ANTIBACTERIAL ACTIVITY OF EXTRACTS OF CAMELLIA SINESIS (GREEN TEA) AND CALOTROPIS PROCERA (GIANT INDIAN MILK WEED) AGAINST MULTI DRUG RESISTANT WOUND ISOLATES

Abstract

The global emergence of multidrug resistant bacteria such as Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, and Pseudomonas aeruginosa caused by their resistance mechanisms to the existing drugs requires effective newer antimicrobial agents. This research evaluated the Antibacterial Activity of Extracts of Camellia sinesis (Green Tea) and Calotropis procera (Giant Indian Milk Weed) against Multi Drug Resistant Wound Isolates. The crude and fractionated leaf extracts were obtained using maceration and liquid-liquid fractionation method respectively. Phytochemical screening of the crude extracts was also done. Wound samples were collected from the inpatients of the Hospital. Pure cultures were obtained using streaking method. Conventional antibiotics were used for Antibiotic Susceptibility Test (AST) of the isolates via disc diffusion method. Multi Drug Resistant Wound Isolates were further subjected to crude and fractionated extracts via Agar well diffusion method. Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) were performed using broth macrodilution assay. Acute and sub-acute toxicity studies were also conducted. Calotropis procera had the highest percentage (%) yield of 14.15 % followed by Camellia sinesis (6.26 %). A total of nineteen (19) wound isolates were obtained and identified, out of which twelve (12) were Multi Drug Resistant (MDR) Bacteria. Aqueous fraction of Calotropis procera had the highest yield of 5.85 grams which could be responsible for the antibacterial activity recorded in most of the isolates and Camellia sinesis had the least value of 3.60grams. The combined extracts at varied concentrations using ratio 1:1 had the highest zone of inhibition on Enterococcus spp. (16.00±1.15 mm) at the concentration of 550mg/ml followed by Pseudomonas aeruginosa>Staphylococcus epidermidis>Enterobacter cloacae. Klebsiella pneumoniae were resistant to the combined extracts. The MIC value ranges from 275-100 mg/mL with Enterococcus spp showing the least. The extracts were bactericidal on all isolates. The LD50 of the extracts was above 5000 mg/kgbw and the subacute toxicity study revealed mortality in the 1000 mg/kgbw/day group on week 2 and week 4 which responsible for the significant differences (p<0.05) in the values recorded in the biochemical and haematological tests conducted on the 1000 mg/kgbw/day group as compared to the control, 200 and 600 mg/kgbw/day groups. Result obtained suggests that these plants are potent against the Multi drug resistant wound isolates with repeated dose not higher than 600 mg/kgbw/day. Hence, the plants can serve as a new therapeutic agent to kill these microorganisms.