Comparative genomics of campylobacter iguaniorum to unravel genetic regions associated with reptilian hosts
2016
Gilbert, Maarten J. | Miller, William G. | Yee, Emma | Kik, Marja | Zomer, Aldert L. | Wagenaar, Jaap A. | Duim, Birgitta
Campylobacter iguaniorum is most closely related to the species C. fetus, C. hyointestinalis, andC. lanienae. Reptiles, chelonians and lizards in particular, appear to be a primary reservoir of this Campylobacter species. Here we report the genome comparison of C. iguaniorumstrain 1485E, isolated from a bearded dragon (Pogona vitticeps), and strain 2463D, isolated froma green iguana (Iguana iguana), with the genomes of closely related taxa, in particular with reptile-Associated C. fetus subsp.Testudinum. In contrast to C. fetus, C. iguaniorum is lacking an S-layer encoding region. Furthermore, a defined lipooligosaccharide biosynthesis locus, encoding multiple glycosyltransferases and bounded by waa genes, is absent from C. iguaniorum. Instead, multiple predicted glycosylation regionswere identified inC. iguaniorum.One of these regions is>50 kb withdeviantG+Ccontent, suggesting acquisition via lateral transfer. These similar, but non-homologous glycosylation regions were located at the same position on the genome in both strains. Multiple genes encoding respiratory enzymes not identified to date within the C. fetus clade were present. C. iguaniorum shared highest homology with C. hyointestinalis and C. fetus. As in reptile-Associated C. fetus subsp.Testudinum, a putative tricarballylate catabolism locus was identified. However, despite colonizing a shared host, no recent recombination between both taxa was detected. This genomic study provides a better understanding of host adaptation, virulence, phylogeny, and evolution of C. iguaniorum and related Campylobacter taxa.
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