Aspects related to biofilm production and antifungal susceptibility of clinically relevant yeasts of the genus Trichosporon.

Trichosporonosis corresponds to a systemic fungal disease that leads to high mortality rates and is frequently associated with medical devices. It affects immunosuppressed patients in particular and is strongly linked to acquired human immunodeficiency, organ and tissue transplants, and malignant hematologic diseases such as leukemia and lymphomas. Trichosporon infections have been increasingly reported worldwide; however, little information is available either about their characteristics or the causative microorganism. Thus, the aims of the present study were: to investigate 59 yeasts of the genus Trichosporon by verifying the biofilm formation capacity of isolates; to analyze the susceptibility patterns of planktonic cells against the antifungals fluconazole, itraconazole, amphotericin-B, voriconazole, and caspofungin by comparing European Committee for Antimicrobial Susceptibility Testing (EUCAST) broth microdilution technique with the commercial method Etest; and to assess the susceptibility patterns of biofilm cells (sessile) against the same antifungals through broth microdilution. The ability to form biofilm on the surface of polystyrene plates was noted for all isolates, and 54.3% of samples were considered strong producers. Comparison between the antifungal susceptibility techniques evidenced that Etest showed higher and discordant minimum inhibitory concentrations (MICs) from those obtained by the microdilution method, especially for fluconazole, itraconazole, and caspofungin. Considering the susceptibility of biofilms, most species had high MIC50 and MIC90 against the tested antifungals, showing 4-to-66-fold higher concentrations for amphotericin B and 2-to-33-fold greater concentrations for caspofungin. These results highlight the importance of further studies with Trichosporon spp. for comparison between laboratory findings and in vivo response, considering both the susceptibility tests and the behavior of biofilm cells against drugs.

This study investigated 59 isolates of the medically important yeast Trichosporon in relation to their ability to form biofilms and the susceptibility of biofilms to antifungal agents. All isolates were able to produce biofilms and biofilms showed lower antifungal susceptibility.

Multicenter study of Candida species in oral mucosa of different patients: analysis of 711 strains and literature review

This study aimed to identify Candida spp. collected from oral mucosa and maintained in culture collections, correlating the findings with the medical history of patients and comparing with data from the literature over the past five years. Seven hundred and eleven oral Candida spp. isolates, collected between 2013 and 2017, were selected and identified using traditional and molecular methods. In addition, a literature review was performed with the key words: "Oral", "Candida" and "Yeast". Seven species of the genus Candida: were identified C. albicans(73.3%); C. tropicalis (9.3%); C. parapsilosis (8.2%); C. glabrata (3.9%); C. guilliermondii(2.8%); C. krusei (1.7%) and C. lusitaniae (0.3%). The strains identified as C. albicans were submitted to molecular methods using specific primers and of these, 5.8% were identified as C. dubliniensis strains. The greatest diversity of strains was found in patients presenting no systemic diseases or HIV +, while the highest percentage of strains of Candidanon-albicanswere observed in cancer patients. This study reports a representative distribution of Candidaspecies among individuals exhibiting distinct clinical conditions, in order to contribute to the design of future research on details of aspects involved in the infections caused by these microorganisms. The correct identification of oral Candida strains contributes to a realistic epidemiological approach and future clinical protocols against these pathogens