In vitro study of the antimicrobial property of Green tea extract against standard (ATCC) bacterial strains and clinical isolates of Methicillin Resistant Staphylococcus aureus & Multidrug Resistant Pseudomonas aeruginosa

Abstract

Objective: To evaluate the antimicrobial activity of Aqueous Green Tea extract against Standard ATCC Strains (Staphylococcus aureus ATCC 25923, Escherichia coli 25922, Pseudomonas aeruginosa 27853) & Clinical Isolates of Methicillin Resistant Staphylococcus aureus (MRSA) & Multidrug Resistant Pseudomonas aeruginosa (MDRPA). Methods: This Cross-sectional Analytical study was conducted in the Department of Microbiology of a Teaching Tertiary care hospital of Central India over a period of two months after obtaining Ethical clearance. Antimicrobial activity of green tea extract was determined by Agar well diffusion method. Results & Interpretation: The results of this study has shown that the aqueous extract of Green tea exhibits a potent antibacterial activity. Inhibition Zone diameter of green tea extract at lowest concentration (12.5 mg/ml) was 8mm, 10mm & 10mm respectively for ATCC strains of E.coli, Pseudomonas aeruginosa & Staphylococcus aureus. However at highest concentration (200mg/ml) it was 20mm, 22mm & 26mm respectively. Amongst six MRSA isolates tested aqueous green tea extract exhibited significant antibacterial activity against five isolates. Amongst six MDRPA isolates tested even at lowest concentration of 12.5 mg/ml aqueous green tea extract showed appreciable antimicrobial activity against four isolates. Conclusion: Aqueous extract of Green tea (Camellia sinensis) prepared by cold extraction method do have a significant antibacterial activity not only against standard ATCC bacterial strains but also against highly resistant clinical isolates of MRSA & MDRPA. Keywords: Camellia sinensis, Green Tea extract, Methicillin Resistant Staphylococcus aureus (MRSA), Multidrug Resistant Pseudomonas aeruginosa (MDRPA), Agar well diffusion, Inhibition zone diameter