Adhesion properties of enterococci to intestinal mucus of different hosts

The adhesive capacity of selected enterococci to human, canine and porcine intestinal mucus was investigated in order to select for potential probiotic strains with good adhesive properties for human or animal use. The adhesion to the human intestinal mucus of the tested strains was found to range from log10 3.8 to log10 8.6 cfu per microtitre plate well. The highest adhesion to the human intestinal mucus was found among strains from horse faeces, dog faeces and dog feed. The adhesion to canine mucus was observed to range from log10 3.8 to log10 8.3 cfu/well, with the highest adhesive capacity among strains from dog faeces, horse faeces and dog's feed; on average log10 7.9, 7.3 and 7.0 cfu/well, respectively. Isolates from dogs did not bind at higher levels to canine mucus than to human mucus. A strong correlation was observed for the adhesion to human and canine intestinal mucus (p < 0.0001) and also between porcine and canine or human mucus (p < 0.05 for both). When comparing the adhesion of Enterococcus faecium and E. faecalis, no statistical significant differences were observed for any of the tested mucus types. The tested Enterococcus strains were found to exhibit a strain dependent on in vitro adhesion to human, canine and porcine intestinal mucus and did not exhibit host specificity in their adhesion, though some sources appeared to contain more adhesive strains than others. To our knowledge, this is the first report on the in vivo adhesion to intestinal mucus of a large number of enterococci from different sources.