Nejvíce citovaný článek - PubMed ID 19835965
Probing into the diversity of trypanosomatid flagellates parasitizing insect hosts in South-West China reveals both endemism and global dispersal
Trypanosomatids are obligate parasites of animals, predominantly insects and vertebrates, and flowering plants. Monoxenous species, representing the vast majority of trypanosomatid diversity, develop in a single host, whereas dixenous species cycle between two hosts, of which primarily insect serves as a vector. To explore in-depth the diversity of insect trypanosomatids including their co-infections, sequence profiling of their 18S rRNA gene was used for true bugs (Hemiptera; 18% infection rate) and flies (Diptera; 10%) in Cuba. Out of 48 species (molecular operational taxonomic units) belonging to the genera Vickermania (16 spp.), Blastocrithidia (7), Obscuromonas (4), Phytomonas (5), Leptomonas/Crithidia (5), Herpetomonas (5), Wallacemonas (2), Kentomonas (1), Angomonas (1) and two unnamed genera (1 + 1), 38 species have been encountered for the first time. The detected Wallacemonas and Angomonas species constitute the most basal lineages of their respective genera, while Vickermania emerged as the most diverse group. The finding of Leptomonas seymouri, which is known to rarely infect humans, confirms that Dysdercus bugs are its natural hosts. A clear association of Phytomonas with the heteropteran family Pentatomidae hints at its narrow host association with the insect rather than plant hosts. With a focus on multiple infections of a single fly host, using deep Nanopore sequencing of 18S rRNA, we have identified co-infections with up to 8 trypanosomatid species. The fly midgut was usually occupied by several Vickermania species, while Herpetomonas and/or Kentomonas species prevailed in the hindgut. Metabarcoding was instrumental for analysing extensive co-infections and also allowed the identification of trypanosomatid lineages and genera.
- Klíčová slova
- biodiversity, diptera, heteroptera, host specificity, monoxenous trypanosomatids, multiple infections, nanopore sequencing, phylogeny, systematics,
- MeSH
- Diptera genetika MeSH
- fylogeneze * MeSH
- Hemiptera parazitologie genetika MeSH
- koinfekce * parazitologie MeSH
- protozoální DNA genetika analýza MeSH
- RNA ribozomální 18S * genetika analýza MeSH
- Trypanosomatina * genetika klasifikace izolace a purifikace MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Kuba epidemiologie MeSH
- Názvy látek
- protozoální DNA MeSH
- RNA ribozomální 18S * MeSH
In this work, we investigated parasites of the firebug Pyrrhocoris apterus in Austria and demonstrated that in addition to the extensively studied Leptomonas pyrrhocoris, it can also be infected by Blastocrithidia sp. and by a mermithid, which for the first time has been characterized using molecular methods. This diversity can be explained by the gregarious lifestyle, as well as the coprophagous and cannibalistic behavior of the insect hosts that makes them susceptible to various parasites. In addition, we showed no tight association of the L. pyrrhocoris haplotypes and geographical locations (at least, considering the relatively small scale of locations in Austria) implying that the natural populations of L. pyrrhocoris are mixed due to the mobility of their firebug hosts.
- Klíčová slova
- Blastocrithidia, Firebugs, Mermithidae, Pyrrhocoris apterus,
- MeSH
- Heteroptera * parazitologie MeSH
- paraziti * MeSH
- Trypanosomatina * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Rakousko MeSH
Monoxenous (insect-restricted) trypanosomatids are highly diverse and abundant in nature. While many papers focus on the taxonomy and distribution of these parasites, studies on their biology are still scarce. In particular, this concerns trypanosomatids inhabiting the ubiquitous mosquitoes. To shed light on the circulation of monoxenous trypanosomatids with the participation of mosquitoes, we performed a multifaceted study combining the examination of naturally- and experimentally-infected insects using light and electron microscopy and molecular identification of parasites. Our examination of overwintering mosquitoes (genera Culex and Culiseta) revealed that their guts contained living trypanosomatids, which can be spread during the next season. Experimental infections with Crithidia spp. demonstrated that imagines represent permissive hosts, while larvae are resistant to these parasites. We argue that for the parasites with wide specificity, mosquitoes act as facultative hosts. Other trypanosomatids may have specific adaptations for vertical transmission in these insects at the expense of their potential to infect a wider range of hosts and, consequently, abundance in nature.
- Klíčová slova
- Crithidia, Paratrypanosoma, Trypanosomatidae, experimental infection, facultative host, overwintering mosquitoes, prevalence, specificity, transmission,
- Publikační typ
- časopisecké články MeSH
In this work, we analyzed viral prevalence in trypanosomatid parasites (Blechomonas spp.) infecting Siphonaptera and discovered nine species of viruses from three different groups (leishbunyaviruses, narnaviruses, and leishmaniaviruses). Most of the flagellate isolates bore two or three viral types (mixed infections). Although no new viral groups were documented in Blechomonas spp., our findings are important for the comprehension of viral evolution. The discovery of bunyaviruses in blechomonads was anticipated, since these viruses have envelopes facilitating their interspecific transmission and have already been found in various trypanosomatids and metatranscriptomes with trypanosomatid signatures. In this work, we also provided evidence that even representatives of the family Narnaviridae are capable of host switching and evidently have accomplished switches multiple times in the course of their evolution. The most unexpected finding was the presence of leishmaniaviruses, a group previously solely confined to the human pathogens Leishmania spp. From phylogenetic inferences and analyses of the life cycles of Leishmania and Blechomonas, we concluded that a common ancestor of leishmaniaviruses most likely infected Leishmania first and was acquired by Blechomonas by horizontal transfer. Our findings demonstrate that evolution of leishmaniaviruses is more complex than previously thought and includes occasional host switching.IMPORTANCE Flagellates belonging to the genus Leishmania are important human parasites. Some strains of different Leishmania species harbor viruses (leishmaniaviruses), which facilitate metastatic spread of the parasites, thus aggravating the disease. Up until now, these viruses were known to be hosted only by Leishmania Here, we analyzed viral distribution in Blechomonas, a related group of flagellates parasitizing fleas, and revealed that they also bear leishmaniaviruses. Our findings shed light on the entangled evolution of these viruses. In addition, we documented that Blechomonas can be also infected by leishbunyaviruses and narnaviruses, viral groups known from other insects' flagellates.
- Klíčová slova
- Blechomonas, Leishbunyaviridae, Leishmaniavirus, Narnaviridae,
- MeSH
- fylogeneze MeSH
- genetická variace MeSH
- genom virový MeSH
- Leishmaniavirus genetika MeSH
- molekulární evoluce * MeSH
- RNA-viry klasifikace izolace a purifikace MeSH
- Siphonaptera parazitologie MeSH
- Trypanosomatina virologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Trypanosomatid flagellates have not been studied in Austria in any detail. In this study, specific nested PCR, targeted on the ribosomal small subunit, was used to determine the occurrence and diversity of trypanosomatids in wild-caught mosquitoes sampled across Eastern Austria in the years 2014-2015. We collected a total of 29,975 mosquitoes of 19 species divided in 1680 pools. Of these, 298 (17.7%), representing 12 different mosquito species, were positive for trypanosomatid DNA. In total, seven trypanosomatid spp. were identified (three Trypanosoma, three Crithidia and one Herpetomonas species), with the highest parasite species diversity found in the mosquito host Coquillettidia richiardii. The most frequent parasite species belonged to the mammalian Trypanosoma theileri/cervi species complex (found in 105 pools; 6.3%). The avian species T. culicavium (found in 69 pools; 4.1%) was only detected in mosquitoes of the genus Culex, which corresponds to their preference for avian hosts. Monoxenous trypanosomatids of the genus Crithidia and Herpetomonas were found in 20 (1.3%) mosquito pools. One third (n = 98) of the trypanosomatid positive mosquito pools carried more than one parasite species. This is the first large scale study of trypanosomatid parasites in Austrian mosquitoes and our results are valuable in providing an overview of the diversity of these parasites in Austria.
- MeSH
- biodiverzita MeSH
- Culicidae parazitologie MeSH
- fylogeneze MeSH
- protozoální DNA MeSH
- ribozomální DNA MeSH
- sekvenční analýza DNA MeSH
- Trypanosoma klasifikace genetika MeSH
- trypanozomiáza parazitologie přenos MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Rakousko MeSH
- Názvy látek
- protozoální DNA MeSH
- ribozomální DNA MeSH
Knowledge of viral diversity is expanding greatly, but many lineages remain underexplored. We surveyed RNA viruses in 52 cultured monoxenous relatives of the human parasite Leishmania (Crithidia and Leptomonas), as well as plant-infecting PhytomonasLeptomonas pyrrhocoris was a hotbed for viral discovery, carrying a virus (Leptomonas pyrrhocoris ostravirus 1) with a highly divergent RNA-dependent RNA polymerase missed by conventional BLAST searches, an emergent clade of tombus-like viruses, and an example of viral endogenization. A deep-branching clade of trypanosomatid narnaviruses was found, notable as Leptomonas seymouri bearing Narna-like virus 1 (LepseyNLV1) have been reported in cultures recovered from patients with visceral leishmaniasis. A deep-branching trypanosomatid viral lineage showing strong affinities to bunyaviruses was termed "Leishbunyavirus" (LBV) and judged sufficiently distinct to warrant assignment within a proposed family termed "Leishbunyaviridae" Numerous relatives of trypanosomatid viruses were found in insect metatranscriptomic surveys, which likely arise from trypanosomatid microbiota. Despite extensive sampling we found no relatives of the totivirus Leishmaniavirus (LRV1/2), implying that it was acquired at about the same time the Leishmania became able to parasitize vertebrates. As viruses were found in over a quarter of isolates tested, many more are likely to be found in the >600 unsurveyed trypanosomatid species. Viral loss was occasionally observed in culture, providing potentially isogenic virus-free lines enabling studies probing the biological role of trypanosomatid viruses. These data shed important insights on the emergence of viruses within an important trypanosomatid clade relevant to human disease.
- Klíčová slova
- Bunyavirales, Trypanosomatidae, coevolution, coinfection, persistent virus infection,
- MeSH
- fylogeneze MeSH
- genetická variace MeSH
- hostitelská specificita MeSH
- infekce prvoky kmene Euglenozoa parazitologie veterinární MeSH
- interakce hostitele a patogenu MeSH
- lidé MeSH
- RNA-viry genetika izolace a purifikace MeSH
- Trypanosomatina virologie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
- Research Support, N.I.H., Intramural MeSH
UNLABELLED: We describe a novel symbiotic association between a kinetoplastid protist, Novymonas esmeraldas gen. nov., sp. nov., and an intracytoplasmic bacterium, "Candidatus Pandoraea novymonadis" sp. nov., discovered as a result of a broad-scale survey of insect trypanosomatid biodiversity in Ecuador. We characterize this association by describing the morphology of both organisms, as well as their interactions, and by establishing their phylogenetic affinities. Importantly, neither partner is closely related to other known organisms previously implicated in eukaryote-bacterial symbiosis. This symbiotic association seems to be relatively recent, as the host does not exert a stringent control over the number of bacteria harbored in its cytoplasm. We argue that this unique relationship may represent a suitable model for studying the initial stages of establishment of endosymbiosis between a single-cellular eukaryote and a prokaryote. Based on phylogenetic analyses, Novymonas could be considered a proxy for the insect-only ancestor of the dixenous genus Leishmania and shed light on the origin of the two-host life cycle within the subfamily Leishmaniinae. IMPORTANCE: The parasitic trypanosomatid protist Novymonas esmeraldas gen. nov., sp. nov. entered into endosymbiosis with the bacterium "Ca. Pandoraea novymonadis" sp. nov. This novel and rather unstable interaction shows several signs of relatively recent establishment, qualifying it as a potentially unique transient stage in the increasingly complex range of eukaryotic-prokaryotic relationships.
- MeSH
- Burkholderiaceae klasifikace cytologie izolace a purifikace fyziologie MeSH
- fylogeneze MeSH
- symbióza * MeSH
- Trypanosomatina klasifikace cytologie genetika mikrobiologie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Ekvádor MeSH
The class Kinetoplastea encompasses both free-living and parasitic species from a wide range of hosts. Several representatives of this group are responsible for severe human diseases and for economic losses in agriculture and livestock. While this group encompasses over 30 genera, most of the available information has been derived from the vertebrate pathogenic genera Leishmaniaand Trypanosoma. Recent studies of the previously neglected groups of Kinetoplastea indicated that the actual diversity is much higher than previously thought. This article discusses the known segment of kinetoplastid diversity and how gene-directed Sanger sequencing and next-generation sequencing methods can help to deepen our knowledge of these interesting protists.
- MeSH
- biodiverzita * MeSH
- biologické markery MeSH
- databáze genetické MeSH
- fylogeneze * MeSH
- Kinetoplastida klasifikace cytologie genetika MeSH
- metagenomika trendy MeSH
- protozoální DNA genetika MeSH
- RNA protozoální genetika MeSH
- RNA ribozomální 18S genetika MeSH
- taxonomické DNA čárové kódování trendy MeSH
- výpočetní biologie MeSH
- vysoce účinné nukleotidové sekvenování metody MeSH
- životní prostředí MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
- Názvy látek
- biologické markery MeSH
- protozoální DNA MeSH
- RNA protozoální MeSH
- RNA ribozomální 18S MeSH
This work summarizes the results of the 8-year study focused on Trypanoplasma sp. parasitizing freshwater fishes in the vicinity of Kyiv, Ukraine. Out of 570 fish specimens of 2 different species analyzed, 440 individuals were found to be infected. The prevalence of infection ranged from 24 % in Abramis brama Linnaeus (freshwater bream) to 100 % in Cobitis taenia Linnaeus (spined loach). The level of parasitemia also varied between moderate in freshwater bream and very high in spined loach. Interestingly, no clinical manifestations of trypanoplasmosis were observed even in extremely heavily infected C. taenia. We hypothesize that different species may differ in evolutionary timing allowing for reciprocal adaptation of the members of the "host-parasite" system. Molecular analysis of the 18S rRNA sequences revealed that several specimens were simultaneously infected with at least two different trypanoplasm species. To the best of our knowledge, this is the first report of the mixed infection with fish trypanoplasms.
- MeSH
- hostitelská specificita MeSH
- infekce prvoky kmene Euglenozoa epidemiologie parazitologie veterinární MeSH
- Kinetoplastida genetika fyziologie MeSH
- koinfekce MeSH
- nemoci ryb epidemiologie parazitologie MeSH
- prevalence MeSH
- ryby parazitologie fyziologie MeSH
- sladká voda MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Ukrajina epidemiologie MeSH