VERA LUCIA TEIXEIRA DE FREITAS
Projetos de Pesquisa
Unidades Organizacionais
Departamento de Moléstias Infecciosas e Parasitárias, Faculdade de Medicina
LIM/48 - Laboratório de Imunologia, Hospital das Clínicas, Faculdade de Medicina
LIM/48 - Laboratório de Imunologia, Hospital das Clínicas, Faculdade de Medicina
16 resultados
Resultados de Busca
Agora exibindo 1 - 10 de 16
- A Real Time PCR strategy for the detection and quantification of Candida albicans in human blood(2020) BUSSER, Felipe Delatorre; COELHO, Vivian Caso; FONSECA, Claudia de Abreu; NEGRO, Gilda Maria Barbaro Del; SHIKANAI-YASUDA, Maria Aparecida; LOPES, Marta Heloisa; MAGRI, Marcello Mihailenko Chaves; FREITAS, Vera Lucia Teixeira deCandidemia is a significant cause of bloodstream infections (BSI) in nosocomial settings. The identification of species can potentially improve the quality of care and decrease human mortality. Quantitative PCR (qPCR) was evaluated for Candida albicans detection using culture suspensions containing C. albicans, spiked human blood. the cloned qPCR target fragment (ITS2 region) and the results of these assays were compared. The assays showed a good detection limit: C. albicans DNA extracted from yeast (sensitivity 0.2 CFU/mu L), spiked human blood (sensitivity 10 CFU/mL), and cloned fragment of ITS2 region (sensitivity 20 target copies/mu L). The efficiency of ITS2 fragment-qPCR ranged from 89.67 to 97.07, and the linearity (R-2) of the standard curve ranged from 0.992 to 0.999. The results showed that this ITS2-qPCR has a great potential as a molecular prototype model for the development of a test to be applied in clinical practice, greatly reducing the time of candidemia diagnosis, which is extremely important in this clinical setting.
- Oral administration of buparvaquone nanostructured lipid carrier enables in vivo activity against Leishmania infantum(2022) MONTEIRO, Lis Marie; LOBENBERG, Raimar; BARBOSA, Eduardo Jose; ARAUJO, Gabriel Lima Barros de; SATO, Paula Keiko; KANASHIRO, Edite; ELIODORO, Raissa H. de Araujo; ROCHA, Mussya; FREITAS, Vera Lucia Teixeira de; FOTAKI, Nikoletta; BOU-CHACRA, Nadia AraciLeishmaniasis, a neglected tropical disease, is prevalent in 98 countries with the occurrence of 1.3 million new cases annually. The conventional therapy for visceral leishmaniasis requires hospitalization due to the severe adverse effects of the drugs, which are administered parenterally. Buparvaquone (BPQ) showed in vitro activity against leishmania parasites; nevertheless, it has failed in vivo tests due to its low aqueous solubility. Though, lipid nanoparticles can overcome this holdback. In this study we tested the hypothesis whether BPQ-NLC shows in vivo activity against L. infantum. Two optimized formulations were prepared (V1: 173.9 +/- 1.6 nm, 0.5 mg of BPQ/mL; V2: 232.4 +/- 1.6 nm, 1.3 mg of BPQ/mL), both showed increased solubility up to 73.00-fold, and dissolution up to 83.29%, while for the free drug it was only 2.89%. Cytotoxicity test showed their biocompatibility (CC50 >554.4 mu M). Besides, the V1 dose of 0.3 mg/kg/day for 10 days reduced the parasite burden in 83.4% +/- 18.2% (p <0.05) in the liver. BPQ-NLC showed similar leishmanicidal activity compared to miltefosine. Therefore, BPQ-NLC is a promising addition to the limited therapeutic arsenal suitable for leishmaniasis oral administration treatment.
- Suspected vertical transmission of Chagas disease caused by DTU TcIV in an infection probably transmitted orally, during anoutbreak in the Brazilian Amazon(2021) FREITAS, Vera Lucia Teixeira de; ESPER, Helena Rangel; NAKANISHI, Erika Shimoda; PIOTTO, Mariana Ramos; ASSY, Joao Guilherme Pontes Lima; BERRETA, Olivia Campos Pinheiro; SAID, Renato do Carmo; SEGURADO, Aluisio Augusto Cotrim; CARVALHO, Noemia Barbosa; FRANCA, Francisco Oscar de Siqueira; LOPES, Marta HeloisaThis study describes difficulties in the monitoring of a child born during an oral outbreak of Chagas disease, in which there are several indications that the transmission occurred through the congenital route: 1. the mother was in the third trimester of pregnancy when she was infected; 2. She presented high parasitemia at the time of delivery; 3. In both, the mother and her daughter, T cruzi was classified as DTU TcIV. The parasites were not found in the blood at birth and the infection was detected only three months later in an asymptomatic infant. As the mother and her child live in a highly endemic area, vector transmission could not be excluded during this period.
- Multilocus Sequence Typing of Candida tropicalis Shows the Presence of Different Clonal Clusters and Fluconazole Susceptibility Profiles in Sequential Isolates from Candidemia Patients in Sao Paulo, Brazil(2013) MAGRI, Marcello Mihailenko Chaves; GOMES-GOUVEA, Michele Soares; FREITAS, Vera Lucia Teixeira de; MOTTA, Adriana Lopes; MORETTI, Maria Luiza; SHIKANAI-YASUDA, Maria AparecidaThe profiles of 61 Candida tropicalis isolates from 43 patients (28 adults and 15 children) diagnosed with candidemia at two teaching hospitals in Sao Paulo, Brazil, were characterized by multilocus sequence typing (MLST). For the 14 patients who had bloodstream infections, 32 isolates were serially collected from their blood and/or catheters. Thirty-nine diploid sequence types (DSTs) were differentiated. According to the C. tropicalis MLST database (http://pubmlst.org/ctropicalis/), 36 DSTs and 23 genotypes identified from the 61 isolates had not previously been described. This report represents the first study to characterize sequential isolates of C. tropicalis from candidemia cases in South America. Microvariation in a single gene was found in the sequential isolates from 7 patients. The main polymorphisms occurred in the alleles of the XYR1 gene, specifically at nucleotide positions 215, 242, and 344. Macrovariation in six gene fragments was detected in the isolates from 3 patients. eBURST analysis added two new groups to this study (groups 6 and 18). Additionally, susceptibility tests indicate that 3 isolates were resistant to fluconazole. No correlation was found between the DSTs and susceptibility to fluconazole and/or selective antifungal pressure. Two patients were sequentially infected with resistant and susceptible strains. MLST is an important tool for studying the genetic diversity of multiple/sequential isolates of patients with candidemia, allowing the comparison of our data with those from other regions of the world, as well as allowing an analysis of the genetic relationship among several clones in sequential isolates from the same or different candidemia patient sites (blood or catheter).
- Detection of Trypanosoma cruzi DTUs TcI and TcIV in two outbreaks of orally-transmitted Chagas disease in the Northern region of Brazil(2023) FREITAS, Vera Lucia Teixeira de; PIOTTO, Mariana Ramos; ESPER, Helena Rangel; NAKANISHI, Erika Yoshie Shimoda; FONSECA, Claudia de Abreu; ASSY, Joao Guilherme Pontes Lima; BERRETA, Olivia Campos Pinheiro; FRANCA, Francisco Oscar de Siqueira; LOPES, Marta HeloisaThis study describes the laboratory investigation of two acute Chagas disease outbreaks that occurred in the riverside communities of Marimarituba and Cachoeira do Arua, in the Santarem municipality, Para State, located in the Northern region of Brazil, and occurred in March 2016 and August 2017, respectively. The generation of data regarding the diversity of Trypanosoma cruzi parasites circulating in the Amazon region is key for understanding the emergence and expansion of Chagas disease. This study aimed to identify T. cruzi Discrete Typing Units (DTUs) involved in two outbreaks of acute Chagas disease (ACD) directly from the patient's biological sample. Nested and multiplex PCR targeting the symbolscript (rRNA) and mini-exon genes, respectively, were used to identify T. cruzi DTU in blood samples from patients diagnosed with ACD. The samples with positive cPCR were submitted for analysis for T. cruzi DTUs, which included 13 samples from the patients with ACD by oral transmission and two samples collected from two newborns of two women with ACD, from Marimarituba and Cachoeira do Arua. The samples were classified as T. cruzi TcIV, from Marimarituba's outbreak, and T. cruzi TcI, from Cachoeira do Arua's outbreak. The molecular identification of T. cruzi may increase understanding of the role of this parasite in Chagas disease's emergence within the Amazon region, contributing to the improvement of the management of this important, but also neglected, disease.
- Interdisciplinary approach at the primary healthcare level for Bolivian immigrants with Chagas disease in the city of Sao Paulo(2017) YASUDA, Maria Aparecida Shikanai; SATOLO, Camila Goncalves; CARVALHO, Noemia Barbosa; ATALA, Magda Maya; FERRUFINO, Rosarlo Quiroga; LEITE, Ruth Moreira; FURUCHO, Celia Regina; LUNA, Expedito; SILVA, Rubens Antonio; HAGE, Marcia; OLIVEIRA, Caroline Medeji Ramos de; BUSSER, Felipe Delatorre; FREITAS, Vera Lucia Teixeira de; WANDERLEY, Dalva Marli Valerio; MARTINELLI, Luzia; ALMEIDA, Sonia Regina; VINAS, Pedro Albajar; CARNEIRO JR., NivaldoBackground/Methods In a pioneering cross-sectional study among Bolivian immigrants in the city of Sao Paulo, Brazil, the epidemiological profile, clinical manifestations and morbidity of Chagas disease were described. The feasibility of the management of Chagas disease at primary healthcare clinics using a biomedical and psychosocial interdisciplinary approach was also tested. Previously, a Trypanosoma cruzi (T. cruzi) infection rate of 4.4% among 633 immigrants was reported. The samples were screened using two commercial enzyme-linked immunoassay (ELISA) tests generated with epimastigote antigens, and those with discrepant or seropositive results were analyzed by confirmatory tests: indirect immunofluorescence (IFI), TESA-blot and a commercial recombinant ELISA. PCR and blood cultures were performed in seropositive patients. Results The majority of the 28 seropositive patients were women, of whom 88.89% were of childbearing age. The predominant clinical forms of Chagas disease were the indeterminate and atypical cardiac forms. Less than 50% received the recommended antiparasitic treatment of benznidazole. An interdisciplinary team was centered on primary healthcare physicians who applied guidelines for the management of patients. Infectologists, cardiologists, pediatricians and other specialists acted as reference professionals. Confirmatory serology and molecular biology tests, as well as echocardiography, Holter and other tests, were performed for the assessment of affected organs in secondary healthcare centers. The published high performance of two commercial ELISA tests was not confirmed. Conclusion An interdisciplinary approach including antiparasitic treatment is feasible at the primary healthcare level for the management of Chagas disease in Bolivian immigrants. The itinerant feature of immigration was associated with a lack of adherence to antiparasitic treatment and was considered a main challenge for the clinical management of this population. This approach is recommended for management of the infected population in endemic and nonendemic areas, although different strategies are needed depending on the severity of the disease and the structure of the healthcare system.
- Quantitative PCR as a marker for preemptive therapy and its role in therapeutic control in Trypanosoma cruzi/HIV coinfection(2024) FREITAS, Vera Lucia Teixeira de; NOVAES, Christina Terra Gallafrio; SARTORI, Ana Marli Christovam; CARVALHO, Noemia Barbosa; SILVA, Sheila Cristina Vicente da; NAKANISHI, erika Shimoda; SALVADOR, Fernando; CASTRO, Cleudson Nery de; BEZERRA, Rita Cristina; WESTPHALEN, Elizabeth Visone Nunes; OLIVEIRA, Caroline Medeji Ramos de; BUSSER, Felipe Delatorre; HO, Yeh-Li; BUCCHERI, Renata; BONILLA, Carolina; SHIKANAI-YASUDA, Maria AparecidaBackground Trypanosoma cruzi and HIV coinfection can evolve with depression of cellular immunity and increased parasitemia. We applied quantitative PCR (qPCR) as a marker for preemptive antiparasitic treatment to avoid fatal Chagas disease reactivation and analyzed the outcome of treated cases. Methodology This mixed cross-sectional and longitudinal study included 171 Chagas disease patients, 60 coinfected with HIV. Of these 60 patients, ten showed Chagas disease reactivation, confirmed by parasites identified in the blood, cerebrospinal fluid, or tissues, 12 exhibited high parasitemia without reactivation, and 38 had low parasitemia and no reactivation. Results We showed, for the first time, the success of the timely introduction of benznidazole in the non-reactivated group with high levels of parasitemia detected by qPCR and the absence of parasites in reactivated cases with at least 58 days of benznidazole. All HIV+ patients with or without reactivation had a 4.0-5.1 higher chance of having parasitemia than HIV seronegative cases. A positive correlation was found between parasites and viral loads. Remarkably, treated T. cruzi/HIV-coinfected patients had 77.3% conversion from positive to negative parasitemia compared to 19.1% of untreated patients. Additionally, untreated patients showed similar to 13.6 times higher Odds Ratio of having positive parasitemia in the follow-up period compared with treated patients. Treated and untreated patients showed no differences regarding the evolution of Chagas disease. The main factors associated with all-cause mortality were higher parasitemia, lower CD4 counts/mu L, higher viral load, and absence of antiretroviral therapy. Conclusion We recommend qPCR prospective monitoring of T. cruzi parasitemia in HIV+ coinfected patients and point out the value of pre-emptive therapy for those with high parasitemia. In parallel, early antiretroviral therapy introduction is advisable, aiming at viral load control, immune response restoration, and increasing survival. We also suggest an early antiparasitic treatment for all coinfected patients, followed by effectiveness analysis alongside antiretroviral therapy.
- Multiple myeloma and Chagas disease: qPCR as a marker forpreemptive antiparasitic therapy: a case reports series and review(2024) CARVALHO, Noemia Barbosa; FREITAS, Vera Lucia Teixeira de; SEGURO, Fernanda Salles; BEZERRA, Rita Cristina; FATOBENE, Giancarlo; NAKANISHI, erika Yoshie Shimoda; VISNADI, Helena; MARTINEZ, Gracia; BATISTA, Marjorie Vieira; ROCHA, Vanderson; DULLEY, Frederico Luis; COSTA, Silvia Figueiredo; SHIKANAI-YASUDA, Maria AparecidaMultiple myeloma (MM) associated with Chagas disease is rarely described. This disease and its therapy suppress T cell and macrophage functions and increase regulatory T cell function, allowing the increase of parasitemia and the risk of Chagas Disease Reactivation (CDR). We aimed to analyze the role of conventional (cPCR) and quantitative Polymerase Chain Reaction (qPCR) for prospective monitoring of T. cruzi parasitemia, searching for markers of preemptive antiparasitic therapy in MM patients with Chagas disease. Moreover, we investigated the incidence and management of hematological diseases and CDR both inside and outside the transplant setting in the MEDLINE database. We found 293 studies and included 31 of them. Around 1.9-2.0% of patients with Chagas disease were reported in patients undergoing Stem Cell Transplantation. One case of CDR was described in eight cases of MM and Chagas disease. We monitored nine MM and Chagas disease patients, seven under Autologous Stem Cell Transplantation (ASCT), during 44.56 +/- 32.10 months (mean +/- SD) using parasitological methods, cPCR, and qPCR. From these patients, three had parasitemia. In the first, up to 256 par Eq/mL were detected, starting from 28 months after ASCT. The second patient dropped out and died soon after the detection of 161.0 par Eq/mL. The third patient had a positive blood culture. Benznidazole induced fast negativity in two cases; followed by notably lower levels in one of them. Increased T. cruzi parasitemia was related to the severity of the underlying disease. We recommend parasitemia monitoring by qPCR for early introduction of preemptive antiparasitic therapy to avoid CDR. KEYWORDS Multiple myeloma; Chagas disease; T. cruzi parasitemia; Conventional PCR; Quantitative PCR
- Fatal evolution of acute Chagas disease in a child from Northern Brazil: factors that determine poor prognosis(2019) ESPER, Helena Rangel; FREITAS, Vera Lucia Teixeira de; ASSY, Joao Guilherme Pontes Lima; SHIMODA, Erika Yoshie; BERRETA, Olivia Campos Pinheiro; LOPES, Marta Heloisa; FRANCA, Francisco Oscar SiqueiraTrypanosoma cruzi is the causative agent of Chagas disease. Nowadays, the transmission in Brazil occurs mainly by oral ingestion of contaminated food that has been associated with more severe clinical manifestations. We report a case of Acute Chagas disease caused by oral transmission in a child from Northern Brazil. In the hospital admission, physical examination showed tachycardia, hepatomegaly. bipalpebral edema and anasarca. Trypanosoma cruzi trypomastigotes were found in microscopy during blood cell count. Twenty-three days before hospitalization, the child had ingested the ""bacaba palm fruit's wine"". Even with the appropriate diagnosis and starting of treatment, she did not survive. Quantitative analysis of Trypanosoma cruzi DNA in a blood sample resulted in 54,053.42 parasite equivalents/mL and the DTU TcIV was identified. The outcome may have been determined by several factors, including the delay to seek a medical service beyond the high parasitemia, detected by qPCR. DTU TcIV could also have influenced the natural history of the disease.
- Role of T. cruzi exposure in the pattern of T cell cytokines among chronically infected HIV and Chagas disease patients(2017) TOZETTO-MENDOZA, Tania Regina; VASCONCELOS, Dewton de Moraes; IBRAHIM, Karim Yaqub; SARTORI, Ana Marli Christovam; BEZERRA, Rita C.; FREITAS, Vera Lucia Teixeira de; SHIKANAI-YASUDA, Maria AparecidaOBJECTIVES: The impact of Chagas disease (CD) in HIV-infected patients is relevant throughout the world. In fact, the characterization of the adaptive immune response in the context of co-infection is important for predicting the need for interventions in areas in which HIV and Chagas disease co-exist. METHODS: We described and compared the frequency of cytokine-producing T cells stimulated with soluble antigen of Trypanosoma cruzi (T. cruzi) using a cytometric assay for the following groups: individuals with chronic Chagas disease (CHR, n=10), those with Chagas disease and HIV infection (CO, n=11), those with only HIV (HIV, n=14) and healthy individuals (C, n=15). RESULTS: We found 1) a constitutively lower frequency of IL-2+ and IFN-gamma+T cells in the CHR group compared with the HIV, CO and healthy groups; 2) a suppressive activity of soluble T. cruzi antigen, which down-regulated IL-2+CD4+ and IFN-gamma+ CD4+ phenotypes, notably in the healthy group; 3) a down-regulation of inflammatory cytokines on CD8+ T cells in the indeterminate form of Chagas disease; and 4) a significant increase in IL-10 + CD8+ cells distinguishing the indeterminate form from the cardiac/digestive form of Chagas disease, even in the presence of HIV infection. CONCLUSIONS: Taken together, our data suggest the presence of an immunoregulatory response in chronic Chagas disease, which seems to be driven by T. cruzi antigens. Our findings provide new insights into immunotherapeutic strategies for people living with HIV/AIDS and Chagas disease.