Efficacy of a live attenuated Escherichia coli O78:K80 vaccine in chickens and turkeys

La Ragione, R. M., Woodward, M. J., Kumar, M., Rodenberg, J., Fan, H., Wales, A. D. and Karaca, K. (2013) Efficacy of a live attenuated Escherichia coli O78:K80 vaccine in chickens and turkeys. Avian Diseases, 57 (2). pp. 273-279. ISSN 0005-2086 doi: 10.1637/10326-081512-Reg.1

Abstract/Summary

A candidate live vaccine for avian pathogenic Escherichia coli (APEC) was constructed from a virulent field APEC O78 strain by mutation of the aroA gene. The mutant was highly similar to the parent wild-type strain in respect of colony morphology, motility, growth in suspension, hemagglutination, Congo Red binding, HEp-2 cell adhesion, and the elaboration of surface antigens type 1 fimbriae and flagella, although production of curli fimbriae was reduced marginally. The mutant proved avirulent when inoculated into 1-day-old chicks by spray application and when presented again in the drinking water at 7 days of age. Chickens and turkeys vaccinated with an O78 aroA mutant were protected against a challenge at 6 wk of age by virulent APEC strains.