BMC infectious diseases
Antibacterial activity of imipenem-encapsulated chitosan/HPMCP nanoparticles against clinical Acinetobacter baumannii isolates
By Alizadeh S, Baseri Salehi M and Bahador N.
Abstract
Background
Multidrug-resistant Acinetobacter baumannii is an important healthcare-associated pathogen, necessitating therapeutic strategies. This study evaluates the antibacterial efficacy of imipenem-encapsulated chitosan/hydroxypropyl methylcellulose phthalate (Imp-Chi) nanoparticles against clinical A. baumannii isolates.
Methods
A. baumannii clinical isolates (n = 105) from hospitalized patients were characterized for antibiotic resistance via broth microdilution and classified as MDR, XDR, or PDR. An exploratory PCR screen was performed for the selected AmpC-family genes mox, cit, and dha. Imp-Chi nanoparticles were synthesized via ionic gelation, characterized for size, zeta potential, morphology, encapsulation efficiency, and drug release. Antibacterial activity was assessed via MIC assays against the A. baumannii clinical isolates. Recoverable bacterial burden in extracellular, cell-associated, and intracellular fractions of A549 and NCI-H292 infection models was quantified, alongside reactive oxygen species (ROS) and cytotoxicity assessments using MTT and LDH assays.