In vitro antibacterial activity of honey against clinical isolates of beta-hemolytic streptococci group A

Introduction: Honey is one of the traditional medicines used for treatment and prevention of various illnesses. Its active compounds show multiple therapeutic effects. Aim: To evaluated in vitro antibacterial activity of horse chestnut honey and acacia honey at different concentrations against clinical isolates of Beta-hemolytic streptococci group A(BHS-A). Materials and methods: Forty four clinical isolates of BHS-A from throat swab were evaluated. A bacterial suspension of BHS-A strains was coated onto Muller-Hinton agar. 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 examined for zones of inhibition. 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±1.24mm 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 significant difference (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: In this study, in order to evaluate the antibacterial activity of two honey varieties (acacia honeyand horse chestnut honey) onto clinical isolates of BHS-A, we concluded that honeys have small, but effective antibacterial activity.