Antibacterial Susceptibility of Klebsiella pneumoniae Isolates from Respiratory Tract Infections to Honey and Lemon

Aims: To assess the effectiveness of lemon and/or honey on some causative agents of Respiratory Tract Infections, Isolation and identification of some infectious bacteria of respiratory tract infections, Collection of pure honey and lemon fruits, Determination of the inhibitory activities of honey, lemon and honey/lemon mixture at varied concentrations on the bacterial isolates by agar diffusion and broth dilution techniques, Evaluation of the rate of kill of the bacterial isolates by the agents (honey and lemon) and Comparative analysis of the susceptibility pattern of the bacterial isolates to the honey and lemon separately and in combination.
Study Design: Isolation, identification and antibiotic susceptibility determination of the test Klebsiella pneumoniae isolates, Zones of inhibition, Minimum Inhibitory and Bactericidal Concentrations and Rate of kill determination.
Place and Duration of Study: Department of Pharmaceutics and Pharmaceutical Microbiology, Ahmadu Bello University Teaching Hospital (A. B. U. T. H.), Zaria, University Hospital Services (U. H. S.) Samaru Campus Ahmadu Bello University (A. B. U.), Zaria, between March 2012 and April 2013.
Methodology: Agar well diffusion and broth dilution methods were employed to ascertain degree of susceptibility of the isolates to honey and/or lemon, and the standard antibiotics. Minimum Inhibitory Concentrations and Minimum Bactericidal Concentrations were carried out. Rate of Kill was also carried out to know the death/survival rate of the bacterial isolates after exposure to the agents.
Results: Mean zones of inhibition (mm) of 14-32 (Ceftriaxone), 7-27 (Gentamicin), 8-35 (Amoxicillin-Clavulanic acid), 12-27 (Levofloxacin), 7-21 (Azithromycin), 10-23 (100% v/v Honey), 10-24 (100% v/v Lemon), and 19-26 (Honey/Lemon mixture) were obtained. However, the Minimum Inhibitory Concentrations range between 1.95-125 µg/ml (Ceftriaxone), 1.56-100 µg/ml (Gentamicin), 3.91-125 µg/ml (Amoxicillin-Clavulanic acid), 0.98-15.6 µg/ml (Levofloxacin), 3.13-100 µg/ml (Azithromycin), 20-65 µg/ml v/v (Honey), 15-35 µg/ml v/v (Lemon), 15-35 µg/ml (Honey/Lemon mixture). Furthermore, for the rate of kill; Lemon, Honey and Lemon mixture (20 µg/ml) effected complete killing at 120 minutes and 240 minutes respectively. Therefore, it was observed that lemon, honey and lemon mixture, Ceftriaxone, Levofloxacin and Gentamicin showed higher antibacterial activity. While Amoxicillin-Clavulanic acid and Azithromycin had less antibacterial activity. At P-value P≥0.05 there is significant difference between Honey and Lemon mixture and Honey, but not with lemon.
Conclusion: It was observed that lemon, honey and lemon mixture, Ceftriaxone, Levofloxacin and Gentamicin showed higher antibacterial activity. While Amoxicillin-Clavulanic acid and Azithromycin had less antibacterial activity. Better bactericidal activity was observed with Lemon and the mixture of Honey and Lemon than the Honey alone. This research therefore scientifically approves the use of Honey and Lemon as an alternative medicine by the populace in the treatment of respiratory tract infections.