Forging biofilms: metal-induced microbial responses in biofilm formation

Biofilms are a major contributor to antibiotic resistance and persistence in hospital environments. These bacterial communities form protective structures that shield microbes from various stressors, such as oxidative stress, pH fluctuations, osmotic pressure, and nutrient deprivation. As our understanding of biofilms has grown, it has become evident that metals play a crucial role in several aspects of biofilm biology. Metals are involved in regulating biofilm formation, facilitating communication and competition among bacteria, and supporting the structural integrity and adherence of bacterial cells within the biofilm. This review discusses the complex relationship between metals and biofilms during bacterial pathogenesis to emphasize how the availability of metals influences biofilm dynamics. We explore mechanisms through which metals impact biofilm architecture and resilience, as well as the ability of bacteria to evade host immune defenses and outcompete other microbes. In polymicrobial environments, some bacteria use metals to collaborate with other microbes within the biofilm, whereas others deprive neighboring microbes of essential metals to dominate the biofilm community. Additionally, metals have roles beyond their nutritional value, where they can promote the integrity and stability of biofilms. By understanding these interactions, researchers can gain valuable insights into the significance of metals in biofilm-associated infections. This knowledge can help identify potential therapeutic targets that will lead to the development of new strategies to combat biofilm-related infections and improve patient outcomes.