Morphological and molecular characterization of brown-banded broodsacs and metacercariae of Leucochloridium (Trematoda: Leucochloridiidae) parasitizing the semi-slug Omalonyx unguis (Succineidae) in Argentina.

Trematodes of the genus Leucochloridium exhibit an unusual transmission strategy among mollusks (intermediate host). The fully developed sporocyst, housing encysted metacercariae, displays vivid coloration and rhythmic activity in the snail's tentacle, mimicking insect larvae. These strategies attract insectivorous birds, their final hosts, thereby increasing the chances of completing their life cycle. In South America, the reports of adults and larval stages of Leucochloridium are scarce. Brown-banded broodsac of Leucochloridium sp. were obtained from Omalonyx unguis collected in a shallow lake from Corrientes Province, Argentina. Here, we morphologically characterized the larval stages (broodsac and metacercaria), identified the parasite through DNA sequences from nuclear 28S-rRNA (28S) and the mitochondrial cytochrome c oxidase I (COI) genes, and explored its evolutionary affinities with the Leucochloridium species available in GenBank. The present broodsac displays brown bands, with a yellowish background in the first two-thirds and yellowish-white in the last third. Based on morphological comparisons, the broodsac and metacercaria described in this study could not be conclusively categorized under any known South American species of Leucochloridium. In relation to the phylogenetic reconstructions, Leucochloridium sp. consistently clustered with L. perturbatum, and species delimitation analyses resulted in recognized Leucochloridium sp. from Argentina as a distinct species. The DNA sequences obtained in this study constitute the first genetic data generated for sporocyst broodsacs in South America. Future studies, incorporating morphology, genetic, and biological data, will be essential for both species identification and the elucidation of leucochloridiid diversity in the region.

The first intermediate host of the invasive frog trematode Glypthelmins quieta in Japan.

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.

Genotypic and morphological diversity of trematodes Leucochloridium paradoxum.

The sporocysts of the trematode Leucochloridium paradoxum parasitise land snails Succinea putris. The sporocysts form broodsacs whose tegument contains green and brown pigments. The colouration changes during maturation. The pattern and colour of the broodsacs may vary in different individuals and sometimes even in one sporocyst. We studied the broodsacs of 253 sporocysts of L. paradoxum collected in the European part of Russia and Belarus, and identified four main colouration types. An analysis of genetic polymorphism by a fragment (757 bp) of the mitochondrial cox1 gene revealed 22 haplotypes. Using the nucleotide sequences of the cox1 gene fragment of L. paradoxum from Japan and Europe available in GenBank, we constructed haplotype networks. A total of 27 haplotypes were identified. The haplotype diversity of L. paradoxum by this gene was rather low, on the average 0.8320. A low genotypic diversity by the mitochondrial marker is consistent with rDNA conservativeness of Leucochloridium spp. noted previously. The most broadly represented haplotypes, Hap_1 and Нap_3, were described in both sporocysts and adults of L. paradoxum. We suggest that the mobility of birds, which are the definitive hosts of L. paradoxum, provides the necessary conditions for the genotypic diversity of its sporocysts parasitising different populations of snails Succinea putris.

Proteomic Analysis of Fractionated Eimeria tenella Sporulated Oocysts Reveals Involvement in Oocyst Wall Formation.

Eimeria tenella is the most pathogenic intracellular protozoan parasite of the Eimeria species. Eimeria oocyst wall biogenesis appears to play a central role in oocyst transmission. Proteome profiling offers insights into the mechanisms governing the molecular basis of oocyst wall formation and identifies targets for blocking parasite transmission. Tandem mass tags (TMT)-labeled quantitative proteomics was used to analyze the oocyst wall and sporocysts of E. tenella. A combined total of 2865 E. tenella proteins were identified in the oocyst wall and sporocyst fractions; among these, 401 DEPs were identified, of which 211 were upregulated and 190 were downregulated. The 211 up-regulated DEPs were involved in various biological processes, including DNA replication, fatty acid metabolism and biosynthesis, glutathione metabolism, and propanoate metabolism. Among these proteins, several are of interest for their likely role in oocyst wall formation, including two tyrosine-rich gametocyte proteins (EtGAM56, EtSWP1) and two cysteine-rich proteins (EtOWP2, EtOWP6). Concurrently, 96 uncharacterized proteins may also participate in oocyst wall formation. The present study significantly expands our knowledge of the proteome of the oocyst wall of E. tenella, thereby providing a theoretical basis for further understanding of the biosynthesis and resilience of the E. tenella oocyst wall.

Histological and electron microscopic analysis of germinal material in miracidia of Schistosoma mansoni.

We performed histological and electron microscopic analysis of miracidia of Schistosoma mansoni in order to examine their germinal elements. In total, about 20 germinal cells at different stages of maturation were found. We described their ultrastructure and proposed a scheme of reproduction of mother sporocysts of S. mansoni based on our data and literature information. According to this scheme, the only germinal elements present in the miracidia are germinal cells (undifferentiated cells were not found). Regardless of their size and localisation, none of the germinal cells in the miracidia has undergone full differentiation. This process is completed after the metamorphosis of the larva into the sporocyst.

First record and distribution of Adelina sp. (Coccidia: Adeleidae) in populations of the Anisoplia segetum Herbst (Coleoptera: Scarabaeidae) in Turkey.

In this study, an Adelina sp. (Coccidia) infection was determined for the first time from Anisoplia segetum (Coleoptera: Scarabaeidae). The infection was observed in the gut and fat body of the host. The determined oocysts were ellipsoidal and measured 36.3 (34-38) × 30.2 (27-32) µm. The number of sporocysts per oocyst varied from 7 to 15. The dizoic sporocysts were usually subspherical, 10.2 (9-12) × 8.9 (8-10) µm. Also, some developmental stages and unsporulated oocysts were determined with electron microscopical observations. The immature microgamonts were observed in different shapes, from ovoid to spherical. And the detected oval unsporulated oocyst was measured 4.9 µm in length and 3.6 µm in width. The formation and distribution of these pathogens were also presented in A. segetum populations.

Parvatrema duboisi (Digenea: Gymnophallidae) Life Cycle Stages in Manila Clams, Ruditapes philippinarum, from Aphae-do (Island), Shinan-gun, Korea.

Life cycle stages, including daughter sporocysts, cercariae, and metacercariae, of Parvatrema duboisi (Dollfus, 1923) Bartoli, 1974 (Digenea: Gymnophallidae) have been found in the Manila clam Ruditapes philippinarum from Aphaedo (Island), Shinan-gun, Jeollanam-do, Korea. The daughter sporocysts were elongated sac-like and 307-570 (av. 395) µm long and 101-213 (av. 157) µm wide. Most of the daughter sporocysts contained 15-20 furcocercous cercariae each. The cercariae measured 112-146 (av. 134) µm in total length and 35-46 (av. 40) µm in width, with 69-92 (av. 85) µm long body and 39-54 (av. 49) µm long tail. The metacercariae were 210-250 (av. 231) µm in length and 170-195 (av. 185) µm in width, and characterized by having a large oral sucker, genital pore some distance anterior to the ventral sucker, no ventral pit, and 1 compact or slightly lobed vitellarium, strongly suggesting P. duboisi. The metacercariae were experimentally infected to ICR mice, and adults were recovered at day 7 post-infection. The adult flukes were morphologically similar to the metacercariae except in the presence of up to 20 eggs in the uterus. The daughter sporocysts and metacercariae were molecularly (ITS1-5.8S rDNA-ITS2) analyzed to confirm the species, and the results showed 99.8-99.9% identity with P. duboisi reported from Kyushu, Japan and Gochang, Korea. These results confirmed the presence of various life cycle stages of P. duboisi in the Manila clam, R. philippinarum, playing the role of the first as well as the second intermediate host, on Aphae-do (Island), Shinan-gun, Korea.

An efficient photograph-based quantitative method for assessing castrating trematode parasites in bivalve molluscs.

Parasitic castration of bivalves by trematodes is common, and may significantly reduce the reproductive capacity of ecologically important species. Understanding the intensity of infection is desirable, as it can indicate the time that has passed since infection, and influence the host's physiological and reproductive response. In addition, it is useful to know the developmental stage of the trematode, to understand trematode population trends and reproductive success. However, most existing methods (e.g. visually estimating the degree of infection) to assess intensity are approximate only and not reproducible. Here, we present a method to accurately quantify the percentage of bivalve gonad filled with digenean trematode tissue, based on small squashes of gonad tissue rapidly photographed under light microscopy. A maximum of 15 photographs is required to determine the percentage of the whole gonad occupied by trematodes with a minimum of 90% confidence, with smaller mussels requiring fewer. In addition, the stage of trematode infection can be assessed because full sporocysts, spent sporocysts and free cercariae are clearly distinguishable. Although variation exists in the distribution of trematodes in gonad tissue, and thus in the estimate of percentage of the gonad filled with trematodes, this method represents a marked improvement on current coarse assessments of infection which typically focus on binary presence/absence measures. This technique can be used to facilitate a more sophisticated understanding of host-parasite interactions in bivalves, and can inform the conservation and reproductive biology of environmentally crucial species.

Reproduction of Echinostoma caproni mother sporocysts (Trematoda).

The localisation and the composition of germinal material in miracidia and mother sporocysts of Echinostoma caproni were studied with the use of histological and electron microscopic methods. Germinal material in miracidia was localised in the posterior body half and was represented by 3-4 undifferentiated cells and 5-7 germinal cells. Taken together, these cells are referred to as the primordium of the germinal mass. In the mother sporocyst, germinal elements also form and develop in the germinal mass, which is located caudally. It comprises undifferentiated cells and germinal cells as well as embryos of various ages (up to the stage of 30-50 blastomeres). Germinal cells divide only by cleavage. New germinal cells are formed only from undifferentiated cells, which can proliferate in the germinal mass and nowhere else. This indicates that the germinal mass is the reproductive organ of E. caproni mother sporocyst.

Characterization of an IgG monoclonal antibody targeted to both tissue cyst and sporocyst walls of Toxoplasma gondii.

Toxoplasma gondii infects animals habiting terrestrial and aquatic environments. Its oocysts and tissue cysts are important for the horizontal transmission of this parasite. The oocyst and tissue cyst walls are crucial for the ability of the parasite to persist in the environment or in animal tissues, respectively. However, the composition of these walls is not well understood. We report the generation of monoclonal antibodies directed against wall components using mice immunized with oocyst antigens of T. gondii. One monoclonal antibody (mAb) G1/19 reacted solely with T. gondii sporozoites. The respective antigen had a relative molecular weight (Mr) of 30 kDa. MAb G1/19 failed to react with sporozoites of any other coccidian parasite species tested (Hammondia hammondi, Hammondia heydorni, Cystoisospora felis, Eimeria bovis, Sarcocystis sp.). Another mAb, designated K8/15-15, recognized antigens in sporocyst walls of the parasite and in the walls of in vivo or in vitro produced tissue cysts, as demonstrated by immunofluorescence and immunoblot assays. Antigens of 80 to a high molecular weight protein of about 350 kDa Mr were recognized by this antibody using antigen extracts from sporocysts, and from in vitro or in vivo generated tissue cysts of the parasite. Tissue cyst and sporocyst walls of H. hammondi and H. heydorni, and tissue cysts of Neospora caninum were also recognized by mAb K8/15-15. Sporocyst walls of C. felis also reacted to this mAb. The cyst walls of Sarcocystis sp. and Besnoitia besnoiti were not recognized by mAb K8/15-15. Reactivity by a single mAb against T. gondii antigens in tissue cysts and sporocysts had not been reported previously. MAb K8/15-15 may be a practical tool for the identification of both cysts and sporocysts of the parasite, and may also be potentially employed in proteomic studies on the identification of new components of the cyst and sporocyst walls of T. gondii.

Human intestinal sarcocystosis in Iran: there but not seen.

Human sarcocystosis is a rare infection caused by the genus Sarcocystis who human serve as definitive (intestinal form of infection) host or intermediate (extraintestinal form) host for some various Sarcocystis species. The detection of Sarcocystis oocysts/sporocysts in the feces usually incidentally and is achieved by microscopic examination of the fresh or preserved specimens. To rule out any parasitological etiology among 23,875 (aged 2 months to 95 years) apparently immunocompetent Iranian individuals (from October of 2010 to June of 2016) with abdominal discomforts referred to several teaching hospitals and local clinical laboratories in Fars Province, Iran, their fecal samples were examined using light microscopy. Most pathogenic parasite-positive and doubtful samples were sent to the Intestinal Protozoology Laboratories of Fasa and Shiraz Universities of Medical Sciences to further examination to detect probable co-infection with other underdiagnose parasitoses. In addition to the common protozoal and helminthic infections, during the course of examining stool specimens using direct smear mixed with saline or iodine mounts and by formalin-ethyl acetate techniques, four cases of intestinal Sarcocystis infection as only or concurrently infected with other parasites were found. The present paper presents cases of human intestinal Sarcocystis infection in Iran. Since Sarcocystis are small in size and usually rare in stool, they often go unnoticed. It should be noted that stool smears must be examined with great care to avoid misinterpretation of Sarcocystis infections in microscopic examinations. To the best of our knowledge, co-infection of intestinal sarcocystosis and other principal parasitoses in stool investigations has not been reported earlier.

Prevalence of Enteric Protozoan Oocysts with Special Reference to Sarcocystis cruzi among Fecal Samples of Diarrheic Immunodeficient Patients in Iran.

The genus Sarcocystis is not usually considered as an important enteric pathogen in immune compromised patients. It might be expected that species for which humans are the final host (Sarcocystis hominis and Sarcocystis suihominis as well as possibly others) would be encountered increasingly often in immunodeficient persons. This study aimed to address how to detect and differentiate Sarcocystis oocysts and/or sporocysts from enteric protozoans in the diarrheal samples of immunodeficient patients in Shiraz, Iran. Diarrheal samples of 741 immunodeficient patients with recurrent persistent or chronic diarrhea were examined by microscopy and molecular biological analysis. Oocysts-positive samples were 68 Cryptosporidium spp., 9 Cystoisospora belli (syn. Isospora belli), 2 Cyclospora cayetanensis, and 15 microsporidia (Enterocytozoon bieneusi). Sarcocystis-like sporocysts found from a woman were identified as Sarcocystis cruzi through 18S rDNA amplification and phylogenetic analysis. To the best of our knowledge, this is the first report of S. cruzi from a human.

Effects of different sizes of glass beads on the release of sporocysts from Eimeria tenella oocysts.

The oocyst wall is severed by means of mechanical injury or chemical agents. This study reports the percentage of in vitro sporocyst release following mechanical shaking in the presence of varying sizes of glass beads. Glass beads measured 0.5, 1, and 3 mm in diameter and were shaken with the oocysts for different times ranging from 5 sec to 5 min. Approximately 80% of sporocysts were released with 5 min of shaking in the presence of 3 mm glass beads, as well as 30 sec with 0.5 mm beads and 1 mm glass beads. The release of sporocysts of E. tenella was most efficient using 1 mm glass beads and treatment times of 30 sec to 1 min. Therefore, the use of 1 mm glass beads with 30 sec to 1 min of agitation is recommended in order to maximize sporocyst release and recovery and to improve the yield of viable sporozoites for use in biochemical, tissue culture, and immunological applications of coccidia.

Sporocysts of Sarcocystis bertrami (syn. Sarcocystis fayeri) shed by dogs: Molecular analysis, morphometry and pattern of excretion.

Sarcocystis bertrami (synonym: Sarcocystis fayeri) is a coccidian parasite that infects horses and donkeys in several countries. Dogs are known as definitive hosts of the parasite, however, the patent period is not well defined, and S. bertrami shed by dogs has never been confirmed by molecular methods. Here we investigated the shedding of S. bertrami by experimentally infected dogs and examined the excreted parasites by morphological and molecular tools. Three dogs of small breeds (one Yorkshire terrier and two miniature Pinschers) were acquired with ages of 30 and 60 days and were exclusively fed commercial dog food. Two dogs consumed equine muscle tissues containing cysts of S. bertrami. The third dog served as negative control and was simultaneously fed commercial dog food. The two animals that received equine tissues shed sporocysts and/or oocysts in their feces after prepatent periods of 13 and 23 days. The patent periods were 47 and 14 days. Sporocysts showed average dimensions of 14.19 µm (± 0.53) x 10.06 µm (± 0.44). The control dog did not shed sporocysts or oocysts of the parasite. Interestingly, patent periods had never been reported, and for one dog, the patent period (47 days) was longer than that reported for other Sarcocystidae parasites. PCRs to the gene 18S and to the internal transcribed spacer 1 (ITS1) of the rDNA were successfully performed with DNA extracted from sporocysts. ITS1 sequences were also obtained from the equine tissue cysts used to infect the dogs. Nucleotide sequences of cloned fragments of 18S from sporocysts, and ITS1 from both stages (tissue cysts and sporocysts) matched with S. bertrami (18S: 97.50-99.88 %; ITS1: 88.76-95.21 %), although high molecular diversity was observed with data from these loci. PCR to cox1 using sporocysts' DNA failed to amplify any product. The possibility of the existence of an additional and undescribed Sarcocystis species in the excreted sporocysts, besides S. bertrami, cannot be excluded from this experiment. To our knowledge, this is the first molecular confirmation of S. bertrami in canine feces. Sporocyst dimensions and prepatent periods observed in this study were similar to those previously described for S. bertrami and S. fayeri. In conclusion, the molecular, morphological and biological data generated here fit in previous descriptions for both S. bertrami and S. fayeri.

Two New Eimerians from American Alligator, Alligator mississippiensis (Crocodilia: Alligatoridae), from Georgia, USA.

PURPOSE: Little is known about the coccidian parasites of the American alligator, Alligator mississippiensis (Daudin). To date, only two species of Eimeria Schneider, 1875 have been previously reported from A. mississippiensis. Here, we report from mensural and morphometric data on two new species of Eimeria from A. mississippiensis from Georgia, USA. METHODS: Fresh feces were collected in June 2023 from a single captive juvenile male A. mississippiensis. Multiple samples were placed in individual zip-lock bags and aqueous potassium dichromate was added. They were examined for sporulated oocysts after flotation in Sheather's sugar solution, measured, and photographed. RESULTS: Samples contained oocysts representing two new species of Eimeria. Oocysts of Eimeria tellezae n. sp. are subspheroidal to ellipsoidal with a pitted bi-layered wall, measure (L × W) 34.5 × 31.5 µm, and have a length/width (L/W) ratio of 1.1; a micropyle and polar granule were absent but an oöcyst residuum was present. Sporocysts are ellipsoidal and measure 17.2 × 7.7 µm, L/W 2.2; a nipple-like Stieda body bearing one to several filaments was present but sub-Stieda and para-Stieda bodies were absent. The sporocyst residuum is composed of various-sized granules in a compact rounded or irregular mass, sometimes dispersed between the sporozoites. Oocysts of Eimeria daudini n. sp. are ellipsoidal with a pitted bi-layered wall, measure (L × W) 32.5 × 20.2 µm, and have a length/width (L/W) ratio of 1.6; a micropyle and polar granule were absent but an oöcyst residuum was present. Sporocysts are ellipsoidal and measure 15.4 × 7.4 µm, L/W 2.1; a nipple-like Stieda body bearing one to several filaments was present but sub-Stieda and para-Stieda bodies were absent. The sporocyst residuum is composed of various-sized granules in a compact rounded or irregular mass, sometimes dispersed between the sporozoites. Both new species can readily be distinguished from previously described eimerians from crocodilians, including those from A. mississippiensis. CONCLUSION: We document two new species of Eimeria from the American alligator. Currently, four species of Eimeria are known from A. mississippiensis examined from both east and west of the Mississippi River, USA.

Sarcocystis sp. shed by the common boa snake (Boa constrictor) in Brazil.

The genus Sarcocystis contains around 200 species and 25 of these infect snakes. Two Sarcocystis spp. shed by snakes have called special attention of the scientific community. S. nesbitti, which is shed by scrub pythons (Simalia amethistina), causes myopathy in humans that consume water or food contaminated with the parasite. Sporocysts of S. singaporensis, excreted by reticulated pythons (Malayopython reticulatus), is letal for rats and was successfully tested in the biological control of these rodents. A high biodiversity of snakes is found in Brazil, however, scarce information is available about Sarcocystis spp. in Brazilian snakes. Herein, we investigated Sarcocystis sp. in feces of the common boa (Boa constrictor) from Salvador, as it is widely distributed in Brazil and it is also bred in other countries. Feces of 65 boas were examined, and Sarcocystis sp. was found in 1/65 (1.53%) snakes. All snakes were alive, and for this reason, intestinal scrapping, which is the most sensitive method to detect the parasite, was not performed. Morphometric evaluation of sporocysts showed significant differences in their sizes. PCR and multilocus sequencing of four genetic markers (cox1, 18S, ITS1, and 28S) revealed that sporocysts corresponded to a new Sarcocystis species. Sequences of cox1 and 18S had identities of 100% and higher than 98%, respectively, with sequences obtained from the rodent Lagostomus maximus in Argentina. ITS1 and 28S sequences did not match with any known Sarcocystis sp. No ITS1 and 28S sequences were available for the Sarcocystis sp. found in the Argentinian L.maximus. Bioassay using the boa sporocysts was conducted in three mouse lineages and in Rattus norvegicus, but no parasitic stages were detected in these rodents. We concluded that the common boa is probably the definitive host of a new species of Sarcocystis sp. that has L. maximus or related rodents as intermediate hosts.

Time series analysis of tegument ultrastructure of in vitro transformed miracidium to mother sporocyst of the human parasite Schistosoma mansoni.

The transformation of Schistosoma mansoni miracidia into mother sporocysts is induced, either in vivo by the penetration of the free-living larval stage, the miracidium, in the snail Biomphalaria glabrata or in vitro following the incubation of the miracidium in Chernin's Balanced Salt Solution (CBSS) or Bge (B. glabrata embryonic cell line) culture medium. The in vitro development of S. mansoni miracidium into mother sporocyst was monitored by Scanning Electron Microscopy (SEM) from 2.5 h to 120 h in CBSS. The transformation starts when the miracidium ciliate plates detach due to the proliferation of the intercellular ridge associated with the degeneration of mid-body papillae of the miracidium. The loss of ciliated plates causes the appearing of scars, filled across time by the proliferation of a new tegument originating from the interplate ridge. This new tegument covers the entire body of the metamorphosing parasite and differentiates over time, allowing some exchanges (uptakes or secretion/excretion) between the parasite and its host. In contrast to the well-described development of adult and free-living larval stages of S. mansoni using SEM, the developmental transformation of intramolluscan stages, especially tegumental changes in the mother sporocyst, has been sparcely documented at the ultrastructural level. In addition, taking into account the latest literature on miracidium electron microscopy and the advances in SEM technologies over the last thirty years, the present study gathers three main objectives: (i) Fill the gap of tegument scanning electron micrographs of in vitro transforming sporocysts; (ii) Update the current bibliographic miracidia and sporocysts image bank due to rapid evolution of SEM technology; (iii) Understand and describe the critical steps and duration of the in vitro miracidium-to-sporocyst transformation process to assist in understanding the interaction between the larval surface and snail immune factors.

Cloning and expression of a cDNA coding for Eimeria acervulina 25 kDa protein associated with oocyst and sporocyst walls.

The purpose of this study was to characterize a gene named EAH 00033530 identified by RNAseq analysis of sporulating Eimeria acervulina oocysts and its encoded protein. Quantitative RT-PCR analysis revealed peak expression of EAH 00033530 mRNA early (3-6 h) in sporulation followed by downregulation at 12-24 h. The gene for EAH 00033530 was expressed in Escherichia coli as a 70 kDa polyHis fusion protein (rEAH 00033530). Antisera prepared against rEAH 00033530 protein identified in immunoblotting a native 25 kDa E. acervulina protein (Ea25) that was present in oocyst-sporocyst extracts after treatment with the reducing agent DTT. Immunofluorescence staining using anti-rEa25 localized the protein to both E. acervulina oocyst and sporocyst walls, but not to sporozoites. The protein may be produced during in vivo oocyst development because immunostaining of duodenal tissue from E. acervulina-infected chickens revealed oocyst wall expression. As observed by ELISA, rEa25 protein appears to elicit a humoral immune response in chickens infected with non-irradiated or radiation-attenuated E. acervulina oocysts.

Effect of household bleach on the structure of the sporocyst wall of Toxoplasma gondii.

Toxoplasma gondii oocysts are responsible for food- and water-borne infections in humans worldwide. They are resistant to common chemical disinfectants, including chlorinated products, presumably due to the structure and molecular nature of the oocyst wall but also the sporocyst wall. In this study, we used fluorescence microscopy and transmission electron microscopy to characterise the structure of both the oocyst and sporocyst walls, exposed to household bleach. Bleach removed the outer layer of the oocyst wall and the outer layer of the wall of sporocysts exposed due to rupture of the oocyst wall. The loss of the outer sporocyst wall layer was associated with a decrease in its autofluorescence, which can be linked to the degradation of dityrosine cross-link proteins, and loss of Maclura pomifera lectin-reactive glycoproteins. This study suggests that the inner layers of the oocyst and sporocyst walls are the main structures responsible for the resistance of the parasite to household bleach.

TITLE: Effet de l'eau de Javel à usage domestique sur la structure de la paroi du sporocyste de Toxoplasma gondii. ABSTRACT: Les oocystes de Toxoplasma gondii sont responsables chez l'homme d'infections cosmopolites d'origine alimentaire et hydrique. Ils sont résistants aux désinfectants chimiques usuels, notamment aux produits chlorés, vraisemblablement en raison de la structure et de la nature moléculaire de la paroi de l'oocyste mais aussi de celle du sporocyste. Dans cette étude, nous avons utilisé la microscopie à fluorescence et la microscopie électronique à transmission pour caractériser la structure de la paroi des oocystes et des sporocystes exposés à l'eau de Javel à usage domestique. L'eau de Javel élimine la couche externe de la paroi de l'oocyste et la couche externe de la paroi des sporocystes exposés en raison de la rupture de la paroi de l'oocyste. La perte de la couche externe de la paroi du sporocyste est associée à une diminution de son autofluorescence, qui peut être liée à la dégradation de polymères protéiques de dityrosine, et à une perte des glycoprotéines réactives à la lectine Maclura pomifera. Cette étude suggère que les couches internes des parois de l'oocyste et du sporocyste sont les principales structures responsables de la résistance du parasite à l'eau de Javel à usage domestique.

The first detection of Dicrocoelium chinensis sporocysts from the land snail Aegista vulgivaga in Gifu Prefecture, Japan.

Trematodes of the genus Dicrocoelium are one of the most common parasites in ruminant animals; however, their life cycles in Japan are unclear. To find the sporocysts of D. chinensis in the natural field, we sampled 269 land snails (14 species) at a location with high level infection of sika deer in Gifu Prefecture, Honshu Island, Japan in autumn between 2017 and 2019. During the sampling period, we found mother sporocysts in the hepatopancreas of Aegista vulgivaga and Cyclophorus herklotsi. DNA barcoding based on the sequences of cytochrome c oxidase subunit 1 showed that the sporocysts from A. vulgivaga belonged to D. chinensis, indicating that this snail has potential as the first intermediate host of D. chinensis at this location.