Evaluation of Antibacterial Activity of Two Different Honeys Against Clinical Isolates of β-hemolytic Streptococci Group A

Abstract

Introduction: Aim of this investigation was to evaluate in vitro antibacterial activity of horse chestnut honey and acacia honey at different concentrations against clinical isolates of β-hemolytic streptococci group A (BHS-A). Honey’s active compounds have multiple therapeutic effects and it is used as traditional medicine for treatment and prevention of various illnesses.

Materials and methods: Antimicrobial effect of two honeys were tested on forty four strains of BHS-A isolated from throat by modified disk diffusion method. A bacterial suspension of BHS-A strains was plated onto Müller-Hinton agar with 5% defibrinated horse blood. Using a sterile 8 mm diameter cork borer, wells were cut in the agar and into each was introduced 100µL of the different concentrations of the honey solution (25 %v/v, 50 %v/v, 75% v/v and 100%v/v). Disk of penicillin was added as the positive control. The plates were incubated aerobically during 18-24 hours at 36 (± 1) °C and zones of inhibition were mesaured.

Results: The average diameter of the inhibition zones of acacia honey (100 %v/v) was 12.48mm±1.73mm, for acacia honey (75 %v/v)was 11.06mm±1.24 mm and for horse chestnut honey (100 %v/v) was 11.08mm±1.02mm. Positive control showed the average diameter of 30.45mm ±3.21mm. Statistically significance (p < 0.05) was observed comparing the zone diameters of the acacia honey (100%) and antibiotic penicillin, and between horse chestnut honey (100%) and antibiotic penicillin.

Conclusion: Acacia and horse chestnut honeys have small, but effective antibacterial activity onto clinical isolates of BHS-A.

Key words: antibacterial activity, acacia honey, horse chestnut honey, beta-hemolytic streptococci group A