Transovarial transmission of a core virome in the Chagas disease vector Rhodnius prolixus

Triatomine assassin bugs comprise hematophagous insect vectors of Trypanosoma cruzi, the causative agent of Chagas disease. Although the microbiome of these species has been investigated to some extent, only one virus infecting Triatoma infestans has been identified to date. Here, we describe for the first time seven (+) single-strand RNA viruses (RpV1-7) infecting Rhodnius prolixus, a primary vector of Chagas disease in Central and South America. We show that the RpVs belong to the Iflaviridae, Permutotetraviridae and Solemoviridae and are vertically transmitted from the mothers to the progeny via transovarial transmission. Consistent with this, all the RpVs, except RpV2 that is related to the entomopathogenic Slow bee paralysis virus, established persistent infections in our R. prolixus colony. Furthermore, we show that R. prolixus ovaries express 22-nucleotide viral siRNAs (vsiRNAs), but not viral piRNAs, that originate from the processing of dsRNA intermediates during viral replication of the RpVs. Interestingly, the permutotetraviruses and sobemoviruses display shared pools of vsiRNAs that might provide the basis for a cross-immunity system. The vsiRNAs are maternally deposited in the eggs, where they likely contribute to reduce the viral load and protect the developing embryos. Our results unveil for the first time a complex core virome in R. prolixus and begin to shed light on the RNAi-based antiviral defenses in triatomines.

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Transovarial transmission fuels persistent infections of a core virome in the Chagas disease vector Rhodnius prolixus

10.1101/2020.10.18.344325 ◽

2020 ◽

Author(s):

Tarcísio Fontenele de Brito ◽

Vitor Lima Coelho ◽

Maira Arruda Cardoso ◽

Ingrid Alexandre de Abreu Brito ◽

Fides Lea Zenk ◽

...

Keyword(s):

Viral Load ◽

South America ◽

Trypanosoma Cruzi ◽

Chagas Disease ◽

Rna Viruses ◽

Rhodnius Prolixus ◽

Transovarial Transmission ◽

Persistent Infections ◽

Primary Vector ◽

First Time

AbstractTriatomine assassin bugs comprise hematophagous insect vectors of Trypanosoma cruzi, the causative agent of the Chagas disease. Although the microbiome of these species has been investigated to some extent, only one virus infecting Triatoma infestans has been identified to date. Here, we describe for the first time seven (+) single-strand RNA viruses (RpV1-7) infecting Rhodnius prolixus, a primary vector of the Chagas disease in Central and South America. We show that the RpVs belong to the Picorna-Calici, Permutotetra and Luteo-Sobemo clades and are vertically transmitted from the mothers to the progeny via transovarial transmission. Consistent with this, all the RpVs, except RpV2 that is related to the entomopathogenic Slow bee paralysis virus, established persistent infections in our R. prolixus colony. Furthermore, we show that R. prolixus ovaries express 22-nucleotide viral siRNAs (vsiRNAs), but not viral piRNAs, that originate from the processing of dsRNA intermediates during viral replication of the RpVs. Interestingly, the Permutotetra and Luteo-Sobemo viruses display shared pools of visRNAs that might provide the basis for a cross-immunity system. The vsiRNAs are maternally deposited in the eggs, where they likely contribute to reduce the viral load and protect the developing embryos. Our results unveil for the first time a complex core virome in R. prolixus and begin to shed light on the RNAi-based antiviral defenses in triatomines.Author summaryRhodnius prolixus is a triatomine insect and a primary vector of Trypanosoma cruzi, the etiologic agent of the Chagas disease, in Central and South America. Despite the medical relevance, very little is known about the viruses that infect these so-called assassin bugs. In this study, we show for the first time that triatomines can support the concomitant infection of a variety of RNA viruses belonging to distantly related viral families. Remarkably, we show that the viruses are vertically transmitted from the mothers to the progeny via transovarial transmission. The detection of 22-nucleotide viral small interfering RNAs in mature eggs strongly suggests that RNAi mechanisms contribute to reduce the viral load during oogenesis and embryogenesis in R. prolixus, thus safeguarding the development of embryos and nymphs. In agreement with these findings, all the viruses, except one, could establish persistent infections in our colony. Our results substantially expand the knowledge of the virus complexity in triatomine species. This viral toolkit might be harnessed to develop novel insect population control strategies to reduce the diffusion of the Chagas disease.

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Satellitome Analysis of Rhodnius prolixus, One of the Main Chagas Disease Vector Species

International Journal of Molecular Sciences ◽

10.3390/ijms22116052 ◽

2021 ◽

Vol 22 (11) ◽

pp. 6052

Author(s):

Eugenia E. Montiel ◽

Francisco Panzera ◽

Teresa Palomeque ◽

Pedro Lorite ◽

Sebastián Pita

Keyword(s):

Chagas Disease ◽

Satellite Dna ◽

Rhodnius Prolixus ◽

Triatoma Infestans ◽

Repeated Dna ◽

Sequencing Data ◽

Bioinformatics Pipeline ◽

Disease Vector ◽

Low Coverage ◽

First Time

The triatomine Rhodnius prolixus is the main vector of Chagas disease in countries such as Colombia and Venezuela, and the first kissing bug whose genome has been sequenced and assembled. In the repetitive genome fraction (repeatome) of this species, the transposable elements represented 19% of R. prolixus genome, being mostly DNA transposon (Class II elements). However, scarce information has been published regarding another important repeated DNA fraction, the satellite DNA (satDNA), or satellitome. Here, we offer, for the first time, extended data about satellite DNA families in the R. prolixus genome using bioinformatics pipeline based on low-coverage sequencing data. The satellitome of R. prolixus represents 8% of the total genome and it is composed by 39 satDNA families, including four satDNA families that are shared with Triatoma infestans, as well as telomeric (TTAGG)n and (GATA)n repeats, also present in the T. infestans genome. Only three of them exceed 1% of the genome. Chromosomal hybridization with these satDNA probes showed dispersed signals over the euchromatin of all chromosomes, both in autosomes and sex chromosomes. Moreover, clustering analysis revealed that most abundant satDNA families configured several superclusters, indicating that R. prolixus satellitome is complex and that the four most abundant satDNA families are composed by different subfamilies. Additionally, transcription of satDNA families was analyzed in different tissues, showing that 33 out of 39 satDNA families are transcribed in four different patterns of expression across samples.

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First Report ofAprostocetus asthenogmus(Hymenoptera: Eulophidae) in South America and Parasitizing Eggs of Triatominae Vectors of Chagas Disease

Journal of Parasitology Research ◽

10.1155/2014/547439 ◽

2014 ◽

Vol 2014 ◽

pp. 1-4 ◽

Cited By ~ 1

Author(s):

Claudiney Biral dos Santos ◽

Marcelo Teixeira Tavares ◽

Gustavo Rocha Leite ◽

Adelson Luiz Ferreira ◽

Leonardo de Souza Rocha ◽

...

Keyword(s):

South America ◽

Chagas Disease ◽

Biological Control Agent ◽

Control Agent ◽

Triatoma Infestans ◽

Disease Vectors ◽

Parasitoid Species ◽

Triatomine Species ◽

Chagas Disease Vectors ◽

First Time

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.

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Structure Determination of Juvenile Hormone from Chagas Disease Vectors, Rhodnius prolixus and Triatoma infestans

Chemistry Letters ◽

10.1246/cl.200126 ◽

2020 ◽

Vol 49 (5) ◽

pp. 538-541

Author(s):

Keiji Matsumoto ◽

Yoko Yasuno ◽

Kohei Yasuda ◽

Tsuyoshi Hayashi ◽

Shin G. Goto ◽

...

Keyword(s):

Juvenile Hormone ◽

Chagas Disease ◽

Structure Determination ◽

Rhodnius Prolixus ◽

Triatoma Infestans ◽

Disease Vectors ◽

Chagas Disease Vectors

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Studies in search of a suitable experimental insect model for xenodiagnosis of hosts with Chagas' disease: 3 - On the interaction of vector species and parasite strain in the reaction of bugs to infection by Trypanosoma cruzi

Revista de Saúde Pública ◽

10.1590/s0034-89101988000500004 ◽

1988 ◽

Vol 22 (5) ◽

pp. 390-400 ◽

Cited By ~ 20

Author(s):

Alina Perlowagora-Szumlewicz ◽

Carlos Alberto Muller ◽

Carlos José de Carvalho Moreira

Keyword(s):

Trypanosoma Cruzi ◽

Chagas Disease ◽

Acute Infection ◽

Rhodnius Prolixus ◽

Triatoma Infestans ◽

Parasite Strain ◽

Vector Species ◽

Panstrongylus Megistus ◽

Acute Infections ◽

Triatoma Sordida

The reaction of nine vector species of Chagas' disease to infection by seven different Trypanosoma cruzi strains; Berenice, Y, FL, CL, S. Felipe, Colombiana and Gávea, are examined and compared. On the basis of the insects' ability to establish and maintain the infection, vector species could be divided into two distinct groups which differ in their reaction to an acute infection by T. cruzi. While the proportion of positive bugs was found to be low in Triatoma infestans and Triatoma dimidiata it was high, ranging from 96.9% to 100% in the group of wild (Rhodnius neglectus, Triatoma rubrovaria)and essentially sylvatic vectors in process of adaptation to human dwellings, maintained under control following successful insecticidal elimination of Triatoma infestans (Panstrongylus megistus, Triatoma sordida and Triatoma pseudomaculata). An intermediate position is held by Triatoma brasiliensis and Rhodnius prolixus. This latter has been found to interchange between domestic and sylvatic environments. The most important finding is the strikingly good reaction between each species of the sylvatic bugs and practically all T. cruzi strains herein studied, thus indicating that the factors responsible for the excellent reaction of P.megistus to infection by Y strain, as previously reported also come into operation in the reaction of the same vector species to acute infections by five of the remaining T.cruzi strains. Comparison or data reported by other investigators with those herein described form the basis of the discussion of Dipetalogaster maximus as regards its superiority as a xenodiagnostic agent.

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Thermal Tolerance Plasticity in Chagas Disease Vectors Rhodnius prolixus (Hemiptera: Reduviidae) and Triatoma infestans

Journal of Medical Entomology ◽

10.1093/jme/tjz022 ◽

2019 ◽

Vol 56 (4) ◽

pp. 997-1003 ◽

Cited By ~ 1

Author(s):

Silvina A Belliard ◽

Gerardo J De la Vega ◽

Pablo E Schilman

Keyword(s):

Chagas Disease ◽

Thermal Tolerance ◽

Rhodnius Prolixus ◽

Triatoma Infestans ◽

Disease Vectors ◽

Abiotic Factor ◽

Seasonal Temperature ◽

Positive Effects ◽

Wide Range ◽

Chagas Disease Vectors

Abstract Temperature is recognized as the most influential abiotic factor on the distribution and dispersion of most insect species including Rhodnius prolixus (Stål, 1859) and Triatoma infestans (Klug, 1834), the two most important Chagas disease vectors. Although, these species thermotolerance range is well known their plasticity has never been addressed in these or any other triatomines. Herein, we investigate the effects of acclimation on thermotolerance range and resistance to stressful low temperatures by assessing thermal critical limits and ‘chill-coma recovery time’ (CCRT), respectively. We found positive effects of acclimation on thermotolerance range, especially on the thermal critical minimum of both species. In contrast, CCRT did not respond to acclimation in either. Our results reveal the plasticity of these Triatomines thermal tolerance in response to a wide range of acclimation temperatures. This presumably represents a physiological adaptation to daily or seasonal temperature variation with concomitant improvement in dispersion potential.

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Novel repellents for the blood-sucking insects Rhodnius prolixus and Triatoma infestans, vectors of Chagas disease

10.1101/789602 ◽

2019 ◽

Author(s):

Melanie Ramírez ◽

Mario I. Ortiz ◽

Pablo Guerenstein ◽

Jorge Molina

Keyword(s):

Chagas Disease ◽

Dimethyl Sulfide ◽

Control Strategies ◽

Statistical Tests ◽

Positive Control ◽

Negative Control ◽

Rhodnius Prolixus ◽

Triatoma Infestans ◽

Host Seeking ◽

Blood Sucking

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.

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