Folia Parasitologica最新文献

Ticks are important vectors of various pathogens that cause infectious diseases in humans. Endosymbiotic bacteria have been explored as targets for tick and tick-borne disease control. However, the tick bacterial community on Hainan Island, which is the largest tropical island in China and has an environment favourable to ticks, has not yet been studied. In this study, we surveyed the bacterial community of ticks collected from grass in one village in Haikou. A total of 20 ticks were morphologically and molecularly identified as Haemaphysalis spp. The tick bacterial 16S rRNA hypervariable region amplicon libraries were sequenced on an Illumina MiSeq platform. A total of 10 possible bacterial genera were detected, indicating a low-diversity bacterial community profile. The dominant bacterial genus, Massilia, accounted for 97.85% of the population. Some other bacterial genera, including Arsenophonus and Pseudomonas, have been reported to play a role in tick development and tick-borne pathogen transmission in other tick species. Overall, the study highlights the first descriptive understanding of the tick bacterial community on Hainan Island and provides a basis for deciphering the interactions between the tick microbiome and tick-borne pathogens.

Evolutionary and ecological processes affecting the interactions between hosts and parasites in the aquatic environment are at display in the Baltic Sea, a young and ecologically unstable marine ecosystem, where fluctuating abiotic and biotic factors affect the parasitofauna in fish. The dynamic infections of Baltic cod, a subpopulation of the Atlantic cod (Gadus morhua Linnaeus), with third stage anisakid nematode larvae of Pseudoterranova decipiens (Krabbe, 1878) and Contracaecum osculatum (Rudolphi, 1802) have increased following a significant increase of the Baltic grey seal Halichoerus grypus (Fabricius) population in the region. Cod serves as a paratenic host and marine mammals, pinnipeds, are definitive hosts releasing parasite eggs, with faeces, to the marine environment, where embryonation and hatching of the third stage larva take place. The parasite has no obligate intermediate hosts, but various invertebrates, smaller fish and cod act as paratenic hosts transmitting the infection to the seal. Contracaecum osculatum has an impact on the physiological performance of the cod, which optimises transmission of the larva from fish to seal. Thus, a muscle mass decrease of nearly 50% may result from heavy C. osculatum infections, probably amplified by a restricted food availability. The muscle atrophy is likely to reduce the escape reactions of the fish when meeting a foraging seal. In certain regions, where fish and seals are restricted in their migration patterns, such as the semi-enclosed Baltic Sea, the predation may contribute to a severe cod stock depletion. The parasites are zoonotic and represent a human health risk, when consumers ingest insufficiently heat- or freeze-treated infected products. Marked infections of the cod were previously reported during periods with elevated seal populations (late 19th and middle 20th century) and various scenarios for management of risk factors are evaluated in an evolutionary context.

Strange oceanographic events such as El Niño and La Niña may have indirect effects on the local transmission processes of intestinal parasites due to the reduction or increase in populations of potential intermediate or definitive hosts. A total of 713 individuals of Lutjanus inermis (Peters) were collected over an 8-year period (October 2015 to July 2022) from Acapulco Bay, Mexico. Parasite communities in L. inermis were quantified and analysed to determine if they experienced interannual variations in species composition and structure as a result of local biotic and abiotic factors influenced by oceanographic events, such as El Niño-Southern Oscillation (ENSO), or La Niña, the cool phase of the ENSO climate pattern. Twenty-six taxa of metazoan parasites were recovered and identified: two Monogenea, eight Digenea, two Acanthocephala, four Nematoda, one Cestoda, seven Copepoda, and two Isopoda. Species richness at the component community level (8 to 17 species) was similar to reported richness in other species of Lutjanus Bloch. Parasite communities of L. inermis exhibited high inter-annual variation in the abundance of component species of parasite. However, the species richness and diversity were fairly stable over time. Climatic episodes of El Niño and La Niña probably generated notable changes in the structure of local food webs, thus indirectly influencing the transmission rates of intestinal parasite species. Changes in species composition and community structure of parasites possibly were due to variations in feeding behaviour during the events and differences in the host body size.

Proteocephalid tapeworms of frogs of the family Ranidae ('true' frogs) are reviewed with emphasis on their species diversity, host specificity and geographical distribution. New molecular data (nuclear lsrDNA and mitochondrial COI sequences) are presented for tapeworms of four species of ranid frogs in North America, including the poorly known Ophiotaenia saphena Osler, 1931 of Rana clamitans Latreille and R. catesbeiana (Shaw), which is redescribed using new material from Arkansas, USA. Tapeworms of R. sphenocephala (Cope) and R. pipiens Schreber, the latter previously identified as O. saphena, represent another, putative new species, but are not formally described due to insufficient available material. Proteocephalus papuensis Bursey, Goldberg et Kraus, 2008 from Sylvirana supragrisea (Menzies) is transferred to Ophiotaenia La Rue, 1911 as a new combination. After a critical review of the literature, only nine nominal species of Ophiotaenia are recognised as valid, which is in contrast to the large number of ranid frogs (> 440 spp.). The reasons for this striking disparity are briefly discussed, and a key based on morphology is presented for the identification of all species of Ophiotaenia from the Ranidae. Molecular data are available for only two taxa from North America that form a monophyletic group. The relationships among tapeworms of ranid frogs occurring in other zoogeographical regions are not yet known. The taxonomic status of Batrachotaenia Rudin, 1917, which was erected to accommodate proteocephalids from amphibians, is also discussed. To facilitate future studies, a tabulated summary of all 32 species of proteocephalids belonging to three genera reported from amphibians (frogs and salamanders) is presented, with information on their hosts, distribution, and taxonomically important characters, including key measurements.

Spirometra Faust, Campbell et Kellogg, 1929 is a genus of cestodes belonging to the family Diphyllobothriidae. To date, amphibians, reptiles, and mammals are known second intermediate hosts of these parasites; humans can also be infected (the zoonotic disease is known as sparganosis or spirometrosis). Although the number of phylogenetic studies on Spirometra spp. has increased worldwide in recent years, there are few in South America. Specifically in Uruguay, molecular studies have shown that tapeworms of S. decipiens (Diesing, 1850) complexes 1 and 2 are present in this country. In this study, we characterised the larvae of Spirometra present in the annual fish Austrolebias charrua Costa et Cheffe. Phylogenetic analysis of the cytochrome c oxidase subunit I (COI) sequences of these larvae showed that they belong to S. decipiens complex 1. This is the first report of teleost fishes serving as a second intermediate host for tapeworms of the genus Spirometra in nature.

The density and spread of tick vector species have increased throughout Europe in the last 30 years, leading to an increase of Lyme borreliosis cases, including in Slovenia. The aim of this study was to isolate Borrelia strains and determine the prevalence of B. burgdorferi sensu lato and B. miyamotoi in adults of Ixodes ricinus (Linnaeus) collected in 2019 in the two regions of the country (Coastal-Karst and Littoral-Inner Carniola) by cultivation and PCR. We isolated B. burgdorferi s.l. by culture method in 28/559 (5%) ticks from both regions. Culture-negative samples (531/559, i.e., 95%) were additionally tested by real-time PCR. In 155/531 (29.2%) PCR-positive samples, a fragment of flaB or glpQ was amplified and further sequenced to identify species of the Borrelia. Using both methods, cultivation and PCR, Borrelia spp. prevalence was 32.7% in the Coastal-Karst region and 33.0% in the Littoral-Inner Carniola region. Genotyping of the Borrelia spp. isolates revealed that 17/28 (60%) were B. garinii subtype Mlg2. Of all tick samples tested for B. miyamotoi 8/398 (2%) were PCR positive. Based on previous studies in these regions, we had expected more ticks to be infected with B. afzelii, but genotyping revealed that B. garinii was the most abundant.

As presently defined, the tapeworm genus Andrya Railliet, 1895 (Cyclophyllidea: Anoplocephalidae sensu stricto) includes the type species A. rhopalocephala (Riehm, 1881) in hares of the genus Lepus Linnaeus (Leporidae) in western Eurasia and four species in cricetid (Neotominae, Sigmodontinae) and octodontid rodents in North and South America. The host range of Andrya is puzzling, because it is the only genus of anoplocephalid (s. s.) cestodes parasitising both rodents and lagomorphs. The present morphological analysis shows that the American species of Andrya share multiple consistent features, in which they differ from those of A. rhopalocephala and the morphologically related Neandrya cuniculi (Blanchard, 1891). The main differences concern the position of the uterus with respect to the longitudinal osmoregulatory canals and testes. Consequently, a new genus Andryoides gen. n. is proposed for the American species, resulting in the following combinations: Andryoides neotomae (Voge, 1946) comb. n. (type species), Andryoides octodonensis (Babero et Cattan, 1975) comb. n., Andryoides vesicula (Haverkost et Gardner, 2010) comb. n. and Andryoides boliviensis (Haverkost et Gardner, 2010) comb. n. However, A. boliviensis is regarded here as a junior synonym of A. vesicula (new synonymy). The present study also defines the morphological key features for all the valid genera of cestodes of the family Anoplocephalidae (s. s.), and discusses the phylogenetic affinities and historical biogeography of Andryoides and other endemic American anoplocephalid cestodes.

Equine piroplasmosis (EP) is a vector borne disease caused by apicomplexans protists Babesia caballi (Nuttal et Strickland, 1910) and Theileria equi (Laveran, 1901). Carrier mares may transmit the infection transplacental resulting in neonatal piroplasmosis or abortions. This event has been described for T. equi by several authors over the world, but no evidence for B. caballi has been reported in Europe. In this study, vertical transmission for both parasites in an Italian breed mare has been confirmed using molecular and microscopic tools. Transplacental transmission is an underestimated problem mainly in endemic areas as it not only contributes to the spread and maintenance of the infection, but also produces significant economic losses.

It is estimated that nearly one-third of the world's human population is infected with Toxoplasma gondii (Nicolle et Manceaux, 1908). Human infection is commonly asymptomatic, multifaceted, and can manifest in severe pathological forms in congenital toxoplasmosis and immunocompromised individuals. This study attempted to recognise the seroprevalence of T. gondii infection in Iranian residents referred to medical laboratories for toxoplasmosis tests throughout the country. This retrospective cross-sectional study was conducted from 2015 to 2019 on individuals referred to diagnostic laboratories in 26 provinces, and these laboratories sent their samples to the referral centres. Accordingly, data associated with serodiagnosis of toxoplasmosis, age, sex, anti-T. gondii IgG, and IgM status in Iranian residents were collected from two referral diagnostic laboratories. All individuals were evaluated using the antibody immunocapture-chemiluminescence assay (CLIA) method with the Immulite^®2000s XPi system. In this study, the first large-scale assay of T. gondii infection in Iran, an overall seroprevalence of 30.4% was among 35,047 patients examined. The highest IgM seropositivity rate was in the 10-20 years old patients. In addition, this study showed a very different prevalence of T. gondii across the country, highest in the humid areas, such as the Caspian Sea basin in the North, and the North West with seroprevalence of 48.6%.

We provide the first ultrastructural evidence of the secretion of extracellular vesicles (EVs) across all parasitic stages of the tapeworm Schistocephalus solidus (Müller, 1776) (Cestoda: Diphyllobothriidea) using a laboratory life cycle model. We confirmed the presence of EV-like bodies in all stages examined, including the hexacanth, procercoids in the copepod, Macrocyclops albidus (Jurine, 1820), plerocercoids from the body cavity of the three-spined stickleback, Gasterosteus aculeatus Linnaeus, and adults cultivated in artificial medium. In addition, we provide description of novel tegumental structures potentially involved in EV biogenesis and the presence of unique elongated EVs similar to those previously described only in Fasciola hepatica Linnaeus, 1758 (Trematoda), Hymenolepis diminuta (Rudolphi, 1819) (Cestoda), and Trypanosoma brucei Plimmer et Bradford, 1899 (Kinetoplastida).