title: Epidemiological association of Campylobacter jejuni groups with pathogenicity-associated genetic markers.
abstract: BACKGROUND
  Campylobacter 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 (ceuE(11168)(-)) 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.
  
  
  RESULTS
  Besides 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.
  
  
  CONCLUSIONS
  Based 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.
authors.affiliation: Universitätsmedizin Göttingen, Abteilung für Medizinische Mikrobiologie, Germany. azautne@gwdg.de
authors.forename: Andreas E
authors.initials: AE
authors.lastname: Zautner
authors.forename: Carolin
authors.initials: C
authors.lastname: Ohk
authors.forename: Abdul Malik
authors.initials: AM
authors.lastname: Tareen
authors.forename: Raimond
authors.initials: R
authors.lastname: Lugert
authors.forename: Uwe
authors.initials: U
authors.lastname: Gross
mesh_terms: D000818:Animals; D002169:Campylobacter Infections / Q000453:epidemiology* / Q000382:microbiology / Q000662:veterinary*; D016123:Campylobacter jejuni / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity*; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000235:genetics; D005798:Genes, Bacterial; D005819:Genetic Markers; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D017720:Molecular Epidemiology; D058885:Multilocus Sequence Typing; D015995:Prevalence; D037521:Virulence Factors / Q000235:genetics*
chemical_list: D004269:DNA, Bacterial; D005819:Genetic Markers; D037521:Virulence Factors