title: The AIDA autotransporter system is associated with F18 and stx2e in Escherichia coli isolates from pigs diagnosed with edema disease and postweaning diarrhea.
abstract: Pathogenic Escherichia coli strains are known to cause edema disease (ED) and postweaning diarrhea (PWD) in piglets. Although the exact mechanisms of pathogenicity that lead to ED-PWD remain to be elucidated, E. coli-borne Shiga-like toxin and adhesion-mediating virulence factors such as F18 adhesin or F4 fimbriae are believed to play a central role in ED-PWD. In light of these observations we investigated whether another E. coli adhesin, the plasmid-encoded AIDA (adhesin involved in diffuse adherence) might also be present in ED-PWD-causing E. coli isolates. For rapid screening for the AIDA system in large numbers of isolates, a multiplex PCR method along with a duplex Western blot procedure was developed. When screening 104 strains obtained from pigs with or without ED-PWD, we observed a high prevalence of the AIDA operon in porcine E. coli isolates, with over 25% of all strains being AIDA positive, and we could demonstrate a significant association of the intact AIDA gene (orfB) with ED-PWD, while defects in orfB were associated with the absence of disease. Although our data hint toward a contribution of AIDA to ED-PWD, further studies will be necessary since the presence of the AIDA genes was also associated with the presence of the Shiga-like toxin and F18 adhesin genes, two reported virulence factors for ED-PWD.
authors.affiliation: Institut für Infektiologie, Zentrum für Molekularbiologie der Entzündung, Westfälische Wilhelms-Universität, Münster, Germany.
authors.forename: U
authors.initials: U
authors.lastname: Niewerth
authors.forename: A
authors.initials: A
authors.lastname: Frey
authors.forename: T
authors.initials: T
authors.lastname: Voss
authors.forename: C
authors.initials: C
authors.lastname: Le Bouguénec
authors.forename: G
authors.initials: G
authors.lastname: Baljer
authors.forename: S
authors.initials: S
authors.lastname: Franke
authors.forename: M A
authors.initials: MA
authors.lastname: Schmidt
mesh_terms: D018830:Adhesins, Escherichia coli / Q000235:genetics*; D000818:Animals; D000942:Antigens, Bacterial; D001426:Bacterial Proteins / Q000235:genetics*; D015153:Blotting, Western / Q000379:methods; D003967:Diarrhea / Q000382:microbiology / Q000662:veterinary*; D004488:Edema Disease of Swine / Q000382:microbiology*; D004926:Escherichia coli / Q000235:genetics* / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000382:microbiology / Q000662:veterinary*; D029968:Escherichia coli Proteins; D036781:Fimbriae Proteins; D005798:Genes, Bacterial; D008040:Genetic Linkage; D014644:Genetic Variation; D009876:Operon; D016133:Polymerase Chain Reaction / Q000379:methods; D012703:Serotyping; D022641:Shiga Toxin 2 / Q000235:genetics*; D013552:Swine; D013997:Time Factors
chemical_list: C075559:AIDA-I protein, E coli; D018830:Adhesins, Escherichia coli; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D022641:Shiga Toxin 2; C080952:DaaE protein, E coli; D036781:Fimbriae Proteins