The Beneficial Effects of Stingless Bee Kelulut Honey Against Pseudomonas aeruginosa and Streptococcus pyogenes Planktonic and Biofilm doi.org/10.26538/tjnpr/v5i10.15

Abstract

Kelulut honey (KH) is produced by the stingless bees from Trigona species and has strong antibacterial activity and is useful medically and therapeutically. The purpose of this study was o investigate the antibacterial and antibiofilm activities of KH against Pseudomonas aeruginosa and Streptococcus pyogenes. Biofilms were cultivated in microtiter plates with and without a range of concentrations of KH, and effects on biofilm were monitored by optical density (at 570 nm), biomass (by staining with crystal violet), metabolic activity (using an  sterase assay) and viability (by determining total cell counts). Structural effects on planktonic and established biofilms were examined by scanning electron microscopy (SEM). KH was found to disrupt microcolony formation in both bacteria at sublethal concentration of KH. The lowestconcentration of KH found to prevent biofilm formation was 19% (w/v), whereas on average, 35.7% (w/v) of KH was required to inhibit established biofilms. Susceptibility was not differed with length of biofilm establishment between 24 and 72 hours. SEM analysis revealed marked changes in the bacterial cell morphology for both bacteria following treatment with KH. Extensive structural changes and loss of biofilm structure were seen in the sample after exposure to KH using scanning electron microscopy. Using a range of methods to evaluate planktonic and biofilm integrity, the results indicate that KH inhibits both bacteria planktonic and biofilm in vitro.