Campylobacter pinnipediorum sp. nov., isolated from pinnipeds, comprising Campylobacter pinnipediorum subsp. pinnipediorum subsp. nov. and Campylobacter pinnipediorum subsp. caledonicus subsp. nov.

Authors: GILBERT, MAARTEN - Utrecht University; Miller, William - Bill; ST. LEGER, JUDY - Hubbs-Sea World; Chapman, Mary; TIMMERMAN, ARJEN - Utrecht University; FOSTER, GEOFFREY - Sruc-Scotland'S Rural College; WAGENAAR, JAAP - Utrecht University

Submitted to: International Journal of Systematic and Evolutionary Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/20/2017
Publication Date: 6/20/2017
Citation: Gilbert, M.J., Miller, W.G., St. Leger, J., Chapman, M.H., Timmerman, A.J., Foster, G., Wagenaar, J.A. 2017. Campylobacter pinnipediorum sp. nov., isolated from pinnipeds, comprising Campylobacter pinnipediorum subsp. pinnipediorum subsp. nov. and Campylobacter pinnipediorum subsp. caledonicus subsp. nov.. International Journal of Systematic and Evolutionary Microbiology. doi:10.1099/ijemo.001894.

Interpretive Summary: Campylobacter species are isolated typically from a wide variety of warm-blooded animals and birds. Several Campylobacter species have been isolated from the marine environment: sea water/beach sand; marine birds and mammals; and shellfish. Infestation of the latter can lead to human food-borne illness. Seals and sea lions have been shown previously to harbor C. insulaenigrae, a species related to the thermotolerant C. lari-like species. However, strains isolated recently from seals and sea lions in both California and Scotland were shown to be unrelated to species normally associated with the marine environment, but were instead shown to be related to Campylobacter concisus group organisms. C. concisus group organisms are typically orally-associated and isolated from terrestrial animals and humans. Genetic and biochemical analysis of these strains indicated that these strains represent a novel species within Campylobacter for which the name C. pinnipedii (of pinnipeds =seals/sea lions) is proposed. The California and Scotland strains can be distinguished by the presence/absence, respectively, of an enzyme that degrades hydrogen peroxide. Thus, the Californian and Scottish strains are proposed to form two subspecies (subsp. pinnipedii and subsp. caledoniensis) within C. pinnipedii.

Technical Abstract: During independent diagnostic screenings of otariid seals in California (US) and phocid seals in Scotland (UK), Campylobacter-like isolates, which differed from the established Campylobacter taxa, were cultured from abscesses and internal organs of different seal species. A polyphasic study was undertaken to determine the taxonomic position of these six isolates. The strains were characterized by 16S rRNA and atpA sequence analysis and by conventional phenotypic testing. The whole genome sequences were determined for all the isolates and the average nucleotide identity (ANI) was determined. The isolates formed a separate phylogenetic clade, divergent from all other Campylobacter taxa and most closely related to C. mucosalis. Although all isolates showed 100% 16S rRNA sequence homology, atpA and ANI analysis indicated divergence between the otariid isolates from California and the phocid isolates from Scotland, which warrants subspecies status for each clade. The two subspecies can also be distinguished phenotypically based on catalase activity. This study shows clearly that the isolates obtained from pinnipeds represent a novel species within the genus Campylobacter, for which the name Campylobacter pinnipedii sp. nov. is proposed. Within this novel species, the Californian isolates represent a separate subspecies, for which the name C. pinnipedii subsp. pinnipedii subsp. nov. is proposed. The type strain for both this novel species and subspecies is RM17260T (= LMG 29472T). The Scottish isolates represent another subspecies, for which the name C. pinnipedii subsp. caledoniensis subsp. nov. is proposed. The type strain of this subspecies is M302/10/6T (=LMG 29473T).