RESUMO
Tuberculosis (TB) has a high incidence, prevalence and mortality in the world. Due to its high level of transmission and long-term pharmacological treatment, it is important to have sensitive and specific diagnostic tests. Recently, the PureLyse® system, which is a novel DNA extraction method, was proposed to be an important tool for molecular diagnosis of TB. Here, we compare the PureLyse® system followed by an IS6110 nested PCR (PureLyse® - IS6110 nested PCR) with the Xpert® MTB/RIF test for Mycobacterium tuberculosis complex (MTBC) identification in 40 clinical samples. Among the 40 samples, 26 samples were positive and 14 negative for the Xpert® MTB/RIF test as well as for the PureLyse® - IS6110 nested PCR. According to the Xpert® MTB/RIF test, positive samples presented different bacillary concentrations from "High" to "Very low" and rifampin resistance was observed in 5 samples. The concordance of both molecular methods makes the PureLyse® - IS6110 nested PCR suitable for MTBC detection in patients for low-income resources.
Assuntos
Testes Diagnósticos de Rotina/instrumentação , Testes Diagnósticos de Rotina/métodos , Técnicas de Diagnóstico Molecular/instrumentação , Técnicas de Diagnóstico Molecular/métodos , Mycobacterium tuberculosis/isolamento & purificação , Reação em Cadeia da Polimerase/métodos , Rifampina/farmacologia , Tuberculose/diagnóstico , Antibióticos Antituberculose/farmacologia , Proteínas de Bactérias/genética , Técnicas Bacteriológicas/instrumentação , Técnicas Bacteriológicas/métodos , DNA Bacteriano/análise , Farmacorresistência Bacteriana , Humanos , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/genética , Sensibilidade e Especificidade , Escarro/microbiologia , Tuberculose/microbiologiaRESUMO
Fusarium oxysporum f. sp. dianthi virus 1 (FodV1) was detected in isolate 116 (116V+) of Fusarium oxysporum f. sp. dianthi, reaching such a high accumulation level that it was clearly visible after agarose gel electrophoresis of total DNA extracts. FodV1 consists of four double-stranded RNA segments that correspond to a new mycovirus in the Chrysoviridae family. We obtained an isolate of F. oxysporum f. sp. dianthi 116 (116V-) with only a residual level of FodV1 RNA accumulation by single-conidia selection. Compared with 116V-, isolate 116V+ showed significant phenotypic alterations in vegetative growth and virulence. Thus, the presence of a high titer of mycovirus FodV1 was associated with a modified morphology and a reduced growth of the colonies on solid medium, and with a diminished conidiation in liquid medium. Inoculation of four susceptible carnation cultivars with either 116V- or 116V+ showed that the presence of a high titer of FodV1 was also correlated with a significantly reduced virulence of its fungal host. All of the results suggest that FodV1 could be associated with hypovirulence, identifying it as a potential biocontrol agent for Fusarium wilt of carnation. This is the first report of a mycovirus potentially associated with the induction of hypovirulence in the species F. oxysporum.
