ISOLATION AND IDENTIFICATION OF ENTEROTOXIGENIC HALOPHILIC BACTERIA IN SOME PICKLED DAIRY PRODUCTS IN ASSIUT GOVERNORATE, EGYPT

A total of one hundred and twenty random samples of pickled Domiati and Kareish cheese (60 each) during the period from May 2023 to June 2024 were collected from dairy shops and markets in Assiut governorate, Egypt; for isolation and identification of enterotoxigenic halophilic bacteria in some pickled dairy products. The results showed that salt concentration in Domiati and Kareish cheese ranged from 2.6 and 2.9 to 6.8 and 12.9 with a mean value of 5.1 and 9.2, respectively. The pH values ranged from 2.7 and 3.4 to 5.1 and 7.9, with a mean value of 4.1 and 5.2, respectively. On the other hand, the count of halophilic bacteria in examined pickled Domiati and Kareish cheese samples recovered on halophilic agar containing 3% salt ranged from <102 and <102 to 1.5x105 and 1.03x104, with a mean value of 1.8x104 ±0.63x104 and 1.1x103 ±0.42x103, respectively. Corresponding counts on halophilic agar containing 10% NaCl ranged from 1.3x103 and 0.23x102 to 1.45x106 and 2.1x104, with a mean value of 0.8x105 ±0.62x105 and 0.56x104 ±0.81x103, respectively. The isolates were identified biochemically as Staph. aureus, S. epidermidis, Micrococci spp., B. cereus, B. licheniformis, and B. coagulence, B. subtilis, B. mycoids, E. coli and Proteus species, and only 31 samples (46.3 %) out of 67 examined S. aureus samples identified as coagulase positive. The Polymerase Chain Reaction (PCR) for coagulase positive S. aureus and B. cereus showed that 19 (61.3%) and 25 (30.9%) samples were enterotoxigenic halophiles, respectively. Some of these halophilic bacteria, such as Staph. Aureus, B. cereus, E. coli and proteus are of public health hazards which cause several food poisoning outbreaks. So, milk must come from dairy farms and apply HACCP system and strict hygiene during processing, storage and handling and finally periodical examination of milk, and dairy products chemically and bacteriologically must be applied.