Molecular Epidemiology of Campylobacter jejuni in Cattle – a Longitudinal Study on Dairy Farms

Department of Medical Microbiology, School of Medicine, University of Manchester, Clinical Sciences Building, Manchester Royal Infirmary, Manchester, M13 9WL, United Kingdom; Health Protection Agency North West Laboratory, Clinical Sciences Building, Manchester Royal Infirmary, Manchester, M13 9WZ, United Kingdom; Epidemiology Group, Faculty of Veterinary Science, University of Liverpool, Neston, CH64 7TE, United Kingdom; FEMS North West, Royal Preston Hospital, Sharoe Green Lane, PR2 9HG, United Kingdom; Institute of Veterinary, Animal and Biomedical Sciences, College of Sciences, Massey University, New Zealand

^* To whom correspondence should be addressed. Email: andrew.fox{at}hpa.org.uk.

	Abstract

Multilocus Sequence Typing (MLST), an accurate and phylogenetically robust characterization method for population studies of Campylobacter, was applied to Campylobacter jejuni isolates (n=297) from the faecal samples of cattle from five dairy farms in Cheshire, UK, collected throughout 2003. The population dynamics of the C. jejuni strains, as identified by the occurrence of sequence types and clonal complexes, demonstrated variation within and between cattle populations over time. Three clonal lineages have emerged to predominate among the cattle isolates, namely, the ST-61 complex (24.2%), ST-21 complex (23.6%) and ST-42 complex (20.5%). This provided further evidence that the ST-61 clonal complex may present a cattle-adapted C. jejuni genotype. In addition, the ST-42 clonal complex may also represent an important cattle associated genotype. Strong geographical associations for these genotypes were also found amongst farms. This is the first longitudinal and largest study to-date for C. jejuni involving cattle populations using MLST for accurate strain characterization. The study has shown the important associations between cattle and C. jejuni clonal complexes ST-61, ST-21 and ST-42, and suggests that cattle and/or dairy products are likely to be a source of the human Campylobacter gastroenteritis caused by such genotypes. The reported findings have significant implications for the design of effective intervention strategies for disease control and prevention.