Over the last two decades my colleagues and I have assembled the literature on a good percentage of most of the coccidians (Conoidasida) known, to date, to parasitise: Amphibia, four major lineages of Reptilia (Amphisbaenia, Chelonia, Crocodylia, Serpentes), and seven major orders in the Mammalia (Carnivora, Chiroptera, Lagomorpha, Insectivora, Marsupialia, Primates, Scandentia). These vertebrates, combined, comprise about 15,225 species; only about 899 (5.8%) of them have been surveyed for coccidia and 1,946 apicomplexan valid species names or other forms are recorded in the literature. Based on these compilations and other factors, I extrapolated that there yet may be an additional 31,381 new apicomplexans still to be discovered in just these 12 vertebrate groups. Extending the concept to all of the other extant vertebrates on Earth; i.e. lizards (6,300 spp.), rodents plus 12 minor orders of mammals (3,180 spp.), birds (10,000 spp.), and fishes (33,000 spp.) and, conservatively assuming only two unique apicomplexan species per each vertebrate host species, I extrapolate and extend my prediction that we may eventually find 135,000 new apicomplexans that still need discovery and to be described in and from those vertebrates that have not yet been examined for them! Even doubling that number is a significant underestimation in my opinion.
- MeSH
- Apicomplexa izolace a purifikace MeSH
- biodiverzita MeSH
- klasifikace MeSH
- obojživelníci parazitologie MeSH
- obratlovci parazitologie MeSH
- plazi parazitologie MeSH
- ptáci parazitologie MeSH
- ryby parazitologie MeSH
- savci parazitologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Spiders rely on venom to catch prey and few species are even capable of capturing vertebrates. The majority of spiders are generalist predators, possessing complex venom, in which different toxins seem to target different types of prey. In this study, we focused on the trophic ecology and venom toxicity of Phoneutria boliviensis F. O. Pickard-Cambridge, 1897, a Central American spider of medical importance. We tested the hypothesis that its venom is adapted to catch vertebrate prey by studying its trophic ecology and venom toxicity against selected vertebrate and invertebrate prey. We compared both trophic ecology (based on acceptance experiments) and toxicity (based on bioassays) among sexes of this species. We found that P. boliviensis accepted geckos, spiders, and cockroaches as prey, but rejected frogs. There was no difference in acceptance between males and females. The venom of P. boliviensis was far more efficient against vertebrate (geckos) than invertebrate (spiders) prey in both immobilization time and LD50. Surprisingly, venom of males was more efficient than that of females. Our results suggest that P. boliviensis has adapted its venom to catch vertebrates, which may explain its toxicity to humans.
- MeSH
- interakce hostitele a parazita * MeSH
- obratlovci parazitologie MeSH
- pavoučí jedy toxicita MeSH
- pavouci parazitologie MeSH
- predátorské chování * MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Střední Amerika MeSH
Systems biology approaches, especially in the big data era, have revolutionized modern parasitology. Of the many different molecules participating in parasite-host interactions, noncoding RNAs (ncRNAs) are now known to be (i) transmitted by the vector to possibly modulate vertebrate host responses and favor vector survival and (ii) regulated in the host by parasites to favor parasite survival. Here we provide an overview of the involvement of ncRNAs in the parasite-vector-host triad and their effect on host homeostasis based on recent advances and accumulating knowledge about the role of endogenous vertebrate noncoding RNAs in vertebrate host physiology.
- MeSH
- homeostáza fyziologie MeSH
- infekce přenášené vektorem * MeSH
- interakce hostitele a parazita genetika imunologie MeSH
- lidé MeSH
- nekódující RNA genetika imunologie MeSH
- obratlovci imunologie parazitologie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
The relationships between parasites and their hosts are intimate, dynamic and complex; the evolution of one is inevitably linked to the other. Despite multiple origins of parasitism in the Cnidaria, only parasites belonging to the Myxozoa are characterized by a complex life cycle, alternating between fish and invertebrate hosts, as well as by high species diversity. This inspired us to examine the history of adaptive radiations in myxozoans and their hosts by determining the degree of congruence between their phylogenies and by timing the emergence of myxozoan lineages in relation to their hosts. Recent genomic analyses suggested a common origin of Polypodium hydriforme, a cnidarian parasite of acipenseriform fishes, and the Myxozoa, and proposed fish as original hosts for both sister lineages. We demonstrate that the Myxozoa emerged long before fish populated Earth and that phylogenetic congruence with their invertebrate hosts is evident down to the most basal branches of the tree, indicating bryozoans and annelids as original hosts and challenging previous evolutionary hypotheses. We provide evidence that, following invertebrate invasion, fish hosts were acquired multiple times, leading to parallel cospeciation patterns in all major phylogenetic lineages. We identify the acquisition of vertebrate hosts that facilitate alternative transmission and dispersion strategies as reason for the distinct success of the Myxozoa, and identify massive host specification-linked parasite diversification events. The results of this study transform our understanding of the origins and evolution of parasitism in the most basal metazoan parasites known.
- MeSH
- biodiverzita * MeSH
- biologická evoluce * MeSH
- časové faktory MeSH
- Cnidaria parazitologie MeSH
- fylogeneze MeSH
- interakce hostitele a parazita MeSH
- Myxozoa fyziologie MeSH
- obratlovci parazitologie MeSH
- pravděpodobnostní funkce MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Ticks are vectors of pathogens affecting human and animal health worldwide. Nevertheless, the ecological and evolutionary interactions between ticks, hosts, and pathogens are largely unknown. Here, we integrated a framework to evaluate the associations of the tickIxodes ricinuswith its hosts and environmental niches that impact pathogen circulation. The analysis of tick-hosts association suggested that mammals and lizards were the ancestral hosts of this tick species, and that a leap to Aves occurred around 120 M years ago. The signature of the environmental variables over the host's phylogeny revealed the existence of two clades of vertebrates diverging along a temperature and vegetation split. This is a robust proof that the tick probably experienced a colonization of new niches by adapting to a large set of new hosts, Aves. Interestingly, the colonization of Aves as hosts did not increase significantly the ecological niche ofI. ricinus, but remarkably Aves are super-spreaders of pathogens. The disparate contribution of Aves to the tick-host-pathogen networks revealed thatI. ricinusevolved to maximize habitat overlap with some hosts that are super-spreaders of pathogens. These results supported the hypothesis that large host networks are not a requirement of tick survival but pathogen circulation. The biological cost of tick adaptation to non-optimal environmental conditions might be balanced by molecular mechanisms triggered by the pathogens that we have only begun to understand.
- MeSH
- biologická adaptace MeSH
- druhová specificita MeSH
- ekologie metody MeSH
- interakce hostitele a patogenu MeSH
- ještěři parazitologie MeSH
- klíšťata mikrobiologie parazitologie fyziologie MeSH
- klíště klasifikace parazitologie fyziologie MeSH
- lidé MeSH
- nemoci přenášené klíšťaty parazitologie přenos MeSH
- obratlovci klasifikace parazitologie MeSH
- ptáci klasifikace parazitologie MeSH
- savci klasifikace parazitologie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The hard tick Ixodes ricinus is an important disease vector whose salivary secretions mediate blood-feeding success on vertebrate hosts, including humans. Here we describe the expression profiles and downstream analysis of de novo-discovered microRNAs (miRNAs) expressed in I. ricinus salivary glands and saliva. Eleven tick-derived libraries were sequenced to produce 67,375,557 Illumina reads. De novo prediction yielded 67 bona fide miRNAs out of which 35 are currently not present in miRBase. We report for the first time the presence of microRNAs in tick saliva, obtaining furthermore molecular indicators that those might be of exosomal origin. Ten out of these microRNAs are at least 100 times more represented in saliva. For the four most expressed microRNAs from this subset, we analyzed their combinatorial effects upon their host transcriptome using a novel in silico target network approach. We show that only the inclusion of combinatorial effects reveals the functions in important pathways related to inflammation and pain sensing. A control set of highly abundant microRNAs in both saliva and salivary glands indicates no significant pathways and a far lower number of shared target genes. Therefore, the analysis of miRNAs from pure tick saliva strongly supports the hypothesis that tick saliva miRNAs can modulate vertebrate host homeostasis and represents the first direct evidence of tick miRNA-mediated regulation of vertebrate host gene expression at the tick-host interface. As such, the herein described miRNAs may support future drug discovery and development projects that will also experimentally question their predicted molecular targets in the vertebrate host.
- MeSH
- genové regulační sítě * MeSH
- infestace klíšťaty genetika parazitologie MeSH
- interakce hostitele a parazita genetika MeSH
- klíště genetika MeSH
- mikro RNA analýza genetika MeSH
- obratlovci parazitologie MeSH
- počítačová simulace MeSH
- slinné žlázy metabolismus MeSH
- sliny chemie metabolismus MeSH
- transkriptom * MeSH
- vysoce účinné nukleotidové sekvenování metody MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
The Echinostomatoidea is a large, cosmopolitan group of digeneans currently including nine families and 105 genera, the vast majority parasitic, as adults, in birds with relatively few taxa parasitising mammals, reptiles and, exceptionally, fish. Despite the complex structure, diverse content and substantial species richness of the group, almost no attempt has been made to elucidate its phylogenetic relationships at the suprageneric level based on molecules due to the lack of data. Herein, we evaluate the consistency of the present morphology-based classification system of the Echinostomatoidea with the phylogenetic relationships of its members based on partial sequences of the nuclear lsrRNA gene for a broad diversity of taxa (80 species, representing eight families and 40 genera), including representatives of five subfamilies of the Echinostomatidae, which currently exhibits the most complex taxonomic structure within the superfamily. This first comprehensive phylogeny for the Echinostomatoidea challenged the current systematic framework based on comparative morphology. A morphology-based evaluation of this new molecular framework resulted in a number of systematic and nomenclatural changes consistent with the phylogenetic estimates of the generic and suprageneric boundaries and a new phylogeny-based classification of the Echinostomatoidea. In the current systematic treatment: (i) the rank of two family level lineages, the former Himasthlinae and Echinochasminae, is elevated to full family status; (ii) Caballerotrema is distinguished at the family level; (iii) the content and diagnosis of the Echinostomatidae (sensu stricto) (s. str.) are revised to reflect its phylogeny, resulting in the abolition of the Nephrostominae and Chaunocephalinae as synonyms of the Echinostomatidae (s. str.); (iv) Artyfechinostomum, Cathaemasia, Rhopalias and Ribeiroia are re-allocated within the Echinostomatidae (s. str.), resulting in the abolition of the Cathaemasiidae, Rhopaliidae and Ribeiroiinae, which become synonyms of the Echinostomatidae (s. str.); and (v) refinements of the generic boundaries within the Echinostomatidae (s. str.), Psilostomidae and Fasciolidae are made.
- MeSH
- Echinostomatidae klasifikace genetika izolace a purifikace MeSH
- fylogeneze * MeSH
- infekce červy třídy Trematoda parazitologie veterinární MeSH
- lidé MeSH
- molekulární evoluce MeSH
- molekulární sekvence - údaje MeSH
- obratlovci klasifikace parazitologie MeSH
- plazi MeSH
- ptáci MeSH
- ryby MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, U.S. Gov't, Non-P.H.S. MeSH
A total of 151 bacterial isolates were recovered from different developmental stages (larvae, nymphs and adults) of field-collected ticks (67 strains from Ixodes ricinus, 38 from Dermacentor reticulatus, 46 from Haemaphysalis concinna). Microorganisms were identified by means of 16S rRNA gene sequencing. Almost 87 % of the strains belonged to G(+) bacteria with predominantly occurring genera Bacillus and Paenibacillus. Other G(+) strains included Arthrobacter, Corynebacterium, Frigoribacterium, Kocuria, Microbacterium, Micrococcus, Plantibacter, Rhodococcus, Rothia, and Staphylococcus. G(-) strains occurred less frequently, comprising genera Advenella, Pseudomonas, Rahnella, Stenotrophomonas, and Xanthomonas. Several strains of medical importance were found, namely Advenella incenata, Corynebacterium aurimucosum, Microbacterium oxydans, M. schleiferi, Staphylococcus spp., and Stenotrophomonas maltophilia. Data on cultivable microbial diversity in Eurasian tick species D. reticulatus and H. concinna are given, along with the extension of present knowledge concerning bacterial flora of I. ricinus.
- MeSH
- arachnida jako vektory mikrobiologie parazitologie růst a vývoj MeSH
- Bacteria genetika izolace a purifikace klasifikace MeSH
- DNA bakterií genetika MeSH
- financování organizované MeSH
- fylogeneze MeSH
- infestace klíšťaty parazitologie MeSH
- Ixodidae mikrobiologie parazitologie růst a vývoj MeSH
- molekulární sekvence - údaje MeSH
- obratlovci parazitologie MeSH
- ribozomální DNA genetika MeSH
- RNA ribozomální 16S genetika MeSH
- techniky typizace bakterií MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH