In-vitro antimicrobial activity of selected honeys on clinical isolates of Helicobacter pylori.

BACKGROUND: Helicobacter pylori is a gram-negative bacterium incriminated in gastroduodenal ulcers, and mucosa-associated lymphoid tissue lymphoma imposing a major burden on health care systems worldwide. Honeys have been shown to have in vitro activity against microorganisms and suitable for use in ulcers, infected wounds and burns.
OBJECTIVE: The study was aimed at evaluating the antimicrobial potential of honeys (Manuka™, Capillano®, Eco- and Mountain) at different concentrations (10%v/v, 20%v/v, 50%v/v and 75%v/v) against clinical isolates of H. pylori.
METHODS: H. pylori was isolated from gastric biopsies of patients with gastroduodenal pathologies following standard microbiological procedures. Antimicrobial susceptibility of the isolates to different honey varieties was determined by the disk diffusion assay. Also, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the most potent honey was determined by the agar dilution method. Data were analysed using the Fisher exact test and statistical significance considered at p<0.05.
RESULTS: All the four honey varieties exhibited antibacterial activity. The strongest inhibitory activity (82.22%) was demonstrated by Mountain honey at 75%v/v, followed by Capillano® and Manuka™ honeys (75.56%), and Eco-honey (73.36%) at the same concentration. However, no statistically significant difference (p>0.05) was noted between the honeys at different concentrations. The MIC and MBC concentrations of Mountain honey were in the range 0.117 - 0.938ì/mL and 0.366 - 2.965ìg/mL respectively. The antimicrobial potential of these honeys at different concentrations were highly comparable to clarithromycin, the positive control.
CONCLUSION: These honeys may contain compounds with therapeutic potential against our local isolates of H. pylori.