THE ANTIBACTERIAL ACTIVITIES OF EUDRILUS EUGENIAE-MEDIATED BIOSYNTHESIZED SILVER NANOPARTICLES AGAINST ISOLATES FROM PATIENTS WITH DIABETIC FOOT INFECTION

Abstract

Individuals with diabetic foot infection are often infected with multidrug resistant organisms due to chronic course of wound, neuropathy and peripheral vascular disease. The antibacterial potentials of crude extract and extract mediated silver nanoparticles of Eudrilus eugeniae were investigated against isolates from patients with diabetic foot infection using agar well diffusion method. Saponins, proteins, terpenoids, phenols and steroids were detected in the crude extract and fractions. Crude ethanol, ethylacetate and aqueous fractions at 100 mg/ml and 200 mg/ml showed very weak inhibitory effect against Psuedomonas aeruginosa, Staphylococcus. aureus, Streptococcus pyogenes, Klebsiella pneumoniae and Escherichia coli. Dark brown aqueous mediated silver nanoparticles (AgNPs) were formed which gave maximum absorbance at 408 nm. The synthesized particles were spherical, less aggregated and contained alkanes, esters and alcohol functional groups. The zones of inhibition produced by the AgNPs (at 1:4 dilution) were 15.33±0.58 mm and 17.67±0.58 mm against Escherichia coli and Pseudomonas aeruginosa while at 1:5 dilution, 12.33±2.08 mm, 14.67±0.58 mm and 15.33±1.16 mm were zones of inhibition produced against Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa respectively. The MIC of the AgNPs against P. aeruginosa was at 6.12 mg/mL while it was at 12.5 mg/mL against E. coli and K. pneumoniae. The extract was bacteriostatic on the test isolates. The results of the findings showed that the extract mediated silver nanoparticles have enhanced activity against the isolates compared to the crude extract. Data generated suggest that AgNPs synthesized from E. eugeniae could be a rich source of antibacterial agent.