title: Identification of hyperinvasive Campylobacter jejuni strains isolated from poultry and human clinical sources.
abstract: Campylobacter jejuni causes gastroenteritis with a variety of symptoms in humans. In the absence of a suitable animal model, in vitro models have been used to study virulence traits such as invasion and toxin production. In this study, 113 C. jejuni isolates from poultry and poultry-related (n=74) environments as well as isolates from human cases (n=39) of campylobacteriosis and bacteraemia were tested for invasiveness using INT 407 cells. The method was sufficiently reproducible to observe a spectrum of invasiveness amongst strains. As a result, strains were classified as low, high and hyper-invasive. The majority of strains (poultry and human) were low invaders (82 % and 88 %, respectively). High invasion was found for 5 % of human strains and 11 % of poultry-related isolates. However, only 1 % of poultry strains were classified as hyperinvasive compared to 13 % of human isolates (P=0.0182). Of those isolates derived from the blood of bacteraemic patients, 20 % were hyperinvasive, though this correlation was not statistically significant. An attempt was made to correlate invasiveness with the presence of seven genes previously reported to be associated with virulence. Most of these genes did not correlate with invasiveness, but gene cj0486 was weakly over-represented, and a negative correlation was observed for the gene ciaB. This trend was stronger when the two genes were analysed together, thus ciaB(-) cj0486(+) was over-represented in high and hyperinvasive strains, with low invaders more commonly found to lack these genes (P=0.0064).
authors.affiliation: Veterinary Laboratories Agency (Weybridge), Surrey KT15 3NB, UK.
authors.forename: Catherine
authors.initials: C
authors.lastname: Fearnley
authors.affiliation: School of Science and Technology, Nottingham Trent University, NG11 8NS, UK.
authors.forename: Georgina
authors.initials: G
authors.lastname: Manning
authors.affiliation: Veterinary Laboratories Agency (Weybridge), Surrey KT15 3NB, UK.
authors.forename: Mary
authors.initials: M
authors.lastname: Bagnall
authors.affiliation: School of Science and Technology, Nottingham Trent University, NG11 8NS, UK.
authors.forename: Muhammad Afzal
authors.initials: MA
authors.lastname: Javed
authors.affiliation: Molecular Microbiology and Genomics Consultants, Zotzenheim, Germany.
authors.forename: Trudy M
authors.initials: TM
authors.lastname: Wassenaar
authors.affiliation: Veterinary Laboratories Agency (Weybridge), Surrey KT15 3NB, UK.
authors.forename: Diane G
authors.initials: DG
authors.lastname: Newell
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D002169:Campylobacter Infections / Q000382:microbiology*; D016123:Campylobacter jejuni / Q000145:classification* / Q000235:genetics / Q000472:pathogenicity; D045744:Cell Line, Tumor; D002645:Chickens / Q000382:microbiology*; D002988:Cloaca / Q000382:microbiology; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology; D005798:Genes, Bacterial; D006799:Housing, Animal; D006801:Humans; D011201:Poultry Diseases / Q000382:microbiology*; D014774:Virulence
chemical_list: D001426:Bacterial Proteins