Inhibition ofStreptococcus pyogenesbiofilm byLactiplantibacillus plantarumandLacticaseibacillus rhamnosus

Abstract

AbstractThe human pathobiontStreptococcus pyogenesforms biofilms and causes invasive infections, such as pharyngotonsillitis and necrotizing fasciitis. Bacterial biofilms are more resilient to antibiotic treatment and new therapeutic strategies are needed to control biofilm-associated infections, such as recurrent pharyngotonsillitis.Lactiplantibacillus plantarumandLacticaseibacillus rhamnosusare two bacterial commensals used for their probiotic properties. This study aimed to elucidate the anti-biofilm properties ofL. plantarumandL. rhamnosuscell-free supernatants (LPSN and LRSN, respectively) onS. pyogenesbiofilms grownin vitroin supplemented minimal medium. When planktonic or biofilmS. pyogeneswere exposed to LPSN or LRSN,S. pyogenessurvival was reduced significantly in a concentration-dependent manner and the effect was more pronounced on preformed biofilms. Enzymatic digestion of LPSN and LRSN suggested that glycolipid compounds might cause the antimicrobial effect. In conclusion, this study indicates thatL. plantarumandL. rhamnosusproduce glycolipid bioactive compounds that reduceS. pyogenesviability in planktonic and biofilm cultures.