Publications by authors named "Patricia Fampa"

Stomoxys calcitrans L. (Diptera: Muscidae), the stable fly, is a hematophagous insect of great veterinary importance, because it is a mechanical vector of diverse pathogens in livestock. The saliva of blood-feeding insects presents important pharmacologically active molecules that impair blood clotting, promote vasodilation and modulate the host immune system response, crucial processes for successful feeding.

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Stomoxys calcitrans is a cosmopolitan hematophagous insect with significant veterinary importance. Besides causing great stress with its bites, the fly is a mechanical vector of several pathogens of the most diverse phylogenetic groups to their hosts. The objective of this study was to test for the presence of Anaplasma marginale in stable flies collected at three points inside the campus of the Federal Rural University of Rio de Janeiro (UFRRJ), Seropédica, Rio de Janeiro, Brazil.

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The adult females of Aedes aegypti mosquitoes are facultative hematophagous insects but they are unable to feed on blood right after pupae emergence. The maturation process that takes place during the first post-emergence days, hereafter named hematophagic and gonotrophic capacitation, comprises a set of molecular and physiological changes that prepare the females for the first gonotrophic cycle. Notwithstanding, the molecular bases underlying mosquito hematophagic and gonotrophic capacitation remain obscure.

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is a species causative of cutaneous and anergic diffuse cutaneous leishmaniasis, treatment-resistant form, in the New World. Plants essential oils exhibit great potential as microbicide agents. We described the composition of the essential oils of two plants native from Brazil, , with geranial and neral as major constituents, and with α-bisabolol.

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Functional insect vector colonies are essential for the study of their biology, evolution, behavior as well as control strategies of these organisms that transmit pathogens of medical and veterinary importance. In addition to the establishment, improvement and adaptation of pre-established protocols in the maintenance of a colony is important, as it may result in higher production of insects. Stomoxys calcitrans or stable fly causes important economic losses in production of beef and milk, besides mechanically transmitting a great variety of pathogens to cattle.

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Trypanosoma cruzi is the causative agent of Chagas disease which affects 8 million people in Latin America. The parasite possesses high capacity to evade host immune system and the available drugs to treat Chagas disease present low efficacy combined to serious side effects to patients. Therefore, the identification of alternative therapeutics is essential.

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Trypanosoma cruzi is the etiological agent of Chagas disease. These parasites undergo dramatic morphological and physiological changes during their life cycle. The human-infective metacyclic trypomastigotes differentiate from epimastigotes inside the midgut of the Triatominae insect vector.

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Blood-sucking insects are responsible for the transmission of several important disease-causing organisms such as viruses, bacteria, and protozoans. The hematophagous hemipteran Rhodnius prolixus is one of the most important vectors of Trypanosoma cruzi, the etiological agent of Chagas disease. Due to the medical importance of this insect, it has been used as a study model in physiology and biochemistry since the 1930s.

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Lipid uptake and metabolism by trypanosomatid parasites from vertebrate host blood have been well established in the literature. However, there is a lack of knowledge regarding the same aspects concerning the parasites that cross the hemolymph of their invertebrate hosts. We have investigated the lipid composition and metabolism of the insect trypanosomatid Herpetomonas muscarum by H- palmitic acid and phosphate (Pi) and the parasite interaction with Lipophorin (Lp) the main lipid carrying protein of insect hemolymph.

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Rhodnius prolixus not only has served as a model organism for the study of insect physiology, but also is a major vector of Chagas disease, an illness that affects approximately seven million people worldwide. We sequenced the genome of R. prolixus, generated assembled sequences covering 95% of the genome (∼ 702 Mb), including 15,456 putative protein-coding genes, and completed comprehensive genomic analyses of this obligate blood-feeding insect.

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Insect trypanosomatids are inhabitants of the insect digestive tract. These parasites can be either monoxenous or dixenous. Plant trypanosomatids are known as insect trypanosomatids once they and are transmitted by phytophagous insects.

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All life cycle stages of the protozoan parasite Trypanosoma cruzi are enveloped by mucin-like glycoproteins which, despite major changes in their polypeptide cores, are extensively and similarly O-glycosylated. O-Glycan biosynthesis is initiated by the addition of αGlcNAc to Thr in a reaction catalyzed by Golgi UDP-GlcNAc:polypeptide O-α-N-acetyl-d-glucosaminyltransferases (ppαGlcNAcTs), which are encoded by TcOGNT1 and TcOGNT2. We now directly show that TcOGNT2 is associated with the Golgi apparatus of the epimastigote stage and is markedly downregulated in both differentiated metacyclic trypomastigotes (MCTs) and cell culture-derived trypomastigotes (TCTs).

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The bloodsucking hemipteran Rhodnius prolixus is a vector of Chagas' disease, which affects 7-8 million people today in Latin America. In contrast to other hematophagous insects, the triatomine gut is compartmentalized into three segments that perform different functions during blood digestion. Here we report analysis of transcriptomes for each of the segments using pyrosequencing technology.

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Trypanosoma cruzi presents considerable genetic and protein profile polymorphism among different parasite populations. In a previous work, our group indicated cysteine and metalloprotease activities as good markers for separating T. cruzi I (TCI) from T.

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Article Synopsis
  • Chagas disease is caused by the protozoan Trypanosoma cruzi, with its severity and incidence influenced by host genetics, environmental factors, and the genetic diversity of the parasites.
  • Previous research found that cysteine and metalloprotease activities are effective markers for distinguishing between two major groups of T. cruzi (TCI and TCII), with TCII showing greater genetic diversity.
  • In this study, researchers analyzed protease activity in 49 sylvatic T. cruzi isolates, revealing significant variability in molecular weights of active proteases, but found no clear separation between TCI and TCII groups, suggesting that the complex behavior of these parasites in nature may be due to their distinct protease expression profiles.
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Monoxenous trypanosomatids inhabit invertebrate hosts throughout their life cycle. However, there have been cases of HIV-positive patients who have presented opportunistic infections caused by these protozoa, offering new perspectives to the study of interactions between monoxenics and hematophagous insect vectors. Some monoxenous trypanosomatids present a symbiotic bacterium in the cytoplasm, which seems to promote biochemical and morphological changes in the host trypanosomatids, such as alterations in plasma membrane carbohydrates and the reduction of the paraxial rod.

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Transmission blocking vaccines are one of the control strategies for vector-transmitted protozoan diseases. Antibodies raised in the vaccinated host prevent the development of the parasite in the insect vector, interrupting the epidemiological cycle. The FML antigen of Leishmania donovani in combination with saponin (FML-vaccine and Leishmune) induced 92-97% of protections against zoonotic visceral leishmaniasis.

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In this work, we characterise metacyclic promastigotes of Leishmania amazonensis, the causative agent of cutaneous and diffuse cutaneous leishmaniasis in the New World. To purify metacyclics from stationary culture by negative selection, we used the monoclonal antibody 3A1-La produced against procyclic promastigotes. The purified forms named 3A1-La(-) promastigotes, present key metacyclic characteristics: slender cell body and long flagella, ultrastructural features, resistance to complement lysis, high infectivity for macrophages and mice and reduced capacity for binding to the sand fly midgut.

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Interaction experiments between hematophagous insects and monoxenous trypanosomatids have become relevant, once cases of human infection involving these protozoa have been reported. Moreover, investigations related to the interaction of insects with trypanosomatids that harbour an endosymbiotic bacterium and thereby lack the paraflagellar rod structure are important to elucidate the role of this structure in the adhesion process. In this work, we compared the interaction of endosymbiont-bearing trypanosomatids and their aposymbiotic counterpart strains (without endosymbionts) with cell lines of Anopheles gambiae, Aedes albopictus and Lutzomyia longipalpis and with explanted guts of the respective insects.

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