Abstract :
[en] An adult female harbour porpoise (Phocoena phocoena) and a juvenile male harbour seal (Phoca vitulina) have been found stranded dead on the Belgian coast in late 2001. As the two bodies were in good condition (CC = 2), necropsy and bacteriological analyses were performed as well as other postmortem investigations. Blood heart and organs (liver, digestive and respiratory tract, lungs, spleen, brain, kidneys) samples have been collected and analyzed. The porpoise showed evidence of septicaemia, and the seal presented lesions of acute enteritis. Pure and abundant growth of a small rod-shaped, Gram-labile bacterium was obtained aerobically and anaerobically on Columbia blood agar from heart blood, mouth, pharynx, lungs, intestine and anus of the porpoise, and from intestine, pharynx, mouth, nose and anus of the seal. The colonies were surrounded by a narrow zone of alpha-hemolysis. Catalase- and peroxydase-tests gave negative results. Rapid ID 32 Strepto (Biomérieux, France) sugar tests identified this isolate as Erysipelothrix rhusiopathiae. E. rhusiopathiae could be therefore considered as the cause of septicaemia on the porpoise as it was present in heart blood and internal organs, and could be associated primary or secondary with the enteritis reported on the seal as the bacterium was isolated in pure culture in the digestive tract. E. rhusiopathiae infections have been reported in captive dolphins and sea lions. This zoonotic pathogen is also involved in human local infections, like the “seal finger”, resulting from captive pinnipeds bites. However, it has not been so far described as systemic pathogens of wild cetaceans and pinnipeds. E. rhusiopathiae could be therefore considered as a potentially emergent pathogen which could have important repercussions on human health, particularly veterinarians, marine mammals rescue teams and zoos.
