Antibacterial Activities of Leaf Extracts and Synthesized Silver Nanoparticles from Allium sativum on Urinary Quinolone-resistant Escherichia coli

Abstract

Aims: The study was aimed at evaluation of the antibacterial activities of crude leaf extracts and synthesized Ag-NPs from Allium sativum on urinary quinolone resistant E. coli. Study Design:  Cross sectional study. Place and Duration of Study: Department of Microbiology, Nasarawa State University, Keffi, between November 2023 and October 2024. Methodology: Confirmed Samples for this study were collected from selected General Hospitals in Abuja Municipal, Nigeria.  The phytochemical screening of the Allium sativum leaf ethanolic extract (ASE) for various phytochemical constituents and detection of AgNPs was conducted using laboratory method and other methods; UV-visible spectra, and Fourier Transform Infrared Spectroscopy (FTIR). Results: All isolates were resistant to AMP and CIP. All the E. coli isolated were MAR isolates. All the MAR isolates had MAR indices of ≥ 0.2. Most isolates were MDR isolates. There was also a PDR and XDR isolates among the selected tested E coli isolates. Phytochemical screening of aqueous, ethanolic, ethyl acetate and n-hexane leaf extracts of Allium sativum showed presence of only glycosides in all the extracts. Phenols and resins followed after as they were only absent in the aqueous extract of A. sativum leaf while tanins, steroids, saponins and pholabatanins were present in two (2) of the four (4) extract analyzed. Antibacterial activity screening of aqueous, ethanoic, ethyl acetate and n-hexane leaf extracts of Allium sativum were evaluated against quinolone resistant E. coli showed activity by only aqueous and ethanolic extracts. The ethanolic extracts were more active. Synthesized silver nanoparticles of the active extracts have shown higher antibacterial activity against the responsive isolates than their corresponding crude extracts. Conclusion: The synthesized silver nanoparticles from the active leaf extracts exhibited greater antibacterial activity against the responsive isolates compared to their corresponding crude extracts. These findings suggest that AgNPs hold potential for use in medicine to prevent both infectious and non-infectious diseases.