Folia Parasitologica最新文献

Tapeworms of the genus Proteocephalus Weinland, 1858 (Cestoda: Proteocephalidae) are common and widespread intestinal parasites of whitefish (Coregonus spp., Salmonidae: Coregoninae). Previous taxonomic studies, based solely on morphology and inconsistently fixed specimens, concluded that all salmoniform fish, including whitefish, are parasitised by a single euryxenous and highly polymorphic species, Proteocephalus longicollis (Zeder, 1800). However, recent molecular phylogenetic analyses have revealed the existence of several species specific to individual genera or even species of salmoniform fish. In this study, Proteocephalus fallax La Rue, 1911 is redescribed based on newly collected and genetically characterised specimens from several Coregonus species in Switzerland, the type locality of the species, and in Norway. This cestode was previously synonymised with P. exiguus La Rue, 1911, a parasite of whitefish in North America, but the two species are not closely related. Proteocephalus fallax differs from P. exiguus in its larger body size, wider proglottids, shorter cirrus sac and broader scolex. In addition, the other Proteocephalus species described in whitefish are briefly discussed, with comments on their validity, host range and distribution.

Multivalvulidan myxosporeans (Multivalvulida) of the genera Unicapsula Davis, 1924 and Kudoa Meglitsch, 1947 are mostly causative agents of latent and imperceptible infection in marine fishes. However, they are sometimes incriminated in causing post-mortem myoliquefaction or unsightly cyst formation in commercial fish. Despite the great commercial impacts of multivalvulidan infection, the biodiversity, host range and epidemiology of multivalvulidan species remain to be explored further, including infection of alternative annelid hosts. Therefore, this study aimed to identify multivalvulidan species and their host and/or distribution records in commercial fishes in China. Multivalvulidan infection was detected in ten commercial fish species of seven families from the South and East China Seas (Northwest Pacific Ocean) and the Eastern Central Atlantic Ocean (an imported Dagetichthys lusitanicus [de Brito Capello]). Based on morphological and molecular-genetic analyses of their small and large subunit of ribosomal RNA genes, five new host and/or geographical distribution records for five fish species are presented, and three new species in five fish species are described, namely Kudoa neoscomberomori sp. n. in Scomberomorus commerson (Lacépède); Kudoa pilosa sp. n. in Helicolenus hilgendorfi (Döderlein) (type host) and Sebastiscus tertius (Barsukov et Chen); and Kudoa tumidisporica sp. n. in Photopectoralis bindus (Valenciennes) (type host) and Nuchequula nuchalis (Temminck et Schlegel). This study provides new data on multivalvulidan diversity in the ocean ecosystem.

In this review, I take the first-person perspective of a neuroscientist interested in Toxoplasma gondii (Nicolle et Manceaux, 1908). I reflect on the value of behavioural manipulation as a perturbation tool to understand the organisation of behaviour within the brain. Toxoplasma gondii infection reduces the aversion of rats to the olfactory cues of cat presence. This change in behaviour is one of the often-discussed exemplars of host-parasite coevolution, culminating in the manipulation of the host behaviour for the benefit of the parasite. Such coevolution also means that we can use host-parasite systems as tools to derive fundamental insights about the host brain itself.

Toxoplasmosis is caused by Toxoplasma gondii (Nicolle et Manceaux, 1908), a coccidian protist (Apicomplexa). It has a strong predilection for infecting the central nervous system. Researchers have therefore investigated its association with several neurological and psychiatric disorders, including Alzheimer's disease, attention-deficit hyperactivity disorder, autism, bipolar disorder, cerebral palsy, depression, Guillain-Barre syndrome, multiple sclerosis, obsessive compulsive disorder, Parkinson's disease, personality disorders, and schizophrenia. Among these disorders the strongest evidence for a role of T. gondii exists for psychosis in general and schizophrenia in particular. This paper reviews the origins of this association, briefly summarises the current evidence in support, and discusses future research strategies.

Myxozoans are microscopical parasites widely distributed in fish, with over 2,600 described species, but their actual diversity is still underestimated. Among salmonids, more than 70 myxozoan species have been identified. This study focuses on species of Chloromyxum Mingazzini, 1890 that infect salmonid kidneys, particularly C. majori Yasutake et Wood, 1957 and C. schurovi Shulman et Ieshko, 2003. Despite their similar spore morphology, they exhibit distinct host preferences, tissue affinities and geographical distributions. Chloromyxum schurovi predominantly infects the renal tubules of Salmo salar Linnaues and S. trutta Linnaeus in Europe, while C. majori targets the glomeruli of Oncorhynchus mykiss (Walbaum) and O. tshawytscha (Walbaum) in North America. The sequence data for C. majori and C. schurovi have been either missing or questionable. In our study, we examined the kidneys of two salmonid species for chloromyxid infections, using both morphological and molecular data to characterise Chloromyxum species in salmonids. The sequence of C. schurovi obtained in our study did not match the previously published parasite data. Instead, it clustered as an independent lineage sister to the Paramyxidium Freeman et Kristmundsson, 2018 clade gathering the species from various fish organs, including the urinary tract. Our findings clarified the taxonomic origin of the previous C. schurovi sequence as Myxidium giardi Cépède, 1906, highlighting the risks associated with the presence of myxozoan blood stages in the bloodstream of their fish host and the challenges of non-specific PCR amplification. We redescribe C. schurovi, thus contributing to a better understanding of the diversity and phylogeny of kidney-infecting species of Chloromyxum.

Echinococcus granulosus (Batsch, 1786), a cestode of the Teniidae family, causes human cystic echinococcosis (CE) also known as hydatid disease. Echinococcus granulosus sensu lato includes the G1, G3, G4, G5, G6/7 and G8/10 genotypes which are known to cause human CE. This study aimed to differentiate genotypes of E. granulosus s.l. complex by employing EmsB, a tandemly repeated multilocus microsatellite, using next-generation sequencing (MIC-NGS). Human and animal histopathology-confirmed hydatid cyst tissue samples and reference DNA samples of E. granulosus G1, G3, G4, G5, G6/7 and G10 underwent MIC-NGS assay with custom primers amplifying a 151 bp EmsB DNA fragment. NGS data were analysed using online Galaxy analysis pipeline, a phylogenetic tree was constructed by MEGA software, and haplotype networking was performed with PopArt 1.7. All sixty samples (49 from animals and 11 from humans) included were successfully identified and genotyped with a 100 % success rate. The study showed improved discrimination power to distinguish all study samples including closely related E. granulosus s.s. genotypes G1-G3. The maximum likelihood tree reaffirmed the monophyly of E. granulosus s.l. The median-joining haplotype networking revealed 12 distinct haplotypes. In conclusion, MIC-NGS assay was shown to be sensitive, specific and simple to apply to clinical samples offering a powerful discriminatory tool for the genotyping of E. granulosus s.l.

European eel, Anguilla anguilla (Linnaeus) (Elopomorpha: Anguilliformes), is a critically endangered fish of ecological and economic importance, hosting numerous parasites, including myxozoans (Cnidaria). Since its initial discovery in the kidney of European eel, Myxidium giardi Cépède, 1906 has been reported with numerous spore sizes and shapes from various tissues of multiple anguillid species. Morphological variability, wide host and tissue spectrum, and lack of sequence data raised doubts about the conspecificity of reported isolates. Subsequent studies provided 18S rDNA sequences of several isolates from anguillids and other elopiform fish, and demonstrated a split of parasite data into two distinct phylogenetic lineages, one comprising the M. giardi sequence, and the other all species infecting elopiform fishes classified under the recently established genus Paramyxidium Freeman et Kristmundsson, 2018. Myxidium giardi was, however, transferred to this genus as Paramyxidium giardi n. comb. and designated as the type species of the genus. In line with this change, the sequence originally identified as M. giardi was considered to have been incorrectly associated with this species. To shed light on the status of M. giardi originally described by Cépède (1906), we conducted microscopic and molecular examinations of various organs of 24 individuals of European eel, originating from diverse Czech habitats. Through morphometric and molecular analyses, we demonstrated that spore and polar capsule morphology, morphometry and tissue tropism of our European eel kidney parasite isolates matched the features of the original M. giardi description. Our isolates clustered in the lineage encompassing the first published M. giardi sequence. Thus, the originally described M. giardi indeed represents an existing species within the genus Myxidium Bütschli, 1882, which we formally resurrect and redescribe. Due to the morphological and molecular differences between M. giardi and P. giardi of Freeman et Kristmundsson (2018), we additionally rename the latter species as Paramyxidium freemani nom. nov.

The present paper comprises a systematic survey of helminths (trematodes, an acanthocephalan and nematodes) found in nine species of freshwater fishes in Ecuador collected in March 1999 and those (a trematode and acanthocephalans) collected from an amphibian and two species of freshwater fishes in Venezuela in 1992, 1996 and 2001. The following 17 helminth species were recorded: Trematoda: Prosthenhystera ornamentosa sp. n., P. obesa (Diesing, 1850), Crassicutis intermedius (Szidat, 1954), C. cichlasomae Manter, 1936 and Glypthelmins eleutherodactyli sp. n. Acanthocephala: Quadrigyrus torquatus Van Cleave, 1920, Gracilisentis variabilis (Diesing, 1851) and Neoechinorhynchus (Neoechinorhynchus) ecuadoris sp. n. Nematoda: Cosmoxynema vianai Travassos, 1949, Travnema travnema Pereira, 1938, Touzeta ecuadoris Petter, 1987, Sprentascaris hypostomi Petter et Cassone, 1984, Sprentascaris sp., Contracaecum sp. Type 1 larvae, Contracaecum sp. Type 2 larvae, Procamallanus (Procamallanus) peraccuratus Pinto, Noronha et Rolas, 1976 and Procamallanus (Spirocamallanus) sp. juv. Nearly all of these parasites are reported from Ecuador or Venezuela for the first time and many of these findings represent new host records. The new species P. ornamentosa sp. n. was collected from the gall-bladder of an unidentified anostomid (Anostomidae, Characiformes) in Ecuador, G. eleutherodactyli sp. n. from the digestive tract of the frog Eleutherodactylus sp. (Eleutherodactylidae, Anura) in Venezuela and N. (N.) ecuadoris sp. n. from the intestine of Lebiasina sp. (Lebiasinidae, Characiformes) in Ecuador. Most parasites are briefly described and illustrated and problems concerning their morphology, taxonomy, hosts and geographical distribution are discussed.

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.

Chagas disease (CD) is a neglected disease caused by Trypanosoma cruzi Chagas, 1909. Causative treatment can be achieved with two drugs: benznidazole or Nifurtimox. There are some gaps that hinder progress in eradicating the disease. There is no test that can efficiently assess cure control after treatment. Currently, the decline in anti-T. cruzi antibody titres is assessed with conventional serological tests, which can take years. However, the search for new markers of cure must continue to fill this gap. The present study aimed to evaluate the decline in serological titres using chimeric proteins after treatment with benznidazole in chronic patients diagnosed with CD. It was a prospective cross-sectional cohort study between 2000 and 2004 of T. cruzi-positive participants from the Añatuya region (Argentina) treated with benznidazole. Serum samples from ten patients were collected before treatment (day zero) and after the end of treatment (2, 3, 6, 12, 24 and 36 months). For the detection of anti-T. cruzi antibodies, an indirect ELISA was performed using two chimeric recombinant proteins (IBMP-8.1 and IBMP-8.4) as antigens. The changes in reactivity index within the groups before and after treatment were evaluated using the Friedman test. All participants experienced a decrease in serological titres after treatment with benznidazole, especially IBMP-8.1. However, due to the small number of samples and the short follow-up period, it is premature to conclude that this molecule serves as a criterion for sustained cure. Further studies are needed to validate tests based on these or other biomarkers to demonstrate parasitological cure.