Phenotypic Detection of Biofilm Formation in Clinically Significant Isolates and Its Correlation with Clinical Outcomes and Antimicrobial Resistance Patterns: A Cross-sectional Study
Keywords:
Biofilm formation, Multidrug resistance, Antimicrobial resistance, Phenotypic detection, Hospital-acquired infections.Abstract
Background:Biofilm formation is a critical virulence mechanism in healthcare-associated infections (HAIs), leading to chronicity, antimicrobial resistance, and poor clinical outcomes. Despite its clinical relevance, routine detection of biofilms is often neglected in diagnostic laboratories, particularly in low- and middle-income settings.
Objective:This study aimed to phenotypically detect biofilm formation among clinically significant isolates and correlate these findings with antimicrobial resistance (AMR) patterns and clinical outcomes.
Methods:A cross-sectional study was conducted over three years in the Department of Microbiology, Datta Meghe Medical College and affiliated hospitals. A total of 782 clinically significant isolates obtained from blood, urine, pus, respiratory samples, and device tips were subjected to phenotypic biofilm detection by Congo Red Agar (CRA), Tube Adherence Method (TAM), and Microtiter Plate Assay (MTP). Antimicrobial susceptibility testing was performed using the Kirby–Bauer method per CLSI guidelines. Clinical data including hospital stay, device usage, complications, and mortality were correlated.
Results:Overall, 55.8% of isolates were biofilm producers by MTP. Pseudomonas aeruginosa (78.8%), Klebsiella pneumoniae (69.7%), and coagulase-negative staphylococci (65.9%) were the predominant biofilm formers. Multidrug resistance (MDR) was observed in 68.5% of biofilm producers versus 32.7% of non-producers (p < 0.001). ESBL production, carbapenem resistance, MRSA, and VRE were significantly higher among biofilm-forming isolates. Clinically, biofilm-associated infections were linked to longer hospital stays (mean 14.2 vs. 9.8 days, p < 0.001), higher device-related infection rates, and increased mortality (18.3% vs. 8.7%, p = 0.009).
Conclusion:Biofilm formation is prevalent among major hospital pathogens and strongly associated with multidrug resistance and adverse clinical outcomes. Incorporating phenotypic biofilm detection into routine diagnostics can guide targeted antimicrobial therapy and strengthen infection control measures.
