Candida species contamination in drinking groundwater from residence wells in three municipalities of midwestern Brazil and the potential human health risks.

Groundwater represents one of the largest safe drinking water sources worldwide; however, it has been threatened by increased human activities in recent years. Candida species express virulence factors that contribute to the establishment and worsening of infections, although little is known about the virulence profiles of these species in potable groundwater. The aim of this study was to detect the presence of yeasts in groundwater from residential wells and to evaluate the antifungal susceptibility profile, hydrolytic enzyme production, adhesion capacity, and biofilm formation of Candida spp. Fifty yeasts representing nine genera were isolated: Candida (48%), Meyerozyma (20%), Pichia (8%), Exophiala (8%), Clavispora (4%), Kodamaea (4%), Rhodotorula (4%), Hanseniaspora (2%), and Kazachstania (2%). Candida parapsilosis was the most commonly isolated species, and approximately 29% of the Candida isolates were resistant to at least one azole. All Candida isolates were able to produce hydrolytic enzymes and adhere to polystyrene, and most were classified as hydrophobic. Candida spp. can establish and form biofilms when cultivated in different media such as Sabouraud broth, water, and calcium hypochlorite. The use of contaminated groundwater for human consumption represents a possible route for the transmission of clinically relevant yeasts that can cause fungal infections, especially in immunocompromised individuals. Therefore, it is important to evaluate and establish effective measures for groundwater treatment to ensure the quality and safety for consumption.

A Promising Copper(II) Complex as Antifungal and Antibiofilm Drug against Yeast Infection.

The high mortality rate of candidemia and the limited option for the treatment of Candida spp. infection have been driving the search for new molecules with antifungal property. In this context, coordination complexes of metal ions and ligands appear to be important. Therefore, this study aimed to synthesize two new copper(II) complexes with 2-thiouracil and 6-methyl-2-thiouracil ligands and to evaluate their mutagenic potential and antifungal activity against Candida. The complexes were synthesized and characterized by infrared vibrational spectroscopy, CHN elemental analysis, UV-Vis experiments and ESI-HRMS spectrometry studies. The antifungal activity was evaluated by broth microdilution against 21 clinical isolates of Candida species. The mutagenic potential was evaluated by the Ames test. The complexes were Cu(Bipy)Cl2(thiouracil) (Complex 1) and Cu(Bipy)Cl2(6-methylthiouracil) (Complex 2). Complex 1 showed fungicidal and fungistatic activities against all isolates. Furthermore, the Minimum Inhibitory Concentration (MIC) from 31 to 125 µg/mL and inhibition percentage of 9.9% against the biofilms of C. krusei and C. glabrata were demonstrated. At the concentrations tested, complex 1 exhibited no mutagenic potential. Complex 2 and the free ligands exhibited no antifungal activity at the concentrations evaluated. Since complex 1 presented antifungal activity against all the tested isolates and no mutagenic potential, it could be proposed as a potential new drug for anti-Candida therapy.