Evaluation of antimicrobial and antibiofilm activities of stingless bee Trigona honey (Malaysia) against Streptococcus pneumoniae

Background: The study aims to evaluate the antibacterial activity of Trigona honey against S. pneumonia. Methods: The effect of Trigona honey on S. pneumonia investigated using agar well diffusion, MIC, MBC, biofilm formation and RT-qPCR. Results: Trigona honey samples showed the larger zones of inhibition against S. pneumonia, 22.2±0.4 at 100% concentration. Trigona honey possessed the lowest MIC, MBC, MIC50 and MIC90 against S. pneumoniae, 25%, 30%, 12.5% and 25% (w/v) respectively. Trigona honey permeated established biofilms of S. pneumonia, resulting in significant decreased the cells from the biofilm. RT-qPCR revealed that the expression of genes amiF, ftsY, mvaS, pnpA, argG, mvd1, purN, miaA and pbp2a were upregulated, glcK, marR, prmA and ccpA­­­ were downregulated after exposure to honey. Conclusion: Trigona honey demonstrated the highest antibacterial activity against S. pneumoniae. By limiting study in vitro on Trigona honey, we infer that Trigona honey impacts on S. pneumoniae.