Involvement of Virulence Genes and Antibiotic Resistance in Clinical and Food Borne Diarrheagenic Escherichia coli Isolates From Egypt

A total of 140 E. coli isolates showed at least one pathogenic determent among the isolated 147 E. coli which were previously collected from clinical and food samples. The other 7 isolates were free from tested virulence genes. Among these 140 isolates, 123 had only the UidA gene, therefore, were classified as non-categorized pathogenic E. coli. The other 17 isolates had at least one characteristic gene of diarrheagenic E. coli and were identified and classified as enteropathogenic E. coli (8), enterotoxigenic E. coli (5) and enterohemrrahagic E.coli (4). Interestingly, a correlation was found among these isolates that increasing the number of virulence genes was accompanied with an increase in the antibiotic resistance until a cutoff of 2 virulence gens, above this limit the relation was inversely proportion. Evidentially, sensitive K12 E. coli was able to acquire ampicillin and/or kanamycin resistance traits from resistant pathogenic E. coli isolate among those collected in the present study. NSEM monitoring of different growth stages of the mated K12 E. coli and the donor resistant pathogenic E. coli showed that horizontal gene transfer by conjugation occur during the growth, suggesting that this was one of possible mechanisms through which the antibiotic resistance characters were transferred or acquired.