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Genome Biology and Evolution Feb 2024Unicellular ciliates like Tetrahymena are best known as free-living bacteriovores, but many species are facultative or obligate parasites. These "histophages" feed on...
Unicellular ciliates like Tetrahymena are best known as free-living bacteriovores, but many species are facultative or obligate parasites. These "histophages" feed on the tissues of hosts ranging from planarian flatworms to commercially important fish and the larvae of imperiled freshwater mussels. Here, we developed a novel bioinformatics pipeline incorporating the nonstandard ciliate genetic code and used it to search for Ciliophora sequences in 34 publicly available Platyhelminthes EST libraries. From 2,615,036 screened ESTs, we identified nearly 6,000 high-confidence ciliate transcripts, supporting parasitism of seven additional flatworm species. We also cultured and identified Tetrahymena from nine terrestrial and freshwater planarians, including invasive earthworm predators from the genus Bipalium and the widely studied regeneration models Dugesia japonica and Schmidtea mediterranea. A co-phylogenetic reconstruction provides strong evidence for the coevolution of histophagous Ciliophora with their Platyhelminthes hosts. We further report the antiprotozoal aminoglycoside paromomycin expels Tetrahymena from S. mediterranea, providing new opportunities to investigate the effects of this relationship on planarian biology. Together, our findings raise the possibility that invasive flatworms constitute a novel dispersal mechanism for Tetrahymena parasites and position the Platyhelminthes as an ideal model phylum for studying the ecology and evolution of histophagous ciliates.
Topics: Animals; Phylogeny; Transcriptome; Ciliophora; Planarians
PubMed: 38242711
DOI: 10.1093/gbe/evae007 -
Frontiers in Cellular and Infection... 2021Cysticercosis is a neglected tropical disease caused by the larvae of in pigs and humans. The current diagnosis of porcine cysticercosis is difficult, and traditional...
Cysticercosis is a neglected tropical disease caused by the larvae of in pigs and humans. The current diagnosis of porcine cysticercosis is difficult, and traditional pathological tests cannot meet the needs of detection. This study established a UPT-LF assay for the detection of . UCP particles were bound to two antigens, TSOL18 and GP50; samples were captured, and the signal from the UCP particles was converted into a detectable signal for analysis using a biosensor. Compared to ELISA, UPT-LF has higher sensitivity and specificity, with a sensitivity of 93.59% and 97.44%, respectively, in the case of TSOL18 and GP50 antigens and a specificity of 100% for both. Given its rapidness, small volume, high sensitivity and specificity, and good stability and reproducibility, this method could be used in the diagnosis of cysticercosis.
Topics: Animals; Cysticercus; Enzyme-Linked Immunosorbent Assay; Reproducibility of Results; Sensitivity and Specificity; Swine; Taenia solium; Technology
PubMed: 34858877
DOI: 10.3389/fcimb.2021.762472 -
PloS One 2021Host preference of symbionts evolves from fitness trade-offs. However, it is often unclear how interspecific variations in host response traits influence this...
Host preference of symbionts evolves from fitness trade-offs. However, it is often unclear how interspecific variations in host response traits influence this evolutionary process. Using the association between the polyclad flatworm Paraprostatum echinolittorinae and its intertidal snail hosts on the Pacific Coast of Panama, we assessed how a symbiont's host preference is associated with varying host defenses and post-infestation performances. We first characterized the prevalence and intensity of worm infestation in five snail hosts (Tegula pellisserpentis, Nerita scabricosta, N. funiculata, Planaxis planicostatus, and Cerithium stercusmuscarum). We then used manipulative experiments to test flatworm's host choice, hosts' behavioral rejection of flatworms, and hosts' growth and survival following the infestation. In the field, flatworms were orders of magnitude more prevalent and dense in T. pellisserpentis, N. scabricosta, N. funiculata than P. planicostatus and C. stercusmuscarum, although the three former hosts were not necessarily more abundant. The results from our laboratory host selection trials mirrored these patterns; flatworms were 3 to 14 times more likely to choose T. pellisserpentis, N. scabricosta, N. funiculata over P. planicostatus and C. stercusmuscarum. The less preferred hosts frequently rejected flatworms via mantle contractions and foot withdrawals, which reduced the infestation rate by 39%-67%. These behaviors were less frequent or absent in the preferred hosts. Flatworm infestation variably influenced host performances in the field, negligibly affecting the growth and survival of T. pellisserpentis and N. funiculata but reducing the growth of P. planicostatus. Flatworms thus preferred less defended hosts that can also support higher worm densities without being harmed. Stable isotope analysis further revealed that flatworms are unlikely to feed on snail tissues and may live as a commensal in their preferred hosts. Our study demonstrates that host response traits can modulate a symbiont's host choice and calls for more explicit considerations of host response variability in host preference research.
Topics: Animals; Aquatic Organisms; Biological Evolution; Cestode Infections; Ecosystem; Host-Parasite Interactions; Oceans and Seas; Panama; Phenotype; Platyhelminths; Prevalence; Snails; Symbiosis
PubMed: 33651807
DOI: 10.1371/journal.pone.0247551 -
Biology Letters Jan 2024While knowledge of early ontogeny in abyssal animals is highly limited in general, it was completely lacking for abyssal, free-living platyhelminths. We discovered...
While knowledge of early ontogeny in abyssal animals is highly limited in general, it was completely lacking for abyssal, free-living platyhelminths. We discovered flatworm egg capsules (or 'cocoons') on rocks collected at depths of 6176-6200 m on the abyssal slope of the Kuril-Kamchatka Trench, northwestern Pacific. The egg capsules were black and spherical, around 3 mm in diameter, and contained three to seven individuals ( = 4) at the same developmental stage, either the spherical (putative early embryo) or vermiform (putative late embryo) stages. A molecular phylogenetic analysis based on 18S and 28S rRNA sequences revealed that the flatworms belong in suborder Maricola in Tricladida and suggested that they may have colonized from shallow to deep waters. This study provides the deepest record for free-living flatworms and the first information on their early life stages in the abyssal zone, which were very similar to those in shallow-water forms. This similarity in development between the relatively benign shallow-water and the extreme abyssal environments suggests that triclads adapting to the latter faced primarily physiological and/or ecological adaptive challenges rather than developmental ones.
Topics: Humans; Animals; Phylogeny; Head; Platyhelminths; Water
PubMed: 38263880
DOI: 10.1098/rsbl.2023.0506 -
Parasites & Vectors Jan 2021Echinococcus multilocularis is a small tapeworm affecting wild and domestic carnivores and voles in a typical prey-predator life cycle. In Italy, there has been a focus...
BACKGROUND
Echinococcus multilocularis is a small tapeworm affecting wild and domestic carnivores and voles in a typical prey-predator life cycle. In Italy, there has been a focus of E. multilocularis since 1997 in the northern Italian Alps, later confirmed in red foxes collected from 2001 to 2005. In this study, we report the results of seven years of monitoring on E. multilocularis and other cestodes in foxes and describe the changes that occurred over time and among areas (eco-regions) showing different environmental and ecological features on a large scale.
METHODS
Eggs of cestodes were isolated from feces of 2872 foxes with a sedimentation/filtration technique. The cestode species was determined through multiplex PCR, targeting and sequencing ND1 and 12S genes. Analyses were aimed to highlight variations among different eco-regions and trends in prevalence across the study years.
RESULTS
Out of 2872 foxes, 217 (7.55%) samples resulted positive for cestode eggs at coproscopy, with differences of prevalence according to year, sampling area and age class. Eight species of cestodes were identified, with Taenia crassiceps (2.65%), Taenia polyacantha (1.98%) and E. multilocularis (1.04%) as the most represented. The other species, Mesocestoides litteratus, Taenia krabbei, T. serialis, T. taeniaeformis and Dipylidium caninum, accounted for < 1% altogether. Echinococcus multilocularis was identified in foxes from two out of six eco-regions, in 30 fecal samples, accounting for 1.04% within the cestode positives at coproscopy. All E. multilocularis isolates came from Bolzano province. Prevalence of cestodes, both collectively and for each of the three most represented species (T. crassiceps, T. polyacantha and E. multilocularis), varied based on the sampling year, and for E. multilocularis an apparent increasing trend across the last few years was evidenced.
CONCLUSIONS
Our study confirms the presence of a focus of E. multilocularis in red foxes of northeast Italy. Although this focus seems still spatially limited, given its persistence and apparent increasing prevalence through the years, we recommend research to be conducted in the future on the ecological factors that, on a smaller scale, allow this zoonotic species to persist. On the same scale, we recommend a health education campaign to inform on the measures to prevent this zoonosis, targeted at people living in the area, especially hunters, dog owners, forestry workers and other potentially exposed categories.
Topics: Animals; Cestoda; Cestode Infections; DNA, Helminth; Echinococcosis; Echinococcus multilocularis; Feces; Female; Foxes; Italy; Male; Parasite Egg Count; Prevalence; Zoonoses
PubMed: 33413547
DOI: 10.1186/s13071-020-04520-5 -
Current Biology : CB Oct 2023Parasites have evolved a variety of astonishing strategies to survive within their hosts, yet the most challenging event in their personal chronicles is the passage from...
Parasites have evolved a variety of astonishing strategies to survive within their hosts, yet the most challenging event in their personal chronicles is the passage from one host to another. It becomes even more complex when a parasite needs to pass through the external environment. Therefore, the free-living stages of parasites present a wide range of adaptations for transmission. Parasitic flatworms from the group Digenea (flukes) have free-living larvae, cercariae, which are remarkably diverse in structure and behavior. One of the cercariae transmission strategies is to attain a prey-like appearance for the host. This can be done through the formation of a swimming aggregate of several cercariae adjoined together by their tails. Through the use of live observations and light, electron, and confocal microscopy, we described such a supposedly prey-mimetic colony comprising cercariae of two distinct morphotypes. They are functionally specialized: larger morphotype (sailors) enable motility, and smaller morphotype (passengers) presumably facilitate infection. The analysis of local read alignments between the two samples reveals that both cercaria types have identical 18S, 28S, and 5.8S rRNA genes. Further phylogenetic analysis of these ribosomal sequences indicates that our specimen belongs to the digenean family Acanthocolpidae, likely genus Pleorchis. This discovery provides a unique example and a novel insight into how morphologically and functionally heterogeneous individuals of the same species cooperate to build colonial organisms for the purpose of infection. This strategy bears resemblance to the cooperating castes of the same species found among insects..
Topics: Humans; Animals; Larva; Parasites; Phylogeny; Swimming; Trematoda; Cercaria
PubMed: 37741283
DOI: 10.1016/j.cub.2023.08.090 -
Parasite (Paris, France) 2020Echinococcoses require the involvement of specialists from nearly all disciplines; standardization of the terminology used in the field is thus crucial. To harmonize...
Echinococcoses require the involvement of specialists from nearly all disciplines; standardization of the terminology used in the field is thus crucial. To harmonize echinococcosis terminology on sound scientific and linguistic grounds, the World Association of Echinococcosis launched a Formal Consensus process. Under the coordination of a Steering and Writing Group (SWG), a Consultation and Rating Group (CRG) had the main missions of (1) providing input on the list of terms drafted by the SWG, taking into account the available literature and the participants' experience; and (2) providing independent rating on all debated terms submitted to vote. The mission of the Reading and Review Group (RRG) was to give an opinion about the recommendation paper in terms of readability, acceptability and applicability. The main achievements of this process were: (1) an update of the current nomenclature of Echinococcus spp.; (2) an agreement on three names of diseases due to Echinococcus spp.: Cystic Echinococcosis (CE), Alveolar Echinococcosis (AE) and Neotropical Echinococcosis (NE), and the exclusion of all other names; (3) an agreement on the restricted use of the adjective "hydatid" to refer to the cyst and fluid due to E. granulosus sensu lato; and (4) an agreement on a standardized description of the surgical operations for CE, according to the "Approach, cyst Opening, Resection, and Completeness" (AORC) framework. In addition, 95 "approved" and 60 "rejected" terms were listed. The recommendations provided in this paper will be applicable to scientific publications in English and communication with professionals. They will be used for translation into other languages spoken in endemic countries.
Topics: Animals; Consensus; Echinococcosis; Echinococcus; Echinococcus granulosus; Humans; Publications; Reference Standards; Terminology as Topic
PubMed: 32500855
DOI: 10.1051/parasite/2020024 -
Nucleic Acids Research Mar 2024Much insight has been gained on how stem cells maintain genomic integrity, but less attention has been paid to how they maintain their transcriptome. Here, we report...
Much insight has been gained on how stem cells maintain genomic integrity, but less attention has been paid to how they maintain their transcriptome. Here, we report that the PIWI protein SMEDWI-1 plays a role in the filtering of dysfunctional transcripts from the transcriptome of planarian stem cells. SMEDWI-1 accomplishes this through association with the ribosomes during the pioneer round of translation, and processing of poorly translated transcripts into piRNAs. This results in the removal of such transcripts from the cytoplasmic pool and at the same time creates a dynamic pool of small RNAs for post-transcriptional surveillance through the piRNA pathway. Loss of SMEDWI-1 results in elevated levels of several non-coding transcripts, including rRNAs, snRNAs and pseudogene mRNAs, while reducing levels of several coding transcripts. In the absence of SMEDWI-1, stem cell colonies are delayed in their expansion and a higher fraction of descendants exit the stem cell state, indicating that this transcriptomic sanitation mediated by SMEDWI-1 is essential to maintain stem cell health. This study presents a new model for the function of PIWI proteins in stem cell maintenance, that complements their role in transposon repression, and proposes a new biogenesis pathway for piRNAs in stem cells.
Topics: Argonaute Proteins; DNA Transposable Elements; Helminth Proteins; Piwi-Interacting RNA; Platyhelminths; Proteins; RNA Interference; RNA, Small Interfering; Stem Cells; Animals
PubMed: 38142432
DOI: 10.1093/nar/gkad1212 -
Marine Drugs May 2022Non-parasitic flatworms are known to temporarily attach to the substrate by secreting a multicomponent bioadhesive to counteract water movements. However, to date, only...
Non-parasitic flatworms are known to temporarily attach to the substrate by secreting a multicomponent bioadhesive to counteract water movements. However, to date, only species of two higher-level flatworm taxa (Macrostomorpha and Proseriata) have been investigated for their adhesive proteins. Remarkably, the surface-binding protein is not conserved between flatworm taxa. In this study, we sequenced and assembled a draft genome, as well as a transcriptome, and generated a tail-specific positional RNA sequencing dataset of the polyclad . This led to the identification of 15 candidate genes potentially involved in temporary adhesion. Using in situ hybridisation and RNA interference, we determined their expression and function. Of these 15 genes, 4 are homologues of adhesion-related genes found in other flatworms. With this work, we provide two novel key components on the flatworm temporary adhesion system. First, we identified a Kringle-domain-containing protein (Tmed-krg1), which was expressed exclusively in the anchor cell. This in silico predicted membrane-bound Tmed-krg1 could potentially bind to the cohesive protein, and a knockdown led to a non-adhesive phenotype. Secondly, a secreted tyrosinase (Tmed-tyr1) was identified, which might crosslink the adhesive proteins. Overall, our findings will contribute to the future development of reversible synthetic glues with desirable properties for medical and industrial applications.
Topics: Animals; Platyhelminths; Proteins; RNA Interference; Sequence Analysis, RNA; Transcriptome
PubMed: 35736161
DOI: 10.3390/md20060359 -
PloS One 2021Since the first complete set of Platyhelminth nuclear receptors (NRs) from Schistosoma mansoni were identified a decade ago, more flatworm genome data is available to...
Since the first complete set of Platyhelminth nuclear receptors (NRs) from Schistosoma mansoni were identified a decade ago, more flatworm genome data is available to identify their NR complement and to analyze the evolutionary relationship of Platyhelminth NRs. NRs are important transcriptional modulators that regulate development, differentiation and reproduction of animals. In this study, NRs are identified in genome databases of thirty-three species including in all Platyhelminth classes (Rhabditophora, Monogenea, Cestoda and Trematoda). Phylogenetic analysis shows that NRs in Platyhelminths follow two different evolutionary lineages: 1) NRs in a free-living freshwater flatworm (Schmidtea mediterranea) and all parasitic flatworms share the same evolutionary lineage with extensive gene loss. 2) NRs in a free-living intertidal zone flatworm (Macrostomum lignano) follow a different evolutionary lineage with a feature of multiple gene duplication and gene divergence. The DNA binding domain (DBD) is the most conserved region in NRs which contains two C4-type zinc finger motifs. A novel zinc finger motif is identified in parasitic flatworm NRs: the second zinc finger of parasitic Platyhelminth HR96b possesses a CHC2 motif which is not found in NRs of all other animals studied to date. In this study, novel NRs (members of NR subfamily 3 and 6) are identified in flatworms, this result demonstrates that members of all six classical NR subfamilies are present in the Platyhelminth phylum. NR gene duplication, loss and divergence in Platyhelminths are analyzed along with the evolutionary relationship of Platyhelminth NRs.
Topics: Animals; Evolution, Molecular; Gene Duplication; Phylogeny; Platyhelminths; Receptors, Cytoplasmic and Nuclear; Zinc Fingers
PubMed: 34388160
DOI: 10.1371/journal.pone.0250750