Innovative Strategies for Identifying and Controlling Staphylococcus aureus in Marine Fish: Evaluating the Impact of Organic Acids

This study investigated the prevalence of Staphylococcus aureus in three types of fish “Sardine , Chrysophyrus, and Pagrus” and assessed their fitness for consumption based on bacterial counts. The results showed that Sardine samples had the highest contamination rate at 27.5%, followed by Chrysophyrus at 15%, and Pagrus at 10%. Notably, 20%, 12.5%, and 5% of these fish, respectively, exceeded permissible bacterial limits, rendering them unfit for consumption according to EOS. The isolated S. aureus strains were produced various enterotoxins in Sardine , Chrysophyrus and Pagrus samples those were A and A+B, , B, and D enterotoxins, respectively. Antimicrobial susceptibility were revealed complete resistance to kanamycin and significant resistance to several antibiotics, while showing high susceptibility to Linezolid, Cefepime, and Daptomycin. The Multiple Antibiotic Resistance (MAR) index ranged from 0.071 to 1, with an average of 0.412. Molecular analysis confirmed the presence of the nuc gene in all strains, while only three strains carried the mecA gene, indicating methicillin resistance. The study also demonstrated the efficacy of organic acids in reducing S. aureus counts. Treatments with acetic and ascorbic acids (3%) were achieved reduction of 43.7% and 31.4% of count. Importantly, these treatments did not compromise sensory qualities, with all samples receiving high ratings in sensory evaluations. This suggests that organic acids can be effectively used to enhance food safety without impacting product quality.