PREVALENCE OF STAPHYLOCOCCUS AUREUS AND SALMONELLA SPECIES IN RETAILED CHICKEN MEAT WITH A REDUCTION TRIAL USING NIGELLA SATIVA AND ROSEMARY ESSENTIAL OILS

Chicken meat represents an importance source of animal derived proteins, vitamins, and minerals. However, chicken meat might act as a potential source of human exposure to foodborne pathogens such as Staphylococcus aureus (S. aureus) and Salmonella species. The objectives of the present study were first to investigate the prevalence rates of S. aureus and Salmonella species in the retailed chicken breast and thigh muscles at Zagazig city, Egypt. Second, serological identification of the isolated bacteria was followed. Third, screening of S. aureus enterotoxin coding genes (sea, seb, sec, sed, and see) and methicillin resistance (mecA) gene, as well as Salmonella virulence associated genes including Salmonella hyper-invasive locus (hilA), and Salmonella enterotoxin (stn) was done using PCR. Thereafter, the inhibitory effects of Nigella sativa, and rosemary essential oils were investigated against S. aureus, and Salmonella Typhimurium. The obtained results revealed isolation of S. aureus from the examined breast and thigh muscles at percentages of 23.3%, and 26.6%, respectively, whereas percentages of Salmonella spp. isolation from both samples were 33.3%, and 16.6%, respectively. Four Salmonella serotypes namely, S. Typhimurium, S. Enteritidis, S. Kentucky, and S. Anatum were further identified. The recovery rates of S. Typhimurium from breast and thigh muscles were 23.33% and 13.33%, respectively followed by S. Enteritidis (3.33% each). Staphylococcus enterotoxin genes (sea, and see), and mecA gene were detected in S. aureus isolates. Besides, Salmonella hilA and stn genes were also detected in Salmonella Typhimurium isolates. Nigella sativa and rosemary essential oils at 0.1%, and 0.5% could significantly reduce S. aureus, and Salmonella Typhimurium in chicken breast meat.