Biofilms in clinical infection: pathophysiology, diagnosis, and the evolving therapeutic landscape

Biofilms are structured communities of microorganisms encased in a self-produced polymeric matrix that typically adhere to surfaces. Recent research, however, has revealed that non-attached aggregates share many common traits with the surface-dependent biofilms. This mode of bacterial growth provides enhanced protection against antibiotics and resistance to host immune defenses. Biofilms require higher antibiotic concentrations than those needed to inhibit planktonic bacteria, necessitating prolonged high-dose and combination therapies to achieve effective eradication. This increased resistance is attributed to multiple factors, including the protective extracellular matrix, reduced metabolic activity of bacteria within the biofilm, and also the ability of bacterial genomes to rapidly adjust in response to environmental changes. Diagnostic modalities such as sonication, tissue culture, and polymerase chain reaction-based assays currently dominate clinical diagnostics of biofilm infections due to their practicality, cost-effectiveness, and proven reliability. Recent research has led to innovative treatment strategies that target biofilm structure, enhance drug delivery, and modulate host-pathogen interactions. This review summarizes our current knowledge of biofilm formation, explores the current techniques for detecting microbial biofilms, and discusses future perspectives for advancing diagnostic and therapeutic strategies.