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1

Trypanosoma cruzi: The early contact between insect-derived metacyclic trypomastigotes and the mammalian cells

100%

Monteon V.

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2019

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tom 65

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nr 3

EN

Natural transmission of Trypanosoma cruzi to human is established when feces of hematophagous triatomines contaminated with insect-derived from metacyclic trypomastigotes get in contact with the skin, conjunctiva or even oral route. Article is aimed at updating the knowledge about the early interaction between insect-derived metacyclic trypomastigotes at the port of entry and the host. There are few works in the literature describing this first contact between host and natural insect-derived metacyclic trypomastigote. Although it is currently accepted that T. cruzi parasites can penetrate through the lesion left by the insect´s bite, pioneer data do not support this hypothesis as the main via; however, once in the dermis metacyclic trypomastigotes can spread rapidly and likely escape from inoculation site through endothelial cells and disseminate to the body via the bloodstream. A moderate inflammatory reaction took place in the skin at the port of entry within hours, the cytokines induces recruit of neutrophils predominantly, probably because triatomine feces microbiota is present in the inoculum that in some way, its presence modify the progress of the infection.

2

Feces from wild Triatoma dimidiata induces local inflammation and specific immune response in a murine model

51%

Monteon V. , May-Gil I. , Nunez-Oreza L. , Lopez R.

Annals of Parasitology

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2018

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tom 64

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nr 4

EN

In endemic regions for Triatoma dimidiata the vector for Chagas disease, subjects can be in contact with insect`s feces several times through a lifetime. The triatomine’s digestive tract is colonized by diverse but few dominant genera of microorganisms. The immune responses to microbiota feces are poorly known in mammal hosts. The goal of this paper is to describe the local inflammation at the port of inoculation and the humoral immune response in a murine model mimicking natural contamination of feces from wild Triatoma dimidiata and its identification of bacterial community. Feces from twenty T. dimidiata insects captured in peridomestic and domestic ecotopes were used for bacteria isolation and phenotypic identification. Five microliters of whole feces or bacteria isolated colonies were used for intradermal inoculation of mice for detection of humoral immune response and local inflammation at the inoculation site. The bacterial community identified corresponded to Kytococcus, Brevibacillus, Kocuria, Chryseobacterium, Pantoe, Proteus, Burkholderia, Acinetobacter and Stapylococcus. The local inflammation at the inoculation site was dominated by neutrophils infiltration, and specific seric IgG immune response was recognized against whole feces as well as Burkholderia, Acinetobacter and Staphylococcus isolates. In conclusion, feces from T. dimidiata were colonized by few culturable microorganism genera that are able to induce local inflammation and IgG immune response in a murine model.

3

Gene expression to contaminated or not contaminated Triatoma dimidiata faeces with Trypanosoma cruzi in vivo and in vitro assay

45%

Monteon V. , Lopez-Monteon A. , Lopez-Dominiguez J. , Lopez R. , Ramos-Ligonio

Annals of Parasitology

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2020

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tom 66

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nr 2

4

Low seroprevalence of Trypanosoma cruzi infection and chronic chagasic cardiomyopathy in a region with abundance of triatomine vectors in Yucatan Peninsula of Mexico

45%

Monteon V. , Solis-Oviedo R. , Lopez R. , Hernandez O. , Tellez C. A.

Annals of Parasitology

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2015

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tom 61

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nr 4

EN

The Yucatan Peninsula of Mexico is endemic with Chagas disease. The main vector responsible for Trypanosoma cruzi transmission is Triatoma dimidiata which is abundant in domestic, peridomestic and sylvan cycles. The abundance of vectors favours T. cruzi transmission and is a high risk for developing chronic chagasic cardiomyopathy (CCC). In the past 10 years, little information was available on parasite seroprevalence and the prevalence of CCC in the Yucatan Peninsula. In the present work, we studied two Mayan communities with a high abundance of T. dimidiata and a random serial sample of 233 patients with an altered electrocardiogram or cardiac failure admitted to the Regional Hospital. A homemade enzyme-linked immunosorbent assay and indirect immunofluorescence standardized techniques were used to detect anti-T. cruzi IgG. In addition, Mayan volunteers were monitored by electrocardiography. In the Mayan communities, 4.8% (3/63) subjects were positive for T. cruzi antibodies none of them presented electrocardiographic alterations, however in seronegative subjects were detected right or left ventricle hypertrophy in 25% (16/63). A remarkable finding was that 90% of the Mayan population recognized the vector and 65% of them had experienced contact with triatomines bites. At the Regional Hospital 0.42% (1/233) were positive for T. cruzi antibodies showing compatible diagnosis with CCC; the most frequent pathology in this population was hypertension in 65% (151/233) and the less frequent was dilated myocardiopathy 6% (14/233). In conclusion, the prevalence of T. cruzi infection and CCC can be considered low in Yucatan, Mexico.

5

Pre-exposure to faeces or saliva of Triatoma dimidiata decreases parasitemia in mice challenged with Trypanosoma cruzi: a description of the inflammatory reaction at the inoculation site

38%

Monteon V. , Quen-Ramirez E. , Macedo-Reyes V. , Lopez R. , Acosta-Viana K. , Pennigton P. , Ramos-Ligonio A.

Annals of Parasitology

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2016

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tom 62

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nr 3

EN

Under natural conditions, Trypanosoma cruzi infection is transmitted to mammals when faeces contaminated with metacyclic trypomastigotes gain access through skin lesions, mucosa or bite wounds. Natural infection of bugs with T. cruzi can vary greatly from less than 1% up to 70%, depending on triatomine species: in the case of Triatoma dimidiata, the percentage of infection is around 30%. In this work uses biological fluids (saliva and faeces) from Triatoma dimidiata to inoculate experimental animals once or multiple times, before inoculation with faeces contaminated with metacyclic trypomastigotes discrete type unit Ia (TcI). The site of infection was analyzed for histological changes based on hematoxile-eosine technique and toluide blue stain for mast cells. Inoculation with saliva led to the recruitment of eosinophils and mononuclear cells at the inoculation site, whereas inoculation with faeces led to the recruitment of neutrophils. Mice inoculated multiple times exhibited a strong inflammatory reaction from the first hour. Mono- or multi-exposure to T. dimidiata fluids before inoculation with metacyclic trypomastigotes helped to control the level of parasitemia. Previous contact with saliva or faeces of T. dimidiata reduces parasitemia in T. cruzi I -infected mice.

6

Comparative 2-D electrophoresis of salivary proteins in Triatoma dimidiata and Rhodnius prolixus (Hemiptera: Reduviidae) and major cross-reactive antigens

38%

Monteon V. , May-Gil I. , Acosta-Viana K. , Ramos-Logonio A. , Hernandez O. , Lopez R.

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nr 2

EN

An immune response to triatomine’s saliva is an immunological marker of exposure to triatomine bites. However, considerable variability in salivary protein profiles did exist among species. In the present work, we compare salivary proteins from Mexican Triatoma dimidiata and Rhodnius prolixus using 2-D electrophoresis. A clear differential saliva profile was found to exist between these two triatomine species. Fewer protein spots were detected in R. prolixus than in T. dimidiata. More than half of the proteins had an isoelectric point between 5 and 7 and a molecular weight between 10 and 30 kDa in T. dimidiata. Mice exposed to T. dimidiata saliva mount an immune response to three major cross-reacting antigens in R. prolixius saliva with weights of 10 kDa and 55 kDa. Our findings may alert for the presence of cross-reacting antigens between triatomine species in regions where two or more species are overlapping in the same geographical area.