Publications by authors named "Alessandra Guarneri"

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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Rhodnius prolixus, a triatomine insect, is one of the most important vectors of Chagas disease in South America. Its interaction with the parasite Trypanosoma cruzi, the causative agent of this disease, is known to be deeply affected by ambient temperature and the nutritional status of the insect vector. In this study, we investigated how starvation affects the life cycle of R.

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The molecular bases of animal behaviour are intricate due to the pleiotropic nature of behaviour-modulating genes, which are often expressed across multiple tissues. The foraging gene (for) encodes a cGMP-dependent protein kinase (PKG), pivotal in regulating downstream target proteins through phosphorylation. In insects, for has been implicated in various behavioural contexts and physiological processes regarding searching for food.

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Chagas disease, caused by the protozoan parasite Trypanosoma cruzi transmitted by blood-sucking insects of the subfamily Triatominae, is a major neglected tropical disease affecting 6 to 7 million of people worldwide. Rhodnius prolixus, one of the most important vectors of Chagas disease in Latin America, is known to be highly sensitive to environmental factors, including temperature. This study aimed to investigate the effects of different temperatures on R.

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The blood-sucking hemipteran Rhodnius prolixus is one of the main vectors of Chagas disease, a neglected tropical disease that affects several million people worldwide. Consuming a blood meal and mating are events with a high epidemiological impact since after each meal, mated females can lay fertile eggs that result in hundreds of offspring. Thus, a better knowledge of the control of R.

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Trypanosoma rangeli is a protozoan parasite that infects triatomines and mammals in the Americas, producing mixed infections with Trypanosoma cruzi, the etiological agent of Chagas disease. The former parasite is not pathogenic to humans, but has different levels of pathogenicity, as well as causing physiological and behavioral alterations, to its invertebrate hosts. In this study, we measured locomotory activity, and the glyceride accumulation profile in the hemolymph and fat body, as well as the expression of key genes related to triglyceride metabolism, of Rhodnius prolixus nymphs infected with T.

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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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Background: The causative agent of Chagas disease, Trypanosoma cruzi, and its nonpathogenic relative, Trypanosoma rangeli, are transmitted by haematophagous triatomines and undergo a crucial ontogenetic phase in the insect's intestine. In the process, the parasites interfere with the host immune system as well as the microbiome present in the digestive tract potentially establishing an environment advantageous for development. However, the coherent interactions between host, pathogen and microbiota have not yet been elucidated in detail.

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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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the causative agent of Chagas disease (American trypanosomiasis), colonizes the intestinal tract of triatomines. Triatomine bugs act as vectors in the life cycle of the parasite and transmit infective parasite stages to animals and humans. Contact of the vector with alters its intestinal microbial composition, which may also affect the associated metabolic patterns of the insect.

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is the second most common American trypanosome that infects man. It is vectored by triatomines from the genus , in which it invades the hemolymph and infects the salivary glands, avoiding the bug immune responses. In insects, these responses are initiated by well conserved pathways, mainly the IMD, Toll, and Jak/STAT.

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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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the causative agent of Chagas disease, colonizes the gut of triatomine insects, including . It is believed that this colonization upsets the microbiota that are normally present, presumably switching the environment to one more favorable for parasite survival. It was previously thought that one particular bacterium, , was essential for insect survival due to its ability to produce vital B-complex vitamins.

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Trypanosoma cruzi has three biochemically and morphologically distinct developmental stages that are programmed to rapidly respond to environmental changes the parasite faces during its life cycle. Unlike other eukaryotes, Trypanosomatid genomes contain protein coding genes that are transcribed into polycistronic pre-mRNAs and have their expression controlled by post-transcriptional mechanisms. Transcriptome analyses comparing three stages of the T.

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The escape kinetics from the anterior midgut (AM) of Trypanosoma cruzi during the initial steps of infection was assessed in Triatoma infestans, as well as its ability to survive migration in the digestive tract of the vector. All the four strains evaluated survived and reached variable parasite densities. After 49-50 days, YuYu [discrete typing units (DTU) I] strain reached the highest parasite numbers in the rectum followed by Bug (DTU V), CL-Brener (DTU VI) and Dm28c (DTU I).

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The infection of triatomines with trypanosomes can be performed with different forms of the parasite, and the procedure is important not only for vector-parasite interaction studies but also for maintaining the infectivity of parasite strains, which guarantees more realistic biological and molecular investigations. Here, I describe how to infect the vector Rhodnius prolixus, a model species, with two different species of Trypanosoma.

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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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The protozoan Trypanosoma cruzi has the ability to spontaneously secrete extracellular vesicles (EVs). In this paper, T. cruzi EVs derived from epimastigote forms were evaluated during interaction with triatomine bugs Rhodnius prolixus and Triatoma infestans.

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The innate immune system in insects is regulated by specific signalling pathways. Most immune related pathways were identified and characterized in holometabolous insects such as Drosophila melanogaster, and it was assumed they would be highly conserved in all insects. The hemimetabolous insect, Rhodnius prolixus, has served as a model to study basic insect physiology, but also is a major vector of the human parasite, Trypanosoma cruzi, that causes 10,000 deaths annually.

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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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Trypanosoma rangeli is a protozoan parasite that infects mammals and triatomines, causing different levels of pathogenicity in its invertebrate vectors, particularly those from the genus Rhodnius. We have recently shown that temperature can modulate T. rangeli growth during in vitro culture, as well as its in vivo pathogenicity to R.

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