Campylobacter coli of porcine origin exhibits an open pan-genome within a single clonal complex: insights from comparative genomic analysis

Our analysis revealed that, in addition to having an open pan-genome, majority (63%) of the typeable isolates of <i>C. coli</i> of pig origin belonged to a single clonal complex, ST-828. The resistome of these <i>C. coli</i> isolates was predominated by the genes <i>tetO</i> (53%), <i>blaOXA-193</i> (49%), and <i>APH (3')-IIIa</i> (21%); however, the virulome analysis revealed a core set of 37 virulence genes. Analysis of the mobile genetic elements in the genomes revealed wide diversity of the plasmids and bacteriophages, while 30 transposons were common to all genomes of <i>C. coli</i> of porcine origin. Phylogenomic analysis showed two discernible clusters comprising isolates originating from Japan and another set of isolates comprising mostly copies of a type strain stored in three different culture collections.