The antimicrobial activities of processed Nigerian and South African black tea

The antibacterial activity of processed Nigerian Lipton Tea and South African 5 Roses Tea, extracted using distilled water, chloroform and 70% ethanol were determined against nine (9) enteropathogenic bacteria which includes; Bacillus subtilis, Proteus sp, Enterobacter sp., Klebsiella pneumoniae, Escherichia coli, Salmonella typhi, Salmonella paratyphi A, Salmonella arizona and Staphylococcus aureus. The 2 tea bags, Nigerian Lipton tea bag and the South African 5 Roses tea bag were extracted through Solvent extraction method using 3 extraction solvents; Distilled water, Chloroform and 70% Ethanol and then inoculated onto the Mueller-Hinton agar plates containing the standard isolates at 6 different points on each plate. The zones of inhibition of the bacterial isolates produced by each of these tea - extracts were determined while meaningful antibacterial activities against five (5) of the standard isolates; Enterobacter sp., K. pneumoniae, S. paratyphi A, B. subtilis and S. aureus were observed. Lipton tea water-extract was a more effective antibacterial agent than water-extract of 5 Roses tea. While the 70% ethanol-extract of 5 Roses tea had the greatest antibacterial activity of all the different tea-extract used for the study, the chloroform-extracts of the tea bags had no antimicrobial effect on all the test organisms used.