The Efficacy of AgNO3 Nanoparticles Alone and Conjugated with Imipenem for Combating Extensively Drug-Resistant Pseudomonas aeruginosa.

The extensive drug-resistant (XDR) Pseudomonas aeruginosa (P. aeruginosa) causes a range of infections with high mortality rate, which inflicts additional costs on treatment. The use of nano-biotechnology-based methods in medicine has opened a new perspective against drug-resistant bacteria. The aim of this study was to evaluate the effectiveness of the AgNO3 nanoparticles alone and conjugated with imipenem (IMI) to combat extensively drug-resistant P. aeruginosa. Antibiotic susceptibility was carried out using disc diffusion method. Detection of different resistant genes was performed using standard polymerase chain reaction (PCR). The chemically synthesized AgNO3 particles were characterized using scanning electron microscope (SEM), dynamic light scattering (DLS) and X-ray diffraction (XRD) methods. Fourier transform infrared spectroscopy (FTIR) was accomplished to confirm the binding of AgNO3 with IMI. The microdilution broth method was used to obtain minimum inhibitory concentration (MIC) of AgNO3 and IMI-conjugated AgNO3. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay was carried out on L929 cell line to study the cytotoxicity of nanoparticles. The data were analyzed by Eta correlation ratio and chi-square (X 2) test. Analysis of the antibiotic resistance pattern showed that 12 (24%) isolates were XDR, and MIC values of IMI were between 64 and 128 μg/mL. Frequency of SHV, TEM, CTX M, IMP, VIM, OPR, SIM, SPM, GIM, NDM, VEB, PER, KPC, OXA, intI, intII, and intIII genes were 29 (58%), 26 (52%), 26 (52%), 32 (64%), 23 (46%), 43 (86%), 3 (6%), 6 (12%), 3 (6%), 4 (8%), 7 (14%), 6 (12%), 18 (36%), 4 (8%), 19 (38%), 16 (32%), and 2 (4%), respectively. The XRD, SEM, DLS, and FTIR analysis confirmed the synthesis of AgNO3 nanoparticles and their conjugation with IMI. The AgNO3 nanoparticles had antimicrobial activity, and their conjugation with IMI showed enhanced effectiveness against XDR isolates. The synthesized AgNO3 showed no cytotoxic effects. The results suggest that IMI-conjugated AgNO3 has a strong potency as a powerful antibacterial agent against XDR P. aeruginosa.