Avian pathogenic Escherichia coli Delta tonB mutants are safe and protective live-attenuated vaccine candidates
Karen M Holden, Glenn F Browning, Amir H Noormohammadi, Philip Markham, Marc S Marenda
Veterinary Microbiology | ELSEVIER | Published : 2014
Avian pathogenic Escherichia coli (APEC) cause colibacillosis, a serious respiratory disease in poultry. Most APEC strains possess TonB-dependent outer membrane transporters for the siderophores salmochelin and aerobactin, which both contribute to their capacity to cause disease. To assess the potential of iron transport deficient mutants as vaccine candidates, the tonB gene was deleted in the APEC wild type strain E956 and a Δfur (ferric uptake repressor) mutant of E956. The growth of the ΔtonB and ΔtonB/Δfur mutants was impaired in iron-restricted conditions, but not in iron-replete media. Day old chicks were exposed to aerosols of the mutants to assess their efficacy as live attenuated va..View full abstract
This work was supported in part by the Australian Poultry Cooperative Research Centre. The authors thank Cheryl Colson and June Daly for assistance with animal handling and Nick Esbert for technical assistance. We thank Anna Kanci for assisting with the chicken experiment and Lambda Red recombineering protocols. The authors declare no conflict of interest.