Anti‐biofilm Activity of Human Milk Oligosaccharides in Clinical Strains of Streptococcus agalactiae with Diverse Capsular and Sequence Types

Abstract

AbstractGroup B Streptococcus (GBS) is an encapsulated Gram‐positive bacterial pathogen that causes severe perinatal infections. Human milk oligosaccharides (HMOs) are short‐chain sugars that have recently been shown to possess antimicrobial and anti‐biofilm activity against a variety of bacterial pathogens, including GBS. We have expanded these studies to demonstrate that HMOs can inhibit and dismantle biofilm in both invasive and colonizing strains of GBS. A cohort of 30 diverse strains of GBS were analyzed for susceptibility to HMO‐dependent biofilm inhibition or destruction. HMOs were significantly effective at inhibiting biofilm in capsular‐type‐ and sequence‐type‐specific fashion, with significant efficacy in CpsIb, CpsII, CpsIII, CpsV, and CpsVI strains as well as ST‐1, ST‐12, ST‐19, and ST‐23 strains. Interestingly, CpsIa as well as ST‐7 and ST‐17 were not susceptible to the anti‐biofilm activity of HMOs, underscoring the strain‐specific effects of these important antimicrobial molecules against the perinatal pathogen Streptococcus agalactiae.