Virulence determinants of Escherichia coli isolated from the milk of sows with coliform mastitis

Escherichia coli isolates recovered from the milk of sows with coliform mastitis u ere examined to determine their biochemical and serologic characteristics, serum resistance and ability to adhere to Fibronectin and bovine fetal fibroblasts. No common biotype was identified, and a variety of serovars were detected. Ninety-five per cent of the investigated strains were serum resistant in swine serum. Binding to fibronectin was demonstrated in most of the strains. At a binding level above 13% % of the added fibronectin the strains also adhered to fibroblasts. The results of the study indicate a galactogenous route of infection. The importance of the identified virulence Factors needs to be further elucidated.