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Objective: To determine the frequency of potential virulence factors
in Escherichia coli isolates from avian colibacillosis.
Design: Descriptive study. Samples: One hundred E. coli isolates from cases of avian
colibacillosis examined in this study were obtained from the
bacterial collection of Poultry Diseases Section, Department of
Clinical Sciences, Faculty of Veterinary Medicine, University of Tehran. Procedure: All isolates were characterized with respect to motility,
serum resistance and ability to produce aerobactin, colicin, colicin
V and hemolysin. Results: No hemolytic isolate was found. Motility and serum resistance were found in 64 and 94% of isolates, respectively. The percentages of isolates that produced aerobactin, colicin and colicin
V were 85, 90 and 22%, respectively. Conclusion: Aerobactin production and serum resistance may be
important factors associated with virulence of avian E. coli isolates.
J. Fac. Vet. Med. Univ. Tehran. 59, 3: 233-240, 2004.