Interação metabólica entre o fungo C. auris e a bactéria P. aeruginosa

Abstract

In n hospital environments, it is common to find a range of microorganisms harmful to human health, among which the bacterium Pseudomonas aeruginosa stands out. Additionally, Candida auris, a pathogenic fungus resistant to hospital disinfection and difficult to control nosocomial, has emerged in this context. However, little is known about the interaction between C. auris and bacteria in the hospital environment and within the host. Thus, the objective of this study was to investigate the interaction between C. auris and P. aeruginosa. Initially, the result of the interaction between C. auris and P. aeruginosa was investigated by co-culturing them in liquid RPMI medium. It was observed that P. aeruginosa can significantly inhibit the growth of the yeast. It was also confirmed that the inhibition occurs regardless of the concentration of yeast and bacteria, starting between 8 and 12 hours and continuing up to 72 hours, the longest time tested. However, there was no significant inhibition when C. auris was cultured with the cell-free filtrate of the P. aeruginosa culture, suggesting that the presence of cells is necessary for antagonism. Furthermore, P. aeruginosa inhibited the yeasts regardless of the medium used (RPMI, RPMI 2x, YPD, and RPMI with 2% glucose), showing that inhibition also occurs in nutritionally richer media, indicating that the antagonism is not simply due to glucose competition. When iron was added to the RPMI medium, however, the growth of C. auris in the presence of the bacteria was significantly greater than in the medium without added iron. Finally, P. aeruginosa was able to inhibit other strains of C. auris, demonstrating a consistent inhibition pattern among the different clades of this yeast. Therefore, it is concluded that P. aeruginosa inhibits the growth of C. auris, possibly due to the production of antagonistic substances with antifungal activity.