Metabolomics-driven Approaches on Interactions Between and Biofilms.

OBJECTIVES

This study aimed to determine the effect of on the cell growth and hyphal formation of and to understand the exact mechanism of candidal inhibition by the existence of by metabolomic analysis.

MATERIALS AND METHODS

Single- and dual-species biofilms of and were formed in a microtiter plate, and the metabolomic profiles of both biofilms was determined by gas chromatography-mass spectrometry. The hyphal cell growth of after treatment with both the supernatant and biofilm cells of was examined microscopically. The expression levels of Efg1 and the images of cell wall in single- and dual-species biofilms were determined by real-time quantitative polymerase chain reaction and transmission electron microscopy, respectively. The violacein levels produced by Chromobacterium violaceum were measured to determine the quorum sensing (QS) inhibitory activity of single- and dual-species biofilms.

RESULTS

The biofilm cell growth, Efg1 expression, and hyphal development of were inhibited by . Compared to single-species biofilms, alterations in carbohydrate, amino acid, and polyamine metabolites were observed in the dual-species biofilm for both microorganisms. Putrescine and pipecolic acid were detected at high levels in dual-species biofilm. A thicker β-glucan chitin and a denser and narrower fibrillar mannan layer of cell wall were observed in dual-species biofilm. QS inhibitory activity was higher in dual-species biofilm suspensions of and than in their single-species biofilms.

CONCLUSION

inhibited the hyphal development and biofilm formation of . Biofilm suspensions of and showed an anti-QS activity, which increased even further in the environment where the two species coexisted. Investigation of putrescine and pipecolic acid can be an important step to understand the inhibition of by bacteria.