Prevalence, antibiogram and enterotoxin production of Staphylococcus aureus in Nile Tilapia, Mullet and Catfish with a reduction trial using acetic and ascorbic acids.

Elsaady, Hosny Abdlkader; Bakeir, Nabil; Darwish, Wageh Sobhy; Ali, Eman Hamdy

doi:10.21608/djvs.2025.384892.1155

Prevalence, antibiogram and enterotoxin production of Staphylococcus aureus in Nile Tilapia, Mullet and Catfish with a reduction trial using acetic and ascorbic acids.

Document Type : Original Article

Authors

¹ Demonstrator at Meat hygiene, Technology and food safety Department, faculty of vet med Damanhour University

² Professor of Infectious diseases,Faculty of veterinary medicine.Damanhour univerisity

³ Professor of food hygiene, Fac. Vet. Med., Zagazig Univ., Egypt

⁴ Food Hygiene and control department, Faculty of veterinary medicine, Damanhour university

10.21608/djvs.2025.384892.1155

Abstract

This study aimed to examine the prevalence of Staphylococcus aureus (S. aureus) in Nile tilapia, mullet, and catfish sold in El-Beheira governorate, Egypt. The antibiotic susceptibility of the isolated S. aureus strains was assessed. Further, the Reverse Passive Latex Agglutination technique (RPLA) was employed for detection and identification of S. aureus enterotoxins. The current results indicated the isolation of S. aureus from Nile tilapia, mullet, and catfish, with incidence rates of 60%, 45%, and 70%, respectively. Catfish exhibited a substantially higher overall S. aureus count (3.64±2.49 log10 cfu/g) as compared to Nile tilapia (3.44±2.27 log10 cfu/g) and mullet (2.00±1.85 log10 cfu/g), respectively (p< 0.05). Accurately, 55%, 35%, and 20% of the analyzed samples of catfish, Nile tilapia, and mullet, respectively, surpassed the Egyptian threshold for S. aureus (3.00 log10 cfu/g). The isolated S. aureus strains exhibited distinct multidrug resistance patterns. However, RPLA testing of specific S. aureus isolates for the presence of Staphylococcal enterotoxin indicated that enterotoxin A was identified in two S. aureus isolates obtained from catfish and in one isolate obtained from tilapia. Enterotoxin C was found solely in one strain obtained from mullet. Enterotoxin D was identified in a single sample from mullet and one strain from tilapia. Enterotoxin A+ D was found solely in one isolate obtained from catfish. Experiments aimed at decreasing S. aureus counts with 1% and 2% acetic acid and 1% and 2% ascorbic acid yielded reduction percentages of 21.2%, 46.1%, 17.3%, and 28.9%, respectively.

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