Genotype analysis of Escherichia coli strains isolated from children and chickens living in close contact

Escherichia coli isolates from rectal swabs from 62 chickens and stools fro m 42 children living in close contact with chickens on the same farms in Ki ambu district, Kenya, were compared for their genetic relatedness. Antibiot ic susceptibility profiles broadly categorized isolates From the children a nd from the chickens into two separate clusters: the majority (144; 85.5%) of the E. coli isolates from children were multidrug resistant, while the m ajority (216; 87.1%) of the E. coli isolates from chickens were either full y susceptible or resistant only to tetracycline, Sixty- and 100- to 110-MDA plasmids were found to encode the transferable resistance to co-trimoxazol e and tetracycline. HindIII restriction endonuclease digestion of the 60- a nd 100- to 110-MDA plasmids produced four distinct patterns for isolates fr om children and three distinct patterns for isolates from chickens. XbaI di gestion of genomic DNA followed by pulsed-field gel electrophoresis (PFGE) analysis produced 14 distinct clusters. There were six distinct PFGE cluste rs among the isolates from children, while among the isolates from chickens there were seven distinct clusters. Only one PFGE cluster contained isolat es from both children and chickens, with the isolates displaying an approxi mately 60% coefficient of similarity. This study showed that although sever al different genotypes of E. coli were isolated from children and chickens from the same farms, the E. coli strains from these two sources were distin ct.