Journal of Microbial & Biochemical Technology

Differentiation of Crohns disease-associated isolates from other pathogenic Escherichia coli by fimbrial adhesion under shear force

CO-ORGANIZED EVENT: International Conference on Chronic Diseases & 6^th International Conference on Microbial Physiology and Genomics

August 31-September 01, 2017 Brussels, Belgium

Julie Bouckaert

Université de Lille, France

Keynote: J Microb Biochem Technol

Abstract:

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. Shear stress protects Escherichia coli cells adhering to surfaces via catch bonds from detachment by soluble inhibitors present in urine. 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 fimbriaemediated bacterial adhesion. In a next stage, we plan to investigate structure-function relationships of FimH using several mannosylated protein receptors and antagonists immobilized on graphene or supplied in solution and interacting with E. coli strains under varying flow conditions.

Biography :

Julie Bouckaert is associated with Université de Lille, France. She has published several papers in reputed journals. She is committed to highest standards of excellence and is proved through her authorship of many books. Her research interests include Systems Biology, Molecular Biology and Microbiology.