Navegando por Autor "Avelar, Daniel Moreira de"
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Item Antibody responses induced by Leish-Tec®, an A2-basedvaccine for visceral leishmaniasis, in a heterogeneous caninepopulation.(2014) Testasicca, Miriam Conceição de Souza; Santos, Mariana Silva dos; Machado, Leopoldo Marques; Serufo, Ângela Vieira; Doro, Daniel; Avelar, Daniel Moreira de; Tibúrcio, Ana Maria Leonardi; Abrantes, Christiane de Freitas; Coelho, George Luiz Lins Machado; Grimaldi Junior, Gabriel; Gazzinelli, Ricardo Tostes; Fernandes, Ana Paula Salles MouraZoonotic visceral leishmaniasis (VL) is a widespread disease, and dogs are the main reser-voirs for human parasite transmission. Hence, development of an effective vaccine thatprevents disease and reduces the transmission of VL is required. As euthanasia of seropos-itive dogs is recommended in Brazil for VL epidemiological control, to include anti-VLcanine vaccines as a mass control measure it is necessary to characterize the humoralresponses induced by vaccination and if they interfere with the reactivity of vaccinateddogs in serological diagnostic tests. Leish-Tec®is an amastigote-specific A2 recombinantprotein vaccine against canine visceral leishmaniasis (CVL) that is commercially availablein Brazil. Here, we tested the immunogenicity of Leish-Tec®in a heterogeneous dog popula-tion by measuring A2-specific antibody responses. Healthy dogs (n = 140) of various breedswere allocated to two groups: one group received Leish-Tec®(n = 70), and the other groupreceived a placebo (n = 70). Anti-A2 or anti-Leishmania promastigote antigen (LPA) antibodylevels were measured by ELISA in serum samples collected before and after vaccination.An immunochromatographic test (DPP) based on the recombinant K28 antigen was alsoused for serodiagnosis of CVL. Vaccinated animals, except one, remained seronegative foranti-LPA total IgG and anti-K28 antibodies. Conversely, seropositivity for anti-A2 total IgGantibodies was found in 98% of animals after vaccination. This value decreased to 81.13% at6 months before rising again (98%), after the vaccination boost. Anti-A2 IgG2 and IgG1 titers.Item Epidemiological aspects of vector, parasite, and domestic reservoir in areas of recent transmission and no reported human cases of visceral leishmaniasis in Brazil.(2015) Silva, Fabiana de Oliveira Lara; Michalsky, Érika Monteiro; Dias, Consuelo Latorre Fortes; Fiuza, Vanessa de Oliveira Pires; Pessanha, José Eduardo Marques; Silva, Shara Regina; Avelar, Daniel Moreira de; Silva, Maiara Alves; Lima, Ana Cristina Vianna Mariano da Rocha; Costa, Ailton Junior Antunes da; Coelho, George Luiz Lins Machado; Dias, Edelberto SantosAbout 97% of the human cases of the American visceral leishmaniasis (VL) occur in Brazil. In the last fewyears, the disease expanded to medium- and large-sized cities, in which surveillance and control actionshave been intensified, in an effort to control VL spreading. Our two-year study was conducted in BeloHorizonte, the sixth most populous city in Brazil, which is endemic for VL. We focused in two particulardistricts of recent transmission of the disease, with no reported human cases and submitted to minorsurveillance and control actions. Our aim was to draw an epidemiological profile of the local situationconcerning Lutzomyia vector, Leishmania parasites, and the main domestic reservoirs (dogs). Lutzomyialongipalpis comprised 96.5% of the total phlebotomine sand flies captured and displayed an expressiveminimal infection rate by Leishmania infantum (16.7%). Positive correlations were found between the pop-ulation densities of L. longipalpis, rainfall and temperature. L. infantum was also detected in the cortelezziicomplex and, for the first time, in Lutzomyia lloydi. Leishmania braziliensis, an etiological agent of theAmerican cutaneous leishmaniasis, was also identified in L. longipalpis. Among the 1408 dogs serologi-cally tested by standard enzyme-linked and fluorescence immune assays (ELISA/IFA) 3.6% were positivefor VL. L. infantum DNA and Leishmania parasites were identified in 100% and 72.5% of the seropositivedogs, respectively. The co-positivity of other diagnostic tests for VL—Leishmania-nested PCR, imprintand myeloculture—was compared to the standard serology. Both symptomatic or asymptomatic dogsdisplayed an equal average number of positive diagnostic tests for VL. The districts studied display favor-able conditions for the rapid spreading of human infection, in terms of L. longipalpis population density,and presence of L. infantum in both vector and main reservoir.Item Evaluation of three recombinant proteins for the development of ELISA and immunochromatographic tests for visceral leishmaniasis serodiagnosis.(2019) Santos, Anna Raquel Ribeiro dos; Serufo, Ângela Vieira; Figueiredo, Maria Marta; Godoi, Lara Carvalho; Vitório, Jéssica Gardone; Marcelino, Andreza Pain; Avelar, Daniel Moreira de; Rodrigues, Fernandes Tenório Gomes; Coelho, George Luiz Lins Machado; Medeiros, Fernanda Alvarenga Cardoso; Jeronimo, Selma Maria Bezerra; Oliveira, Edward José de; Nascimento, Frederico Crepaldi; Teixeira, Santuza Maria Ribeiro; Gazzinelli, Ricardo Tostes; Nagem, Ronaldo Alves Pinto; Fernandes, Ana Paula Salles MouraBACKGROUND Visceral Leishmaniasis (VL) is an infectious disease that is a significant cause of death among infants aged under 1 year and the elderly in Brazil. Serodiagnosis is a mainstay of VL elimination programs; however, it has significant limitations due to low accuracy. OBJECTIVE This study aimed to evaluate three recombinant Leishmania infantum proteins (rFc, rC9, and rA2) selected from previous proteomics and genomics analyses to develop enzyme-linked immunosorbent assay (ELISA) and immunochromatographic tests (ICT) for the serodiagnosis of human VL (HVL) and canine VL (CVL). METHODS A total of 186 human (70 L. infantum-infected symptomatic, 20 other disease-infected, and 96 healthy) and 185 canine (82 L. infantum-infected symptomatic, 27 L. infantum-infected asymptomatic, and 76 healthy) sera samples were used for antibody detection. FINDINGS Of the three proteins, rA2 (91.5% sensitivity and 87% specificity) and rC9 (95.7% sensitivity and 87.5% specificity) displayed the best performance in ELISA-HVL and ELISA-CVL, respectively. ICT-rA2 also displayed the best performance for HVL diagnosis (92.3% sensitivity and 88.0% specificity) and had high concordance with immunofluorescence antibody tests (IFAT), ELISA-rK39, IT-LEISH®, and ELISAEXT. ICT-rFc, ICT-rC9, and ICT-rA2 had sensitivities of 88.6%, 86.5%, and 87.0%, respectively, with specificity values of 84.0%, 92.0%, and 100%, respectively for CVL diagnosis. MAIN CONCLUSIONS The three antigens selected by us are promising candidates for VL diagnosis regardless of the test format, although the antigen combinations and test parameters may warrant further optimisation.