Multiple Species of Trichosporon Produce Biofilms Highly Resistant to Triazoles and Amphotericin B

Autor(es)

Iturrieta-Gonzalez, Isabel Antonieta ^[1] ; Barbosa Padovan, Ana Carolina ^{[1, 2]} ; Bizerra, Fernando Cesar ^[1] ; Hahn, Rosane Christine ^[3] ; Colombo, Arnaldo Lopes ^[1]

Afiliação do(s) autor(es)

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

^[2] Univ Fed Alfenas, Inst Ciencias Biomed, Dept Microbiol & Immunol, Alfenas, MG - Brazil

^[3] Univ Fed Mato Grosso, Fac Med, Microbiol Lab, Cuiaba, MT - Brazil

• Tipo de documento: Artigo Científico
• Fonte: PLoS One; v. 9, n. 10 OCT 31 2014.
• Citações Web of Science: 28

Resumo

Invasive infections caused by Trichosporon spp. have increased considerably in recent years, especially in neutropenic and critically ill patients using catheters and antibiotics. The genus presents limited sensitivity to different antifungal agents, but triazoles are the first choice for treatment. Here, we investigated the biofilm production and antifungal susceptibility to triazoles and amphotericin B of 54 Trichosporon spp. isolates obtained from blood samples (19), urine (20) and superficial mycosis (15). All isolates and 7 reference strains were identified by sequence analysis and phylogenetic inferences of the IGS1 region of the rDNA. Biofilms were grown on 96-well plates and quantitation was performed using crystal violet staining, complemented with Scanning Electron Microscopy (SEM). Susceptibility tests for fluconazole, itraconazole, voriconazole and amphotericin B were processed using the microdilution broth method (CLSI) for planktonic cells and XTT reduction assay for biofilm-forming cells. Our results showed that T. asahii was the most frequent species identified (66.7%), followed by T. faecale (11.1%), T. asteroides (9.3%), T. inkin (7.4%), T. dermatis (3.7%) and one T. coremiiforme (1.8%). We identified 4 genotypes within T. asahii isolates (G1, G3, G4 and G5) and 2 genotypes within T. faecale (G1 and G3). All species exhibited high adhesion and biofilm formation capabilities, mainly T. inkin, T. asteroides and T. faecale. Microscopy images of high biofilm-producing isolates showed that T. asahii presented mainly hyphae and arthroconidia, whereas T. asteroides exhibited mainly short arthroconidia and few filaments. Voriconazole exhibited the best in vitro activity against all species tested. Biofilm-forming cells of isolates and reference strains were highly resistant to all antifungals tested. We concluded that levels of biofilm formation by Trichosporon spp. were similar or even greater than those described for the Candida genus. Biofilm-forming cells were at least 1,000 times more resistant to antifungals than planktonic cells, especially to voriconazole. (AU)

• 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: 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