The purpose of the study was to verify the existence and pathogenicity of Aeromonas hydrophila (A. hydrophila) in fish by validating the bactericidal effects of microwave and Gamma radiation on infected fish fillets. A total of 100 frozen Basa fish fillet samples were collected randomly from different markets in Zagazig, Sharkia Governorate, Egypt, and subjected to microbiological examination. The results revealed a 14% prevalence rate of A. hydrophila in fish fillets, which were tested for the presence of seven virulence genes: aerA, act, ast, alt, hyl, ahhR, and ahh1. All isolates exhibited traits related to virulence. The most predominated gene was ast (64.2%), followed by aerA, act, hyl, and ahhR (57.14% for each). Then, an experimental protocol for several treatments showed that Gamma radiation at a dose of 1 kGy decreased the count of A. hydrophila in fish fillets by 4.4 log10 CFU/g whereas doses of 2 and 3 kGy eradicated the pathogen. The same positive effect was recorded towards the microwave after cooking for 1, 2, and 3 minutes. Therefore, using microwave cooking and Gamma-irradiation alone and in combination with other decontamination methods may be more efficient in lowering the pathogen counts in fish meat.

Aflatoxins are one of the most dangerous toxic residues in various foods including poultry. This study was conducted to assess the reducing effect of gamma radiation on the levels of aflatoxin B1 in poultry meat, skin, and liver. To this end, a total of 80 poultry samples including meat, skin, and liver were surveyed for the incidence of aflatoxins, where only positive samples (27 samples of muscle, skin, and liver; 9 samples each) were selected for testing the effect of treatment by gamma radiation. The levels of aflatoxins were estimated in the examined samples using High Performance Liquid Chromatography (HPLC) whereas positive samples were exposed to 0 kGy, 5 kGy, or 10 kGy, and the differences in aflatoxin contents before and after exposure were calculated. The obtained results clarified that radiation achieved reduction rates in aflatoxin B1 level in muscle samples with a mean value 99.259±0.741, and 100.00±0.00% when treated with 5 kGy and 10 kGy, respectively. Whereas in skin samples, 98.676±1.324 and 100.00±0.00 % when treated 5 kGy and 10 kGy, respectively. While in liver samples, reduction rates accounted for 84.312±7.406 and 88.249±10.882 were obtained when treated with 5 kGy and 10 kGy, respectively. In conclusion, the exposure of poultry meat, skin, and liver to gamma radiation (5kGy or 10 kGy) has a significant reducing effect (p<0.05) in aflatoxins B1. The results were discussed from the hygienic point of view and compared with the national and international standards to assess their reliability for consumption.