Biochemical characteristics of E. coli isolated from food of animal origin

Food of animal origin is a potential source of pathogenic E. coli that are dangerous to humans. While most strains are intestinal commensals, some can cause intestinal and extraintestinal infections. Their pathogenicity is associated with the presence of virulence genes, phylo-group and, in some strains, biochemical characteristics. In this study, a total of 61 E. coli isolates from meat, minced meat, meat preparations and carcass swabs from different animal species were analysed. The biochemical properties of the strains were determined using VITEK2 system and the data was compared with the presence of virulence genes from previous studies. The results showed a correlation between the presence of the eae virulence gene and the alkalinization of succinate. In addition, the presence of the virulence gene cnf1 was correlated with the enzyme tyrosine arylamidase, though the correlation between biochemical characteristics and the presence of virulence genes is questionable due to the small sample size and more strains need to be tested for further conclusions. Although no significant correlations were found between biochemical characteristics and the presence of virulence genes, this study describes the diversity of E. coli in the Republic of Croatia. The collected data also reveal new insights into biochemical characteristics of E. coli isolated from domestic and wild animals in the Republic of Croatia.