Escherichia coli Strains that Cause Hemorrhagic Pneumonia in Animals

Hemorrhagic pneumonia (HP) is a rare but highly lethal disease, mainly of dogs and cats, caused by hemolytic Escherichia coli strains that contain cnf1 (encoding cytotoxic necrotizing factor 1). The HP clinical isolates represented a narrow range of phylogenetic group B2 lineages and these isolates' virulence genotypes qualified as extraintestinal pathogenic E. coli (ExPEC). Comparison with a with a large private pulsotype library of diverse-source E. coli and household sharing studies suggest these E. coli type are shared extensively between hosts, and likely function in nature mainly as intestinal colonizers and uropathogens.