Antimicrobial and Antibiofilm Potential of PEGylated Chitosan-Based Nano-Antibiotics Against Multidrug-Resistant E Coli Strains

Abstract

Antibiotic resistance is a major public health burden in the contemporary world, imposing high levels of mortality, morbidity, and financial losses annually. Escherichia coli is a widespread food and waterborne pathogen causing severe ailments. In the current study, chitosan (CS) and polyethylene glycol (PEG) based hybrid nanosystems were developed and their intrinsic and synergistic (with antibiotics) antibacterial activity was assessed against multidrug-resistant E. coli strains. Enteropathogenic (EPEC) and enterotoxigenic (ETEC) strains of E. coli exhibited resistance against multiple classes of antibiotics. PEGylated CS nanosystems demonstrated higher encapsulation efficiency for ciprofloxacin (61.3 ± 0.76%), compared to ceftriaxone encapsulation (49.4 ± 0.52%). Scanning electron microscopy revealed a smooth surface and homogenous distribution of void and loaded nanosystems.  Fourier Transform Infrared Spectroscopy (FTIR) spectra indicated no new chemical bonding and change in functional groups therefore it can be said antibiotics were successfully incorporated into the nanosystems by electrostatic interactions. Growth kinetics and colony forming unit (CFU) assay revealed restored activity of antibiotics encapsulated in hybrid PEGylated CS nano-conjugates against resistant E. coli strains. Furthermore, PEGylated CS hybrid nanosystems with intrinsic activity effectively curbed the biofilm formation in EPEC and ETEC strains. For future biopharmaceutical manufacturing, we propose that PEGylated CS hybrid nanosystems can be a potential therapy against resistant E. coli and biofilm-associated chronic illnesses.