Evaluation of the in Vitro Antibacterial Activity of Natural kinds of Multi-floral Honey Against Selected Gram-Positive and Gram-Negative Bacterial Strains

Abstract

The increasing emergence of antibiotic-resistant bacteria has raised concerns about the effectiveness of conventional antimicrobial therapies, prompting the search for alternative treatments. Honey, especially multifloral honey, has gained attention for its potential antibacterial properties. This study aimed to evaluate the in vitro antibacterial activity of different natural multifloral honeys against selected Gram-positive and Gram-negative bacterial strains. The antibacterial activity was evaluated using the Kirby-Bauer disc diffusion method on six bacterial strains: Gram-positive strains such as Staphylococcus aureus subsp. aureus Rosenbach ATCC®25923™, Enterococcus faecalis (Andrewes and Horder) Schleifer and Kilpper-Balz ATCC®29212™, vancomycin-susceptible Enterococcus faecalis (Andrewes and Horder) Schleifer and Kilpper-Balz ATCC®51299™, and Gram-negative strains such as Pseudomonas aeruginosa (Schroeter) Migula ATCC®27853™, Escherichia coli (Migula) Castellani and Chalmers ATCC®25922™ and Escherichia coli (Migula) Castellani and Chalmers ATCC®35218™. Honey samples were obtained from different Polish and Hungarian apiaries. The results showed that while the kinds of honey showed varying antibacterial activity degrees, some strains showed resistance, particularly Pseudomonas aeruginosa and Staphylococcus aureus. However, all the honeys tested showed significant inhibitory effects against Escherichia coli and and Enterococcus faecalis, with significant increases in the 0-zone of inhibition compared to the control groups. These results suggest that natural multi-floral kinds of honey may have promising antibacterial properties, especially against Gram-negative bacteria, and could serve as potential adjuncts to conventional antimicrobial therapies. Further research is needed to explore the specific compounds responsible for this antibacterial activity and its clinical implications.