Factores de virulencia de Escherichia coli aviar asociados a la colisepticemia en pollos de engorde / Avian Escherichia coli virulence factors associated with coli septicemia in broiler chickens

In order to detect phenotypic characteristics associated with pathogenicity, 25 strains of Escherichia coli, isolated from clinical cases of colisepticemia in broiler chickens, were examined to determine the following properties: colicinogenicity, colicin V production, type 1 fimbriae, hemolysin expression and motility. Colicinogenicity occurred in 72 of the strains, 56 of all strains produced colicin V, 84 were positive for type 1 fimbriae and 80 were positive for motility. None of the strains had hemolytic activity; however, all of them, expressed at least one of the other characteristics studied. These results suggest that the diversity of phenotypes detected partially explain the multifactorial nature of avian colisepticemia.