A Preliminary Study on the Evaluation of In-vitro Inhibition Potential of Antimicrobial Efficacy of Raw and Commercial Honey on Escherichia coli: An Emerging Periodontal Pathogen.

Periodontitis, a multiple pathogen disease has the latest addition to the family i.e. Escherichia coli as a potential and emerging periodontal pathogen owing to its lipopolysaccharide more potent than Porphyromonas gingivalis, which makes it an emerging threat in periodontal disease. The role of antimicrobial agents in the management of periodontal diseases is of utmost importance. However, in the present scenario, antibiotic resistance is a public health concern now and there are very few options left for treatment. So, honey, a pioneer in traditional medicine was tried in the treatment against Escherichia coli to evaluate and compare the "in-vitro" antibacterial activity and efficacy of raw and commercial honey at different concentrations in comparison to tetracycline as a control on patient-isolated Escherichia coli and the American Type Culture Collection (ATCC) Escherichia coli 25922 strain from 5th Aug 2018 to 15th Feb 2019 at the Department of Microbiology, Rama Medical College, Kanpur (UP), India. In the in-vitro study different concentrations (100%, 75%, 50% and 25% v/v) of raw and commercial honey were studied and sensitivity tests were used to evaluate their antibacterial effect on patient-isolated Escherichia coli and the ATCC Escherichia coli 25922 strain. Minimum inhibitory concentration (MIC) and Minimum bactericidal concentration (MBC) were also determined for raw honey, and commercial honey in comparison to tetracycline. In case of raw honey, zone of inhibition was seen at 100%, 75% and 50% concentration, with maximum inhibition being 27±1.154mm and 23±0.666mm for patient-isolated Escherichia coli and ATCC Escherichia coli 25922 strain respectively at 100% concentration, whereas, the commercial honey was effective only at 100% and 75% concentration, with maximum inhibition zone of 13±1.054mm and 17±0.942mm at 100% concentration on patient-isolated Escherichia coli and ATCC Escherichia coli 25922 strain respectively. However, no effect was observed at 25% concentration for both raw and commercial honey. The MIC and MBC of raw and commercial honey were determined by the broth dilution method, where raw honey exhibited both MIC and MBC at 512 mg/ml whereas, and commercial honey exhibited MIC at 512mg/ml and MBC at 1024 mg/ml respectively. While comparing the zone of inhibition of raw and commercial honey, it was observed that the raw honey showed almost equivalent potency and efficacy as compared to a positive control tetracycline (2.5%). There was statistically significant difference (p≤0.01) in zone of inhibition of raw and commercial honey at 100% concentration on patient-isolated Escherichia coli and ATCC Escherichia coli 25922 strain. Antimicrobial activity of raw honey at 100% concentration was equivalent to that of tetracycline and was significantly better than commercial honey.