title: Virulence characteristics of translocating Escherichia coli and the interleukin-8 response to infection.
abstract: Four efficiently translocating Escherichia coli (TEC) strains isolated from the blood of humans (HMLN-1), pigs (PC-1) and rats (KIC-1 and KIC-2) were tested for their ability to adhere and translocate across human gut epithelial Caco-2 and HT-29 cells, to elicit a proinflammatory response and for the presence of 47 pathogenic E. coli virulence genes. HMLN-1 and PC-1 were more efficient in adhesion and translocation than rat strains, had identical biochemical phenotype (BPT) and serotype (O77:H18) and phylogenetic group (D). KIC-2 adhered more than KIC-1, belonged to different BPT and serotype but the same phylogenetic group as KIC-1. TEC strains elicited significantly higher IL-8 response in both cell lines (P < 0.05) and monocytic THP-1 (P < 0.0001) cells than non-TEC strains. KIC-2 induced the highest IL-8 response which may be associated with its immunostimulatory flagellin. Apart from adhesin genes fimH and bmaE that were carried by all strains, HMLN-1 and PC-1 carried capsule synthesis gene kpsMT III and KIC-2 carried the EAST1 toxin gene. The lack of known virulence genes and the ability of TEC to efficiently adhere and translocate whilst causing proinflammatory response suggests that these strains may carry as yet unidentified genes that enable their translocating ability.
authors.affiliation: Faculty of Science, Health and Education, University of the Sunshine Coast, Maroochydore DC, Queensland, Australia. nlr003@student.usc.edu.au
authors.forename: Nubia L
authors.initials: NL
authors.lastname: Ramos
authors.forename: Agaristi
authors.initials: A
authors.lastname: Lamprokostopoulou
authors.forename: Toni A
authors.initials: TA
authors.lastname: Chapman
authors.forename: James C
authors.initials: JC
authors.lastname: Chin
authors.forename: Ute
authors.initials: U
authors.lastname: Römling
authors.forename: Annelie
authors.initials: A
authors.lastname: Brauner
authors.forename: Mohammad
authors.initials: M
authors.lastname: Katouli
mesh_terms: D000818:Animals; D001422:Bacterial Adhesion; D018988:Bacterial Translocation; D018938:Caco-2 Cells; D004926:Escherichia coli / Q000145:classification / Q000235:genetics / Q000472:pathogenicity* / Q000502:physiology*; D004927:Escherichia coli Infections / Q000276:immunology / Q000382:microbiology* / Q000662:veterinary*; D019073:HT29 Cells; D006801:Humans; D016209:Interleukin-8 / Q000235:genetics / Q000276:immunology*; D008969:Molecular Sequence Data; D010802:Phylogeny; D051381:Rats; D012376:Rodent Diseases / Q000276:immunology / Q000382:microbiology; D013552:Swine; D013553:Swine Diseases / Q000276:immunology / Q000382:microbiology; D014774:Virulence; D037521:Virulence Factors / Q000235:genetics / Q000276:immunology
chemical_list: D016209:Interleukin-8; D037521:Virulence Factors