Activity of Biocidin^® against microbial biofilms

Biofilms-microbial communities-are present throughout the environment and interact with humans as part of the resident microbiome or when causing infection and disease. Antibiotics are commonly used to treat bacterial infections, including those due to biofilms. However, antimicrobial tolerance and resistance are common traits of these microbial communities. Resistance to antimicrobials is now widespread, and the search for alternative treatments, such as plant- or herbal-derived extracts, essential oils, and honey, is on the rise. Here, we investigated the effect of Biocidin^®, a botanical supplement, on biofilms of Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Candida albicans. A single (bolus) dose of Biocidin^® resulted in a significant decrease (> 2 Log) of biofilm and planktonic populations, while a 24-h continuous dose of 25% and 50% Biocidin^® led to a typical biphasic killing curve, with the latter concentration resulting in biofilm eradication of P. aeruginosa, S. aureus, and E. coli. Exposure to sub-inhibitory concentrations of Biocidin^® did not affect biofilm viability. Results from this work have implications for the use of Biocidin^® as a treatment for biofilm-associated infections and as a supplement in natural medicine.