Differentiation of Crohn’s Disease-Associated Isolates from Other Pathogenic Escherichia coli by Fimbrial Adhesion under Shear Force

Sabine Szunerits (1) , Oleksandr Zagorodko , Virginie Cogez (2) , Tetiana Dumych (2) , Thibaut Chalopin (3) , Dimitri Alvarez Dorta , Adeline Sivignon (4) , Nicolas Barnich (5) , Anne Harduin-Lepers (2) , Iban Larroulet , Aritz Yanguas Serrano , Aloysius Siriwardena (6) , Amaia Pesquera , Amaia Zurutuza , Sébastien G. Gouin (3) , Rabah Boukherroub (7, 1) , Julie Bouckaert (2)

1 IEMN - Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520
2 UGSF - Unité de Glycobiologie Structurale et Fonctionnelle - UMR 8576
3 CEISAM - Chimie Et Interdisciplinarité : Synthèse, Analyse, Modélisation
4 M2iSH - Microbes, Intestin, Inflammation et Susceptibilité de l'Hôte
5 MICA - Département Microbiologie et Chaîne Alimentaire
6 LG2A - Laboratoire de Glycochimie, des Antimicrobiens et des Agro-ressources - UMR CNRS 7378
7 IRI - Institut de Recherche Interdisciplinaire [Villeneuve d'Ascq]

Shear force exerted on uropathogenic Escherichia coli adhering to surfaces makes type-1 fimbriae stretch out like springs to catch on to mannosidic receptors. This mechanism is initiated by a disruption of the quaternary interactions between the lectin and the pilin of the two-domain FimH adhesin and transduces allosterically to the mannose-binding pocket of FimH to increase its affinity. Mannose-specific adhesion of 14 E. coli pathovars was measured under flow, using surface plasmon resonance detection on functionalized graphene-coated gold interfaces. Increasing the shear had important differential consequences on bacterial adhesion. Adherent-invasive E. coli, isolated from the feces and biopsies of Crohn's disease patients, consistently changed their adhesion behavior less under shear and displayed lower SPR signals, compared to E. coli opportunistically infecting the urinary tract, intestines or loci of knee and hip prostheses. We exemplified this further with the extreme behaviors of the reference strains UTI89 and LF82. Whereas their FimA major pilins have identical sequences, FimH of LF82 E. coli is marked by the Thr158Pro mutation. Positioned in the inter-domain region known to carry hot spots of mutations in E. coli pathotypes, residue 158 is indicated to play a structural role in the allosteric regulation of type-1 fimbriae-mediated bacterial adhesion.

Mots clés: adherent-invasive Escherichia coli; shear force; surface plasmon resonance; graphene; heptyl α-D-mannose

Domaines: Biochimie, Biologie Moléculaire

Sabine Szunerits, Oleksandr Zagorodko, Virginie Cogez, Tetiana Dumych, Thibaut Chalopin, et al.. Differentiation of Crohn’s Disease-Associated Isolates from Other Pathogenic Escherichia coli by Fimbrial Adhesion under Shear Force. Biology, 2016, 5 (2), ⟨10.3390/biology5020014⟩. ⟨hal-01741244⟩