Genetic and chemical differentiation ofCampylobacter coliandCampylobacter jejunilipooligosaccharide pathways

Abstract

ABSTRACTDespite the importance of lipooligosaccharides (LOS) in the pathogenicity of campylobacteriosis, little is known about the genetic and phenotypic diversity of LOS inC. coli. In this study, we investigated the distribution of LOS locus classes among a large collection of unrelatedC. coliisolates sampled from several different host species. Furthermore, we pairedC. coligenomic information and LOS chemical composition for the first time to identify mechanisms consistent with the generation of LOS phenotypic heterogeneity. After classifying three new LOS locus classes, only 85% of the 144 isolates tested were assigned to a class, suggesting higher genetic diversity than previously thought. This genetic diversity is at the basis of a completely unexplored LOS structure heterogeneity. Mass spectrometry analysis of the LOS of nine isolates, representing four different LOS classes, identified two features distinguishingC. coliLOS fromC. jejuni’s. GlcN-GlcN disaccharides were present in the lipid A backbone in contrast to the GlcN3N-GlcN backbone observed inC. jejuni. Moreover, despite that many of the genes putatively involved in Qui3pNAcyl were absence in the genomes of various isolates, this rare sugar was found in the outer core of allC. coli. Therefore, regardless the high genetic diversity of LOS biosynthes is locus inC. coli, we identified species-specific phenotypic features ofC. coliLOS which might explain differences betweenC. jejuniandC. coliin terms of population dynamics and host adaptation.Depositories (where applicable)The whole genome sequences ofC. coliare publicly available on the RAST server (http://rast.nmpdr.org) with guest account (login and password ‘guest’) under IDs: 195.91, 195.96-195.119, 195.124-195.126, 195.128-195.130, 195.133, 195.134, 6666666.94320