Occurrence of a monophasic strain of Salmonella group B isolated from cetaceans in England and Wales between 1990 and 2002

• Published in: Environmental Microbiology
• Main Authors: Valderrama Vasquez, Carlos A., Macgregor, Shaheed K., Rowcliffe, J. Marcus, Jepson, Paul D.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2008
• Subjects: Phocoena phocoena
• Online Access: http://dx.doi.org/10.1111/j.1462-2920.2008.01651.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1462-2920.2008.01651.x; http://onlinelibrary.wiley.com/wol1/doi/10.1111/j.1462-2920.2008.01651.x/fullpdf

Summary Between September 1990 and December 2002, 511 cetacean carcasses stranded or caught in commercial fisheries in England and Wales were examined post mortem . Salmonella group B was isolated from 60 of 279 (21.51%) harbour porpoises ( Phocoena phocoena ), predominantly from lung tissue. Forty‐three of the Salmonella group B isolates were subsequently serotyped and all found to have the antigenic structure O4,12:a:‐. The annual proportion of harbour porpoises testing positive for Salmonella O4,12:a:‐ increased significantly from 6% in the early 1990s to 27% after 1999. The cause(s) of the increasing prevalence of Salmonella O4,12:a:‐ are not known, but may reflect natural variation in the epidemiological cycle of Salmonella O4,12:a:‐ in harbour porpoises. The probability of isolating Salmonella O4,12:a:‐ from harbour porpoises increased with age, suggesting that the mode of transmission is principally horizontal. There appeared to be a weak degree of seasonality in the probability of isolating Salmonella O4,12:a:‐ with a low proportion of cases in the months of April and May. Based on pathological findings from infected carcasses, Salmonella O4,12:a:‐ may be part of the normal commensal flora of the lungs of cetaceans with the potential to act as an opportunistic pathogen.