Efficacy of Green Synthesised Iron Oxide Nanoparticles against Various Uropathogens: A Cross-sectional Study

Introduction: The shoot up of antimicrobial resistance leading to the Multidrug Resistance (MDR) phenomenon in clinical pathogens has forced us to develop novel technologies to cease this global threat immediately. Iron oxide nanoparticles can be a breakthrough solution to this dilemma due to its magnetic properties and biocompatibility. Non toxic and biocompatible applications of magnetic nanoparticles can be enriched further by special surface coating with organic or inorganic molecules. Aim: To determine the antibacterial activity of green synthesised iron oxide nanoparticles against various clinical isolates. Materials and Methods: This was a cross-sectional study conducted from June 2021 to April 2022. This study was conducted at the Department of Microbiology, SRM Medical College Hospital and Research Centre (SRMMCH&RC), Kattankulathur, Chengalpattu, Tamil Nadu, India. Nanoparticles underwent surface modifications and characterisation using X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDX), Ultraviolet (UV) Visible Absorption Spectra, and Fourier-Transform Infrared Spectroscopy (FTIR) followed by charge characterisation through agarose gel electrophoresis. Kirby-Bauer Disc Diffusion method was used for screening the sensitivity and resistance pattern of 50 selected isolates and Minimum Inhibitory Concentration (MIC) was assessed using MIC Microbroth Dilution technique with the help of resazurin. Tukey post-hoc multiple comparisons test to analyse the zone of inhibition of antibacterial efficacy. Results: Out of the four different concentrations of bare and coated nanoparticles (0.0375 mg/mL, 0.07 mg/mL, 0.15 mg/mL, 0.3 mg/mL), bare nanoparticles inhibited the growth of Methicillin Resistant Staphylococcus aureus (MRSA) at 0.3 mg/mL while citrate coated nanoparticles inhibited the growth at 0.15 mg/mL, 0.018 mg/mL, 0.0375 mg/mL, 0.07 mg/mL, and 0.15 mg/mL dilutions were used in case of Carbapenem-resistant Klebsiella pneumoniae (CR K. pneumoniae) and MDR Escherichia coli, from which both organisms were inhibited at 0.15 mg/mL of bare and coated nanoparticles. Conclusion: Iron nanoparticles synthesised from the marine algae Chaetomorpha antennina could be used in the future as a drug carrier or as an antimicrobial agent.