In vitro study on the efficacy of silver nanoparticles against metallo-betalactamase and biofilm producing pseudomonas aeruginosa isolates

Metallo beta-lactamase (MBL) and biofilm production is the most worrisome resistant mechanisms observed in Pseudomonas aeruginosa. Increased resistance of Pseudomonas to antibiotic therapy is an emerging global health concern which can be overcomed by Silver nanoparticles (AgNPs). Therefore this study aims to evaluate the antibacterial and antibiofilm activity of Silver nanoparticles on MBL and biofilm producing P. aeruginosa isolates using Transmission Electron microscope (TEM) and Confocal laser scanning microscope (CLSM) respectively. A total 40 isolates of p. aeruginosa were screened for MBL production by combined disc test. Then the isolates were screened for biofilm forming ability by tissue culture plate assay. Commercially available Silver nanoparticles were obtained and tested against MBL and biofilm producing isolates. The antibacterial activity of AgNps was tested by MIC and MBC methods and by TEM. The CLSM results exhibited AgNPs concentration dependent inhibition of bacterial growth and EPS matrix of the biofilm. Therefore, AgNps serve as the next generation antimicrobials in protection against the biofilm mediated infections. It is suggested that coating of medical devices with silver nanoparticles is recommended for treatment of resistant bacterial infections.