Programa de Pós-Graduação em Biologia de Agentes Infecciosos e Parasitários - PPGBAIP/ICB

URI Permanente desta comunidadehttps://repositorio.ufpa.br/handle/2011/4696

O Programa de Pós-Graduação em Biologia de Agentes Infecciosos e Parasitários (PPGBAIP) é um programa do Instituto de Ciências Biológicas (ICB) da Universidade Federal do Pará (UFPA). O PPGBAIP contempla a formação de profissionais das áreas das Ciências Biológicas, Biomédicas, Médicas e afins em nível de mestrado e doutorado.

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Acesso aberto (Open Access)
Estudo genotípico de Trypanosoma cruzi: epidemiologia e caracterização molecular de isolados do homem, triatomíneos e mamíferos silvestres do Pará, Amapá e Maranhão
(Universidade Federal do Pará, 2011) VALENTE, Vera da Costa; TEIXEIRA, Marta Maria Geraldes; http://lattes.cnpq.br/8067345143353691
The acute Chagas disease (ACD) is endemic in the Brazilian Amazon, and its main transmission route is oral, throughout family and multi-family outbreaks. This route is independent from the colonization of triatomine bugs in dwellings and its occurrence is regular, with mean rates of 100 cases per year and a lethality rate of 5%. The disease has a well-defined spatio-temporal distribution, which makes it a relevant public health concern in the states of Pará, Amapá and Amazonas. The existence of wild mammals and triatomine bugs naturally infected with Trypanosoma cruzi inhabiting different terrestrial and arboreal ecotopes maintains an intense enzootic cycle all over the Amazon region. Molecular profiles of T. Cruzi lineages in the region are associated with mammal reservoirs (including humans), triatomine bugs, ecotopes and clinical manifestations. We analyzed four ACD outbreaks in the municipalities of Barcarena, Belém and Cachoeira do Arari on Pará State, and Santana on Amapá State, based on epidemiologic features (laboratory, parasitological and serological diagnoses, clinical manifestations and the reservoirs and wild triatomines related to the outbreaks). We also investigated the domestic and wild transmission cycles of T. cruzi in São Luis on Maranhão State, without the occurrence of ACD cases. This study comprised molecular genotyping of T. cruzi on the mini-exon gene of the isolates associated with both transmission cycles (humans, mammals and wild triatomine vectors). Parasitological diagnosis was confirmed in 63 patients with the following sensitivity rates: 41.3% (26/63) for the thick blood film method; 58.7% (37/63) for QBC; 79.4% (50/63) for xenodiagnosis; and 61.9% (39/63) for blood culture. The serological diagnosis of 2648 individuals by indirect hemagglutination assay (IHA) was of 3.05% (81/2648), whereas the results of the indirect immunofluorescence test (IIF) were 2.49% (66/2648) for IgG and 2.37% (63/2648) for IgM. All tests carried out in São Luís were negative. A total of 24 mammals, 13 Didelphis marsupialis, 1 Marmosa cinerea, 5 Philander opossum, 3 Metachirus nudicaudatus, 1 Oryzomys macconnelli, 1 Oecomys bicolor and 433 R. rattus were captured. The infection rate for T. cruzi was of 7.14% (29/404). A total of 3279 triatomine bugs were captured: T. rubrofasciata (n=3008) and infection rate (IR) of 30.46%, (39/128) and R. robustus (n=137) IR of 76% (79/104), R. pictipes (n=94), IR of 56.9% (49/86%) E. mucronatus (n=6) and P. geniculatus (n=12) IR of 50% and the other non-infected species R. neglectus (n=5) and P. lignarius (n=6). Palm trees were the main ecotopes for the wild triatomine bugs. S. martiana was infested with 47.41% (101/213) of the triatomines; Maximiliana regia, 35,21% (75/213); Orbgnya speciosa, 5.16% (11/213); Eleas melanoccoca), 1.87% (4/213); and Oenocarpus bacaba, 10.32% (22/213). Genotyping was carried out using 46 isolates of trypanosomes obtained from humans, 31 from wild mammals and 74 from samples of triatomine bugs. All isolates were characterized as belonging to the Tcl lineage. All human cases in Pará were characterized as positive by parasitological testing. Not all the cases in Santana were tested positive because of the delay on diagnosis, but they were defined as positive. Xenodiagnosis, blood culture and QBC® were more sensitive than the thick blood film. Serological examinations by IHA and IIF (IgG and IgM) presented an optimal sensitivity to detect acute cases in different moments of infection. Mammals (D. marsupialis) and wild triatomine bugs (R. pictipes and P. geniculatus) infected with high infection rates of T. cruzi in the patients’ peridomicile area account for the importance of these reservoirs in the transmission cycle of the ACD, and are associated with its transmission. Even though several genotypes of T. cruzi circulate in the Amazon Region, only the Tcl lineage was identified in the patients, mammals and triatomines investigated in this study. In São Luís, in spite of these having no record of human cases of ACD, it has a domestic cycle associated with the black rat and the triatomine bugs of the species T. rubrofasciata, as well as a sylvatic cycle associated with didelphids. The Tcl cycles circulate in both cycles. Studies with isolates of local T. cruzi using markers with a higher definition might help clarify the transmission cycles, transmission routes and the reservoirs involved in cases of ACD in the Amazon Region.
Acesso aberto (Open Access)
Identificação molecular de espécies do complexo Anopheles albitarsis (Diptera, Culicidae, Anophelinae), coletadas em dois municípios da Amazônia brasileira, com análise de suscetibilidade natural a plasmódios humanos
(Universidade Federal do Pará, 2010-12-03) SILVA, Ana de Nazaré Martins da; ISHIKAWA, Edna Aoba Yassui; http://lattes.cnpq.br/3074963539505872; PÓVOA, Marinete Marins; http://lattes.cnpq.br/2256328599939923
Members of Anopheles cryptic species complexes may exhibit behavioral differences among them, the susceptibility to malaria infection, and resistance to insecticides, thus, the specific identification has epidemiological relevance, which is not always possible by morphological criteria. Alternative methods have been employed such as those that analyze highly conserved regions of ribosomal DNA, which varies among species, known as internal transcribed spacer (ITS). Anopheles albitarsis complex is currently composed of six species: An. albitarsis s.s., An. oryzalimnetes, An. albitarsis F, An. marajoara, An. deaneorum and An. janconnae. At least the last three are incriminated as malaria parasite vectors in the Brazilian Amazon. The aim of this study was to perform molecular identification of An. albitarsis complex species, for analysis of ITS2 rDNA sequences, in order to assess their importance in malaria transmission in the cities of Macapá, Amapa and Peixe-Boi, Para, including investigating the first time the occurrence of An. Albitarsis F in two epidemiologically distinct areas: the first with a history of high risk of malaria transmission and the second not (Peixe-Boi). All-night human landing catches of mosquitoes were carried out in the peridomestic environment, from January 2009 and April 2010. The females collected were morphologically identified and only An. albitarsis s.l. was dissected: head and thorax were separated for analysis of natural infection by ELISA; ovaries for parity analysis and the carcass, legs and wings for molecular identification. In Macapá were collected 584 mosquitoes: 366 An. albitarsis s.l. (62.7%), 167 An. darlingi (28.6%), 33 An. triannulatus s.l. (5.6%), 15 An. braziliensis (2.6%) and 3 An. nuneztovari (0.5%). It was possible to visualize the specific band An. marajoara in 320 specimens of An. albitarsis s.l. tested. Of the remainder, 33 were negative and 13 amplified a fragment of ~ 490pb, not allowing to reach the specific diagnosis. The An. marajoara specimens showed biological and behavioral characteristics that confirm their epidemiological importance in malaria transmission in Macapa, such as being the most prevalent species, with a higher proportion of parous females (73.0%), and therefore with the greatest chances of infected with Plasmodium, occur in both seasons (dry and wet), presenting biting activity in all hours worked, moreover, was found infected by P.vivax and P. falciparum (natural infection rate of 3.1%). In Peixe-Boi, were captured 43 anophelines: An. triannulatus s.l. (20 specimens, 46.5%), An. albitarsis s.l. (13, 30.2%) An. darlingi (8, 18.6%), and An. nuneztovari (2, 4.7%). All An. albitarsis s.l. collected were identified by ITS2 as An. oryzalimnetes. None was found infected by Plasmodium, and the vast majority was parous females (84.6%). Systematic entomological surveys are needed to analyse the importance of An. oryzalimnetes in malaria transmission in the city. The An. albitarsis F was not found in the two areas studied. Our results contribute to our understanding of the epidemiology of malaria in the Brazilian Amazon region.
Acesso aberto (Open Access)
A importância do Anopheles darlingi Root, 1926 e Anopheles marajoara Galvão e Damasceno, 1942 na transmissão de malária no município de Macapá/AP - Brasil
(Universidade Federal do Pará, 2010-03-11) GALARDO, Allan Kardec Ribeiro; PÓVOA, Marinete Marins; http://lattes.cnpq.br/2256328599939923
Malaria in the municipality of Macapá is mainly peri urban, which are characterized by flooding area, presence of forest fragments and disorganized settlements. The aim of this study was to determine the importance of Anopheles darlingi e Anopheles marajoara in the malaria transmission in Macapá. The study was carried out from October 2007 to September 2008, in the Lagoa dos Índios community, Macapá. It was collected 4,601 mosquitoes, from which 3,029 were Anopheles marajoara (65,8%), 917 Anopheles darlingi (19,9%), 429 Anopheles braziliensis (9,3%), 208 Anopheles triannulatus (4,5%), 18 Anopheles peryassui (0,4%) and 5 Anopheles nuneztovari (0,1%). Only 32.8% (1.511) of the adult mosquitoes were collected indoors and 67.2% (3.090) outdoors. The index of the bites by man and by hour for An. darlingi in the intradomicile had ranged from 0 to 6.5 and in the peridomicile from 0 a 22. As for the An. marajoara the range was from 0 to 22 in the intradomicile and from 0 to 175.5 in the peridomicile. The analysis of the exuvia and the genitalia dissecation had resulted in the confirmation of the two species, An. darlingi and An. marajoara, and that the An. marajoara is the only albitarsis complex specie that is circulating in the study area. The vectors abundance had flutuated associated with the sazonal pattern of the rain. An. darlingi is the most frequent at the beginning and end of the rain, while An. marajoara was present, in high density, during the rainy season. From the 4,601 tested mosquitoes, 100 were positive for human malaria parasites by the ELISA method with a infection index of 2.17%. The infection index for An. marajoara was 2,34% (71/3,029) and for An. darlingi 3.05% (28/917). This study had demonstrated that the two studied species are responsible for the malaria transmission maintenance during the whole year, thus confirming the importance of both.

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