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Soares M.R.A.,Federal University of Piaui | Soares M.R.A.,Institute Doencas Tropicais Natan Portela | Carvalho C.C.,Federal University of Maranhao | Silva L.A.,Federal University of Maranhao | And 3 more authors.
Cadernos de Saude Publica

The main purpose of this study was to investigate natural infection by Leishmania chagasi in female sand flies in a visceral leishmaniasis (VL) focus on São Luís Island, Maranhão State, Brazil. Molecular analysis by polymerase chain reaction (PCR) was applied to determine the rate of natural infection of Lutzomyia longipalpis by L. chagasi in areas of old and recent human settlement on São Luís Island. Based on a sample of 800 female specimens captured from March to August 2005, the natural infection rate was 1.25% in an area of old settlement and 0.25% in two recently settled areas. Infection of L. longipalpis was detected in both areas, regardless of the number of reported human VL cases, indicating that other factors modulating infection in the wild need to be investigated. The results confirm PCR as a specific technique and an important tool for epidemiological surveillance. Source

Brand G.D.,EMBRAPA - Empresa Brasileira de Pesquisa Agropecuaria | Brand G.D.,Federal University of Piaui | Santos R.C.,Federal University of Piaui | Arake L.M.,EMBRAPA - Empresa Brasileira de Pesquisa Agropecuaria | And 9 more authors.

Antimicrobial peptides (AMPs) from the dermaseptin and phylloseptin families were isolated from the skin secretion of Phyllomedusa nordestina, a recently described amphibian species from Northeastern Brazil. One dermaseptin and three phylloseptins were chosen for solid phase peptide synthesis. The antiprotozoal and antimicrobial activities of the synthetic peptides were determined, as well as their cytotoxicity in mouse peritoneal cells. AMPs are being considered as frameworks for the development of novel drugs inspired by their mechanism of action. © 2013 by the authors. Source

Soares V.Y.R.,Institute Doencas Tropicais Natan Portela | da Silva J.C.,Institute Doencas Tropicais Natan Portela | da Silva K.R.,Federal University of Piaui | Pires e Cruz M.S.,Federal University of Piaui | And 6 more authors.
Memorias do Instituto Oswaldo Cruz

An analysis of the dietary content of haematophagous insects can provide important information about the trans- mission networks of certain zoonoses. The present study evaluated the potential of polymerase chain reaction- restriction fragment length polymorphism (PCR-RFLP) analysis of the mitochondrial cytochrome B (cytb) gene to differentiate between vertebrate species that were identified as possible sources of sandfly meals. The complete cytb gene sequences of 11 vertebrate species available in the National Center for Biotechnology Information database were digested with Aci I, Alu I, Hae III and Rsa I restriction enzymes in silico using Restriction Mapper software. The cytb gene fragment (358 bp) was amplified from tissue samples of vertebrate species and the dietary contents of sandflies and digested with restriction enzymes. Vertebrate species presented a restriction fragment profile that differed from that of other species, with the exception of Canis familiaris and Cerdocyon thous. The 358 bp fragment was identified in 76 sandflies. Of these, 10 were evaluated using the restriction enzymes and the food sources were predicted for four: Homo sapiens (1), Bos taurus (1) and Equus caballus (2). Thus, the PCR-RFLP technique could be a potential method for identifying the food sources of arthropods. However, some points must be clarified regarding the applicability of the method, such as the extent of DNA degradation through intestinal digestion, the potential for multiple sources of blood meals and the need for greater knowledge regarding intraspecific variations in mtDNA. Source

da Silva M.R.B.,Federal University of Goais | da Silva M.R.B.,Institute Doencas Tropicais Natan Portela | Brandao N.A.A.,Federal University of Goais | Dorta M.L.,Federal University of Goais | And 4 more authors.
Tropical Biomedicine

Visceral leishmaniasis (VL) is a tropical neglected disease endemic in 98 countries and affects more than 58 000 individuals per year. Several serological tests are available for VL diagnosis, including an immunochromatographic (IC) test with the rK39 antigen and finger prick-collected blood, a rapid and low-invasive test. Here, we investigate the possibility to use saliva as a non-invasive source of biological material for the rK39 IC test. Blood samples from 84 patients with suspected VL were screened by the rK39 IC test, and 29 were confirmed as being infected by a positive rK39 IC test and the presence of amastigotes on smears slides or parasite DNA (detected using PCR-RFLP) from bone marrow aspirate. The rK39 IC test using saliva samples was positive for 17 of the 29 confirmed VL cases (58.6%). The amount of Leishmania-specific IgG or total IgG, as evaluated by an immunoenzymatic assay, was higher in the saliva of patients who had rK39 IC test positivity using saliva, whereas the amount of Leishmania-specific IgA or total IgA was similar to the healthy donors. These results suggest that saliva is not an appropriated material for diagnosing VL with this test. © 2015, Malaysian Society for Parasitology. All rights reserved. Source

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