Comprehensive analysis of flagellin glycosylation inCampylobacter jejuniNCTC 11168 reveals incorporation of legionaminic acid and its importance for host colonization

Abstract

Campylobacter jejuni is the leading cause of bacterial gastroenteritis. It relies on several virulence factors for host colonization, including glycosylated flagella. C. jejuni NCTC 11168 modifies its flagellins with pseudaminic acid derivatives. It is also presumed to modify these proteins with legionaminic acid, although no glycopeptide evidence was available at the onset of this study. The enzyme encoded by cj1319 can be used to make legionaminic acid in vitro, but the pathway for legionaminic acid synthesis partially inferred by knockout mutagenesis in Campylobacter coli VC167 excludes Cj1319. To address this contradiction, we examined the presence of legionaminic acid in flagellin glycopeptides of wild-type (WT) C. jejuni NCTC 11168 and of a cj1319 knockout mutant. We used high-energy collision-induced dissociation to obtain amino acid sequences while also visualizing signature sugar oxonium ions. Data analysis was performed with PEAKS software, and spectra were manually inspected for glycopeptide determination and verification. We showed that legionaminic acid is present on the flagellins of C. jejuni NCTC 11168 and that flagellin glycosylation is highly heterogeneous, with up to six different sugars singly present at a given site. We found that the cj1319 mutant produces more legionaminic acid than WT, thus excluding the requirement for Cj1319 for legionaminic acid synthesis. We also showed that this mutant has enhanced chicken colonization compared with WT, which may in part be attributed to the high content of legionaminic acid on its flagella.

Temperature-Dependent Gene Expression in Yersinia ruckeri: Tracking Specific Genes by Bioluminescence During in Vivo Colonization

“…This cluster is only present in Y. ruckeri serotype O1 ( Welch and LaPatra, 2016 ; Cascales et al, 2017 ), and vaccination with a strain carrying a deletion of the second gene of the cluster encoding for the nab2 gene, a nonulosonic acid biosynthesis gene ( nab gene), resulted in absence of protection against yersiniosis infection, showing the importance of this cluster for ERM bacterin vaccine efficiency ( Welch and LaPatra, 2016 ). According to this and to data reported from other bacteria such as Legionella pneumophila ( Lüneberg et al, 1998 ) and Campylobacter jejuni ( Zebian et al, 2016 ), it is possible that legionaminic acid is involved in the virulence of Y. ruckeri . Additional selected genes related to the cellular wall were an O -acyltransferase and a polysaccharide deacetylase which are probably involved in peptidoglycan biosynthesis.…”

Leishmania-Derived Trimannose Modulates the Inflammatory Response To Significantly Reduce Leishmania major-Induced Lesions

“…lycoconjugate cell surface molecules of many pathogens are often key virulence factors that promote pathogen survival (1)(2)(3)(4)(5). Antigen glycosylation has become increasingly recognized as a critical component of immune modulation by pathogens (6)(7)(8)(9).…”

The Infection Process of Yersinia ruckeri: Reviewing the Pieces of the Jigsaw Puzzle

“…Thus, a cluster of 18 genes related to the biosynthesis of legionaminic acid, the major component of the LPS, was exclusively present in serotype O1 strains. This cluster was absent in serotype O2 strains as well as in other Yersinia species, but present in different aquatic pathogenic bacteria such as Vibrio vulnificus, Aeromonas salmonicida, Vibrio fischeri (Cascales et al, 2017 ) and also in Campylobacter jejuni , where it is involved in virulence (Zebian et al, 2016 ). In addition to this cluster, serotype O1 strains share a total of 268 genes, among which are the invasin and the type IV secretion system corresponding with the traHIJKCLMN operon (Méndez et al, 2009 ).…”