The epidemiology of a pasteurellosis outbreak in captive seals

Two sequential deaths in captive fur seals occured at Sea World, Australia. A fibrinosuppurative bronchopneumonia in a Subantarctic fur seal (Arctocephalus tropicalis) resulted in death within 24 hours of nonspecific signs of illness, whereas a septic peritonitis in a New Zealand fur seal (Arctocephalus forsteri) resulted in death within 12 hours of clinical presentation. The cases happened within three days in two different pool locations, although both had previously been housed in the same area. A total of six Pasteurella multocida isolates were obtained from several internal organs at necropsy in both cases. In silico typing of the isolates revealed that all belonged to Multi-Locus Sequence Type 7 and carried lipopolysaccharide outer core biosynthesis loci type 3. Phylogenomic analysis of the isolates confirmed that the isolates were near identical at the core genome level, suggesting acquisition from a common source.