Epidemiological association of Campylobacter jejuni groups with pathogenicity-associated genetic markers

Abstract

BackgroundCampylobacter jejuni, the most leading cause for bacterial gastroenteritis worldwide, shows a high genetic diversity among its isolates. Recently, we demonstrated the existence of six C. jejuni-groups by combining MLST with six genetic markers. These groups were further characterized by the detection of cj1321-cj1326, fucP, cj0178, cj0755/cfrA, ceuE, pldA, cstII, and cstIII in order (I.) to show further associations between these different genetic markers and MLST CCs. Moreover, different studies were able to associate several of these markers: a sialylated lipoologosaccharide (cstII/III+), the gamma-glytamyl-transpeptidase (ggt+), and the absence of a certain allele of the enterochelin-uptake-binding-protein (ceuE11168-) with severe campylobacteriosis, bloody diarrhea and unpleasant outcome. Additionally more than half of human Campylobacter-isolates were assigned to a non-livestock clade associated with the absence of cj1321-cj1326. These isolates were considered as mere colonizers.From the combination of marker genes, the ratio of human isolates in a specific group, and clinical data (II.) it should be demonstrated to which of the previous defined groups these Campylobacter-subpopulations, associated with higher virulence, correspond.ResultsBesides the marker gene pldA, all new estimated genetic markers show significant differences in their distribution among the various MLST-based groups. Especially the genes for cj1321-cj1326, fucP, cj0178, cj0755/cfrA are widely associated with each other and split the study population into two major and seven intermediate groups substantiating the previous group-definition, whereas cstII and cstIII indicate at least three groups following an independent distribution pattern.ConclusionsBased on these data a group of C. jejuni-isolates characterized by the presence of ansB, dmsA, ggt, and the absence of cj1365c, cj1585c, cj1321-cj1326, fucP, cj0178, cj0755/cfrA, and cstII/III was associated with a higher prevalence in human campylobacteriosis, bloody diarrhea as well as hospitalization and bears obviously a higher virulence for humans. In contrast to that better livestock-adapted groups characterized by the ability to utilize L-fucose and the presence of all of the five identified putative C. jejuni iron-uptake systems as well as cj1321-cj1326, cj1365c, cj1585c, and cstII and/or cstIII (sialylated lipoologosaccharide) is more prevalent in animal hosts and was secondary associated with less severe campylobacteriosis.

Campylobacter sequence typing databases: applications and future prospects

“…What is perhaps extraordinary is that so much has been learned about the epidemiology, pathogenesis and population biology of these organisms from the highly diverse seven MLST and three AGST loci, corresponding to a tiny fraction of the genome: this is presumably a reflection of the extensive genetic structuring of Campylobacter populations, evidenced by the correlation of MLST data with whole-genome sequences and hybridization studies (Hepworth et al, 2011;Lang et al, 2010;Taboada et al, 2008;Zautner et al, 2011). The association of particular genotypes with given phenotypes presumably reflects an important role of selectiondriven adaptation to particular niches in the emergence of these types (Sheppard et al, 2011b).…”

Association of Campylobacter jejuni Metabolic Traits with Multilocus Sequence Types

“…It has been proposed that explorations of the divergence in metabolic traits could yield new insights into colonization requirements and pathogenicity (9,12,18). Indeed, diversity in various secondary metabolic traits among isolates is evident (11,18,40). While the use of amino acids, including serine, proline, aspartate, and glutamic acid, by C. jejuni isolates as energy sources has been demonstrated (2,12,18,24,38), only some isolates are able to metabolize glutamine, asparagine (17), and L-fucose (28,36).…”

“…Previously, we demonstrated that the presence of ggt was associated with the host source of the isolates (10), and recently, Zautner et al (40) showed that ggt and ansB(s) were strongly associated with certain MLSTs and clonal complexes (29).…”

Is theCampylobacter jejunisecretory protein Cj0069 a suitable antigen for serodiagnostics?

“…For cj0036, cj0069 and cj0125c, PCR analysis confirmed broad presence (results not shown) in genetic diverse C. jejuni isolates (the genetic diversity of these isolates was known from a preliminary study [34]). A colony blot assay after successful cloning and transformation of the three genes with an anti-hexa-histidine-tag antibody (results not shown) revealed that the proteins Cj0036, Cj0069 and Cj0125c were expressed in most of the transformants.…”