Abstract

MICROBIAL MEDIATED SILVER NANOPARTICLES BY PSEUDOMONAS AERUGINOSA AND THEIR POTENT ANTIBACTERIAL ACTIVITY IN COMBINATION WITH COMMERCIAL ANTIBIOTICS

*Thangapandiyan S.

ABSTRACT

Nowadays the study of microbial mediated nanomaterials offers a valuable contribution to nanobiotechnology. In this regard, the current study has been aimed to fabricate silver nanoparticles (AgNPs) and to evaluate its bactericidal effect in combination with commercial antibiotics. Microbial mediated silver nanoparticles were prepared by reducing Ag+ ions with the culture supernatant of Pseudomonas aeruginosa. The resulting silver nanoparticles were characterized by UV, AFM, XRD and EDS analysis. The antibacterial activity of silver nanoparticles demonstrated that Staphylococcus aureus (14.50 ± 0.14 mm) was found to be more susceptible among the tested strains. Combinatorial effect of antibiotics with silver nanoparticles revealed that there is an enhancement in the bactericidal activity. The greatest enhancement was observed against Vibrio vulnificus (33.58%) followed by Staphylococcus aureus (20.13%), Bacillus cereus (17.48%) and Klebsiella pneumoniae (16.33%). Results obtained from the present study suggested that combining antibiotics and microbial mediated AgNPs can be used therapeutically for the treatment of infectious diseases caused by both gram-positive and gram-negative bacterial strains.

Keywords: Silver nanoparticles, antibacterial activity, combinatorial effect, inhibition zone, fold increase.