Applied Microbiology and Beneficial Microbes

Biography

Biography: Nguyen V.U

Abstract

Diseases, such as diarrhea and/or edema disease, frequently can occur in pigs shortly after weaning pigs. Main causes are enterotoxigenic (ETEC) or verotoxigenic Escherichia coli (VTEC) expressing F18 fimbriae. Infections lead to considerable economic losses due to mortality, decreased growth rate and cost of medication. F18⁺ E. coli use their fimbriae to attach to specific receptors on the pig intestinal epithelium and produce enterotoxins (LT, STa and/or STb) and/or verotoxins (VTx2e) leading to diarrhea or edema disease, respectively. Antibiotics are routinely used to combat these infections, but due to the emergence of antimicrobial resistance, there is an urgent need for alternatives. The lab of Immunology discovered that F18⁺ E. coli specifically interacts with blood group ABH determinants on type 1 core chains (Coddens et al., 2009; PCT/EP2009/062699; INHIBITORS OF F18⁺ E COLI BINDING). Based on this fundamental discovery, we developed an anti-adhesive therapy. A high dose of the monomeric compounds (e.g. A6-1) could inhibit in vitro the binding of F18⁺ E. coli to porcine intestinal villi. Multimerization of the monomeric receptor structure could significantly enhance efficacy. The multimer was able to decrease binding in vitro with 66 % at a more than 2,500 times lower concentration than the monomeric sugar. In small intestinal perfused intestinal segments, a 10 times higher dosage than in vitro was able to prevent fluid loss (a measure of diarrhoea) due to inoculation with F18⁺ STa⁺STb⁺ ETEC.  In an in vivo experiment, this dose in feed significantly reduced the duration and height of the faecal excretion of pigs inoculated with an F18⁺ VTEC strain.