Novel insights into pasteurellosis in captive pinnipeds

• Published in: Veterinary microbiology 2019-04, Vol.231, p.232-237
• Main Authors: Crawford, Rebecca L., Blyde, David, Blackall, Patrick J., Forde, Brian M., Beatson, Scott A., Harris, Louise M., Turni, Conny, Omaleki, Lida
• Format: Article
• Language: English
• Subjects: Animals; Arctocephalus forsteri; Arctocephalus tropicalis; Australia; Bioinformatics; Biosynthesis; Birds - microbiology; Bronchopneumonia; Bronchopneumonia - microbiology; Bronchopneumonia - mortality; Bronchopneumonia - veterinary; Fur Seals - microbiology; Genetic Variation; Genome, Bacterial; Genomes; Lipopolysaccharides; Multilocus sequence typing; Necropsy; New Zealand; Organs; Outbreaks; Pasteurella Infections - transmission; Pasteurella Infections - veterinary; Pasteurella multocida; Pasteurella multocida - classification; Pasteurella multocida - genetics; Pasteurella multocida pinnipeds; Pasteurellosis; Peritonitis; Peritonitis - microbiology; Peritonitis - mortality; Peritonitis - veterinary; Phylogeny; Pneumonia; Seals; Septicemia; Whole Genome Sequencing; Zoonoses
• ISSN: 0378-1135; 1873-2542
• DOI: 10.1016/j.vetmic.2019.03.017

•Two different disease manifestations in 2 fur seals associated with P. multocida.•Whole genome sequencing revealed the presence of within-host diversity of P. multocida, a novel finding for this important pathogen.•The isolates from several internal organs of the two seals belonged to the same genetic lineage.•Results suggest that transiting birds could have been responsible for introducing the outbreak strain. Pasteurella multocida is a heterogeneous bacterium, which has the capacity to cause disease in a wide range of host species and is also recognized as an important zoonotic pathogen. Two sequential deaths in captive fur seals occurred at Sea World, Australia during December 2017. A fibrinosuppurative bronchopneumonia in a Subantarctic fur seal (Arctocephalus tropicalis) resulted in death within 24 h of nonspecific signs of illness, whereas a septic peritonitis in a New Zealand fur seal (Arctocephalus forsteri) resulted in death within 12 h 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 and were subjected to whole genome sequencing and phylogenomic analysis. 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. The results also revealed the presence of within host and across animal diversity of P. multocida isolates for the first time even in a clearly connected outbreak.