Detecção rápida de Cryptococcus gattii usando Nanopartículas de ouro

Abstract

Rapid identification of Cryptococcus sp is imperative for the facilitation of prompt treatment, the reduced impact of diseases and the improvement of survival rates. In this paper, we present the development of a gold nanoparticle (AuNPs) technique, focusing on C. gattii detection. DNA from 21 clinical isolates of Cryptococcus gattii and four of C. neoformans from humans and animals were investigated. Reference isolates (WM148, WM626, WM628, WM629, WM179, WM178, WM161 and WM779) representing each of the eight major molecular types were used as controls. To test specificity the isolates of Candida albicans, Malassezia pachydermatis, Conidiobolus lamprauges, Aspergillus fumigatus and Pichia sp were used. Oligonucleotides designed from the regional superoxide dismutase gene associated with AuNPs and used for hybridisation and specific detection, allowed for diagnosis based on the visual colorimetric properties of the particles and readings from spectrophotometer absorption. The technique detected both the DNA C. gattii isolates and the reference strains patterns used as controls. The clinical isolates and standard strain of C. neoformans, as well as the yeasts used for specificity, were negative. The technique was used for the detection of other pathogens with good sensitivity and specificity results. In this study, the AuNPs technique was rapid and low cost for the detection of suspected C. gattii clinical isolates.