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.

• 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

Publikace se zaměřuje na virová, bakteriální, mykotická a parazitní onemocnění a jejich léčbu. Určeno odborné veřejnosti.; Publikace předkládá přehled mikroorganismů, tj. virů a subvirálních částic, bakterií, mykromycet a prvoků, a některých makroskopicky viditelných helmintů a členovců, kteří mohou vyvolávat onemocnění člověka.

• MeSH
• Bacteria MeSH
• bakteriální infekce MeSH
• farmakoterapie MeSH
• houby MeSH
• mikrobiologické techniky MeSH
• mykózy MeSH
• parazitární nemoci MeSH
• paraziti MeSH
• virové nemoci MeSH
• viry MeSH

• Konspekt
• Mikrobiologie
• NLK Obory
• mikrobiologie, lékařská mikrobiologie
• NLK Publikační typ
• kolektivní monografie

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.

• 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

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.

• 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

BACKGROUND: Salivary proteins of Triatoma infestans elicit humoral immune responses in their vertebrate hosts. These immune responses indicate exposure to triatomines and thus can be a useful epidemiological tool to estimate triatomine infestation. In the present study, we analyzed antibody responses of guinea pigs to salivary antigens of different developmental stages of four T. infestans strains originating from domestic and/or peridomestic habitats in Argentina, Bolivia, Chile and Peru. We aimed to identify developmental stage- and strain-specific salivary antigens as potential markers of T. infestans exposure. METHODOLOGY AND PRINCIPAL FINDINGS: In SDS-PAGE analysis of salivary proteins of T. infestans the banding pattern differed between developmental stages and strains of triatomines. Phenograms constructed from the salivary profiles separated nymphal instars, especially the 5th instar, from adults. To analyze the influence of stage- and strain-specific differences in T. infestans saliva on the antibody response of guinea pigs, twenty-one guinea pigs were exposed to 5th instar nymphs and/or adults of different T. infestans strains. Western blot analyses using sera of exposed guinea pigs revealed stage- and strain-specific variations in the humoral response of animals. In total, 27 and 17 different salivary proteins reacted with guinea pig sera using IgG and IgM antibodies, respectively. Despite all variations of recognized salivary antigens, an antigen of 35 kDa reacted with sera of almost all challenged guinea pigs. CONCLUSION: Salivary antigens are increasingly considered as an epidemiological tool to measure exposure to hematophagous arthropods, but developmental stage- and strain-specific variations in the saliva composition and the respective differences of immunogenicity are often neglected. Thus, the development of a triatomine exposure marker for surveillance studies after triatomine control campaigns requires detailed investigations. Our study resulted in the identification of a potential antigen as useful marker of T. infestans exposure.

• MeSH
• biologické markery krev   MeSH
• elektroforéza v polyakrylamidovém gelu MeSH
• hmyzí proteiny imunologie   MeSH
• kousnutí a bodnutí imunologie   MeSH
• morčata MeSH
• proteom analýza   MeSH
• protilátky krev   MeSH
• slinné proteiny a peptidy analýza   imunologie   MeSH
• Triatoma * MeSH
• western blotting 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
• Jižní Amerika 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

• MeSH
• parazitární nemoci MeSH
• paraziti MeSH
• parazitologie MeSH
• Publikační typ
• atlasy MeSH

• Konspekt
• Buněčná biologie. Cytologie
• NLK Obory
• parazitologie

• MeSH
• Chagasova nemoc MeSH
• parazitární nemoci MeSH
• protozoální infekce MeSH
• trypanozomiáza MeSH

• Konspekt
• Veřejné zdraví a hygiena
• NLK Obory
• veřejné zdravotnictví
• parazitologie
• infekční lékařství

• MeSH
• infekce přenášené vektorem MeSH
• kontrola infekčních nemocí MeSH

• Konspekt
• Patologie. Klinická medicína
• NLK Obory
• infekční lékařství
• parazitologie
• cestovní a tropická medicína
• NLK Publikační typ
• publikace WHO

• MeSH
• biofyzika MeSH

• Konspekt
• Biochemie. Molekulární biologie. Biofyzika
• NLK Obory
• fyzika, biofyzika
• NLK Publikační typ
• učebnice vysokých škol