Prevalence of Aeromonashydrophila and Yersinia Enterocolitica in some sea foods sold in sharkia governorate markets and the effects of heat treatments on their viabilities

Total of 120 samples of fresh mullet fish, frozen tilapia fillet and chilled shrimps (40 samples from each) were collected from Sharkia Governorate markets to assess the presence of Aeromonas hydrophila and Yersinia enterocolitica short methods. The results showed that the prevalence of Aeromonas spp. were 34 (85%), 12 (30%) and 28 (70%) for mullet fish, frozen tilapia fillet and shrimp samples respectively, the mean total colony count of this microorganism were 4.91 ±0.247, 4.383 ±0.463 and 4.44 ±0.125 log/ CFU in the same order. Aeromonas hydrophila, A. caviae and A. sobria were present in the examined samples, but A. hydrophila was the common species. Concerning Yersinia spp., it was detected in 26 (65%), 6 (15%) and 20 (50%) samples of mullet fish, frozen tilapia fillet and shrimp samples respectively, with the mean total colony counts of 5.142±0.353, 4.284 ±0.671 and 3.06±0.221 log/ CFU respectively in the same order. Y. enterocolitica, Y. fredrediksenii, Y. Intermedia and Y. Kristensenii were detected in the examined samples, while; Y. enterocolitica is the most predominant isolate. From the present investigation, both A. hydrophila and Y. enterocolitica are sensitive to heat treatment. Thus, good ripening of sea foods is adequate to control these microorganisms.