Genomic variations define divergence of water/wildlife-associated Campylobacter jejuni niche specialists from common clonal complexes.
Bottom Line: Studies employing multilocus sequence typing have indicated that some clonal complexes are more commonly associated with particular sources.By genome sequencing one representative of this diverse group (C. jejuni 1336), and a representative of the bank-vole niche specialist ST-3704 (C. jejuni 414), we identified deletions of genomic regions normally carried by human food-chain-associated C. jejuni.We suggest that the genomic divergence observed constitutes evidence of adaptation leading to niche specialization.
Affiliation: Institute of Infection and Global Health Institute of Integrative Biology National Centre for Zoonosis Research, University of Liverpool, Liverpool L69 3GA, UK.Show MeSH
Related in: MedlinePlus
Mentions: A dendrogram based on phylogenomic cluster analysis of the CGH data revealed that strains generally clustered according to clonal complex, and there was no clear evidence for subdivisions according to isolate source within the clonal complexes (Fig. 1). Most strikingly, the eight WW group isolates included in the study formed a distinct clade. In addition, strain 414, representing ST-3704, was also genetically distinct from the food-chain-associated clonal complexes, clustering between the WW group and C. coli isolates (Fig. 1). It was clear from the CGH data that the separation of WW/ST-3704 isolates was due to a number of genes or gene clusters where deletion or divergence was apparent (Fig. 1). Regions of divergence or deletions associated with the WW/ST-3704 isolates are listed in Table S2 (PH01–PH15). The distribution of nine regions of divergence, which included the virulence-associated cytolethal distending toxin (cdt) genes (Dorrell et al., 2001; Taboada et al., 2004; Parker et al., 2006), is shown in Fig. 1. The regions chosen for inclusion in the figure are those generally conserved among clonal complexes commonly associated with isolates from human infections, but highly diverse among the WW/ST-3704 isolates.
Affiliation: Institute of Infection and Global Health Institute of Integrative Biology National Centre for Zoonosis Research, University of Liverpool, Liverpool L69 3GA, UK.