ABSTRACTCampylobacter jejuniandCampylobacter coliare the most common causes of bacterial gastroenteritis in the world. Ganglioside mimicry byC. jejunilipooligosaccharide (LOS) is the triggering factor of Guillain-Barré syndrome (GBS), an acute polyneuropathy. Sialyltransferases from glycosyltransferase family 42 (GT-42) are essential for the expression of ganglioside mimics inC. jejuni. Recently, two novel GT-42 genes,cstIVandcstV, have been identified inC. coli. Despite being present in ∼11% of currently availableC. coligenomes, the biological role ofcstIVandcstVis unknown. In the present investigation, mutation studies with two strains expressing eithercstIVorcstVwere performed and mass spectrometry was used to investigate differences in the chemical composition of LOS. Attempts were made to identify donor and acceptor molecules usingin vitroactivity tests with recombinant GT-42 enzymes. Here we show that CstIV and CstV are involved inC. coliLOS biosynthesis. In particular,cstVis associated with LOS sialylation, whilecstIVis linked to the addition of a diacetylated nonulosonic acid residue.IMPORTANCEDespite the fact thatCampylobacter colia major foodborne pathogen, its glycobiology has been largely neglected. The genetic makeup of theC. colilipooligosaccharide biosynthesis locus was largely unknown until recently.C. coliharbors a large set of genes associated with lipooligosaccharide biosynthesis, including genes for several putative glycosyltransferases involved in the synthesis of sialylated lipooligosaccharide inCampylobacter jejuni. In the present study,C. coliwas found to express lipooligosaccharide structures containing sialic acid and other nonulosonate acids. These findings have a strong impact on our understanding ofC. coliecology, host-pathogen interaction, and pathogenesis.
Whole genome-based characterisation of antimicrobial resistance and genetic diversity in Campylobacter jejuni and Campylobacter coli from ruminants
