Triatomine bug
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Dirofilaria immitis and D. repens are mosquito-borne nematodes, primarily infecting dogs, but also other species of carnivores and even humans. Given their impact on animal and human health, the transmission of these filarioids has been widely studied. The microfilariaemia has been shown to have a circadian variation for both Dirofilaria species infecting dogs. Due to methodological difficulties, the periodicity was only studied using venous blood samples, while the mosquitoes feed, in fact, on capillary blood. In this context, the present study aimed to test the feasibility of using triatomine bugs for the collection of capillary blood and to comparatively evaluate the level of microfilariaemia and its circadian variation in capillary blood vs. peripheral venous blood in a dog naturally co-infected with D. immitis and D. repens. The results showed a feeding success of 50%, with variations in the blood meal volume that the bugs ingested. The relative values of microfilariaemia (mf/bug) were strongly correlated with the volume of blood recovered: the more blood recovered from each bug, the higher values of microfilariaemia in the evening samples while the opposite results were obtained for the morning samples. The counting of microfilariae revealed a dominance of D. immitis in all the samples, but with significantly higher microfilariaemia in the venous blood. Meanwhile, for D. repens, the situation was opposite, with higher counts in the capillary blood samples. Our study showed that triatomine bugs can be used as a model for the collection and study of microfilariaemia in the capillary blood in mammals.
- Klíčová slova
- Co-infection, Dirofilaria, Periodicity, Triatomine bug,
- MeSH
- cirkadiánní rytmus MeSH
- Dirofilaria immitis izolace a purifikace fyziologie MeSH
- Dirofilaria repens izolace a purifikace fyziologie MeSH
- dirofilarióza diagnóza parazitologie MeSH
- kapiláry parazitologie MeSH
- koinfekce diagnóza parazitologie veterinární MeSH
- mikrofilárie klasifikace izolace a purifikace MeSH
- nemoci psů diagnóza parazitologie MeSH
- odběr vzorku krve metody veterinární MeSH
- parazitemie diagnóza parazitologie veterinární MeSH
- psi MeSH
- studie proveditelnosti MeSH
- Triatominae * MeSH
- vény parazitologie MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- psi MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
An intracellular symbiotic bacterium was isolated from the hemolymph of Triatoma infestans and cultured in an Aedes albopictus cell line. 16S ribosomal DNA sequence analysis revealed that the bacterium was a member of the gamma-3 subgroup of the class Proteobacteria, having 96.2% sequence identity with the most closely related bacterium, Arsenophonus nasoniae, the causative agent of the son-killer trait in the parasitoid wasp Nasonia vitripennis. These bacteria share morphological features and a common tissue distribution and transmission mode. The A. nasoniae-T. infestans symbiont branch represents a lineage of insect symbionts which may be capable of horizontal transmission between phylogenetically distant host insects. We propose that the intracellular symbiont from T. infestans be classified as "Candidatus Arsenophonus triatominarum." The bacterium found in the hemocytes of T. infestans is designated the type strain of this species.
- MeSH
- DNA bakterií analýza MeSH
- elektronová mikroskopie MeSH
- fylogeneze MeSH
- gramnegativní bakterie klasifikace genetika ultrastruktura MeSH
- RNA ribozomální 16S analýza MeSH
- symbióza MeSH
- Triatoma mikrobiologie fyziologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- DNA bakterií MeSH
- RNA ribozomální 16S MeSH
Insecticide-impregnated nets can kill triatomine bugs, but it remains unclear whether they can protect against Chagas disease transmission. In a field trial in Quequeña, Peru, sentinel guinea pigs placed in intervention enclosures covered by deltamethrin-treated nets showed significantly lower antibody responses to saliva of Triatoma infestans compared with animals placed in pre-existing control enclosures. Our results strongly suggest that insecticide-treated nets prevent triatomine bites and can thereby protect against infection with Trypanosoma cruzi. Anti-salivary immunoassays are powerful new tools to evaluate intervention strategies against Chagas disease.
- MeSH
- Chagasova nemoc prevence a kontrola MeSH
- dezinsekce metody MeSH
- imunoanalýza MeSH
- kousnutí a bodnutí hmyzem imunologie prevence a kontrola MeSH
- morčata MeSH
- parazitologie metody MeSH
- sítě nad lůžka napuštěné insekticidy * MeSH
- sliny imunologie MeSH
- Triatoma imunologie MeSH
- zvířata MeSH
- Check Tag
- morčata MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
- Geografické názvy
- Peru MeSH
Chagas disease, caused by the kinetoplastid Trypanosoma cruzi (Chagas, 1909), and transmitted by triatomine bugs, poses a significant public health challenge. Variability in the susceptibility of different triatomine species to T. cruzi infection can profoundly influence disease transmission dynamics and control measures. In this study, we assessed the susceptibility to T. cruzi infection in the first and third nymphal stages across eight triatomine species to T. cruzi infection using experimental inoculation with the NINOA strain and optical microscopy. The evaluated species were Dipetalogaster maximus (Uhler), Triatoma bassolsae (Alejandre-Aguilar, Nogueda-Torres, Cortéz-Jiménez, Jurberg, Galvão, Carcaballo), T. infestans (Klug), T. lecticularia (Stål), T. mexicana (Herrich-Schaeffer), T. pallidipennis (Stål), T. phyllosoma (Burmeister) and T. picturata (Usinger). The results indicated that T. bassolsae exhibited the highest susceptibility to infection, followed by T. pallidipennis and D. maximus. Our analysis also revealed that T. cruzi (NINOA) infection was significantly associated with triatomine species rather than nymphal stage (p < 0.0001), with substantial variability observed in susceptibility among species (p < 0.001). We ranked triatomine species susceptibility to T. cruzi infection as follows: T. bassolsae > D. maximus = T. pallidipennis = T. picturata = T. mexicana > T. phyllosoma = T. lecticularia = T. infestans. These findings enhance our understanding of T. cruzi transmission dynamics and offer valuable insights for the development of effective control strategies against this neglected tropical disease.
- Klíčová slova
- Chagas disease, nymphal stages, triatomine infections, vector competence,
- MeSH
- Chagasova nemoc přenos parazitologie MeSH
- druhová specificita MeSH
- hmyz - vektory * parazitologie MeSH
- nymfa parazitologie růst a vývoj MeSH
- Triatoma * parazitologie MeSH
- Triatominae * parazitologie MeSH
- Trypanosoma cruzi * fyziologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Mexiko MeSH
BACKGROUND: Kissing bugs (Triatominae) are blood-feeding insects best known as the vectors of Trypanosoma cruzi, the causative agent of Chagas' disease. Considering the high epidemiological relevance of these vectors, their biology and bacterial symbiosis remains surprisingly understudied. While previous investigations revealed generally low individual complexity but high among-individual variability of the triatomine microbiomes, any consistent microbiome determinants have not yet been identified across multiple Triatominae species. METHODS: To obtain a more comprehensive view of triatomine microbiomes, we investigated the host-microbiome relationship of five Triatoma species sampled from white-throated woodrat (Neotoma albigula) nests in multiple locations across the USA. We applied optimised 16S rRNA gene metabarcoding with a novel 18S rRNA gene blocking primer to a set of 170 T. cruzi-negative individuals across all six instars. RESULTS: Triatomine gut microbiome composition is strongly influenced by three principal factors: ontogeny, species identity, and the environment. The microbiomes are characterised by significant loss in bacterial diversity throughout ontogenetic development. First instars possess the highest bacterial diversity while adult microbiomes are routinely dominated by a single taxon. Primarily, the bacterial genus Dietzia dominates late-stage nymphs and adults of T. rubida, T. protracta, and T. lecticularia but is not present in the phylogenetically more distant T. gerstaeckeri and T. sanguisuga. Species-specific microbiome composition, particularly pronounced in early instars, is further modulated by locality-specific effects. In addition, pathogenic bacteria of the genus Bartonella, acquired from the vertebrate hosts, are an abundant component of Triatoma microbiomes. CONCLUSION: Our study is the first to demonstrate deterministic patterns in microbiome composition among all life stages and multiple Triatoma species. We hypothesise that triatomine microbiome assemblages are produced by species- and life stage-dependent uptake of environmental bacteria and multiple indirect transmission strategies that promote bacterial transfer between individuals. Altogether, our study highlights the complexity of Triatominae symbiosis with bacteria and warrant further investigation to understand microbiome function in these important vectors. Video abstract.
- Klíčová slova
- Bacteria, Blood, Hematophagous, Insect, Microbiome, Ontogeny, Pathogen, Triatominae, Vector,
- MeSH
- Chagasova nemoc parazitologie MeSH
- divoká zvířata klasifikace mikrobiologie MeSH
- mikrobiota genetika fyziologie MeSH
- RNA ribozomální 16S genetika MeSH
- Triatominae klasifikace mikrobiologie MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- audiovizuální média MeSH
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- RNA ribozomální 16S MeSH
Triatomines are vectors of Chagas disease and important model organisms in insect physiology. "Kissing bugs" are obligatory hematophagous insects. A blood meal is required to successfully complete oogenesis, a process primarily controlled by juvenile hormone (JH). We used Dipetalogaster maxima as an experimental model to further understand the roles of JH in the regulation of vitellogenesis and oogenesis. A particular focus was set on the role of JH controlling lipid and protein recruitment by the oocytes. The hemolymph titer of JH III skipped bisepoxide increased after a blood meal. Following a blood meal there were increased levels of mRNAs in the fat body for the yolk protein precursors, vitellogenin (Vg) and lipophorin (Lp), as well as of their protein products in the hemolymph; mRNAs of the Vg and Lp receptors (VgR and LpR) were concomitantly up-regulated in the ovaries. Topical administration of JH induced the expression of Lp/LpR and Vg/VgR genes, and prompted the uptake of Lp and Vg in pre-vitellogenic females. Knockdown of the expression of LpR by RNA interference in fed females did not impair the Lp-mediated lipid transfer to oocytes, suggesting that the bulk of lipid acquisition by oocytes occurred by other pathways rather than by the endocytic Lp/LpR pathway. In conclusion, our results strongly suggest that JH signaling is critical for lipid storage in oocytes, by regulating Vg and Lp gene expression in the fat body as well as by modulating the expression of LpR and VgR genes in ovaries.
- Klíčová slova
- Endocytic receptors, Juvenile hormone, Lipid metabolism, Lipophorin, Oogenesis, Triatomine,
- MeSH
- hmyz metabolismus fyziologie MeSH
- hmyzí proteiny metabolismus MeSH
- juvenilní hormony metabolismus MeSH
- lipoproteiny metabolismus MeSH
- metabolismus lipidů * MeSH
- oocyty metabolismus MeSH
- oogeneze fyziologie MeSH
- ovarium metabolismus MeSH
- receptory cytoplazmatické a nukleární metabolismus MeSH
- RNA interference MeSH
- signální transdukce MeSH
- Triatominae * metabolismus fyziologie MeSH
- vitelogeneze fyziologie MeSH
- vitelogeniny metabolismus MeSH
- zvířata MeSH
- Check Tag
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
- Názvy látek
- hmyzí proteiny MeSH
- juvenilní hormony MeSH
- lipophorin receptor MeSH Prohlížeč
- lipophorin MeSH Prohlížeč
- lipoproteiny MeSH
- receptory cytoplazmatické a nukleární MeSH
- vitelogeniny MeSH
The importance of gut microbiomes has become generally recognized in vector biology. This study addresses microbiome signatures in North American Triatoma species of public health significance (vectors of Trypanosoma cruzi) linked to their blood-feeding strategy and the natural habitat. To place the Triatoma-associated microbiomes within a complex evolutionary and ecological context, we sampled sympatric Triatoma populations, related predatory reduviids, unrelated ticks, and environmental material from vertebrate nests where these arthropods reside. Along with five Triatoma species, we have characterized microbiomes of five reduviids (Stenolemoides arizonensis, Ploiaria hirticornis, Zelus longipes, and two Reduvius species), a single soft tick species, Ornithodoros turicata, and environmental microbiomes from selected sites in Arizona, Texas, Florida, and Georgia. The microbiomes of predatory reduviids lack a shared core microbiota. As in triatomines, microbiome dissimilarities among species correlate with dominance of a single bacterial taxon. These include Rickettsia, Lactobacillus, "Candidatus Midichloria," and Zymobacter, which are often accompanied by known symbiotic genera, i.e., Wolbachia, "Candidatus Lariskella," Asaia, Gilliamella, and Burkholderia. We have further identified a compositional convergence of the analyzed microbiomes in regard to the host phylogenetic distance in both blood-feeding and predatory reduviids. While the microbiomes of the two reduviid species from the Emesinae family reflect their close relationship, the microbiomes of all Triatoma species repeatedly form a distinct monophyletic cluster highlighting their phylosymbiosis. Furthermore, based on environmental microbiome profiles and blood meal analysis, we propose three epidemiologically relevant and mutually interrelated bacterial sources for Triatoma microbiomes, i.e., host abiotic environment, host skin microbiome, and pathogens circulating in host blood. IMPORTANCE This study places microbiomes of blood-feeding North American Triatoma vectors (Reduviidae) into a broader evolutionary and ecological context provided by related predatory assassin bugs (Reduviidae), another unrelated vector species (soft tick Ornithodoros turicata), and the environment these arthropods coinhabit. For both vectors, microbiome analyses suggest three interrelated sources of bacteria, i.e., the microbiome of vertebrate nests as their natural habitat, the vertebrate skin microbiome, and the pathobiome circulating in vertebrate blood. Despite an apparent influx of environment-associated bacteria into the arthropod microbiomes, Triatoma microbiomes retain their specificity, forming a distinct cluster that significantly differs from both predatory relatives and ecologically comparable ticks. Similarly, within the related predatory Reduviidae, we found the host phylogenetic distance to underlie microbiome similarities.
- Klíčová slova
- Ornithodoros, Reduviidae, Triatoma, environment, microbiome,
- MeSH
- Bacteria genetika MeSH
- fylogeneze MeSH
- mikrobiota * MeSH
- Triatoma * MeSH
- Trypanosoma cruzi * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Two distinct hemocyte populations are determined in the hemolymph of the triatomine bug Triatoma infestans Klug, oenocytoids and plasmatocytes, and their independent origin from separate stem cells is shown. Both hemocyte populations differ considerably in their morphology, ultrastructure and lectin-binding properties. While oenocytoids are quite uniform with easily definable cells which do not to bind any assayed lectin, the plasmatocytes are a very polymorphic population possessing several morphological types and displaying a positive reactivity with lectins.
- MeSH
- hemocyty klasifikace imunologie ultrastruktura MeSH
- lektiny metabolismus MeSH
- Triatoma imunologie ultrastruktura MeSH
- vazba proteinů MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- lektiny MeSH
Incorporation of 3H-thymidine by splenic lymphocytes was studied in CBA mice that were bitten by the triatomine bug Rhodnius prolixus (Stål) 14, 7, 4, and 2 d before lymphocyte isolation, respectively. In bitten mice, both spontaneous and mitogen-induced proliferative responses were reduced. The most pronounced effect was observed 4 d after exposure when lymphocytes were significantly suppressed in proliferative response to the mitogens concanavalin A, phytohemagglutinin, and bacterial lipopolysaccharide. The maximum inhibition caused an 85% reduction of proliferation and was observed in phytohemagglutinin-stimulated cell cultures. The immunosuppressive effect was caused neither by stress nor by an nonspecific cytotoxic effect of R. prolixus saliva. The described immunosuppressive activity of saliva could aid in successful repeated feedings of R. prolixus on the same host and possibly could play a role in transmission of Trypanosoma cruzi.
BACKGROUND: Triatominae are vectors of the protozoan Trypanosoma cruzi, the causative agent of Chagas disease. This study aims to report an infestation on Triatominae colonies by a beetle, previously identified as a pest. METHODS: The management of these colonies should be improved to maximize their usefulness, and factors that may cause harm to them should be avoided as much as possible. RESULTS: This is the first report on a coleopteran infestation on living Triatominae colonies worldwide. CONCLUSIONS: The present record provides an important warning to researchers who maintain insectaries in general, especially those who rear triatomines, to carry protective measures against such invasions.
- MeSH
- brouci * MeSH
- Chagasova nemoc * MeSH
- hmyz - vektory MeSH
- Reduviidae * MeSH
- Triatominae * MeSH
- Trypanosoma cruzi * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
