National Centre for Zoonosis Research hosted by the University of Liverpool

INFECTION AND IMMUNITY GROUP

The infection and immunity group focus on the biology of major foodborne pathogens in production animals and the biology of these and other bacterial pathogens in wildlife and the environment.  The work involves close collaboration with disease ecology and genomics groups of the University of Liverpool. Currently the group is involved with three main pathogens:

1.       Salmonella
Birds, and in particular poultry, are a major source of Salmonella. The group focuses on how Salmonella may cause disease or colonise the intestines of animals and how the animals respond to infection or vaccination. The ultimate aim is to control salmonellosis in poultry through improved vaccination or through selective breeding of chickens.  In particular we are interested in why eggs may be infected with Salmonella and how changes in the immune system in laying hens may play an important role in this through a project funded by BBSRC.

We are also interested in how Salmonella survive in the environment or in wildlife and how this affects the bacteria’s ability to be transmitted to humans or livestock and to cause disease.  Recently we have described Salmonella Typhimurium associated with wild birds and are using a comparative genomics approach to understand why certain strains of this Salmonella have become adapted to survival in wild birds. We are also investigating how Salmonella survive within protozoa like amoeba and how this may have played a major part in the way Salmonella have evolved to cause disease in humans and other animals through development of bacterial machines called Type III secretion systems that allow Salmonella to survive inside cells of the host’s immune system.

 2.       Campylobacter

Campylobacter spp. (C. jejuni & C. coli) are the most common cause of bacterial ‘food poisoning’ in man. Using Campylobacter from diverse sources (chickens, wild rodents, water) we are using whole genome sequencing, microarray technology and infection models to understand better how Campylobacter survive in livestock and are transmitted to man. This unique pathogenomic approach may increase our understanding of this poorly known process, allowing effective control measures to be developed.

 3.       Mycobacteria

Mycobacteria are best known as the cause of tuberculosis in man and cattle. Human and bovine TB form part of a group of organisms called the ‘TB complex’. Amongst this complex is Myocbacterium microti, which causes a TB-like illness in field voles, one of the UK’s commonest mammals. By comparing genomes and understanding how M. microti interacts with vole cells (macrophages) in the laboratory, we hope to develop novel methods to understand how TB is caused in a natural infection model.

recent publications

Bleasdale, B., Lott, P.J., Jagannathan, A., Stevens, M.P., Birtles R.J., & Wigley P (2009) The Salmonella pathogenicity island (SPI)-2-encoded type III secretion system is essential for survival of Salmonella enterica serovar Typhimurium in free-living amoebae. Applied Environ Microbiol in press

Chappell, L., Kaiser, P. Johnston, C., Barrow P., Jones M, & Wigley P (2009) Immunobiology of avian systemic salmonellosis. Vet Immunol Immunopathol  doi:10.1016/j.vetimm.2008.10.295

Timothy, S., Shafi, K., Jordan, F.T.W & Wigley P.(2008) Molecular epidemiology of atypical avian pathogenic Escherichia coli associated with reproductive tract infection. Avian Pathol 37 375-378

Hughes, L, Shopland, S. Wigley P., et al (2008) Characterisation of Salmonella enterica serovar Typhimurium from wild birds in northern England from 2005-2007. BMC Vet Res 4:4

Jones, M.A, Hulme, S.D., Barrow P.A. & Wigley P (2007) The Salmonella pathogenicty island 1 and  pathogenicity island 2 type III secretion systems play a key role in pathogenesis and gastrointestinal tract colonisation of Salmonella enterica serovar Typhimurium in the chicken. Avian Pathol 36 199-203

Beal RK, Wigley P, Powers C, Barrow PA & Smith PA (2006) Cross-reactive cellular and humoral immune responses to Salmonella enterica serovars Typhimurium and Enteritidis are associated with protection to heterologous re-challenge. Vet Immunol Immunopathol 114, 84-93

Wigley, P., Hulme, S., Rothwell, L., Bumstead, N., Kaiser, P. & Barrow, P. (2006). Macrophages isolated from chickens genetically resistant or susceptible to systemic salmonellosis show magnitudinal and temporal differential expression of cytokines and chemokines following Salmonella enterica challenge. Infect Immun 74, 1425-1430.

Beal RK, Wigley P, Powers C, Kaiser P., Barrow PA, Smith AL (2005) A strong antigen-specific T cell response associates with age and genetic-dependent resistance to avian enteric salmonellosis. Infect Immun 73 7509-7516

Wigley P, Hulme S, Powers C, Beal R, Barrow P. (2005) Oral infection with the Salmonella enterica serovar Gallinarum 9R attenuated live vaccine as a model to characterise immunity to fowl typhoid in the chicken. BMC Vet Res.;1:2.

G. S. K. Withanage, Paul Wigley, Pete Kaiser, Pietro Mastroeni, Heather Brooks, Claire Powers, Richard Beal, Paul Barrow, Duncan Maskell and  IanMcConnell  (2005) Cytokine and chemokine responses associated with clearance of a primary Salmonella enterica serovar Typhimurium infection in the chicken and in protective immunity to rechallenge. Infect Immun. 73 5173-5182

Paul Wigley, Scott. D. Hulme, Claire Powers, Richard K. Beal, Angelo Berchieri Jr., Adrian Smith and Paul Barrow (2005) Infection of the reproductive tract and eggs by Salmonella enterica serovar Pullorum in the chicken is associated with suppression of cellular immunity at sexual maturity. Infect Immun. 73 2986-2990.

Iqbal, M., Philbin, V., Withanage, S., Wigley, P., Beal, K., Goodchild, M., Barrow, P., McConnell, I., Maskell, D., Young, J., Bumstead, N., Boyd, Y and Smith, A. (2005) Identification and functional characterisation of chicken TLR5 reveals a fundamental role in the biology of infection with Salmonella enterica serovar Typhimurium. Infect Immun. 73