Prevenção domiciliar da dengue: avaliação preliminar de tela protetora para pratos de vasos de planta

Avaliou-se em laboratório a eficácia de um protótipo de capa de tela de poliéster (evidengue®) destinada a vedar o acesso de fêmeas do mosquito Aedes aegypti a pratos de vasos de planta. Dois pratos de vasos com água foram envolvidos individualmente com a capa e colocados com os seus respectivos vasos em duas gaiolas entomológicas, um em cada gaiola. Numa terceira gaiola foi colocado um conjunto idêntico de prato e vasos sem a capa. Cada gaiola recebeu 20 fêmeas copuladas do mosquito, alimentadas com sangue de camundongo. Os resultados mostram que a capa foi eficaz como barreira ao acesso de fêmeas. Novos testes são necessários para se avaliar a eficácia da capa como dispositivo de prevenção da ovipostura nos pratos.The effectiveness of a polyester mesh cover (evidengue®), aimed at preventing the access of female Aedes aegypti mosquitoes to flowerpot saucers, was evaluated in laboratory. Two saucers of flowerpot with water were individually wrapped with the cover was placed with their respective pots in two entomological cages. One identical set of flowerpot and saucer was placed in a third cage. In each cage, 20 gravid females, fed on mouse blood, were released. Results show that the cover was effective to prevent access of females. Further tests are necessary to assess cover effectiveness as a device to prevent saucer oviposition.Se evaluó en laboratorio la eficiencia de una cubierta de tela de polyester (evidengue®) con el objetivo de vedar el acceso de hembras del mosquito Aedes aegypti a platos de macetas de planta. Fueron utilizadas tres jaulas entomológicas, dos de ellas con evidengue® y una para control. En cada jaula fueron colocados dos conjuntos de macetas de planta y platos y 20 hembras copuladas, alimentadas con sangre de ratón. Los resultados muestran que la cubierta fue eficaz como barrera al acceso de hembras. Nuevas pruebas son necesarias para evaluar la eficiencia de la cubierta como dispositivo de prevención de la oviposición en los platos

Prevenção domiciliar da dengue: avaliação preliminar de tela protetora para pratos de vasos de planta

Avaliou-se em laboratório a eficácia de um protótipo de capa de tela de poliéster (evidengue®) destinada a vedar o acesso de fêmeas do mosquito Aedes aegypti a pratos de vasos de planta. Dois pratos de vasos com água foram envolvidos individualmente com a capa e colocados com os seus respectivos vasos em duas gaiolas entomológicas, um em cada gaiola. Numa terceira gaiola foi colocado um conjunto idêntico de prato e vasos sem a capa. Cada gaiola recebeu 20 fêmeas copuladas do mosquito, alimentadas com sangue de camundongo. Os resultados mostram que a capa foi eficaz como barreira ao acesso de fêmeas. Novos testes são necessários para se avaliar a eficácia da capa como dispositivo de prevenção da ovipostura nos pratos

Development of Leishmania (Leishmania) infantum chagasi in its natural sandfly vector Lutzomyia longipalpis

Submitted by Nuzia Santos ([email protected]) on 2014-03-26T17:00:54Z No. of bitstreams: 1 Development of Leishmania (Leishmania) infantum chagasi in its natural sandfly vector Lutzomyia longipalpis.pdf: 1905562 bytes, checksum: 66300806ee4ff3ae5f010b1b7686e384 (MD5)Made available in DSpace on 2014-03-26T17:00:54Z (GMT). No. of bitstreams: 1 Development of Leishmania (Leishmania) infantum chagasi in its natural sandfly vector Lutzomyia longipalpis.pdf: 1905562 bytes, checksum: 66300806ee4ff3ae5f010b1b7686e384 (MD5) Previous issue date: 2013Fundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Laboratório de Entomologia Médica. Belo Horizonte, MG, BrazilFundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Laboratório de Entomologia Médica. Belo Horizonte, MG, BrazilFundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Laboratório de Entomologia Médica. Belo Horizonte, MG, BrazilFundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Laboratório de Entomologia Médica. Belo Horizonte, MG, BrazilFundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Laboratório de Entomologia Médica. Belo Horizonte, MG, BrazilWe analyzed the development of Leishmania (Leishmania) infantum chagasi in its natural sandfly vector Lutzomyia longipalpis. In addition, we compared sandfly infections initiated with axenic amastigotes or promastigotes. Our data showed no important difference between Lu. longipalpis infection rates resulting from either type of infections. Furthermore, development of infection was equivalent in both cases. All promastigote forms were found inside the sandfly and, after blood digestion, most of the population consisted of procyclics and nectomonads. A low percentage of metacyclic forms was coincident with a high number of nectomonads during late stages of infection, but which form gives rise to metacyclic forms in L. infantum chagasi is unknown. These results also show that the promastigote infection model, at least for this situation, is suitable for obtaining of infected sandflies because it is easier and less laborious

Lutzomyia umbratilis from an area south of the Negro River is refractory to in vitro interaction with Leishmania guyanensis

Submitted by Nuzia Santos ([email protected]) on 2019-06-25T18:49:06Z No. of bitstreams: 1 Lutzomyia umbratilis from.pdf: 505469 bytes, checksum: 02b08372f2472409beef937a1e28bb4e (MD5)Approved for entry into archive by Nuzia Santos ([email protected]) on 2019-06-25T18:54:59Z (GMT) No. of bitstreams: 1 Lutzomyia umbratilis from.pdf: 505469 bytes, checksum: 02b08372f2472409beef937a1e28bb4e (MD5)Made available in DSpace on 2019-06-25T18:54:59Z (GMT). No. of bitstreams: 1 Lutzomyia umbratilis from.pdf: 505469 bytes, checksum: 02b08372f2472409beef937a1e28bb4e (MD5) Previous issue date: 2018Fundação Oswaldo Cruz. Instituto René Rachou, Belo Horizonte, MG, Brasil.Fundação Oswaldo Cruz. Instituto René Rachou, Belo Horizonte, MG, Brasil.Fundação Oswaldo Cruz. Instituto René Rachou, Belo Horizonte, MG, Brasil.Fundação Oswaldo Cruz. Instituto Leônidas e Maria Deane. Manaus, AM, Brasil.Fundação Oswaldo Cruz. Instituto Leônidas e Maria Deane. Manaus, AM, Brasil.Fundação Oswaldo Cruz. Instituto Leônidas e Maria Deane. Manaus, AM, Brasil.BACKGROUND: Lutzomyia umbratilis, the vector for Leishmania guyanensis in northern South America, has been found naturally infected with L. guyanensis only in areas north of the Negro and Amazon rivers. While populations of this sand fly species are also found in areas south of these rivers, these populations have never been reported to be infected and/or transmitting L. guyanensis. However, no studies on the corresponding host-parasite interactions are available. OBJECTIVES: This study evaluated the interaction between Lu. guyanensis promastigotes and field-collected Lu. umbratilis sand flies from Rio Preto da Eva and Manacapuru, which are located to the north and south, respectively, of the Negro River. METHODS: Procyclic and metacyclic attachment was quantified using an in vitro system. FINDINGS: Low attachment of parasites to the midguts of insects collected from Manacapuru was detected. Conversely, greater binding of metacyclic parasites was observed in the midguts of insects collected from Rio Preto da Eva, and this attachment was more pronounced than that observed for procyclics (p < 0.03). MAIN CONCLUSIONS: The Lu. umbratilis population from an area south of the Negro River has lower in vitro interaction with L. guyanensis. The higher attachment of L. guyanensis to midguts of insects from Rio Preto da Eva may suggest better vector competence. These findings are in accordance with previously reported epidemiological information of American cutaneous leishmaniasis (ACL) transmission in the Amazon

Lutzomyia umbratilis from an area south of the Negro River is refractory to in vitro interaction with Leishmania guyanensis

BACKGROUND Lutzomyia umbratilis, the vector for Leishmania guyanensis in northern South America, has been found naturally infected with L. guyanensis only in areas north of the Negro and Amazon rivers. While populations of this sand fly species are also found in areas south of these rivers, these populations have never been reported to be infected and/or transmitting L. guyanensis. However, no studies on the corresponding host-parasite interactions are available. OBJECTIVES This study evaluated the interaction between Lu. guyanensis promastigotes and field-collected Lu. umbratilis sand flies from Rio Preto da Eva and Manacapuru, which are located to the north and south, respectively, of the Negro River. METHODS Procyclic and metacyclic attachment was quantified using an in vitro system. FINDINGS Low attachment of parasites to the midguts of insects collected from Manacapuru was detected. Conversely, greater binding of metacyclic parasites was observed in the midguts of insects collected from Rio Preto da Eva, and this attachment was more pronounced than that observed for procyclics (p < 0.03). MAIN CONCLUSIONS The Lu. umbratilis population from an area south of the Negro River has lower in vitro interaction with L. guyanensis. The higher attachment of L. guyanensis to midguts of insects from Rio Preto da Eva may suggest better vector competence. These findings are in accordance with previously reported epidemiological information of American cutaneous leishmaniasis (ACL) transmission in the Amazon

Dengue-2 virus artificial infection of brazilian colonized Aedes aegypti

Submitted by Nuzia Santos ([email protected]) on 2013-06-19T13:23:44Z No. of bitstreams: 1 25.CAMPANELLI, E. S..pdf: 419329 bytes, checksum: 92c70330e3c5da863d1bc51810975893 (MD5)Made available in DSpace on 2013-06-19T13:23:44Z (GMT). No. of bitstreams: 1 25.CAMPANELLI, E. S..pdf: 419329 bytes, checksum: 92c70330e3c5da863d1bc51810975893 (MD5) Previous issue date: 2007CNPq, Capes, FIOCRUZ and FUNEDFundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Laboratory of Medical Entomology. Belo Horizonte, MG, Brazil.Fundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Laboratory of Medical Entomology. Belo Horizonte, MG, BrazilFundação Ezequiel Dias. Laboratory of Molecular Virology. Belo Horizonte, MG, BrazilFundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Laboratory of Medical Entomology. Belo Horizonte, MG, Brazil.Fundação Ezequiel Dias. Laboratory of Molecular Virology. Belo Horizonte, MG, Brazil.Fundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Laboratory of Medical Entomology. Belo Horizonte, MG, Brazil.Dengue is a viral disease transmitted by mosquitoes and caused by four viral serotypes (DENV 1-4). This mosquito-borne disease is a major public health problem and a threat to more than 2.5 billion people, who live in endemic areas. Aedes aegypti is the primary vector of dengue in the Americas. The present study shows the susceptibility of a colony strain of A. aegypti to Dengue 2 virus (DENV-2). A. aegypti females from a laboratory colony were infected with DENV-2 using a membrane feeding technique. The engorged females were dissected on different days (3, 6, 9, 12 and 15). The midguts, ovaries, carcasses and heads were separated. The samples were fixed and immunolabeled with anti-DENV-2 antibody to be analyzed by laser confocal microscopy (LCM). Infected mosquitoes from the 15 th day had their heads and bodies dissected, separated and analyzed by RT-PCR with specific primers. Immunolabeling of the midguts and ovaries showed the presence of DENV-2 in the mosquitoes dissected from the third day until the last day of the experiment. The RT-PCR reactions of the heads and the bodies confirmed the mosquito infection with DENV-2. These results showed that the methodology used for the artificial infection with dengue virus was successful and demonstrated that our colonized A. aegypti mosquitoes were susceptible to artificial dengue infection. Future studies are in progress to better understand the processof invasion by dengue vírus in Aedes mosquito

Bacterial diversity of wild-caught Lutzomyia longipalpis (a vector of zoonotic visceral leishmaniasis in Brazil) under distinct physiological conditions by metagenomics analysis

Abstract Background The leishmaniases are a group of diseases caused by protozoans of the genus Leishmania, which are transmitted by the bite of phlebotomine sand flies. In the New World, Lutzomyia longipalpis is the most important vector of visceral leishmaniasis and is a proven vector for Leishmania infantum chagasi in Brazil. During development within the vector, Leishmania can interact with a variety of microorganisms such as fungi and bacteria. The presence of bacteria in the midgut of sand flies can influence the development and survival of the parasite. Results The bacteria-targeted metagenomic analysis revealed different community compositions between the distinct physiological stages of those tested. The amplicon-oriented metagenomic profiling revealed 64 bacterial genera and 46 families. By crossing the taxa indices from each experimental condition a core composed of 6 genera was identified (Enterobacter, Serratia, Stenotrophomonas, Enhydrobacter, Pseudomonas and Chryseobacterium). Conclusions The observed dynamic nature of the bacterial community expands the knowledge pertaining to the tripartite host-microbiota-pathogen interactions. Further studies addressing how laboratory and field collected communities differ are critical to successfully develop control strategies based on bacterial symbionts and paratransgenesis, as already tested in other arthropod vectors

Standardization of conditions for PCR detection of Leishmaniaspp. DNA in sand flies (Diptera, Psychodidae)

Submitted by Nuzia Santos ([email protected]) on 2013-07-01T18:39:29Z No. of bitstreams: 1 84 PAIVA BR.pdf: 347726 bytes, checksum: ae77d169cefed5a65da774992e2ee453 (MD5)Made available in DSpace on 2013-07-01T18:39:29Z (GMT). No. of bitstreams: 1 84 PAIVA BR.pdf: 347726 bytes, checksum: ae77d169cefed5a65da774992e2ee453 (MD5) Previous issue date: 2007CNPq, CAPES e FAPESPUniversidade de São Paulo. Instituto de Medicina Tropical de São Paulo. São Paulo, SP, Brasil/ Universidade de São Paulo. Instituto de Ciências Biomédicas. São Paulo, SP, BrasilFundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Belo Horizonte, MG, BrasilFundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Belo Horizonte, MG, BrasilUniversidade de São Paulo. Faculdade de Saúde Pública. São Paulo, SP, Brasil.Universidade de São Paulo. Instituto de Medicina Tropical de São Paulo. São Paulo, SP, Brasil/ Universidade de São Paulo. Instituto de Ciências Biomédicas. São Paulo, SP, BrasilUniversidade de São Paulo. Instituto de Medicina Tropical de São Paulo. São Paulo, SP, Brasil/ Universidade de São Paulo. Faculdade de Medicina. São Paulo, SP, Brasil.A correta identificação dos agentes etiológicos em insetos vetores é de crucial importância aos estudos epidemiológicos. A pesquisa de flagelado nesses vetores, pela dissecção de seu trato digestivo, observação microscópica do seu conteúdo ou por isolamento dos parasitas provenientes de insetos em meios de cultura, tem-se mostrado operacionalmente inadequada e com baixa especificidade do diagnóstico, pois fêmeas de flebotomíneos também podem albergar outros flagelados como Trypanosoma e Endotrypanum. Acreditamos que por sua eficiência e especificidade, a amplificação de seqüências-alvo do DNA da Leishmania, por meio da reação em cadeia de polimerase, pode ser aplicada na investigação de sua presença em flebotomíneos, desde que estes estejam devidamente acondicionados e o DNA do parasita extraído a partir de metodologia adequada. Este trabalho descreve metodologias utilizadas na padronização da conservação dos espécimes de flebotomíneos e extração do DNA da Leishmania como uma alternativa mais prática que os métodos tradicionais.The correct identification of etiological agents in vector insects is crucial for epidemiological studies. Identification of flagellates in such vec-tors, usually by dissection of the digestive tract and microscopic observation of the contents as well as attempts at parasite isolation from in-sects in culture media, have proven operation-ally inadequate and with poor diagnostic speci-ficity, since female sand flies are also hosts for other flagellates like Trypanosomaand Endo-trypanum. Due to the efficiency and specificity of DNA target sequence amplification by poly-merase chain reaction (PCR), the latter could be used to investigate the presence of Leishmaniain sand flies, although the insects need to be prop-erly stored and the Leishmania DNA extracted using appropriate methodology. This paper de-scribes methodologies to standardize sand fly storage and Leishmania DNA extraction in such specimens as a more practical method in field studies

Asymptomatic dogs are highly competent to transmit Leishmania (Leishmania) infantum chagasi to the natural vector

We evaluated the ability of dogs naturally infected with Leishmania (Leishmania) infantum chagasi to transfer the parasite to the vector and the factors associated with transmission. Thirty-eight infected dogs were confirmed to be infected by direct observation of Leishmania in lymph node smears. Dogs were grouped according to external clinical signs and laboratory data into symptomatic (n= 24) and asymptomatic (n= 14) animals. All dogs were sedated and submitted to xenodiagnosis with F1-laboratory-reared Lutzomyia longipalpis. After blood digestion, sand flies were dissected and examined for the presence of promastigotes. Following canine euthanasia, fragments of skin, lymph nodes, and spleen were collected and processed using immunohistochemistry to evaluate tissue parasitism. Specific antibodies were detected using an enzyme-linked immunosorbent assay. Antibody levels were found to be higher in symptomatic dogs compared to asymptomatic dogs (p= 0.0396). Both groups presented amastigotes in lymph nodes, while skin parasitism was observed in only 58.3% of symptomatic and in 35.7% of asymptomatic dogs. Parasites were visualized in the spleens of 66.7% and 71.4% of symptomatic and asymptomatic dogs, respectively. Parasite load varied from mild to intense, and was not significantly different between groups. All asymptomatic dogs except for one (93%) were competent to transmit Leishmania to the vector, including eight (61.5%) without skin parasitism. Sixteen symptomatic animals (67%) infected sand flies; six (37.5%) showed no amastigotes in the skin. Skin parasitism was not crucial for the ability to infect Lutzomyia longipalpis but the presence of Leishmania in lymph nodes was significantly related to a positive xenodiagnosis. Additionally, a higher proportion of infected vectors that fed on asymptomatic dogs was observed (p= 0.0494). Clinical severity was inversely correlated with the infection rate of sand flies (p= 0.027) and was directly correlated with antibody levels (p= 0.0379). Age and gender did not influence the transmissibility. Our data show that asymptomatic dogs are highly infective and competent for establishing sand fly infection, indicating their role in maintaining L. (L.) infantum chagasi cycle as well as their involvement in VL spreading in endemic areas. © 2013 Elsevier B.V