Antimicrobial susceptibility, hemolysis, and hemagglutination among Aeromonas spp. isolated from water of a bovine abattoir

The presence of Aeromonas spp. in food has been demonstrated. They are often introduced from water, which is the natural habitat of many species and is thought to be the main source of contamination. The occurrence of Aeromonas spp. was investigated in 70 water samples of a bovine abattoir. Aeromonas spp. were present in 21.4% of water samples. A. hydrophila was isolated from 11.4% of supplying water samples and from 25.7% of the water drained from carcasses, whereas A. sobria was sole isolated from 5.7% of supplying water samples. Although greater number of positive samples were from water drained from carcasses, only A. hydrophila isolates were present. This suggests that the supplying water is the source of contamination. The antibiotic susceptibility testing revealed all strains were resistant to b-lactam antibiotics. However, the susceptibility to other antimicrobials was variable, being A. hydrophila more resistant than A. sobria strains. The investigation for virulence factors revealed positive reactions of hemolysis and hemagglutination. The results indicate that Aeromonas spp. are present in the supplying water system. These microorganisms may be a potential contaminant of carcasses and widespread in derived food