Occurrence and Antibacterial Susceptibility Profile of Staphylococcus aureus Isolated from Dairy Products in Pastoral Communities in Niger State, Nigeria

Abstract

Staphylococcus aureus is a significant cause of food poisoning in dairy products around the world. This study investigates the prevalence and antibacterial susceptibility profile of S. aureus obtained from dairy products and possible dairy products contaminating sources in pastoral communities of Niger State, Nigeria. A total of 2760 samples, comprising of 360 each of Ghee (Maishanu), Cheese (Awara), Local Yoghurt (Kindirmo), Raw Milk (Madara), and Fermented Milk (Nono), and 240 each from contaminating sources (such as handler’s hands, containers, udders, and water), were randomly obtained from various pastoral communities in Niger State, Nigeria. Isolation and identification of S. aureus was carried out according to standard microbiological methods. The results revealed a total of 204 (7.4%) S. aureus strains were isolated from the collected samples. Among the dairy products, raw milk accounted for the highest frequency of S. aureus 31 (8.6%), while cheese and ghee had 4.4% and 4.7% S. aureus, respectively. While from the possible contaminating sources, the handler’s hand the highest percentage of occurrence (4.2%), while the least (1.1%) was recorded from water. The S. aureus isolates showed >80% susceptibility to ceftazidime, cefuroxime, ciprofloxacin, vancomycin, minocycline, and trimethoprim/sulfamethoxazole. The isolates were resistant to oxacillin (31.4%), cefoxitin (29.4%), gentamicin (23.5%), ampicillin (20.6%), and ceftazidime (18.6%). Moreover, 87.5% of the S. aureus exhibit multidrug resistance. The presence of multidrug-resistant S. aureus in dairy products is of great public health concern; therefore, appropriate food safety measures should be implemented to improve the conditions under which these products are processed and sold.