Mechanisms of influence for viruses on biofilms during coinfections.

Biofilms represent highly structured microbial communities embedded in an extracellular matrix, exhibiting profound resilience against environmental stresses and antimicrobial interventions. While the bacterial and fungal components of biofilms are well characterized, the influence of viruses—either as active participants in biofilm formation or as modulators during coinfection—remains underexplored. This review synthesizes current evidence on viral interactions with biofilms, highlighting their roles in promoting microbial attachment, sustaining growth, enhancing virulence, and facilitating dispersal and transmission. Examples include viral modulation of host receptors to promote bacterial adherence, the impact of influenza and respiratory syncytial virus on biofilm expansion in respiratory diseases, and herpes simplex virus contributions to fungal and bacterial biofilm dynamics. Moreover, viral–biofilm interactions complicate therapeutic outcomes by enabling persistence, immune evasion, and reservoirs of infection. We also discuss emerging strategies targeting these complex interactions, including antivirals with antibiofilm activity and novel therapeutics such as antimicrobial peptides and iron chelation in cystic fibrosis. By elucidating mechanisms of viral influence on biofilms, this review underscores the importance of incorporating virological perspectives into biofilm research, with implications for both clinical management and the development of innovative treatment strategies.