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Your search keyword '"Braga, Érika M."' showing total 126 results
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126 results on '"Braga, Érika M."'

2. Loss of forest cover and host functional diversity increases prevalence of avian malaria parasites in the Atlantic Forest

Author

Fecchio, Alan, Lima, Marcos R., Bell, Jeffrey A., Schunck, Fabio, Corrêa, Aline H., Beco, Renata, Jahn, Alex E., Fontana, Carla S., da Silva, Thaiane W., Repenning, Márcio, Braga, Érika M., Garcia, José E., Lugarini, Camile, Silva, Jean C.R., Andrade, Leontina H.M., Dispoto, Janice H., dos Anjos, Carolina C., Weckstein, Jason D., Kirchgatter, Karin, Ellis, Vincenzo A., Ricklefs, Robert E., and De La Torre, Gabriel M.

Published
2021
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3. Higher infection probability of haemosporidian parasites in Blue-black Grassquits (Volatinia jacarina) inhabiting native vegetation across Brazil

Author

Fecchio, Alan, Ribeiro, Rayanne M., Ferreira, Francisco C., de Angeli Dutra, Daniela, Tolesano-Pascoli, Graziela, Alquezar, Renata D., Khan, Asmat U., Pichorim, Mauro, Moreira, Patrícia A., Costa-Nascimento, Maria J., Monteiro, Eliana F., Mathias, Bruno S., Guimarães, Lilian O., Simões, Roseli F., Braga, Érika M., Kirchgatter, Karin, and Dias, Raphael I.

Published
2021
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11. Global drivers of avian haemosporidian infections vary across zoogeographical regions

Author

Fecchio, Alan, primary, Clark, Nicholas J., additional, Bell, Jeffrey A., additional, Skeen, Heather R., additional, Lutz, Holly L., additional, De La Torre, Gabriel M., additional, Vaughan, Jefferson A., additional, Tkach, Vasyl V., additional, Schunck, Fabio, additional, Ferreira, Francisco C., additional, Braga, Érika M., additional, Lugarini, Camile, additional, Wamiti, Wanyoike, additional, Dispoto, Janice H., additional, Galen, Spencer C., additional, Kirchgatter, Karin, additional, Sagario, M. Cecilia, additional, Cueto, Victor R., additional, González‐Acuña, Daniel, additional, Inumaru, Mizue, additional, Sato, Yukita, additional, Schumm, Yvonne R., additional, Quillfeldt, Petra, additional, Pellegrino, Irene, additional, Dharmarajan, Guha, additional, Gupta, Pooja, additional, Robin, V. V., additional, Ciloglu, Arif, additional, Yildirim, Alparslan, additional, Huang, Xi, additional, Chapa‐Vargas, Leonardo, additional, Álvarez‐Mendizábal, Paulina, additional, Santiago‐Alarcon, Diego, additional, Drovetski, Serguei V., additional, Hellgren, Olof, additional, Voelker, Gary, additional, Ricklefs, Robert E., additional, Hackett, Shannon J., additional, Collins, Michael D., additional, Weckstein, Jason D., additional, Wells, Konstans, additional, and Kamath, Pauline, additional

Published
2021
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17. Polymorphism at the apical membrane antigen 1 locus reflects the world population history of Plasmodium vivax

Author

Braga Érika M, Hughes Austin L, Fontes Cor, and Grynberg Priscila

Subjects
Evolution, QH359-425
Abstract

Abstract Background In malaria parasites (genus Plasmodium), ama-1 is a highly polymorphic locus encoding the Apical Membrane Protein-1, and there is evidence that the polymorphism at this locus is selectively maintained. We tested the hypothesis that polymorphism at the ama-1 locus reflects population history in Plasmodium vivax, which is believed to have originated in Southeast Asia and is widely geographically distributed. In particular, we tested for a signature of the introduction of P. vivax into the New World at the time of the European conquest and African slave trade and subsequent population expansion. Results One hundred and five ama-1 sequences were generated and analyzed from samples from six different Brazilian states and compared with database sequences from the Old World. Old World populations of P. vivax showed substantial evidence of population substructure, with high sequence divergence among localities at both synonymous and nonsynonymous sites, while Brazilian isolates showed reduced diversity and little population substructure. Conclusion These results show that genetic diversity in P. vivax AMA-1 reflects population history, with population substructure characterizing long-established Old World populations, whereas Brazilian populations show evidence of loss of diversity and recent population expansion. Note Nucleotide sequence data reported is this paper are available in the GenBank™ database under the accession numbers EF031154 – EF031216 and EF057446 – EF057487

Published
2008
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18. Low sensitivity of nested PCR using Plasmodium DNA extracted from stained thick blood smears: an epidemiological retrospective study among subjects with low parasitaemia in an endemic area of the Brazilian Amazon region

Author

Horta Maria, Nunes Álvaro C, Fontes Cor JF, Scopel Kézia KG, and Braga Érika M

Subjects
Arctic medicine. Tropical medicine, RC955-962, Infectious and parasitic diseases, RC109-216
Abstract

Abstract Background The success of PCR technique depends on many factors, such as high quality DNA pellets obtained from blood samples, good reagents and adequate conditions of amplification. Taking these limitations into account, a retrospective epidemiological study for malaria diagnosis was conducted in a mesoendemic area in the Brazilian Amazon. Methods A nested PCR protocol with DNA extracted from two blood storage devices obtained from Giemsa-stained thick blood smears and filter-papers was used for malaria diagnosis. The extracted DNA was used as a template to amplify approximately 100 bp species-specific sequences of the small subunit of the ribosomal RNA (18S SSU rRNA) of Plasmodium sp. The prevalence of single and mixed infections was examined in a cross-sectional survey carried out among 369 miners living in the district of Apiacás, Mato Grosso State. The parasitemia levels detected by microscopic examination were compared to the PCR results. Results DNA samples isolated from blood on filter-paper allowed the detection and identification of Plasmodium in 165 (44.7%) of the 369 individuals evaluated, while only 62 (16.8%) had positive results using DNA obtained from thick smears, a similar rate observed by microscopic examination. The sensitivities of PCR using DNA from blood smears and filter-papers were 65% and 73.0%, respectively. Low parasite infections (below 20 parasites/µL blood) were not detected when thick blood smears were used as a DNA source. Conclusions Although the blood preserved as thick blood smears provides an alternative and useful tool for malaria molecular diagnosis, its relatively poor performance at low level parasitemias impairs the correct determination of malaria prevalence in epidemiological studies. However, the results obtained in the present study confirm that the use of filter-paper to collect blood is useful for field studies.

Published
2004

27. Correction: Outbreak of Avian Malaria Associated to Multiple Species of Plasmodium in Magellanic Penguins Undergoing Rehabilitation in Southern Brazil

Author

Vanstreels, Ralph Eric Thijl, primary, Kolesnikovas, Cristiane K. M., additional, Sandri, Sandro, additional, Silveira, Patrícia, additional, Belo, Nayara O., additional, Ferreira, Francisco C., additional, Epiphanio, Sabrina, additional, Steindel, Mário, additional, Braga, Érika M., additional, and Catão-Dias, José Luiz, additional

Published
2014
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29. Effect of the Aedes fluviatilis saliva on the development of Plasmodium gallinaceum infection in Gallus (gallus) domesticus

Author

Rocha, Ana CVM da, Braga, Érika M, Araújo, Márcio SS, Franklin, Bernardo S, and Pimenta, Paulo FP

Subjects
saliva, animal structures, sporozoites, stomatognathic system, parasitic diseases, avian malaria, antibodies, mosquitoes
Abstract

Effect of Aedes fluviatilis saliva on the development of Plasmodium gallinaceum experimental infection in Gallus (gallus) domesticus was studied in distinct aspects. Chickens subcutaneously infected with sporozoites in the presence of the mosquito salivary gland homogenates (SGH) showed higher levels of parasitaemia when compared to those ones that received only the sporozoites. However, the parasitaemia levels were lower among chickens previously immunized by SGH or non-infected mosquito bites compared to the controls, which did not receive saliva. High levels of anti-saliva antibodies were observed in those immunized chickens. Moreover, 53 and 102 kDa saliva proteins were recognized by sera from immunized chickens. After the sporozoite challenge, the chickens also showed significant levels of anti-sporozoite antibodies. However, the ability to generate anti-sporozoites antibodies was not correlated to the saliva immunization. Our results suggest that mosquito saliva components enhance P. gallinaceum parasite development in naive chickens. However, the prior exposure of chickens to salivary components controls the parasitemia levels in infected individuals.

Published
2004

31. Outbreak of Avian Malaria Associated to Multiple Species of Plasmodium in Magellanic Penguins Undergoing Rehabilitation in Southern Brazil

Author

Vanstreels, Ralph Eric Thijl, primary, Kolesnikovas, Cristiane K. M., additional, Sandri, Sandro, additional, Silveira, Patrícia, additional, Belo, Nayara O., additional, Ferreira Junior, Francisco C., additional, Epiphanio, Sabrina, additional, Steindel, Mário, additional, Braga, Érika M., additional, and Catão-Dias, José Luiz, additional

Published
2014
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37. Epidemiology and control of frontier malaria in Brazil: lessons from community-based studies in rural Amazonia

Author

da Silva, Natal S., primary, da Silva-Nunes, M., additional, Malafronte, Rosely S., additional, Menezes, Maria J., additional, D’Arcadia, Rosane R., additional, Komatsu, Natália T., additional, Scopel, Kézia K.G., additional, Braga, Érika M., additional, Cavasini, Carlos E., additional, Cordeiro, José A., additional, and Ferreira, Marcelo U., additional

Published
2010
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45. Low sensitivity of nested PCR using Plasmodium DNA extracted from stained thick blood smears: an epidemiological retrospective study among subjects with low parasitaemia in an endemic area of the Brazilian Amazon region

Author

Scopel, Kézia KG, Fontes, Cor JF, Nunes, Álvaro C, Horta, Maria de Fátima, and Braga, Érika M

Subjects
Blood Specimen Collection, Plasmodium, Methodology, DNA, Protozoan, Parasitemia, DNA, Ribosomal, Polymerase Chain Reaction, Sensitivity and Specificity, Malaria, Cross-Sectional Studies, parasitic diseases, Prevalence, RNA, Ribosomal, 18S, Animals, Humans, Brazil, Retrospective Studies
Abstract

Background The success of PCR technique depends on many factors, such as high quality DNA pellets obtained from blood samples, good reagents and adequate conditions of amplification. Taking these limitations into account, a retrospective epidemiological study for malaria diagnosis was conducted in a mesoendemic area in the Brazilian Amazon. Methods A nested PCR protocol with DNA extracted from two blood storage devices obtained from Giemsa-stained thick blood smears and filter-papers was used for malaria diagnosis. The extracted DNA was used as a template to amplify approximately 100 bp species-specific sequences of the small subunit of the ribosomal RNA (18S SSU rRNA) of Plasmodium sp. The prevalence of single and mixed infections was examined in a cross-sectional survey carried out among 369 miners living in the district of Apiacás, Mato Grosso State. The parasitemia levels detected by microscopic examination were compared to the PCR results. Results DNA samples isolated from blood on filter-paper allowed the detection and identification of Plasmodium in 165 (44.7%) of the 369 individuals evaluated, while only 62 (16.8%) had positive results using DNA obtained from thick smears, a similar rate observed by microscopic examination. The sensitivities of PCR using DNA from blood smears and filter-papers were 65% and 73.0%, respectively. Low parasite infections (below 20 parasites/µL blood) were not detected when thick blood smears were used as a DNA source. Conclusions Although the blood preserved as thick blood smears provides an alternative and useful tool for malaria molecular diagnosis, its relatively poor performance at low level parasitemias impairs the correct determination of malaria prevalence in epidemiological studies. However, the results obtained in the present study confirm that the use of filter-paper to collect blood is useful for field studies.

Published
2004

46. Outbreak of Avian Malaria Associated to Multiple Species of Plasmodium in Magellanic Penguins Undergoing Rehabilitation in Southern Brazil.

Author

Vanstreels, Ralph Eric Thijl, Kolesnikovas, Cristiane K. M., Sandri, Sandro, Silveira, Patrícia, Belo, Nayara O., Ferreira Junior, Francisco C., Epiphanio, Sabrina, Steindel, Mário, Braga, Érika M., and Catão-Dias, José Luiz

Subjects
AVIAN malaria, MEDICAL rehabilitation, PLASMODIUM, MOSQUITO vectors, PATHOGENIC microorganisms, BIRD populations
Abstract

Avian malaria is a mosquito-borne disease caused by Plasmodium spp. Avian plasmodia are recognized conservation-threatening pathogens due to their potential to cause severe epizootics when introduced to bird populations with which they did not co-evolve. Penguins are considered particularly susceptible, as outbreaks in captive populations will often lead to high morbidity and rapid mortality. We used a multidisciplinary approach to investigate an outbreak of avian malaria in 28 Magellanic penguins (Spheniscus magellanicus) at a rehabilitation center during summer 2009 in Florianópolis, Brazil. Hemosporidian infections were identified by microscopic and molecular characterization in 64% (18/28) of the penguins, including Plasmodium (Haemamoeba) tejerai, Plasmodium (Huffia) elongatum, a Plasmodium (Haemamoeba) sp. lineage closely related to Plasmodium cathemerium, and a Haemoproteus (Parahaemoproteus) sp. lineage closely related to Haemoproteus syrnii. P. tejerai played a predominant role in the studied outbreak and was identified in 72% (13/18) of the hemosporidian-infected penguins, and in 89% (8/9) of the penguins that died, suggesting that this is a highly pathogenic parasite for penguins; a detailed description of tissue meronts and lesions is provided. Mixed infections were identified in three penguins, and involved P. elongatum and either P. tejerai or P. (Haemamoeba) sp. that were compatible with P. tejerai but could not be confirmed. In total, 32% (9/28) penguins died over the course of 16 days despite oral treatment with chloroquine followed by sulfadiazine-trimethoprim. Hemosporidian infections were considered likely to have occurred during rehabilitation, probably from mosquitoes infected while feeding on local native birds, whereas penguin-mosquito-penguin transmission may have played a role in later stages of the outbreak. Considering the seasonality of the infection, rehabilitation centers would benefit from narrowing their efforts to prevent avian malaria outbreaks to the penguins that are maintained throughout summer. [ABSTRACT FROM AUTHOR]

Published
2014
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48. Potential Immune Mechanisms Associated with Anemia in Plasmodium vivaxMalaria: a Puzzling Question

Author

Castro-Gomes, Thiago, Mourão, Luiza C., Melo, Gisely C., Monteiro, Wuelton M., Lacerda, Marcus V. G., and Braga, Érika M.

Abstract

ABSTRACTThe pathogenesis of malaria is complex, generating a broad spectrum of clinical manifestations. One of the major complications and concerns in malaria is anemia, which is responsible for considerable morbidity in the developing world, especially in children and pregnant women. Despite its enormous health importance, the immunological mechanisms involved in malaria-induced anemia remain incompletely understood. Plasmodium vivax, one of the causative agents of human malaria, is known to induce a strong inflammatory response with a robust production of immune effectors, including cytokines and antibodies. Therefore, it is possible that the extent of the immune response not only may facilitate the parasite killing but also may provoke severe illness, including anemia. In this review, we consider potential immune effectors and their possible involvement in generating this clinical outcome during P. vivaxinfections.

Published
2014
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49. Investigation of Babesia sp. in pygoscelid penguins at the South Shetland Islands.

Author

Vanstreels, Ralph Eric Thijl, Ferreira Junior, Francisco C., Dutra, Daniela de Angeli, Epiphanio, Sabrina, Braga, Érika M., Pistorius, Pierre A., and Catão-Dias, José Luiz

Subjects
BABESIA, TICK-borne diseases, ADELIE penguin, GENTOO penguin
Abstract

Babesia spp. are tick-borne parasites, and 16 avian-infecting species have been described to date, including one species (Babesia peircei) that infects penguins. Considering the results of a recent study reporting Babesia sp. in penguins on Deception Island, South Shetland Islands, we re-examined the samples obtained in a previous investigation on the occurrence of blood parasites in adult Adélie (Pygoscelis adeliae), chinstrap (Pygoscelis antarcticus) and gentoo penguins (Pygoscelis papua) on King George and Elephant islands, South Shetland Islands. Notwithstanding a comprehensive re-examination of the blood smears, Babesia sp. was not detected. When we employed two nested PCR tests targeting the 18S rRNA gene of Babesia, a considerable proportion of the samples produced positive results; however, gene sequencing revealed these were due to cross-amplification of non-target organisms. We therefore did not detect Babesia sp. infection in penguins on King George and Elephant islands. Additional studies will be valuable to clarify the distribution and epidemiology of tick-borne pathogens in sub-Antarctic and Antarctic seabirds. [ABSTRACT FROM AUTHOR]

Published
2018
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