O-antigen repeat number in Salmonella enterica serovar Enteritidis is important for egg contamination, colonisation of the chicken reproductive tract and survival in egg albumen


Correspondence: Chris Coward, Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES, UK. Tel.: +44 1223 765811; fax: +44 1223 337610; e-mail: cc122@cam.ac.uk


Salmonella enterica serovar Enteritidis is a major cause of human gastrointestinal disease, infection being due in large part to consumption of contaminated eggs. The lipopolysaccharide (LPS) of Salmonella is known to play a role in colonisation of the host and survival in hostile conditions including egg albumen. We investigated the contribution of LPS O-antigen length to colonisation of the reproductive tract of laying hens, contamination of eggs and survival in albumen. We show that expression of very-long O-antigen is essential for contamination of eggs, probably as a consequence of enhanced reproductive tract colonisation and survival in the forming egg.