Adhesive properties and iron uptake ability in Escherichia coli lethal and nonlethal for chicks.

Escherichia coli that are virulent for poultry usually result in a respiratory disease, which is frequently followed by a general infection. Adhesiveness of E. coli to epithelial cells and iron-uptake ability of E. coli could be involved in different steps of the disease. These properties were studied in 59 E. coli strains originating from poultry, with reference to lethality for day-old chicks. Adhesive properties were found in 64% of the lethal strains and in only 23% of the nonlethal strains. The ability to grow in limited iron conditions was strongly correlated with lethality. Fifty-two percent of the lethal E. coli strains, but none of the nonlethal strains, possessed both adhesive and iron-uptake abilities. It is suggested that these two properties play a role in the virulence of E. coli for poultry.