Exploring the anti-biofilm activity of 2-hydroxy pyridine against clinical isolate of A. baumannii

Abstract

Acinetobacter baumannii (A. baumannii) is a major multidrug-resistant (MDR) nosocomial pathogen associated with persistent infections and limited treatment
options. In this study, the antimicrobial and antibiofilm potential of 2-Hydroxypyridine (2-HP) was evaluated against a clinical isolate (A. baumannii SD-AB-023).
Antibacterial activity was assessed using agar well diffusion and broth microdilution assays, while antibiofilm activity at sub-MIC was determined using crystal
violet staining, air-liquid interface assays, and light microscopy. The effect on bacterial metabolic activity was evaluated using the Alamar Blue assay. 2-HP
exhibited significant antibacterial activity, with a zone of inhibition of 25 mm and a MIC of 20 mg/mL. At sub-MIC concentrations, 2-HP significantly inhibited
biofilm formation in a dose-dependent manner, achieving up to 58.02% reduction, and disrupted biofilm architecture as confirmed by microscopic observations.
Notably, Alamar Blue assay results demonstrated no significant reduction in metabolic activity at sub-MIC levels, indicating that biofilm inhibition was not due to
bactericidal effects. Altogether, these findings suggest that 2-HP possesses both antibacterial and antibiofilm properties and may serve as a promising candidate
for the development of alternative therapeutic strategies against MDR A. baumannii, although further studies are required to elucidate its mechanism of action and
in-vivo efficacy.