Reproduction of Lesions and Clinical Signs with a Cnf2-Producing Escherichia Coli in Neonatal Calves

CNF2-producing necrotoxigenic E. coli (NTEC2) are associated with diarrhoea and septicaemia in calves. We orally inoculated neonatal calves with a NTEC2 strain in order to reproduce clinical signs and lesions. We observed diarrhoea in each inoculated calf, bacteraemia (80%), the presence of CNF2+ bacteria in the lungs (80%) and in the liver (20%). The observed lesions were inflammation of the entire gut, hypertrophy of the mesenteric lymph nodes and hepatisation of the lungs. We were unable to detect characteristic lesions that are classical signs of septicaemia.