Evaluation of electromagnetic field effects on the viability and structure of Candida albicans and Streptococcus...

Biofilms formed by Candida albicans and Streptococcus mutans contribute substantially to persistent oral infections due to their structural complexity, cooperative interactions, and high tolerance to antimicrobial agents. Electromagnetic fields (EMFs) have emerged as a promising non-chemical strategy to modulate microbial behavior; however, their effects on cross-kingdom biofilms remain poorly characterized. This study investigated the impact of low-frequency EMF exposure on biofilm biomass, cell viability, and morphological organization in single- and dual-species biofilms of C. albicans and S. mutans. A custom-built solenoid-based EMF system was calibrated to deliver a low-intensity alternating magnetic field (~ 105 mG; 50-60 Hz), ensuring non-contact exposure conditions. Biofilm biomass and cell viability were quantified using Crystal Violet (CV) and MTT assays, respectively, while structural changes were examined using scanning electron microscopy (SEM). EMF exposure significantly reduced biomass and metabolic activity in single-species biofilms of both microorganisms (p < 0.05), whereas dual-species biofilms showed a non-significant reduction, indicating enhanced resilience through interspecies cooperation. SEM analysis revealed EMF-induced inhibition of hyphal and pseudohyphal development in C. albicans and disruption of S. mutans clustering and adherence. Moreover, the characteristic physical association between species in dual biofilms was absent under EMF treatment. These findings indicate that low-frequency EMF disrupts key morphological and structural features that support biofilm maturation, highlighting its potential as a non-chemical approach for modulating biofilm-associated pathogens.