BACKGROUND: In Europe, avian schistosomes of the genus Trichobilharzia are the most common etiological agents involved in human cercarial dermatitis (swimmer's itch). Manifested by a skin rash, the condition is caused by an allergic reaction to cercariae of nonhuman schistosomes. Humans are an accidental host in this parasite's life cycle, while water snails are the intermediate, and waterfowl are the final hosts. The study aimed to conduct a molecular and phylogenetic analysis of Trichobilharzia species occurring in recreational waters in North-Eastern Poland. METHODOLOGY: The study area covered three water bodies (Lake Skanda, Lake Ukiel, and Lake Tyrsko) over the summer of 2021. In total, 747 pulmonate freshwater snails (Radix spp., Lymnaea stagnalis) were collected. Each snail was subjected to 1-2 h of light stimulation to induce cercarial expulsion. The phylogenetic analyses of furcocercariae were based on the partial sequence of the ITS region (ITS1, 5.8S rDNA, ITS2 and 28SrDNA). For Radix spp. phylogenetic analyses were based on the ITS-2 region. RESULTS: The prevalence of the Trichobilharzia species infection in snails was 0.5%. Two out of 478 (0.4%) L. stagnaliswere found to be infected with Trichobilharzia szidati. Moreover, two out of 269 (0.7%) snails of the genus Radix were positive for schistosome cercariae. Both snails were identified as Radix auricularia. One of them was infected with Trichobilharzia franki and the other with Trichobilharzia sp. CONCLUSIONS: Molecular identification of avian schistosome species, both at the intermediate and definitive hosts level, constitutes an important source of information on a potential threat and prognosis of local swimmer's itch occurrence, and helps to determine species diversity in a particular area.
- MeSH
- DNA helmintů genetika MeSH
- fylogeneze * MeSH
- hlemýždi parazitologie MeSH
- infekce červy třídy Trematoda parazitologie veterinární epidemiologie MeSH
- jezera parazitologie MeSH
- lidé MeSH
- Schistosomatidae * genetika MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Polsko MeSH
Glypthelmins quieta is a frog trematode native to North and Central America. This trematode was recently detected in Japan in the American bullfrog Lithobates catesbeianus, which was introduced from North America to Japan. As the first intermediate host of G. quieta, typically a snail, has not yet been identified in Japan, we conducted a snail survey in eastern Japan to screen for an intermediate host using DNA barcoding based on the nuclear 28S ribosomal RNA and mitochondrial cytochrome c oxidase subunit 1. We sampled 3 different snail species, Orientogalba ollula, Physella acuta, and Sinotaia quadrata histrica (157 individuals in total), and only the freshwater snail Physella acuta, which is also believed to have been introduced from North America to Japan, had sporocysts of G. quieta in its hepatopancreas. The introduction of the intermediate and definitive hosts from North America may have facilitated the invasion of G. quieta into Japan.
- MeSH
- hlemýždi * parazitologie MeSH
- interakce hostitele a parazita MeSH
- RNA ribozomální 28S genetika MeSH
- Trematoda * genetika MeSH
- zavlečené druhy MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Japonsko MeSH
Schistosomiasis is a snail-borne disease that has a considerable impact on human and animal health, particularly in sub-Saharan Africa. The intermediate hosts of the schistosome parasites are freshwater snails of the genera Biomphalaria Preston, 1910 and Bulinus Müller, 1781. In order to identify existing gaps in the spread of the disease in the Democratic Republic of Congo (DRC), this study compiled the available knowledge of the distribution, population dynamics and ecology of the intermediate hosts of schistosomiasis. A systematic literature search was conducted in PubMed, Embase and Scopus for all malacological studies on schistosoma intermediate hosts in DRC published between 1927 and October 2022. A total of 55 records were found, of which 31 met the inclusion criteria: these were published field and experimental studies conducted in the DRC and focused on snails as intermediate hosts of schistosomes. The analysis of these studies revealed that more up-to-date data on the distribution of snail intermediate hosts in the DRC are needed. Moreover, ecological factors have been less studied for Bulinus species than for Biomphalaria species. These factors play a crucial role in determining suitable snail habitats, and the lack of comprehensive information poses a challenge in snail control. This review makes it clear that there are no current malacological data in the DRC. There is a clear need for molecular and ecological research to update the exact species status and population dynamics of all potential intermediate host species. This will facilitate targeted snail control measures that complement drug treatment in the control of schistosomiasis in the country.
- MeSH
- Biomphalaria * parazitologie MeSH
- Bulinus parazitologie MeSH
- hlemýždi parazitologie MeSH
- lidé MeSH
- Schistosoma fyziologie MeSH
- schistosomóza * epidemiologie veterinární MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- systematický přehled MeSH
- Geografické názvy
- Konžská demokratická republika MeSH
BACKGROUND: Angiostrongylus cantonensis (rat lungworm) is recognised as the leading cause of human eosinophilic meningitis, a serious condition observed when nematode larvae migrate through the CNS. Canine Neural Angiostrongyliasis (CNA) is the analogous disease in dogs. Both humans and dogs are accidental hosts, and a rapid diagnosis is warranted. A highly sensitive PCR based assay is available but often not readily accessible in many jurisdictions. An alternative DNA amplification assay that would further improve accessibility is needed. This study aimed to assess the diagnostic utility of a newly designed LAMP assay to detect DNA of globally distributed and invasive A. cantonensis and Angiostrongylus mackerrasae, the other neurotropic Angiostrongylus species, which is native to Australia. METHODOLOGY/PRINCIPAL FINDINGS: Cerebrospinal fluid (CSF) from dogs with a presumptive diagnosis of A. cantonensis infection (2020-2022) were received for confirmatory laboratory testing and processed for DNA isolation and ultrasensitive Angiostrongylus qPCR targeting AcanR3390. A newly designed LAMP assay targeting the same gene target was directly compared to the reference ultrasensitive qPCR in a diagnostic laboratory setting to determine the presence of A. cantonensis DNA to diagnose CNA. The LAMP assay (Angie-LAMP) allowed the sensitive detection of A. cantonensis DNA from archived DNA specimens (Kappa = 0.81, 95%CI 0.69-0.92; n = 93) and rapid single-step lysis of archived CSF samples (Kappa = 0.77, 95%CI 0.59-0.94; n = 52). Only A. cantonensis DNA was detected in canine CSF samples, and co-infection with A. mackerrasae using amplicon deep sequencing (ITS-2 rDNA) was not demonstrated. Both SYD.1 and AC13 haplotypes were detected using sequencing of partial cox1. CONCLUSIONS/SIGNIFICANCE: The Angie-LAMP assay is a useful molecular tool for detecting Angiostrongylus DNA in canine CSF and performs comparably to a laboratory Angiostrongylus qPCR. Adaptation of single-step sample lysis improved potential applicability for diagnosis of angiostrongyliasis in a clinical setting for dogs and by extension, to humans.
- MeSH
- Angiostrongylus cantonensis * genetika MeSH
- Angiostrongylus * genetika MeSH
- hlemýždi genetika MeSH
- infekce hlísticemi řádu Strongylida * diagnóza veterinární MeSH
- krysa rodu rattus MeSH
- lidé MeSH
- meningitida * diagnóza veterinární MeSH
- psi MeSH
- ribozomální DNA MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- lidé MeSH
- psi MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Lymnaea stagnalis is a common freshwater gastropod. Importantly, the snail serves as the intermediate host for more than one hundred species of digenetic trematodes, including the avian schistosome Trichobilharzia szidati, a causative agent of cercarial dermatitis in humans. Infection of L. stagnalis by T. szidati initiates a dynamic confrontation between the host and the parasite that culminates in immunocompatibility ensuring survival and development of larvae. Unfortunately, the molecular mechanisms determining this immunocompatibility remain poorly characterised. By employing a variety of immune elicitors, including chemical compounds, PAMPs and bacteria, research in the last two decades has elucidated some of the molecular processes that regulate the snail internal defence response such as haemocyte signalling pathways. These discoveries provide a framework for future studies of molecular interactions between T. szidati and L. stagnalis to help elucidate factors and mechanisms enabling transmission of schistosome parasites. Moreover, support from recently available next generation sequence data and CRISPR-enabled functional genomics should further enable L. stagnalis as an important model for comparative immunology and contribute to a more comprehensive understanding of immune functions in gastropod molluscs.
- MeSH
- hemocyty imunologie parazitologie MeSH
- imunomodulace MeSH
- infekce červy třídy Trematoda parazitologie přenos MeSH
- interakce hostitele a parazita imunologie MeSH
- lidé MeSH
- Lymnaea imunologie parazitologie MeSH
- Schistosomatidae fyziologie MeSH
- signální transdukce imunologie MeSH
- stadia vývoje MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
Human cercarial dermatitis is a parasitic disease that causes an allergic reaction in the skin (swimmer's itch) as a consequence of contact with cercariae of bird schistosomes present in water, mainly of the genus Trichobilharzia Skrjabin et Zakarow, 1920. The main objective of the study was to confirm the presence of the zoonotic disease agent following reports of human infections in recreational water in Slovakia. We identified two species of freshwater snails at Košice Lake, Radix auricularia (Linnaeus, 1758) and Physa acuta (Draparnaud, 1805). Trematode infections were observed only in R. auricularia. Of the 62 snails collected, 11 (17.7%) were infected with 5 different species of larval stages of trematodes. The blood fluke Trichobilharzia franki was found in 2 (3.2%) of the examined snails. The present record provides the first evidence that T. franki from the pulmonate snail R. auricularia represents a source of human cercarial dermatitis in recreational water in Slovakia. Our finding complements the easternmost records of both swimmer's itch and the confirmed occurrence of a bird schistosome in a waterbody in Europe. The present work suggests that the health risks associated with trichobilharziasis need to be further studied by detailed monitoring of the occurrence of the major causative agent of human cercarial dermatitis, T. franki.
- MeSH
- dermatitida epidemiologie parazitologie MeSH
- epidemický výskyt choroby MeSH
- hlemýždi parazitologie MeSH
- infekce červy třídy Trematoda epidemiologie parazitologie přenos MeSH
- jezera parazitologie MeSH
- lidé MeSH
- parazitární onemocnění kůže parazitologie přenos MeSH
- Schistosomatidae klasifikace genetika izolace a purifikace MeSH
- schistosomóza epidemiologie parazitologie přenos MeSH
- zoonózy epidemiologie parazitologie přenos MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Slovenská republika MeSH
Microcercous cercariae possess a very short tail and are produced by digenean species of several families including medically important species, such as members of the genera Paragonimus Braun, 1899, Nanophyetus Chapin, 1927 and Troglotrema Odhner, 1914. During our survey of cercariae of Paragonimus spp. in Vietnam, we found microcercous cercariae from ten (0.29%) out of 3,400 snails of Triculinae gen. sp. 2. They were morphologically and molecularly analysed for species identification. The molecular analysis, based on ITS2 sequences, revealed two distinct species: four specimens were identical to Paragonimus proliferus Hsia et Chen, 1964 (Paragonimidae Dollfus, 1939), and the other six specimens were closest to members of the family Troglotrematidae Odhner, 1914 and were temporarily named Troglotrematidae gen. sp. Morphologically, cercariae of the two species found in this study are similar to each other in their gross characteristics but can be distinguished from one another by subtle morphological details. The cercaria of P. proliferus has an I-shaped excretory bladder and does not have mucous gland cells. In contrast, that of Troglotrematidae gen. sp. has a Y-shaped excretory bladder and mucous gland cells. Besides, the redia of P. proliferus is elongate with a short intestine and contains 5-6 cercariae whereas that of Troglotrematidae gen. sp. is more round with a longer intestine and harbours 3-4 cercariae. Our results have shown the importance of the shape of the excretory bladder and the presence/absence of mucous gland cells of the cercaria as well as the shape and size of the redia, and its intestinal length as valuable taxonomic characters of intramolluscan trematode larvae. In addition, the finding of similar microcercous cercariae of different species in the same snail species suggests that careful attention to morphological details is required in the differentiation of Paragonimus cercariae and those of closely related species.
- MeSH
- cerkárie klasifikace genetika růst a vývoj izolace a purifikace MeSH
- DNA helmintů analýza MeSH
- fylogeneze MeSH
- hlemýždi parazitologie MeSH
- mezerníky ribozomální DNA analýza MeSH
- Paragonimus klasifikace růst a vývoj izolace a purifikace MeSH
- sekvenční analýza RNA MeSH
- Troglotrematidae klasifikace genetika růst a vývoj izolace a purifikace MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Vietnam MeSH
Parasites comprise a huge part of the biodiversity on earth. However, on a local scale, not much is known about their diversity and community structure. Here, we assess the diversity of larval trematode communities in an interconnected freshwater system of the River Ruhr in Germany and analyse how the parasites are spatially and temporally distributed in the ecosystem. A total of 5347 snail hosts belonging to six species revealed a highly diverse parasite fauna with 36 trematode species. More abundant snail species harboured more species-rich trematode faunas and communities, with the two dominant snail species, Radix auricularia and Gyraulus albus, accounting for almost 90% of the trematode diversity and harbouring spatially and temporally stable parasite communities. The results highlight the important role of stable keystone host populations for trematode transmission, structure and diversity. This local trematode diversity reveals information on definitive host occurrence and trophic interactions within ecosystems.
- MeSH
- biodiverzita * MeSH
- ekosystém * MeSH
- hlemýždi parazitologie MeSH
- interakce hostitele a parazita genetika MeSH
- larva parazitologie MeSH
- lidé MeSH
- populační dynamika MeSH
- řeky MeSH
- sladká voda parazitologie MeSH
- Trematoda klasifikace patogenita MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Německo MeSH
Naive use of molecular data may lead to ambiguous conclusions, especially within the context of "cryptic" species. Here, we integrated molecular and morphometric data to evaluate phylogenetic relationships in the widespread terrestrial micro-snail genus, Euconulus. We analyzed mitochondrial (16S + COII) and nuclear (ITS1 + ITS2) sequence across 94 populations from Europe, Asia and North America within the nominate species E. alderi, E. fulvus and E. polygyratus, and used the southeastern USA E. chersinus, E. dentatus, and E. trochulus as comparative outgroups. Phylogeny was reconstructed using four different reconstruction methods to identify robust, well-supported topological features. We then performed discriminant analysis on shell measurements between these genetically-identified species-level clades. These analyses provided evidence for a biologically valid North American "cryptic" species within E. alderi. However, while highly supported polyphyletic structure was also observed within E. fulvus, disagreement in placement of individuals between mtDNA and nDNA clades, lack of morphological differences, and presence of potential hybrids imply that these lineages do not rise to the threshold as biologically valid cryptic species, and rather appear to simply represent a complex of geographically structured populations within a single species. These results caution that entering into a cryptic species hypothesis should not be undertaken lightly, and should be optimally supported along multiple lines of evidence. Generally, post-hoc analyses of macro-scale features should be conducted to attempt identification of previously ignored diagnostic traits. If such traits cannot be found, i.e. in the case of potentially "fully cryptic" species, additional criteria should be met to propound a cryptic species hypothesis, including the agreement in tree topology among both mtDNA and nDNA, and little (or no) evidence of hybridization based on a critical analysis of sequence chromatograms. Even when the above conditions are satisfied, it only implies that the cryptic species hypothesis is plausible, but should optimally be subjected to further careful examination.
- MeSH
- analýza hlavních komponent MeSH
- buněčné jádro genetika MeSH
- fylogeneze MeSH
- hlemýždi klasifikace genetika MeSH
- pravděpodobnostní funkce MeSH
- respirační komplex IV klasifikace genetika MeSH
- RNA ribozomální 16S klasifikace genetika MeSH
- sekvence nukleotidů MeSH
- sekvenční analýza DNA MeSH
- sekvenční seřazení MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Terrestrial gastropod molluscs are widely distributed and are well known as pests of many types of plants that are notoriously difficult to control. Many species of nematodes are able to parasitize land snails and slugs, but few of them are lethal to their host. Species and/or populations of mollusc-parasitic nematodes (MPNs) that kill their hosts are promising for biological control purposes. The recent discovery of new nematode species of the genus Phasmarhabditis in Europe and the associations between Alloionema spp. and slugs are expanding the possibilities of using MPNs as control agents. However, very little is known about the distribution and ecology of these species. Using molecular techniques based on qPCR methods for quick identification and quantification of various species of MPN isolated directly from the soil or from infected hosts can assist in providing information on their presence and persistence, as well as the composition of natural assemblages. Here, we developed new primers and probes for five species of the genus Phasmarhabditis and one species of the genus Alloionema. We employed these novel molecular techniques and implemented a published molecular set to detect MPN presence in soil samples coming from natural and agricultural areas in Switzerland. We also developed a method that allows the detection and quantification of Phasmarhabditis hermaphrodita directly from the tissues of their slug host in a laboratory experiment. The new molecular approaches were optimized to a satisfactory limit of detection of the species, with only few cross-amplifications with closely related species in late cycles (>32). Using these tools, we detected MPNs in 7.5% of sampled sites, corresponding to forest areas (P. hermaphrodita and Alloionema appendiculatum) and wheat-oriented agricultural areas (Phasmarhabditis bohemica). Moreover, we confirmed that the method can be used to detect the presence of P. hermaphrodita inside slug hosts, with more detections in the susceptible slug Deroceras larvae compared to the resistant Arion vulgaris. These primers/probe sets provide a novel and quick tool to identify MPNs from soil samples and infected slugs without having to culture and retrieve all nematode life stages, as well as a new tool to unravel the ecology of nematode-slug complexes.
- MeSH
- biologická kontrola škůdců MeSH
- DNA helmintů genetika MeSH
- hlemýždi parazitologie MeSH
- hlístice genetika izolace a purifikace parazitologie MeSH
- interakce hostitele a parazita MeSH
- kvantitativní polymerázová řetězová reakce MeSH
- půda parazitologie MeSH
- Rhabditoidea genetika izolace a purifikace parazitologie MeSH
- ribozomální DNA genetika MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Švýcarsko MeSH