Evaluation of the anti-biofilm potential of biosynthesized silver nanoparticles against Escherichia coli and Klebsiella pneumoniae isolated from urinary tract infection patients in Zahedan, 2023

Urinary tract infections (UTIs) are among the most prevalent infections worldwide and a significant contributor to morbidity and mortality, with bacterial biofilm formation playing a critical role in their persistence and resistance to treatment. This study evaluated the biofilm-forming ability of Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae) isolates obtained from UTI patients and investigated the anti-biofilm activity of biosynthesized silver nanoparticles (AgNPs) against biofilm-producing strains. Bacterial identification and confirmation were performed using selective culture media and polymerase chain reaction (PCR) assays. Biofilm production and the anti-biofilm efficacy of AgNPs were assessed through a quantitative microtiter plate assay, while antimicrobial susceptibility testing was conducted using standard antibiotic disc diffusion methods. The results revealed a high prevalence of biofilm-positive strains, with E. coli exhibiting a higher proportion of strong biofilm producers compared to K. pneumoniae. Antibiotic resistance analysis demonstrated significant resistance in both uropathogens, particularly to beta-lactam antibiotics. The synthesized AgNPs exhibited potent anti-biofilm activity, effectively inhibiting biofilm formation in both bacterial species. Interestingly, despite the higher biofilm-forming capacity of E. coli, AgNPs displayed greater inhibitory effects on E. coli biofilms compared to those of K. pneumoniae. These findings underscore the clinical relevance of biofilm formation in UTI pathogenesis and highlight biosynthesized AgNPs as a promising therapeutic agent for managing biofilm-associated infections. This study emphasizes the need for innovative approaches to combat biofilm-related antimicrobial resistance and improve UTI treatment outcomes.