scholarly journals Trypanosoma cruzi Parasite Load Modulates the Circadian Activity Pattern of Triatoma infestans

Insects ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 76
Author(s):  
Francisco Chacón ◽  
Catalina Muñoz-San Martín ◽  
Antonella Bacigalupo ◽  
Bárbara Álvarez-Duhart ◽  
Rigoberto Solís ◽  
...  

American trypanosomiasis is a disease caused by the flagellate protozoan Trypanosoma cruzi, which is transmitted mainly in endemic areas by blood-sucking triatomine vectors. Triatoma infestans is the most important vector in the southern cone of South America, exhibiting a nocturnal host-seeking behavior. It has been previously documented that the parasite produces changes in some triatomine species, but this is the first time that the behavior of a vector has been evaluated in relation to its parasite load. After comparing the movement events and distance traveled of infected and non-infected T. infestans, we evaluated the change produced by different T. cruzi parasite loads on its circadian locomotor activity. We observed differences between infected and non-infected triatomines, and a significant relation between the parasite load and the increase in locomotor activity of T. infestans, which was accentuated during the photophase. This could have direct implications on the transmission of T. cruzi, as the increased movement and distance traveled could enhance the contact of the vector with the host, while increasing the predation risk for the vector, which could both constitute a risk for vectorial and oral transmission to mammals.

2020 ◽  
Vol 5 (2) ◽  
pp. 87
Author(s):  
Aaron W. Tustin ◽  
Ricardo Castillo-Neyra ◽  
Laura D. Tamayo ◽  
Renzo Salazar ◽  
Katty Borini-Mayorí ◽  
...  

Blood-sucking triatomine bugs transmit the protozoan parasite Trypanosoma cruzi, the etiologic agent of Chagas disease. We measured the prevalence of T. cruzi infection in 58,519 Triatoma infestans captured in residences in and near Arequipa, Peru. Among bugs from infected colonies, T. cruzi prevalence increased with stage from 12% in second instars to 36% in adults. Regression models demonstrated that the probability of parasite acquisition was roughly the same for each developmental stage. Prevalence increased by 5.9% with each additional stage. We postulate that the probability of acquiring the parasite may be related to the number of feeding events. Transmission of the parasite does not appear to be correlated with the amount of blood ingested during feeding. Similarly, other hypothesized transmission routes such as coprophagy fail to explain the observed pattern of prevalence. Our results could have implications for the feasibility of late-acting control strategies that preferentially kill older insects.


2014 ◽  
Vol 2014 ◽  
pp. 1-4 ◽  
Author(s):  
Claudiney Biral dos Santos ◽  
Marcelo Teixeira Tavares ◽  
Gustavo Rocha Leite ◽  
Adelson Luiz Ferreira ◽  
Leonardo de Souza Rocha ◽  
...  

We report for the first time the parasitism of eggs of two triatomine Chagas disease vectors,Triatoma infestansandT. vitticeps, by the microhymenopterous parasitoidAprostocetus asthenogmus. We also describe the first identification of this parasitoid in South America.A. asthenogmuswere captured near unparasitized triatomine colonies in the municipality of Vitória, state of Espírito Santo, Brazil, and placed into pots with recently laid triatomine eggs. After 24 days, we observed wasps emerging fromT. infestansandT. vitticepseggs. Several characteristics of this parasitoid species suggest that it could be a potential biological control agent of triatomine species.


2015 ◽  
Vol 9 (1) ◽  
pp. e3433 ◽  
Author(s):  
Ricardo Castillo-Neyra ◽  
Corentin M. Barbu ◽  
Renzo Salazar ◽  
Katty Borrini ◽  
Cesar Naquira ◽  
...  

2009 ◽  
Vol 25 (suppl 1) ◽  
pp. S32-S44 ◽  
Author(s):  
Antonio R. L. Teixeira ◽  
Clever Gomes ◽  
Silene P. Lozzi ◽  
Mariana M. Hecht ◽  
Ana de Cássia Rosa ◽  
...  

An epidemiological chain involving Trypanosoma cruzi is discussed at the environmental level, and in terms of fine molecular interactions in invertebrate and vertebrate hosts dwelling in different ecosystems. This protozoan has a complex, genetically controlled plasticity, which confers adaptation to approximately 40 blood-sucking triatomine species and to over 1,000 mammalian species, fulfilling diverse metabolic requirements in its complex life-cycle. The Tr. cruzi infections are deeply embedded in countless ecotypes, where they are difficult to defeat using the control methods that are currently available. Many more field and laboratory studies are required to obtain data and information that may be used for the control and prevention of Tr. cruzi infections and their various disease manifestations. Emphasis should be placed on those sensitive interactions at cellular and environmental levels that could become selected targets for disease prevention. In the short term, new technologies for social mobilization should be used by people and organizations working for justice and equality through health information and promotion. A mass media directed program could deliver education, information and communication to protect the inhabitants at risk of contracting Tr. cruzi infections.


2020 ◽  
Author(s):  
Aaron W. Tustin ◽  
Ricardo Castillo-Neyra ◽  
Laura D. Tamayo ◽  
Katty Borini-Mayorí ◽  
Renzo Salazar ◽  
...  

AbstractBlood-sucking triatomine bugs transmit the protozoan parasite Trypanosoma cruzi, the etiologic agent of Chagas disease. We measured the prevalence of T. cruzi infection in 58,519 Triatoma infestans captured in residences in and near Arequipa, Peru. Among bugs from infected colonies, T. cruzi prevalence increased with stage from 12% in second instars to 36% in adults. Regression models demonstrated a linear relationship between infection prevalence and developmental stage. Prevalence increased by 5.4 percentage points with each additional stage. We postulate that the probability of acquiring the parasite may be related to the number of feeding events. Transmission of the parasite does not appear to be correlated with the amount of blood ingested during feeding. Similarly, other hypothesized transmission routes such as coprophagy fail to explain the observed pattern of prevalence. Our results could have implications for the feasibility of late-acting control strategies that preferentially kill older insects.


2019 ◽  
Vol 110 (1) ◽  
pp. 169-176 ◽  
Author(s):  
N. Pereyra ◽  
P.A. Lobbia ◽  
G. Mougabure-Cueto

AbstractTransmission of Trypanosma cruzi (Kinetoplastida: Trypanosomatidae) occurs when feces/urine of infected triatomines come into contact with mucous membranes or damaged skin, and this occurs mainly when insects defecate while feeding on the host. Thus, the vector competence of the triatomines is associated with their feeding and excretion/defecation behavior. This work studied for the first time the effect of T. cruzi infection on feeding and excretion/defecation patterns of Triatoma infestans (Hemiptera: Reduviidae). Uninfected and infected fifth-instar nymphs were fed ad libitum and their feeding behavior and defecations were registered during and after feeding. The feeding pattern did not show differences between the experimental groups. However, the infected nymphs began to defecate earlier, defecated in greater quantity and there was a greater proportion of defecating individuals compared to uninfected nymphs. These results show that T. cruzi affected the excretion/defecation pattern of T. infestans in a way that would increase the probability of contact between infective feces and the mammalian host.


2019 ◽  
Author(s):  
Melanie Ramírez ◽  
Mario I. Ortiz ◽  
Pablo Guerenstein ◽  
Jorge Molina

AbstractBackgroundStudying the behavioral response of blood-sucking, disease-vector insects to potentially repellent volatile compounds could shed light on the development of new control strategies. Volatiles released by human facial skin microbiota play different roles in the host-seeking behavior of triatomines. We assessed the repellency effect of such compounds of bacterial origin on Triatoma infestans and Rhodnius prolixus, two important vectors of Chagas disease in Latin America.MethodsUsing an exposure device, insects were presented to human odor alone (negative control) and in the presence of three individual tested compounds (2-mercaptoethanol, dimethyl sulfide and 2-phenylethanol, which was only tested in R. prolixus) and the gold-standard repellent NN-diethyl-3-methylbenzamide–DEET (positive control). We quantified the time the insects spent in the proximity of the host and performed nonparametric statistical tests to determine if any of the compounds evaluated affected the behavior of the insect.ResultsWe found volatiles that significantly reduced the time spent in the proximity of the host. These were 2-phenylethanol and 2-mercaptoethanol for R. prolixus, and dimethyl sulfide and 2-mercaptoethanol for T. infestans. Such an effect was also observed in both species when DEET was presented, although only at the higher doses tested.ConclusionsThe new repellents modulated the behavior of two Chagas disease vectors belonging to two different triatomine tribes, and this was achieved using a dose up to three orders of magnitude lower than that needed to evoke the same effect with DEET. Future efforts in understanding deeply the mechanism of action of repellent compounds such as 2-mercaptoethanol, as well as an assessment of their temporal and spatial repellent properties, could lead to the development of novel control strategies for insect vectors refractory to DEET.


2019 ◽  
Vol 26 (36) ◽  
pp. 6519-6543 ◽  
Author(s):  
Adriana Egui ◽  
Paola Lasso ◽  
Elena Pérez-Antón ◽  
M. Carmen Thomas ◽  
Manuel Carlos López

Chagas disease courses with different clinical phases and has a variable clinical presentation and progression. The acute infection phase mostly exhibits a non-specific symptomatology. In the absence of treatment, the acute phase is followed by a chronic phase, which is initially asymptomatic. This chronic asymptomatic phase of the disease is characterized by a fragile balance between the host’s immune response and the parasite replication. The loss of this balance is crucial for the progression of the sickness. The virulence and tropism of the T. cruzi infecting strain together to the inflammation processes in the cardiac tissue are the main factors for the establishment and severity of the cardiomyopathy. The efficacy of treatment in chronic Chagas disease patients is controversial. However, several studies carried out in chronic patients demonstrated that antiparasitic treatment reduces parasite load in the bloodstream and leads to an improvement in the immune response against the Trypanosoma cruzi parasite. The present review is mainly focused on the cellular patterns associated to the clinical status and the evolution of the disease in chronic patients, as well as the effectiveness of the treatment related to T. cruzi infection control. Therefore, an emphasis is placed on the dynamics of specific-antigens T cell subpopulations, their memory and activation phenotypes, their functionality and their contribution to pathogenesis or disease control, as well as their association with risk of congenital transmission of the parasite.


2021 ◽  
Vol 12 (7) ◽  
Author(s):  
Marcela Hernández-Torres ◽  
Rogério Silva do Nascimento ◽  
Monica Cardozo Rebouças ◽  
Alexandra Cassado ◽  
Kely Catarine Matteucci ◽  
...  

AbstractChagas disease is a life-threatening disorder caused by the protozoan parasite Trypanosoma cruzi. Parasite-specific antibodies, CD8+ T cells, as well as IFN-γ and nitric oxide (NO) are key elements of the adaptive and innate immunity against the extracellular and intracellular forms of the parasite. Bim is a potent pro-apoptotic member of the Bcl-2 family implicated in different aspects of the immune regulation, such as negative selection of self-reactive thymocytes and elimination of antigen-specific T cells at the end of an immune response. Interestingly, the role of Bim during infections remains largely unidentified. To explore the role of Bim in Chagas disease, we infected WT, Bim+/−, Bim−/− mice with trypomastigotes forms of the Y strain of T. cruzi. Strikingly, our data revealed that Bim−/− mice exhibit a delay in the development of parasitemia followed by a deficiency in the control of parasite load in the bloodstream and a decreased survival compared to WT and Bim+/− mice. At the peak of parasitemia, peritoneal macrophages of Bim−/− mice exhibit decreased NO production, which correlated with a decrease in the pro-inflammatory Small Peritoneal Macrophage (SPM) subset. A similar reduction in NO secretion, as well as in the pro-inflammatory cytokines IFN-γ and IL-6, was also observed in Bim−/− splenocytes. Moreover, an impaired anti-T. cruzi CD8+ T-cell response was found in Bim−/− mice at this time point. Taken together, our results suggest that these alterations may contribute to the establishment of a delayed yet enlarged parasitic load observed at day 9 after infection of Bim−/− mice and place Bim as an important protein in the control of T. cruzi infections.


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