Comparison of the Antimicrobial Effects of Manuka Honey, Local Honey, Sugar, Molasses and Silkworm Sericins on Commonly Isolated Wound Microbes

Abstract

Study Background: Proper wound management is continually challenged by the almost inevitable installation of bacterial infection with subsequent poor prognosis and a spike in treatment costs. Despite advances in infection management using antibiotic-treated wound dressings, increased antibiotic resistance still offers a huge barrier. With the slow progress in the innovation of novel antibiotics that would otherwise overcome this challenge, the use of natural antibacterial agents such as honey, sugar and molasses offer an alternative. These agents are additionally easily available and affordable. They also seem to improve quality of patient care in the setting of chronic wounds since they are non-adherent and result in minimal pain and discomfort during change of dressing. However, comparison of their antimicrobial efficacy remains under-explored, especially in the local African and more so in the Kenyan setting despite the aforementioned. Broad Objective: To compare the antimicrobial effects of manuka honey, local honey, sugar, sugarcane molasses and silkworm sericins on commonly isolated wound microbes. Study Design: Controlled quasi-experimental laboratory study. Study Site: Kenyatta National Hospital Microbiology Department and the Microbiology Department, University of Nairobi. Participants and Methods: Bacterial and fungal isolates from KNH and UON Microbiology Department were randomly grouped into 6 study groups: Manuka honey, local honey, sugar, sugarcane molasses, silkworm sericins, and controls. Pure cultures were obtained on nutrient agar and Sabouraud Dextrose agar. McFarland standard solutions were prepared, and 100 microliters were transferred to culture bottles with test samples and controls. After incubation and streaking, MIC and MBC were determined by serial dilutions on agar plates. Findings were recorded on data collection sheets. Data Management: Data was analyzed using SPSS version 25.0. Normality was assessed using the Shapiro-Wilk test, histograms, box plots, and Q-Q plots. Skewed data led to the use of medians and non-parametric tests. The Chi-square test compared growth rates, while the Kruskal-Wallis test examined growth rate type and presence. A p-value ≤0.05 indicated significance. Results: Different growth patterns were observed with Silk Sericin and Molasses. Molasses showed increased susceptibility compared to Silk Sericin, with 64% growth of Pseudomonas versus 92% in Silk Sericin. Local honey had inferior antimicrobial effect compared to Manuka honey, with 12% growth observed versus no growth, respectively, for Pseudomonas. xiv Significant differences in antimicrobial susceptibility were found among the three organisms (p=0.000 for Pseudomonas, Staphylococcus, and Candida). Manuka honey and Local honey showed potent antimicrobial effects, while Molasses and Silk Sericin exhibited moderate effects. Sugar had the weakest antimicrobial effect. Conclusions: Manuka honey and Local honey are effective against pseudomonas, staphylococcus aureus, and candida. Molasses and Silk Sericin have moderate effects, while sugar has weak antimicrobial effects. Honey-based products could be valuable natural antimicrobials for wound management, including drug-resistant infections. Our recommendation is that Local honey may be routinely used for chronic and infected wounds not responding to conventional therapy