A strain of Enterococcus faecium (18C23) inhibits adhesion of enterotoxigenic Escherichia coli K88 to porcine small intestine mucus

Few studies, if any, have addressed the adhesion of enterococci to the inte stinal mucosa and their interference with the adhesion of pathogens, althou gh more than 60% of probiotic preparations in the market contain strains of enterococci, The objective of this study was to investigate if Enterococcu s faecium 18C23 has the ability to inhibit the adhesion of Escherichia coil K88ac and K88MB to the small intestine mucus of piglets. Approximately 9% of E. faecium 18C23 organisms adhered to the small intestine mucus, and the adhesion was found to be specific. Living E. faecium 18C23 culture efficie ntly inhibited the adhesion of E, coil K88ac and K88MB to the piglet intest ine mucus. Inhibition of the adhesion of E. coli K88ac to the small intesti ne mucus was found to be dose dependent. Inhibition of >90% was observed wh en 10(9) CFU or more of living E, faecium 18C23 culture per mi was added si multaneously with E, coil to immobilized mucus. The substances from both th e 18C23 cells and the spent culture supernatant contributed to the inhibiti on of adhesion of E. coil K88 to the small intestine mucus receptors, The i nhibiting effect was not solely a pH effect since considerable inhibitory a ction was demonstrated after neutralizing the mixture or spent culture supe rnatant to pH 7.0. Part of the inhibition of adhesion of E, coil K88ac by E , faecium 18C23 or its supernatant might occur through. steric hindrance.