Effects of heparosan and heparin on the adhesion and biofilm formation of several bacteria in vitro

Bacterial adhesion to intestinal mucus and epithelia are important for individual stability of microbial flora. Here we studied the effects of heparosan and heparin on the adhesion and biofilm formation of a Lactobacillus rhamnosus strain and several selected pathogens in vitro. Results indicated that both heparosan and heparin blocked the adhesion of tested Escherichia coli, Pasteurella multocida, Staphylococcus aureus strains, but did not block the adhesion of L. rhamnosus to enterocytes and mucus. Both heparosan and heparin had no significant effect on the biofilm formation of S. aureus, while heparin promoted the biofilm formation of L. rhamnosus. The increase of biofilm formation might be related to the negative charge of heparin, since no biofilm formation was observed when chitosan was present. This study provides evidence, for the first time, that heparosan can serve as an effective blocker in inhibiting adhesion of pathogens.