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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Molecular Identification, Antifungal Susceptibility Profile, and Biofilm Formation of Clinical and Environmental Rhodotorula Species Isolates

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Nunes, Jorge Meneses [1] ; Bizerra, Fernando Cesar [1] ; Carmona e Ferreira, Renata [1] ; Colombo, Arnaldo Lopes [1]
Total Authors: 4
[1] Univ Fed Sao Paulo, Lab Especial Micol, Disciplina Infectol, Sao Paulo - Brazil
Total Affiliations: 1
Document type: Journal article
Source: Antimicrobial Agents and Chemotherapy; v. 57, n. 1, p. 382-389, JAN 2013.
Web of Science Citations: 35

Rhodotorula species are emergent fungal pathogens capable of causing invasive infections, primarily fungemia. They are particularly problematic in immunosuppressed patients when using a central venous catheter. In this study, we evaluated the species distribution of 51 clinical and 8 environmental Rhodotorula species isolates using the ID32C system and internal transcribed spacer (ITS) sequencing. Antifungal susceptibility testing and biofilm formation capability using a crystal violet staining assay were performed. Using ITS sequencing as the gold standard, the clinical isolates were identified as follows: 44 R. mucilaginosa isolates, 2 R. glutinis isolates, 2 R. minuta isolates, 2 R. dairenensis isolates, and 1 Rhodosporidium fluviale isolate. The environmental isolates included 7 R. mucilaginosa isolates and 1 R. slooffiae isolate. Using the ID32C system, along with a nitrate assimilation test, only 90.3% of the isolates tested were correctly identified. In the biofilm formation assay, R. mucilaginosa and R. minuta exhibited greater biofilm formation ability compared to the other Rhodotorula species; the clinical isolates of R. mucilaginosa showed greater biofilm formation compared to the environmental isolates (P = 0.04). Amphotericin B showed good in vitro activity (MIC <= 1 mu g/ml) against planktonic cells, whereas voriconazole and posaconazole showed poor activity (MIC50/MIC90, 2/4 mu g/ml). Caspofungin and fluconazole MICs were consistently high for all isolates tested (>= 64 mu g/ml and >= 4 mu g/ml, respectively). In this study, we emphasized the importance of molecular methods to correctly identify Rhodotorula species isolates and non-R. mucilaginosa species in particular. The antifungal susceptibility profile reinforces amphotericin B as the antifungal drug of choice for the treatment of Rhodotorula infections. To our knowledge, this is the first study evaluating putative differences in the ability of biofilm formation among different Rhodotorula species. (AU)

FAPESP's process: 07/08575-1 - Hematogenic candidiasis: a multidisciplinary approach for the improvement of diagnostic tools and caracterization of biomarkers related to its prognosis
Grantee:Arnaldo Lopes Colombo
Support type: Research Projects - Thematic Grants
FAPESP's process: 09/01230-4 - Clinical aplications on the molecular systematic of Candida spp. in the perspective of comparative genomics of gene genealogies and Bayesian analyses
Grantee:Renata Carmona e Ferreira
Support type: Scholarships in Brazil - Post-Doctorate
FAPESP's process: 10/17179-5 - Proteomics as a strategy to identify biomarkers for early diagnosis of candidemia
Grantee:Fernando César Bizerra
Support type: Scholarships in Brazil - Post-Doctorate