Campylobacter devanensis sp. nov., Campylobacter porcelli sp. nov., and Campylobacter vicugnae sp. nov., three novel Campylobacter lanienae-like species recovered from swine, small ruminants, and camelids

Authors: Miller, William - Bill; LOPES, BRUNO - Teesside University; RAMJEE, MEENAKSHI - University Of Glasgow; JAY-RUSSELL, MICHELE - University Of California, Davis; Chapman, Mary; Williams, Tina; Wood, Delilah - De; GRUNTAR, IGOR - University Of Ljubljana; PAPIC, BOJAN - University Of Ljubljana; FORBES, KEN - University Of Aberdeen

Submitted to: International Journal of Systematic and Evolutionary Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/21/2024
Publication Date: 6/6/2024
Citation: Miller, W.G., Lopes, B.S., Ramjee, M., Jay-Russell, M., Chapman, M.H., Williams, T.G., Wood, D.F., Gruntar, I., Papic, B., Forbes, K.J. 2024. Campylobacter devanensis sp. nov., Campylobacter porcelli sp. nov., and Campylobacter vicugnae sp. nov., three novel Campylobacter lanienae-like species recovered from swine, small ruminants, and camelids. International Journal of Systematic and Evolutionary Microbiology. 74(6). Article 006405. https://doi.org/10.1099/ijsem.0.006405.
DOI: https://doi.org/10.1099/ijsem.0.006405

Interpretive Summary: Strains of the species Campylobacter are commonly associated with human illness. Campylobacter jejuni is considered the leading cause of bacterial human gastroenteritis worldwide. In addition to C. jejuni, other Campylobacter species have also been linked with disease in both humans and livestock. Strains from one branch of Campylobacter, called 'non-thermotolerant' because they can only grow up to the body temperature of humans and most mammals, are often recovered from livestock and other food animals. This study describes three new species within Campylobacter. Two of the species were recovered strictly from pigs. The third species was isolated from multiple animals, including goats, sheep and alpaca. These species are related to the livestock pathogen C. fetus and all share the same trait of being unable to incorporate the element selenium into their proteins. In a related study, strains similar to these novel species were also recovered from human clinical samples in rural Africa. It is likely that transmission there occurred via local livestock. The ability of these new Campylobacter species to cause illness in humans is unknown and still under investigation.

Technical Abstract: In a previous study characterizing Campylobacter strains deficient in selenium metabolism, fifty strains were found to be similar to, but distinct from, the selenonegative species Campylobacter lanienae. Initial characterization based on MLST and the phylogeny of a set of twenty core genes determined that these strains comprised three putative taxa within the selenonegative cluster. A polyphasic study was undertaken here to further clarify their taxonomic position within the genus. The fifty selenonegative strains underwent phylogenetic analyses based on the sequences of the 16S rRNA gene and an expanded set of 330 core genes. Standard phenotypic testing was also performed. All strains were microaerobic and anaerobic, Gram-negative, spiroform or curved cells with coccoid cells present in some cultures. Strains were motile, oxidase, catalase and alkaline phosphatase positive, urease negative, and reduced nitrate. Strains within each clade had unique phenotypic profiles that distinguished them from other members of the genus. Core genome phylogeny clearly placed the fifty strains into three clades. Pairwise average nucleotide identity and digital DNA–DNA hybridization values were all below the recommended cut-offs for species delineation with respect to C. lanienae and other related Campylobacter species. The data presented here clearly show that these strains represent three novel species within the genus, for which the names Campylobacter devanae sp. nov. (type strain =RM3662T =LMG 33097T =NCTC 15074T), Campylobacter porcellus sp. nov. (type strain =RM6137T =LMG 33098T =CCUG 77054T =NCTC 15075T) and Campylobacter vicugnae sp. nov. (type strain =RM12175T =LMG 33090T =CCUG 77055T =NCTC 15076T) are proposed.