Susceptibility to fluconazole of Candida clinical isolates determined by FUN-1 staining with flow cytometry and epifluorescence microscopy

• Tipo: Artigo em Revista Científica Internacional
• Data: 2001

Autores

pina-vaz, c (Autor) FMUP; sansonetty, f (Autor) Outra; rodrigues, ag (Autor) FMUP; costa-de-oliveira, s (Autor) FMUP; martinez-de-oliveira, j (Autor) Outra; fonseca, af (Autor) Outra

Revista

Título: Journal of Medical Microbiology

Vol. 50

Páginas: 375-382

ISSN: 0022-2615

Editora: Microbiology Society

Indexação

ISI Web of Knowledge - 30 Citações

Scopus - 27 Citações

Classificação Científica

FOS: Ciências exactas e naturais > Ciências biológicas

Outras Informações

ID Authenticus: P-000-W03

Abstract (EN): The susceptibility of clinical Candida isolates to fluconazole was assayed by flow cytometry (FCM) and epifluorescence microscopy (EFM), with FUN-1 staining. In all, 25 clinical isolates of Candida spp. (12 sensitive, 3 dose-dependently sensitive and 10 resistant to fluconazole according to the NCCLS M27-A protocol) were treated with increasing concentrations of fluconazole during 1 or 2 h staining with FUN-1 for 30 min and analysed, respectively, by FCM at 575 nm (FL2) and by EFM. Fluconazole-susceptible strains showed an increased accumulation of FUN-1 in comparison with controls as determined by FCM and a reduced metabolic processing of the probe, confirmed by EFM. Conversely, resistant strains showed decreased FUN-1 staining and were able to process the probe. The fluconazole minimal inhibitory concentrations (MICs) determined by FCM or EFM after FUN-1 staining compared very well with the corresponding values determined by the M27-A protocol, indicating that FUN-1 staining can be used as an alternative to the conventional method. MIC values of resistant strains, with the exception of C. krusei, were lower when treatment with fluconazole followed pre-incubation with 0.1 mM sodium azide, a concentration known to inhibit the activity of efflux pumps. These results show that FUN-1 staining can be used as an alternative and rapid method for the assessment of susceptibility of Candida clinical isolates to fluconazole. Furthermore, the results suggest that resistance of Candida cells to fluconazole, with the exception of C. krusei strains, is likely to be due to the activity of efflux pumps.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 8