Frances Colles

Post-doctoral researcher


Research Interests

·         The impact of disease, health and welfare of commercial chicken flocks on colonisation by Campylobacter.

·         The molecular epidemiology of pathogens of clinical and veterinary interest, including Campylobacter, Salmonella, Clostridia and Eimeria species.

·         The dynamics, transmission and virulence of different Campylobacter strains colonising chicken flocks; from individual birds within a flock, to those circulating on a farm, within a company and even at international level.

Campylobacter is the principal organism I work on. It can cause severe gastrointestinal disease in humans, with the yearly number of reported UK cases being equivalent to one person becoming infected every two minutes.  Contaminated chicken meat has been identified as a major source of infection, and effective ‘on-farm’ intervention strategies are urgently sought to support the biosecurity measures that are currently used. 

Work for my DPhil demonstrated that, contrary to popular belief, wild birds are not a major source of contamination for broiler chicken flocks, with Campylobacter strains more likely to colonise particular bird species across disparate continents, than to cross host species barriers on the same farm.  Further study of a free-range broiler breeder flock revealed a sharp decline in shedding levels amongst mature birds, with C. jejuni and C. coli species differing in colonisation attributes. Detailed information such as this is essential if we are to gain understanding as to how Campylobacter colonisation levels in commercial flocks may be controlled.

Current research forms part of a multidisciplinary approach using state of the art technology to formally test links between chicken flock behaviour, welfare and Campylobacter prevalence, and to explore good husbandry as a potential measure to reduce colonisation of chicken flocks by Campylobacter, and ultimately to reduce the incidence of human disease.

Additional Information

·         State registered Biomedical Scientist (Microbiology)

·         Outreach for primary and secondary students at the Farm Inspiration Trust’s Outdoor Classroom, based on an organic, working farm.

·         Associate fellow of the Higher Education Academy.




Selected Publications

  • 1. Colles FM, McCarthy ND, Bliss, CM, Layton R, Maiden MC. The long-term dynamics of Campylobacter colonizing a free-range broiler breeder flock: an observational study. (2014) Environmental Microbiology. DOI 10.1111/1462-2920.

    2. Griekspoor P, Colles FM, McCarthy ND, Hansbro PM, Ashhurst-Smith C, Olsen B, Hasselquist D, Maiden MC, Waldenström J. Marked host specificity and lack of phylogeographic population structure of Campylobacter jejuni in wild birds. (2013) Molecular Ecology 22(5):1463-72.

    3. Colles FM, Maiden MC.  Campylobacter sequence typing databases: applications and future prospects. (2012) Microbiology 158 (PT111):2695-709.

    4. Colles FM, McCarthy ND, Layton R, Maiden MC. The prevalence of Campylobacter amongst a free-range broiler breeder flock was primarily affected by flock age. (2011) PLoS One 6(12):e22825

    5. Colles FM, McCarthy ND, Howe JC, Devereux CL, Gosler AG, Maiden MC. Dynamics of Campylobacter colonization of a natural host Sturnus vulgaris (European Starling). (2009) Environmental Microbiology 11(1):258-67.

    6. Colles FM, Jones TA, McCarthy ND, Sheppard SK, Cody AJ, Dingle KE, Dawkins MS, Maiden MC. Campylpbacter infection of broiler chickens in a free-range environment.  (2008) Environmental Microbiology 10(8):2042-50.