Monitored Variations in Microbial Load of Aquacultured Tilapia Fish in Kafr El-Sheikh and El-Faiyum Governorates, Egypt

The main aim of the Egyptian government is not only to increase tilapia fish production, but also to improve the quality of the fish produced. Contaminated water causes damage to farmed fish and is also considered an important factor affecting the fish quality. To avoid losses in fish farms, it is critical to obtain information on the microbial load. This research aimed to study the microbial load in four fish farms in the governorates of Kafr El-Sheikh and El-Faiyum (two farms in each governorate), in Egypt. Water and fish samples were collected at various locations within each farm pond for two seasons (autumn and spring) to assess the microbiological characteristics. Total coliform count of aquaculture water samples was the highest mean count of 3.93×103±1.81×103 CFU/ml in farm (3) of El-Faiyum. However, Clostridium counts were highest in farm (2) of Kafr El-Sheikh at 1.85×102 ±1.76×102 in autumn of 2021. Total coliform count (1.196×103±8.38×102) was the highest in farm (1) of Kafr El-Sheikh in spring 2022. Also, Salmonella spp. was only detected in farm (2) of Kafr El-Sheikh in autumn 2021, but in spring 2022 it was positive in farm (3) of El-Faiyum. Nevertheless, Listeria spp. was not detected in the aquaculture water samples examined. In addition, Salmonella spp. was detected in farm (1) of Kafr El-Sheikh and in farms (3 and 4) of El-Faiyum in spring 2022. It was concluded that the presence of pathogenic bacteria such as Staphylococcus aureus, Salmonella and Clostridium in fish samples in some farms in Kafr El-Sheikh and El-Faiyum may contribute to foodborne illness. So that, the microbiological criteria are recommended to be applied as guidelines to develop additional control programs in fish farms. This can help in the pollution control of the agricultural drainage water that is used in aquaculture; consequently, prevent the growth and toxin production by pathogens