Rhamnolipid-involved antibiotics combinations improve the eradication of Helicobacter pylori biofilm in vitro: A comparison with conventional triple therapy

Abstract Antibiotics resistance of H. pylori has been increasing constantly accompanied with decreasing clearance rate clinically, which is demonstrated to be closely related to biofilms with higher resistance than planktonic bacteria for the dense extracellular polymeric substances. Rhamnolipid (RHL) is proved to not only damage the structure of biofilm, but also potentially inhibit bacterial adhesion. To investigate if RHL could promote eradicating rate of the conventional triple therapy to H. pylori biofilm and hence attenuate the resistance and relapse of H. pylori , first-line antibiotics clarithromycin (CLR), amoxicillin (AMX) or/and proton pump inhibitor (PPI) involved single, dual or triple therapies were compared with RHL-containing drug combinations on eradicating H. pylori biofilm. The residual biofilm biomass, the survival of bacteria inside the remaining biofilm and the planktonic bacteria dispersed from the biofilm after treatment were tested. Combination with RHL significantly improved the ability of antibiotics to eradicate H. pylori biofilm, especially RHL combined with AMX and PPI could eradicate more than 95% of biofilm showing much more effective ability than the conventional triple therapy CLR + AMX + PPI. Additionally, the combination of RHL and antibiotics could effectively inhibit the biofilm formation at lower concentration. Thus, RHL might be used as a potential antibiotic adjuvant on anti- H. pylori therapy to enhance eradicating ability of antibiotics to biofilms.