ANTIBACTERIAL ACTIVITIES OF LEECH SALIVARY EXTRACT-MEDIATED SILVER NANOPARTICLES AGAINST SOME PATHOGENIC BACTERIA

Abstract

Leech salivary extract (LSE) and its salivary extract-mediated silver nanoparticles (LSE-Ag) were screened for its antibacterial activities against Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus and Klebsiella species using agar well diffusion method. The activity was compared with augmentin. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of LSE-Ag were assayed using micro broth dilution method with tetrazolium dye as indicator. The LSE-Ag was biologically synthesized and characterized by ultraviolet spectroscopy and a nanosizer. The wavelength of the LSE-Ag was set at 456 nm while the size was at 98.04 nm. The crude LSE was inactive on all the test isolates while the LSE-Ag inhibited the growth of P. aeruginosa with zones of inhibition of 8.3 ± 0.88 mm and 12.3 ± 0.88 mm at 100 μL and 200 μL respectively and Klebsiella sp with the zones of inhibition of 12.0 ± 0.57 mm and 12.3 ± 0.33 mm at 100 μL and 200 μL respectively. The MIC of LSE-Ag was at 100 μL for P. aeruginosa and Klebsiella sp., while the MBC for both organisms were at 200 μL. Staphylococcus aureus and E. coli were resistant to the LSE-Ag. The results obtained in this study suggest that LSE-Ag could be used in treating infectious diseases caused by Pseudomonas aeruginosa and Klebsiella species.