In Vitro Analysis of Interactions Between and During Biofilm Formation.

UNLABELLED

and are classified as ESKAPE pathogens that present a significant challenge to treatment due to their increased resistance to a considerable number of antimicrobial agents. Background/Objective Biofilms exacerbate treatment challenges by providing enhanced antimicrobial and environmental protection. Mixed-species biofilms further complicate treatment options through numerous complex interspecies interactions, leading to potentially severe adverse clinical outcomes.

METHODS

This study assessed the interaction between clinical and isolates during biofilm formation using microplate biofilm formation assays, scanning electron microscopy, and confocal microscopy.

RESULTS

We identified a competitive relationship between and , where both pathogens exhibited a reduction in biofilm formation during mixed-species biofilms compared with monocultures, although outcompeted . Furthermore, we found that the cell-free conditioned media (CFCM) of significantly reduced the biofilms. Using fractioned CFCM, we identified that the anti-staphylococcal activity of the >10 kDa fraction was almost identical to the non-fractioned CFCM. Our confocal microscopy results suggest that CFCM depolarize membranes and reduces the biofilm burden.

CONCLUSIONS

These findings contribute to our understanding of the mechanisms underlying the interactions between these pathogens, suggesting that there is an antagonistic relationship between and in a biofilm setting.