Enhancing Probiotic Stability against Methicillin Resistant Staphylococcus Aureus In Milk Product Industry

As health awareness rises among consumers, there is an increasing demand for nutritious probiotic options. Dairy products serve as effective carriers for these beneficial probiotics, enhancing colonic microflora, and offering various health benefits. A total of ninety random samples of Kareish cheese, Damietta cheese, and Yogurt (30 samples each) collected from retail outlets were bacteriologically tested to determine the presence of Staphylococcus aureus. Of the 90 S. aureus isolates, 22 (24.4%) were isolated from the examined products. S. aureus isolates exhibited high resistance levels to oxacillin (81.8%) and penicillin (77.3%). Polymerase chain reaction (PCR) was utilized to indicate the presence of the mecA gene in S. aureus, which was detected at a percentage of 100%. Lactobacillus acidophilus and Bifidobacterium lactis exposed to UV radiation demonstrated significant antimicrobial effects against S. aureus in the agar well diffusion assay. Additionally, these probiotic strains were utilized in the Kareish cheese production, which was injected with S. aureus as an in vitro experiment and then kept at 4 ± 1°C for 14 days. The treated groups were assessed to identify the presence of S. aureus counts, which established a significant reduction in counts during the periods of incubation in the treated groups compared to the control group. RT-qPCR findings revealed a down-regulation of mecA gene expression in the treated groups G2, followed by G4 and G3, respectively when compared to the control group.