Comparative Genomics of Campylobacter fetus from Reptiles and Mammals Reveals Divergent Evolution in Host-Associated Lineages

Maarten J. Gilbert, William G. Miller, Emma Yee, Aldert L. Zomer, Linda van der Graaf-van Bloois, Collette Fitzgerald, Ken J. Forbes, Guillaume Méric, Samuel K. Sheppard, Jaap A. Wagenaar, Birgitta Duim

Research output: Contribution to journalArticle

15 Citations (Scopus)
4 Downloads (Pure)

Abstract

Campylobacter fetus currently comprises three recognized subspecies, which display distinct host association. Campylobacter fetus subsp. fetus and C fetus subsp. venerealis are both associated with endothermic mammals, primarily ruminants, whereas C fetus subsp. testudinum is primarily associated with ectothermic reptiles. Both C. fetus subsp. testudinum and C. fetus subsp. fetus have been associated with severe infections, often with a systemic component, in immunocompromised humans. To study the genetic factors associated with the distinct host dichotomy in C. fetus, whole-genome sequencing and comparison of mammal- and reptile-associated C fetus was performed. The genomes of C fetus subsp. testudinum isolated from either reptiles or humans were compared with elucidate the genetic factors associated with pathogenicity in humans. Genomic comparisons showed conservation of gene content and organization among C fetus subspecies, but a clear distinction between mammal- and reptile-associated C fetus was observed. Several genomic regions appeared to be subspecies specific, including a putative tricarballylate catabolism pathway, exclusively present in C fetus subsp. testudinum strains. Within C fetus subsp. testudinum, sapA, sapB, and sapAB type strains were observed. The recombinant locus iamABC (mlaFED) was exclusively associated with invasive C fetus subsp. testudinum strains isolated from humans. A phylogenetic reconstruction was consistent with divergent evolution in host-associated strains and the existence of a barrier to lateral gene transfer between mammal- and reptile-associated C fetus Overall, this study shows that reptile-associated C fetus subsp. testudinum is genetically divergent from mammal-associated C fetus subspecies.

Original languageEnglish
Pages (from-to)2006-2019
Number of pages14
JournalGenome biology and evolution
Volume8
Issue number6
Early online date22 Jun 2016
DOIs
Publication statusPublished - Jun 2016

Keywords

  • campylobacter fetus
  • reptile
  • mammal
  • comparative genomics
  • recombination
  • evolution

Fingerprint Dive into the research topics of 'Comparative Genomics of Campylobacter fetus from Reptiles and Mammals Reveals Divergent Evolution in Host-Associated Lineages'. Together they form a unique fingerprint.

  • Cite this

    Gilbert, M. J., Miller, W. G., Yee, E., Zomer, A. L., van der Graaf-van Bloois, L., Fitzgerald, C., Forbes, K. J., Méric, G., Sheppard, S. K., Wagenaar, J. A., & Duim, B. (2016). Comparative Genomics of Campylobacter fetus from Reptiles and Mammals Reveals Divergent Evolution in Host-Associated Lineages. Genome biology and evolution, 8(6), 2006-2019. https://doi.org/10.1093/gbe/evw146