Antimicrobial Activity of Metal-Based Danofloxacin Complexes Against Pathogenic Microorganisms.

Area of Science:

• Veterinary Medicine
• Medicinal Chemistry
• Antimicrobial Research

Background:

• Fluoroquinolone antibiotics, such as danofloxacin, are vital in veterinary medicine due to their broad-spectrum antibacterial efficacy and favorable pharmacology.
• Widespread use of fluoroquinolones has led to increasing microbial resistance, posing a significant global health concern.
• Development of novel antimicrobial agents is crucial to combat resistance and enhance treatment efficacy in veterinary applications.

Purpose of the Study:

• To synthesize and characterize novel silver and copper complexes of the fluoroquinolone antibiotic danofloxacin.
• To evaluate the antimicrobial activity of these metal-based danofloxacin complexes against key veterinary bacterial and fungal strains.
• To assess the cytotoxicity of the novel complexes toward eukaryotic cells.

Main Methods:

• Synthesis of silver(I) and copper(II) complexes with danofloxacin.
• Characterization using spectroscopic techniques (¹H NMR, ¹⁹F NMR, IR) and mass spectrometry (ESI-MS).
• Antimicrobial susceptibility testing (Minimum Bactericidal Concentration - MBC) against bacterial and fungal pathogens.
• Cytotoxicity assays on eukaryotic cells.

Main Results:

• The synthesized silver(I) and copper(II) danofloxacin complexes demonstrated significant antimicrobial activity against important veterinary bacteria, including *Listeria monocytogenes* and *Campylobacter jejuni*.
• The MBC values for the metal-based danofloxacin complexes were 1.5 times lower than those of danofloxacin alone, indicating enhanced potency.
• The silver-danofloxacin complex exhibited a fungicidal effect against *Candida* and *Aspergillus* species, and the tested concentrations were non-cytotoxic to eukaryotic cells.

Conclusions:

• Novel silver and copper complexes of danofloxacin possess potent antimicrobial and fungicidal properties relevant to veterinary medicine.
• These metal-based danofloxacin complexes offer a promising strategy to overcome existing antibiotic resistance.
• The non-cytotoxic nature of the complexes at effective concentrations supports their potential for therapeutic applications in animal health.