Genome diversity of Borrelia garinii in marine transmission cycles does not match host associations but reflects the strains evolutionary history

• Published in: Infection, Genetics and Evolution
• Main Authors: Margos, Gabriele, Hofmann, Markus, Casjens, Sherwood, Dupraz, Marlene, Heinzinger, Susanne, Hartberger, Christine, Hepner, Sabrina, Schmeusser, Mercy, Sing, Andreas, Fingerle, Volker, Mccoy, Karen
• Other Authors: Bavarian Health and Food Safety Authority, School of Medicine University of Utah, Salt Lake City, University of Utah, Maladies infectieuses et vecteurs : écologie, génétique, évolution et contrôle (MIVEGEC), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD France-Sud )-Université de Montpellier (UM), ANR-13-BSV7-0018,ESPEVEC,Facteurs historiques et contemporains dans l'évolution de la spécialisation d'hôte chez les organismes vecteurs(2013)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2023
• Subjects: Borrelia garinii; Genomics; In vitro culture; Ixodes ricinus; Ixodes uriae; Seabirds; [SDV]Life Sciences [q-bio]; Pacific; Atlantic puffin; Razorbill
• Online Access: https://hal.science/hal-04251123; https://hal.science/hal-04251123/document; https://hal.science/hal-04251123/file/Margos_2023_IGE.pdf; https://doi.org/10.1016/j.meegid.2023.105502

International audience Borrelia burgdorferi sensu lato is a species complex of spirochetal bacteria that occupy different ecological niches which is reflected in their reservoir host- and vector-associations. Borrelia genomes possess numerous linear and circular plasmids. Proteins encoded by plasmid genes play a major role in host- and vector-interaction and are important for Borrelia niche adaptation. However, the plasmid composition and therewith the gene repertoire may vary even in strains of a single species. Borrelia garinii, one of the six human pathogenic species, is common in Europe (vector Ixodes ricinus), Asia (vector Ixodes persulcatus) and in marine birds (vector Ixodes uriae). For the latter, only a single culture isolate (Far04) and its genome were previously available. The genome was rather small containing only one circular and six linear plasmids with a notable absence of cp32 plasmids. To further investigate B. garinii from marine transmission cycles and to explore i) whether the small number of plasmids found in isolate Far04 is a common feature in B. garinii from marine birds and presents an adaptation to this particular niche and ii) whether there may be a correlation between genome type and host species, we initiated in vitro cultures from live I. uriae collected in 2017 and 2018 from marine avian hosts and their nests. Hosts included common guillemots, Atlantic Puffin, razorbill, and kittiwake. We obtained 17 novel isolates of which 10 were sequenced using Illumina technology, one also with Pacific Bioscience technology. The 10 genomes segregated into five different genome types defined by plasmid types (based on PFam32 loci). We show that the genomes of seabird associated B. garinii contain fewer plasmids (6-9) than B. garinii from terrestrial avian species (generally ≥10), potentially suggesting niche adaptation. However, genome type did not match an association with the diverse avian seabird hosts investigated but matched the clonal complex they originated from, perhaps reflecting the ...