Phenotypic and Genotypic Characterizations of Aeromonas hydrophila Complex Isolated from Fresh and Frozen Beef and Poultry Meats

Abstract

This study was aimed to identify the phenotypic and geneotypic characteristics of Aeromonas hydrophila isolated from fresh and frozen beef and poultry meat, determine its harmfulness, and identify the sources of contamination of meat. To achieve these objectives, a total of 200 bacteriological swabs was collected from meat as following: (66) fresh beef, (43) fresh poultry meat, (57) frozen beef and (34) frozen poultry meat. In addition, 9 swabs from the hands of the workers who handling meat and also 5 samples of washing water used in the slaughterhouse and meat retail shops. The samples were examined by microbiological and biochemical screening tests followed by molecular biological and examined some of aerolysin, lipase and enterotoxin genes by PCR. The results revealed that out of 200 meat swabs samples, 129 (64.5%) were positive for Aeromonas spp. Out of 9 samples from workers' hands, 6 (66.67%) was identified to Aeromonas spp.. However, the 5 water samples was negative for Aeromoans spp.. Biochemical characterization identified to species level of 129 Aeromonas strain isolates identified to the A. hydrophila (no= 112; 86.82%), and other motile Aeromonas spp. (no= 17; 13.18 %). Concerning the bacteriological examination of samples from worker hands, 5 (83.34%) out of 6 samples was identified as A. hydrophila and 1 (16.66%) was identified to other motile Aeromonas spp. The prevalence of A. hydrophila of Fresh meet (74.31%) was significantly higher than that in frozen meat (47.25%) at <0.01. Results revealed that out of 45 isolates from samples, the rate of aeroA, lip and act genes were 31.11 %, 22.22 %, and 73.33 %, respectively. Results of this study revealed that there is a clear presence of A. hydrophila strains isolated from frozen and 64 Enany et al fresh meat and worker hands, as well as high levels of genes responsible for the virulent microbe indicate the presence of a potential risk of infection from food poisoning.