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Introduction: Since 2018, World Health Organization (WHO) recommended the Xpert MTB/RIF Ultra use for pulmonary and extrapulmonary TB diagnosis, and suggested that Xpert Ultra should be tested in various populations, with different geographical and epidemiological settings., Methods: Cross-sectional study with prospective data collection. Outpatients aged >18 years with respiratory symptoms suggestive of pulmonary TB were invited to participate. Sensitivity, specificity, positive and negative predictive values of the test were calculated and compared with the traditional Xpert MTB/RIF., Results: During the study period, 180 patients met the inclusion and were included in the analysis. Xpert MTB/RIF Ultra test was positive in 33 patients (18.3%), and RIF resistance was detected in 1 (3.1%) patient. Considering culture as the gold standard, the sensitivity, specificity, positive predictive value, and negative predictive value of Xpert MTB/RIF Ultra were 100.0% (95% CI 85.2-100.0), 93.6% (95% CI 88.6-96.9), 69.7% (95% CI 55.8-80.7), and 100.0% (95% CI 87.2-100.0), respectively. The area under the ROC curve was 0.97 for the Xpert MTB/RIF Ultra test (95% CI 0.93 to 0.99; p < 0.0001). There was no difference statistically significant between sensitivities and specificities of Xpert MTB/RIF and Xpert MTB/RIF Ultra (p > 0.05)., Conclusions: This is the first study in Brazil to evaluate the accuracy of Xpert MTB/RIF Ultra in individuals with presumptive pulmonary TB. The test showed an excellent sensitivity and a high specificity, demonstrating that it is a useful tool for pulmonary TB diagnosis., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Background and Objectives: As for all tests, the diagnostic performances of Xpert MTB/RIF might be different in settings with different tuberculosis prevalence. Aim of the study is to evaluate the performances of Xpert MTB/RIF to diagnose tuberculosis in Brazil, where 407 culture-confirmed tuberculosis patients were retrospectively enrolled in Rio Grande do Sul, between 2015 and 2016., Methods: Sensitivity, specificity, positive and negative predictive values of the test were calculated and a logistic regression analysis was performed to assess the role played by explanatory variables in the occurrence of true positive and negative diagnostic results., Results: Sensitivity of Xpert MTB/RIF was 100.0%, specificity 92.8%; positive and negative predictive values were 71.4% and 100.0%, respectively. In the HIV- infected sub-group specificity was 59.3%. In the multivariate logistic regression analysis, true positivity was associated with increasing age (1.0; p-value: 0.02) while true positivity and negativity were negatively associated with alcohol abuse., Conclusions: Xpert is sensitive and specific in the Brasilian settings., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

The dimorphic fungi Paracoccidioides spp. are the etiological agents of paracoccidioidomycosis (PCM), a prevalent systemic mycosis in Latin America. The Paracoccidioides lutzii response to oxidative stress is largely unexplored. Thioredoxins (TRX) are involved in the regulation of the redox environment in the cell, responding to oxidative stress in several organisms. In this study, we describe the isolation and characterization of a cDNA encoding a thioredoxin 1 from yeast cells from P. lutzii. The cDNA codes for a 12kDa protein containing the characteristic thioredoxin active site. The thioredoxin 1 gene was expressed in Escherichia coli and the isolated thioredoxin 1 recombinant protein as the native PlTRX1 from yeast cells showed insulin reduction activity in vitro. We also showed by semi-quantitative RT-PCR analysis that the expression of thioredoxin 1 gene was induced in response to H 2 O 2 and may exert an antioxidant activity in vivo. Our results suggest that the thioredoxin 1 may play an important role in controlling the redox status in P. lutzii which may contribute to this organism's virulence., (Copyright © 2017 Elsevier B.V. All rights reserved.)

We developed a 96-well microtiter-plate high-throughput screening (HTS) assay for the detection of modulators of transcription. This HTS assay consists of three steps: (1) the in vitro transcription reaction; (2) modification and hybridization of RNA products; and (3) washing and quantification. During the first step, a DNA template containing the promoter of interest upstream of a cassette lacking guanosine residues in one of its strands (G-less cassette) is incubated with nuclear extract and the necessary cofactors/activators and substrates. During the second step, the in vitro synthesized transcripts are digested with RNase T1 and hybridized to two DNA oligonucleotides. One oligonucleotide is biotinylated for trapping of the RNA products to a streptavidin-coated plate, and the other is europium-labeled for detection by time-resolved fluorescence. We show that this assay is highly reproducible and robust, yielding results comparable to those obtained by standard methodologies employing radioactive nucleotide incorporation and gel electrophoresis while offering a very significant advantage in terms of throughput (>2000 assay points per operator per day). We demonstrate the usefulness of the assay for the discovery of small molecule inhibitors of transcription, and applications of this approach for the high-throughput discovery of transcriptional modulators are discussed.