Cloning and Sequencing of from Incriminated in Mink and Bovine Colibacillosis

Colibacillosis is responsible for significant losses to the mink and cattle industries. Previous work in our laboratory and by others has suggested that possession of , the gene encoding cytotoxic necrotizing factor (CNF1), may contribute to the virulence of isolates of from mink and cattle. The gene from isolated from a mink with colisepticaemia and a bovid with scours was amplified and cloned as a 3.5 kb fragment, and the fragment was sequenced. The sequences from the mink and bovine isolates of were compared to each other and to sequences of from urinary tract and diarrhoea-associated infections of humans. The difference was only 7 nucleotides between the sequences of the mink and bovine isolates of , which translated into 7 differences in amino acids. The sequence of the mink isolate of had 15 nucleotide differences from the sequences of the human isolate of (GenBank X70670), which translated into 11 differences in amino acids between these proteins. The sequence of the bovine isolate of had 14 nucleotide differences from the sequence of the human isolate of (GenBank X70670), which translated into 10 differences in amino acids between these proteins. The highly conserved sequences of the amino acids of CNF1 proteins make them a promising target for detection and control of the CNF1-producing involved in disease among various host species.