Antibacterial Activity of Tamarindus indica Seeds Extract on Biofilm Forming Pseudomonas aeruginosa

Abstract

Tamarindus indica L., commonly known as Tamarind tree is one of the most important multipurpose tropical fruit tree species in the Indian subcontinent, the name Tamarind comes from a Persian word "Tamar-I-hind," meaning date of India. It has numerous chemical values and is rich in phytochemicals, and hence the plant is reported to possess antidiabetic activity, antimicrobial activity, antivenomic activity, antioxidant activity, antimalarial activity, hepatoprotective activity, antiasthmatic activity, laxative activity, and anti-hyperlipidemia activity. Biofilm is an association of micro-organisms in which microbial cells adhere to each other on a living or non-living surfaces within a self-produced matrix of extracellular polymeric substance. Bacterial biofilm is infectious in nature and can results in nosocomial infections. One of these bacteria is Pseudomonas aeruginosa. Pseudomonas aeruginosais an opportunistic pathogenic bacterium responsible for both acute and chronic infections. Beyond its natural resistance to many drugs it is ability to form biofilms, a complex biological system, render ineffective the clearance by immune defense system and antibiotic therapy. This is descriptive case study conducted to determine the antimicrobial activity of different concentration of methanolic Tamarindusindica seeds extract (50μg/ml, 100μg/ml, 150μg/ml, and 200μg/ml) on biofilms forming Pseudomonas aeruginosa by using microtitre plate method. Sixty one Pseudomonas aeruginosa isolated from clinical specimens were included in this study; containing urinary tract isolates, wound infection isolates, blood isolates, eye infection isolates, otitis media isolates, respiratory tract isolates and Pseudomonas aeruginosa ATCC (27853). Different concentration of methanolic extract of Tamarindus indica seeds was tested against biofilm forming Pseudomonas aeruginosa and the result indicate that the seed extract exhibited antibacterial activity at concentration 50μg/ml mean (0.047±0.036 SD), 100μg/ml mean (0.035±0.029 SD), 150μg/ml mean (0.027±0.027 SD), 200μg/ml mean (0.020±0.023 SD) compared with zero μg/ml mean (0.049±0.034 SD). Urinary tract isolates and wound infection isolates show high antibacterial activity in concentration 100μg/ml, 150μg/ml and 200μg/ml, the mean of absorption for urinary tract isolates are (0.014±0.007 SD, 0.011±0.007 SD and 0.008±0.006 SD) respectively and the mean absorption of wound infection isolates (0.022±0.016 SD, 0.019±0.017 SD and 0.014±0.013 SD) respectively, with high statistical significant correlation (P value = 0.00) for the three concentrations. The blood isolates showed higher antibacterial activity to all concentrations of Tamarindus indica seeds extract of 50μg/ml, 100μg/ml, 150μg/ml and 200μg/ml with means(0.034±0.019 SD, 0.012±0.006 SD, 0.007±0.005 SD and 0.005±0.007 SD) respectively, with statistical significant correlation to all concentrations, P value (0.04, 0.03, 0.02 and 0.02) respectively. While eye swab isolates, otitis media isolates and respiratory tract isolates showed lowest antibacterial activity for all concentrations of Tamarindus indica seeds extract with no statistical significant correlation (P value > 0.05). Finally the absorption of Pseudomonas aeruginosa ATCC (27853) biofilm in concentration 50μg/ml, 100μg/ml, 150μg/ml and 200μg/ml were (0.050, 0.040, 0.039 and 0.023) respectively compared with zero μg/ml (0.065). This study concluded that methanolic Tamarindus indica seeds extract has antibacterial activity against biofilms forming Pseudomonas aeruginosa. The susceptibility of blood isolates of Pseudomonas aeruginosa biofilms formation were associate with all concentrations of Tamarindus indica seeds extract, while urinary tract and wound infection isolates were associate with high concentrations of Tamarindus indica seeds extract.