Monophasic group B Salmonella species infecting harbour porpoises (Phocoena phocoena) inhabiting Scottish coastal waters

A monophasic strain of Salmonella group B having the antigenic structure 4, 12: a: - was isolated in culture from various tissues of 39 harbour porpoises (Phocoena phocoena). The tissue from which the organism was recovered most frequently was lung in 33 animals and intestine in 16 animals, but it was also isolated from heart valve, liver, kidney, spleen, mesenteric lymph node, pulmonary lymph node, hepatic lymph node, urethra, sheath and epididymis. As far as we are aware this is the first record of this strain from an animal source, raising the possibility that it may be host-adapted to harbour porpoises. The possible modes of transmission of monophasic group B Salmonella between porpoises are discussed.