In vitro study to elucidate the antibacterial effect of silver nanoparticles against multidrug resistant Pseudomonas aeruginosa / Athirah Nur Amirulhusni Alshukor

The antimicrobial activities of silver have been well known since ancient history. However, the effects of this compound against resistant organism have not been well explored. Multi drug resistant organisms have been taunting the medical world for the last few decades. Even with newly developed antibiotics, new resistant strains emerge soon after in many cases which leads to complications in treatment regiments. Colloidal silver was synthesized by adding an excess of the reducing agent NaBHi to AgNO3 which reduced the ionic silver into nanoparticle state. Optical characterization of the silver nanoparticles was done using UV-VIS spectroscopy and the particle size was analyzed using scanning electron microscope. Silver nanoparticles of spherical shape, 30 to 70 nm of size was successfully produced. We investigated silver in the form of nanoparticles for its antimicrobial activity against resistant strains of Pseudomonas aeruginosa. This organism is one of the most common multi drug resistant, opportunistic pathogens, contributing to the high morbidity and mortality in immune-compromised patients. Five strains of multi-drug resistant P. aeruginosa were selected from patients in Hospital Selayang, Malaysia as samples for this study. Antibacterial activity was evaluated by disc diffusion method, broth microdilution method and biofilm inhibition assay.