. The S. aureus isolates were identified according to recommended biochemical tests, and polymerase chain reaction (PCR) targeting the nuc gene; as a species-specific marker gene for S. aureus. Meanwhile, E. coli isolates were identified based on biochemical tests, serological tests, haemolytic activity and multiplex PCR has been done to assess capability of producing STs based on targeting stx1 and stx2 genes.  Result revealed that S. aureus and E. coli were observed in 66.66% and 36% of samples, respectively. The antimicrobial resistance of isolates was phenotypically-investigated against eleven different antibiotics and results showed the presence of a variable multidrug-resistance among isolates against selected antibiotics. These findings highlighted the importance of periodical screening of food-borne pathogens in artisanal products due to lack of strict hygienic measures in markets; the reason that facilitate the contamination of such artisanal products by several food-borne pathogens.