Prevalence of Carbapenem Resistance and Antibacterial Potential of Nanoparticles in Pseudomonas aeruginosa Isolated from Burn Units in Egypt

Abstract

Background: Pseudomonas aeruginosa is an opportunistic microorganism and quite frequently associated with skin infections. Biosynthesized silver nanoparticles can be a promising key to eliminate these microbes. Objectives: The current work aims to identify P. aeruginosa carrying metallo-β-lactamase from burn infections and assess the impact of silver nanoparticles and antibiotics on them. Methods: A total of 120 samples collected from patients suffering from burn wound infections were subjected to conventional microbiological techniques to identify P. aeruginosa isolates. Testing for antimicrobial susceptibility was conducted utilizing the Kirby Bauer disc diffusion method. Carbapenemase-producing strains were detected both phenotypically by detecting metallo-beta-lactamases through performing modified carbapenem inactivation method (mCIM) and genotypically using PCR. Using the agar well diffusion method, AgNPs' antibacterial activity was assessed. The synergistic effect of a combination of antimicrobials (colistin, gentamicin, and ciprofloxacin) and AgNPs was estimated by the checkerboard method. Results:Out of 120 isolates, 46 (38%) P. aeruginosa isolates were identified and confirmed by PCR assay. Total 25 isolates (54%) were multidrug resistant isolates. Modified carbapenem inactivation method showed that 39 isolates (84.78%) were producing carbapenemases whereas 35 isolates (76%) were confirmed for carbapenemases by performing PCR. The prevalence of carbapenemase encoding genes was as follows blaSPM (14%), blaVIM (25.7%), blaNDM (40%), blaKPC (2.85%) and blaIMP (17%). Conclusions: P. aeruginosa isolates showed high-level carbapenem resistance. The majority of the isolates were multi drug resistant (MDR), indicating a concerning spread of resistant isolates. AgNPs exhibited considerable antibacterial effects, so they should be considered as an effective means of combating MDR.