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Latrofa M.S.,University of Bari | Dantas-Torres F.,University of Bari | Dantas-Torres F.,Aggeu Magalhaes Research Center Fiocruz | Annoscia G.,University of Bari | And 2 more authors.
Infection, Genetics and Evolution | Year: 2013

The genus Rhipicephalus (Acari: Ixodidae) comprises a large number of vectors of pathogens of substantial medical and veterinary concern; however, species identification based solely on morphological features is often challenging. In the present study, genetic distance within selected Rhipicephalus species (i.e., Rhipicephalus bursa, Rhipicephalus guilhoni, Rhipicephalus muhsamae, Rhipicephalus sanguineus sensu lato and Rhipicephalus turanicus), were investigated based on molecular and phylogenetic analyses of fragments of the mitochondrial 16S, 12S and cytochrome c oxidase subunit 1 (cox1) genes, as well as of the whole sequences of the ribosomal internal transcribed spacer-2 (ITS-2) region. Mean values of inter-specific genetic distance (e.g., up to 12.6%, 11.1% and 15.2%), as well as of intra-specific genetic distance (e.g., 0.9%, 0.9% and 1%), calculated using the Kimura-2 parameter substitution model with uniform rates among sites for 16S, 12S and cox1 genes, respectively, confirmed the differentiation of the rhipicephaline species herein examined. The molecular identification was also supported by the distinct separation of species-specific clades inferred from the phylogenetic analyses of all mitochondrial sequences. Conversely, little interspecific divergence was detected amongst ribosomal ITS-2 sequences (i.e., up to 2.8%) for species belonging to the R. sanguineus complex, which resulted in the ambiguous placement of selected R. sanguineus s.l. and R. turanicus sequences in the corresponding phylogenetic tree. Results from this study confirm the suitability of mtDNA markers for the reliable identification of ticks within the Rhipicephalus genus and provide a framework for future studies of taxonomy, speciation history and evolution of this group of ticks. © 2013 Elsevier B.V. Source


Coimbra I.,Federal University of Pernambuco | Maruza M.,Federal University of Pernambuco | De Fatima Pessoa Militao Albuquerque M.,Aggeu Magalhaes Research Center Fiocruz | Batista J.D.L.,Federal University of Pernambuco | And 7 more authors.
PLoS ONE | Year: 2014

Background: The challenge of diagnosing smear-negative pulmonary TB (tuberculosis) in people living with HIV justifies the use of instruments other than the smear test for diagnosing the disease. Considering the clinical-radiological similarities of TB amongst HIV-infected adults and children, the proposal of this study was to assess the accuracy of a scoring system used to diagnose smear-negative pulmonary TB in children and adolescents, in HIV-infected adults suspected of having smear-negative pulmonary TB. Methods: A Phase III validation study aiming to assess the diagnostic accuracy of a scoring system for diagnosing smear-negative pulmonary TB in HIV-infected adults. The study assessed sensitivity, specificity, positive and negative likelihood ratios, and positive and negative predictive values of the scoring system. Three versions of the scoring system were tested. Results: From a cohort of 2,382 (HIV-infected adults), 1276 were investigated and 128 were diagnosed with pulmonary TB. Variables associated with the diagnosis of TB were: coughing, weight loss, fever, malnutrition, chest X-ray, and positive tuberculin test. The best diagnostic performance occurred with the scoring system with new scores, with sensitivity = 81.2% (95%-CI 74.5% -88%), specificity = 78% (75.6% -80.4%), PPV = 29.2% (24.5% -33.9%) and NPV = 97.4% (96.4% -98.4%), LR+ = 3.7 (3.4-4.0) and LR2 = 0.24 (0.2-0.4). Conclusion: The proposed scoring system (with new scores) presented a good capacity for discriminating patients who did not have pulmonary TB, in the studied population. Further studies are necessary in order to validate it, thus permitting the assessment of its use in diagnosing smear-negative pulmonary TB in HIV-infected adults. © 2014 Coimbra et al. Source


Lira L.A.S.,Aggeu Magalhaes Research Center Fiocruz | Santos F.C.F.,Aggeu Magalhaes Research Center Fiocruz | Carvalho M.S.Z.,Aggeu Magalhaes Research Center Fiocruz | Montenegro R.A.,Aggeu Magalhaes Research Center Fiocruz | And 3 more authors.
Journal of Applied Microbiology | Year: 2013

Aim: Evaluate the IS6110-Taqman system performance in sputum samples from patients with pulmonary tuberculosis from health services in north-eastern Brazil as a diagnostic laboratory tool for pulmonary tuberculosis. Methods and Results: 165 sputum samples from respiratory symptomatic patients were evaluated in the IS6110-TaqMan assay: 66 patients with pulmonary tuberculosis and 99 without TB. When the IS6110-TaqMan assay was evaluated using culture and/or clinical response to the specific treatment as the gold standard, IS6110-TaqMan assay obtained a sensitivity of 87·9% and specificity of 98%. The performance of IS6110-TaqMan assay was also evaluated with the sputum smear microscopy, resulting in a sensitivity of 79·7% and specificity 94·8%. Conclusions: The IS6110-TaqMan was rapid, sensitive and specific for the diagnosis of pulmonary TB. Significance and Impact of the Study: IS6110-TaqMan assay is a promising auxiliary tool for the diagnosis of pulmonary TB when used in conjunction with routine laboratory tests, clinical and epidemiological criteria of the patient, thus increasing the sensitivity and specificity of diagnosis. © 2012 The Society for Applied Microbiology. Source


Montenegro R.A.,Aggeu Magalhaes Research Center Fiocruz | Guarines K.M.,Aggeu Magalhaes Research Center Fiocruz | Montenegro L.M.L.,Aggeu Magalhaes Research Center Fiocruz | Lira L.A.S.,Aggeu Magalhaes Research Center Fiocruz | And 7 more authors.
Journal of Applied Microbiology | Year: 2014

Aims: To analyse the performance of RT-qPCR using 85B mRNA in the diagnosis of Mycobacterium tuberculosis infection and in the assessment of the response to treatment for pulmonary tuberculosis (TB). Methods and Results: Ninety-eight patients with signs of pulmonary TB were selected: 56 were considered infected with Myco. tuberculosis and they had positive cultures or evident clinical response to anti-TB treatment. Patients with pulmonary tuberculosis were evaluated by culture and RT-qPCR for a 30-day specific treatment. It was found that both tests demonstrated a decline in viable bacilli at 15 and 30 days after the beginning of the therapy in most of the patients. The quantification of the 85B mRNA target was performed in 52 patients who had initially shown positive results by RT-qPCR and who were followed on the days 15 and 30 after the specific treatment. Thus 85B mRNA was detectable in sputum samples in 52 patients with a confirmed diagnosis of pulmonary tuberculosis on day 0. During the specific treatment the 85B mRNA was detectable in 13 patients on day 15 and in only three patients on day 30. Conclusions: Mycobacterium tuberculosis mRNA in the sputum is a useful prognostic marker and its quantification, an early and reliable indicator for monitoring response to treatment, drug resistance, re-infection and relapse. Significance and Impact of the Study: RT-qPCR is a tool that can be used in clinical and therapeutic monitoring as an indicator of bacterial resistance and indicator of the period of transmissibility of Myco. tuberculosis in patients with pulmonary TB undergoing treatment. © 2014 The Society for Applied Microbiology. Source

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