Some virulence factors of Escherichia coli isolated from diarrheic calves

Escherichia coliare the most common cause of diarrhea in calves. Diarrhea in calvesremains one of the most important problems faced by livestock, causing greateconomic losses. Some strains ofE. coli characterized by the presence of specificvirulence factors including haemolysin production, resistance to bactericidal effectsof serum and Congo red binding activity. In this studyfecal samples were collectedfrom 115 diarrheic calves aged from 3 days to one year and from different localities in Egypt along the period from February to August 2015.The prevalence of E. coli in diarrheic calves was 72.2%. 39.8% of isolated E. coli were haemolytic to sheep blood agar, 68.7% were serum resistant, 100% showed Congo red binding activity.