Publications by authors named "Alessandra Aparecida Guarneri"

Triatomines are vectors of Trypanosoma cruzi, the causative agent of Chagas disease. Their locomotor activity is influenced by endogenous and exogenous factors, but whether individual behavioral profiles persist across developmental stages remains unclear. This study evaluated non-oriented locomotor activity in Rhodnius prolixus under varying nutritional states (short-fasting, long-fasting, fed), developmental stages (5th instar nymphs and adults), sex (males and females), and light phase (photophase vs.

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Background: Trypanosoma rangeli is a haemoflagellate parasite that infects triatomine bugs and mammals in South and Central America. Trypanosoma cruzi, the etiological agent of Chagas disease, has a partially overlapping geographical distribution with T. rangeli, that leads to mixed human infections and cross-reactivity in immunodiagnosis.

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Article Synopsis
  • Rhodnius prolixus is a key insect in studying Chagas disease and has had its genome sequenced, leading to research on how gene expression affects behavior and adaptation to its environment.
  • The study utilized RNA sequencing to analyze gene expression in the brains of starved fifth instar nymphs, focusing on neuromodulatory genes related to neuropeptides, receptors, and neurotransmitters.
  • The findings suggest that understanding these highly expressed genes can lead to new pest control strategies and highlight the need for further research on gene expression in specific brain areas.
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is a protozoan that infects triatomines and mammals in Central and South America. Although it does not cause disease to humans, this parasite produces different levels of pathogenicity to its invertebrate host, mainly in species of the genus . In this study, we followed -infected and uninfected pairs throughout their adult lives and measured the amount of blood ingested, number of eggs laid, number of eggs hatched and proportion of infertile eggs, as well as female life expectancy.

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Background: Rhodnius prolixus is an important vector of Trypanosoma cruzi, the causal agent of Chagas disease in humans. Despite the medical importance of this and other triatomine vectors, the study of their immune responses has been limited to a few molecular pathways and processes. Insect immunity studies were first described for holometabolous insects such as Drosophila melanogaster, and it was assumed that their immune responses were conserved in all insects.

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Article Synopsis
  • Trypanosoma rangeli is a protozoan that infects insects and mammals in Latin America, but it does not cause disease in humans and primarily affects the survival and reproduction of its insect hosts.
  • Recent research showed that when triatomine bugs (Rhodnius prolixus) are infected with T. rangeli, they exhibit increased activity levels and can be more easily found outside their shelters, leading to higher predation rates.
  • Although infected bugs don't transmit T. rangeli to predatory mice, the increase in their foraging behavior may enhance the chances of transmitting the parasite through bites to other hosts.
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Triatomine bugs aggregate with conspecifics inside shelters during daylight hours. At dusk, they leave their refuges searching for hosts on which to blood feed. After finding a host, triatomines face the threat of being killed, because hosts often prey on them.

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Trypanosoma rangeli is a non-pathogenic protozoan parasite that infects mammals, including humans, in Chagas disease-endemic areas of South and Central America. The parasite is transmitted to a mammalian host when an infected triatomine injects metacyclic trypomastigotes into the host's skin during a bloodmeal. Infected mammals behave as parasite reservoirs for several months and despite intensive research, some major aspects of T.

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, a hemoflagellate parasite, is the etiological agent of Chagas disease that affects about 6-7 million people worldwide, mostly in Latin America. The parasite life cycle is complex and alternates between an invertebrate host-Triatominae vector-and a mammalian host. The parasite adaptation to the several microenvironments through which it transits is critical to success in establishing infection.

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The triatomine bug Rhodnius prolixus is a main vector of Chagas disease, which affects several million people in Latin-America. These nocturnal insects spend most of their locomotory activity during the first hours of the scotophase searching for suitable hosts. In this study we used multivariate analysis to characterize spontaneous locomotory activity profiles presented by 5th instar nymphs.

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Article Synopsis
  • Researchers developed a method using halogenated thymidine analogues and immunostaining to effectively detect and quantify fused-cell hybrids of the parasite Trypanosoma cruzi.
  • * The study specifically identified hybrids from T. cruzi clones CL Brener and Y, revealing a higher prevalence of these hybrids in a naturally occurring hybrid strain.
  • * The findings suggest that the recombinase Rad51 plays a significant role in the genetic exchange process, as its overexpression correlates with increased detection of fused-cell hybrids in T. cruzi.
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In the protozoan parasite Trypanosoma cruzi - the causative agent of Chagas disease - gene expression control is mainly post-transcriptional, where RNA-binding proteins (RBPs) play a central role, by controlling mRNA stability, distribution and translation. A large variety of RBPs are encoded in the T. cruzi genome, including the CCCH-type zinc finger (CCCH ZnF) protein family, which is characterized by the presence of the C-X-C-X-C-X-H (CCCH) motif.

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Trypanosoma cruzi is exposed to oxidative stresses during its life cycle, and amongst the strategies employed by this parasite to deal with these situations sits a peculiar trypanothione-dependent antioxidant system. Remarkably, T. cruzi's antioxidant repertoire does not include catalase.

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Trypanosoma cruzi, the etiologic agent of Chagas disease, has a complex life cycle in which four distinct developmental forms alternate between the insect vector and the mammalian host. It is assumed that replicating epimastigotes present in the insect gut are not infective to mammalian host, a paradigm corroborated by the widely acknowledged fact that only this stage is susceptible to the complement system. In the present work, we establish a T.

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Triatomines are hematophagous insects that feed on the blood of vertebrates from different taxa, but can occasionally also take fluids from invertebrate hosts, including other insects. During the blood ingestion process, these insects can acquire diverse parasites that can later be transmitted to susceptible vertebrates if they complete their development inside bugs. Trypanosoma cruzi, the etiological agent of Chagas disease, and Trypanosoma rangeli are protozoan parasites transmitted by triatomines, the latter only transmitted by Rhodnius spp.

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Trypanosoma cruzi, the etiological agent of Chagas disease, is ingested by triatomines during their bloodmeal on an infected mammal. Aiming to investigate the development and differentiation of T. cruzi inside the intestinal tract of Rhodnius prolixus at the beginning of infection we fed insects with cultured epimastigotes and blood trypomastigotes from infected mice to determine the amount of recovered parasites after ingestion.

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Trypanosoma rangeli infects several triatomine and mammal species in South America. Its transmission is known to occur when a healthy insect feeds on an infected mammal or when an infected insect bites a healthy mammal. In the present study we evaluated the classic way of T.

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Background: As a result of evolution, the biology of triatomines must have been significantly adapted to accommodate trypanosome infection in a complex network of vector-vertebrate-parasite interactions. Arthropod-borne parasites have probably developed mechanisms, largely still unknown, to exploit the vector-vertebrate host interactions to ensure their transmission to suitable hosts. Triatomines exhibit a strong negative phototaxis and nocturnal activity, believed to be important for insect survival against its predators.

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The insect Rhodnius prolixus is responsible for the transmission of Trypanosoma cruzi, which is the etiological agent of Chagas disease in areas of Central and South America. Besides this, it can be infected by other trypanosomes such as Trypanosoma rangeli. The effects of these parasites on vectors are poorly understood and are often controversial so here we focussed on possible negative effects of these parasites on the reproductive performance of R.

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Article Synopsis
  • Triatomines have become key subjects in behavioral research, exploring areas like host search, communication, and activity patterns over the last two decades.
  • Recent advances in molecular genetics and the complete genome sequence of Rhodnius prolixus enhance opportunities to study the genetic basis of insect physiology and behavior.
  • Focusing on the molecular aspects of triatomine behavior and sensory ecology can improve our understanding of insect biology, particularly regarding vector species, leading to better comparative studies of sensory function and cognition in insects.
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