Antibacterial Activity of Ginger (Zingiber officinale) Against Isolated Bacteria from the Respiratory Tract Infections

Abstract

This study was designed to investigate the bacteria found in association with respiratory tract infections (RTI) and the susceptibility of such bacteria to aqueous and methanolic extracts of Zingiber officinale (ginger). Bacteriological studies were carried out on sputum from 110 patients, made up of 57 males and 53 females, aged 24-80 years, attending Chest Clinic at Ekiti State University Teaching Hospital Ado-Ekiti in the year 2013. Seventeen bacteria species namely Luteococcus  sanguinuis, Corynebacterium accolens,  Vibrio fluvialis, Serratia ficaria, Enterobacter aerogenes, Staphylococus aureus, Pasteurella pneumotropica, Aeromonas caviae, Vibrio mimicus, Vibrio parahaemolyticus, Pleisomonas shigelloides, Pseudomonas aeruginosa, Citrobacter youngae, Chromobacterium violaceum, Luteococcus pertonei, Actinomyces radicidentis and Klebsiella  pneumoniae were isolated from the sputum specimens. Klebsiella pneumoniae, Corynebacterium accolens, Aeromonas caviae and Luteococcus sanguinis were commonly isolated from both sexes. Enterobacter aerogenes, Vibrio parahaemolyticus, Luteococcus peritonei, Citrobacter youngae, Pleisomonas shigelloides and Serratia ficaria were isolated mainly from male patients while Staphylococcus aureus, Pseudomonas aeruginosa, Vibrio fluvialis, Vibrio mimicus, Citrobacter  youngae and Chromobacterium violaceum were isolated from female patients. The bacteria showed a high degree of resistance to the antibiotics used. All the Gram positive bacteria were resistant to cloxacillin, augmentin and tetracycline, with varied resistance to erythromycin (85%), streptomycin (68.75%) and cotrimoxazole (75%). The gram negative bacterial isolates were all resistant to augmentin, tetracyclin and amoxicillin, but were all susceptible to ofloxacin. All the bacteria tested were susceptible to both aqueous and the methanol extracts of ginger, but with higher susceptibility of bacteria to methanolic extract than the water extract. The phytochemical analysis of the ginger extracts indicated that the methanolic extract possessed phenolics, saponin, tannin and flavonoids, but no glycoside detected. On the other hand only cardiac glycoside, out of the 5 phytochemicals, was detected from the aqueous extract of ginger.

Key words: Antimicrobial Activity, Ginger, Respiratory Tract Infection