Phenotypic Detection of Biofilm Formation in Clinically Significant Isolates

Abstract

Biofilms are structured microbial communities embedded in a self-produced extracellular matrix, contributing significantly to chronic and device-associated infections. They are linked with prolonged hospital stays, multidrug resistance (MDR), and therapeutic failures. Phenotypic detection of biofilm formation is crucial in clinical microbiology to guide infection control and patient management, particularly in low- and middle-income countries. This narrative review examines the biological basis of biofilm formation, summarizes commonly used phenotypic detection methods such as Congo Red Agar (CRA), Tube Adherence Method (TAM), and Microtiter Plate (MTP) assay, and explores their correlation with antimicrobial resistance and clinical outcomes. A structured literature search identified relevant studies between 2010 and 2025. CRA and TAM are simple and affordable for routine use, whereas MTP remains the gold standard. Biofilm formation strongly correlates with MDR phenotypes such as ESBL, MRSA, and carbapenem resistance, leading to worse clinical outcomes including prolonged hospital stay and increased mortality. Standardizing phenotypic detection in diagnostic laboratories can improve infection surveillance and clinical care.