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

Autor(es)

Nunes, Jorge Meneses ^[1] ; Bizerra, Fernando Cesar ^[1] ; Carmona e Ferreira, Renata ^[1] ; Colombo, Arnaldo Lopes ^[1]

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Paulo, Lab Especial Micol, Disciplina Infectol, Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Antimicrobial Agents and Chemotherapy; v. 57, n. 1, p. 382-389, JAN 2013.
• Citações Web of Science: 37

Resumo

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)

• Processo FAPESP: 07/08575-1 - Candidíase hematogênica: uma abordagem multidisciplinar para o aprimoramento de ferramentas diagnósticas e caracterização de biomarcadores relacionados ao seu prognóstico
• Beneficiário: Arnaldo Lopes Colombo
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 10/17179-5 - Estudo de proteômica como estratégia para identificação de biomarcadores para diagnóstico precoce de candidemia
• Beneficiário: Fernando César Bizerra
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 09/01230-4 - Aplicação clínica da sistemática molecular de Candida spp. na perspectiva da genômica comparativa por genealogias em rede e análise bayesiana
• Beneficiário: Renata Carmona e Ferreira
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado