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Bernard Fried - One of the best experts on this subject based on the ideXlab platform.
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Collar spine models in the genus Echinostoma (Trematoda: Echinostomatidae)
Parasitology Research, 2009Co-Authors: Ivan Kanev, Bernard Fried, Valentin RadevAbstract:This paper discusses collar spine arrangements in the genus Echinostoma . All arrangements are of uneven numbers of collar spines on the oral collar. The total number of collar spines in these arrangements ranges from a low 31 to a high 51. There are 11 models of collar spine arrangements in the Echinostoma consisting of spine numbers 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, and 51. Representative species with these collar spine arrangements are given in the article. The number of collar spines in a species is identical in both the larval and adult forms. Reports of even numbered spine counts in the genus Echinostoma are erroneous and probably reflect counts on worms with lost, retracted, or supernumerary spines.
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Excystation of the encysted metacercariae of Echinostoma trivolvis and Echinostoma caproni in a trypsin-bile salts-cysteine medium and morphometric analysis of the excysted larvae
Journal of Parasitology, 2008Co-Authors: Tyler M. Saxton, Bernard Fried, Robert C. PeoplesAbstract:A trypsin-bile salts-cysteine (TBC) medium was used to excyst the encysted metacercariae of Echinostoma caproni and Echinostoma trivolvis, 2 allopatric species of Echinostoma. This medium was used to replace a previously used trypsin-bile salts (TB) medium that was no longer effective because of the unavailability of the original stocks of trypsin. The TBC medium maintained at 41 C allowed for 68.6% excystation of E. caproni at 1 hr and 57.5% excystation of E. trivolvis at 2 hr. The cysteine reductant in the TBC medium was necessary; if it was omitted, excystation was nil. Morphometric analysis was done on the excysted metacercariae following fixation of the larvae in hot, 5% neutral buffered formalin and mounting them on slides in glycerin jelly. Body and organ measurements were made on these larvae. The diameter of the acetabulum of E. caproni was significantly greater than that of E. trivolvis. Likewise, the number and diameter of the excretory concretions found in E. caproni were significantly larger ...
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Hemozoin formation in Echinostoma trivolvis rediae.
International Journal for Parasitology, 2005Co-Authors: John M. Pisciotta, Bernard Fried, Elizabeth L. Ponder, David J. SullivanAbstract:Abstract Rediae of the trematode Echinostoma trivolvis, from naturally infected Helisoma trivolvis snails, form a black pigment while inside the snail host. Here we examine the black pigment to show that the insolubility characteristics in detergent and weak base solution are identical to Plasmodium falciparum hemozoin. Laser desorption mass spectrometry of the purified pigment demonstrates the presence of heme. Examination of purified pigment under polarized light microscopy illuminates ordered birefringent crystals. Field emission in lens scanning electron microscopy reveals irregular ovoid crystals of 200–300 nm in diameter. The purified pigment crystals seeded extension of monomeric heme onto the crystal which by Fourier Transform Infrared analysis is β-hematin. Rediae of a second echinostome parasite, Echinostoma caproni, from experimentally infected Biomphalaria glabrata, do not produce measurable or recoverable heme crystals. These observations are consistent with heme crystal formation by a hematophagous parasite within a non-vertebrate intermediate host.
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Effects of tonicity on the release of neutral lipids in Echinostoma caproni adults and observations on lipids in excysted metacercariae
Parasitology Research, 2004Co-Authors: Jessica L. Schneck, Bernard Fried, Joseph ShermaAbstract:High performance thin layer chromatography was used to analyze neutral lipids in worm incubates isotonic, hypotonic, and hypertonic to the intestinal habitat of adult Echinostoma caproni . Qualitative analysis revealed the presence of free sterols, free fatty acids, triacylglycerols, and a steryl ester/hydrocarbon fraction in all incubate samples. The most abundant neutral lipid fraction released into the incubation medium was the triacylglycerol fraction. This fraction was quantified after worms were maintained for 2 h at 37.5°C in hypertonic (Locke’s 2× solution), isotonic (Locke’s 0.5× solution) and hypotonic (deionized water) media. Percentages of triacylglycerols on a wet-weight basis found in Locke’s 2×, 0.5×, and deionized water were 0.369, 3.23, and 0.242, respectively, suggesting that the optimal medium to obtain maximal excretory-secretory products is the Locke’s 0.5× solution. Histochemical staining of whole excysted metacercariae with oil red O did not detect neutral lipids. Analysis of 500 excysted metacercariae incubated for 2 h at 37.5°C revealed that free sterols, free fatty acids, and triacylglycerols were released in amounts of 16.2, 1.59, and 5.34 ng/organism, respectively. Our results were compared with previous studies on neutral lipids in excysted metacercariae and adults of E. trivolvis. Variations in the results of our study compared with others reflect intrinsic differences in the species of echinostome used.
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KINETICS OF Echinostoma CAPRONI (TREMATODA: EchinostomaTIDAE) ANTIGENS IN FECES AND SERUM OF EXPERIMENTALLY INFECTED HAMSTERS AND RATS
Journal of Parasitology, 2004Co-Authors: Rafael Toledo, Bernard Fried, Ana Espert, Carla Muñoz-antoli, Antonio Marcilla, J. Guillermo EstebanAbstract:This study reports on the kinetics of antibody production to Echinostoma caproni and the dynamics of antigens in feces and sera in 2 experimental hosts (hamsters and rats) that display different degrees of susceptibility with this echinostome. Echinostoma caproniproduced chronic infections in hamsters, whereas rats lost the infection at 49-56 days postinfection (DPI). Hamsters developed higher antibody responses than rats, probably in relation to different intestinal absorptions of worm antigens in each host species. The levels of coproantigens were indicative of the course of infection in each host. Positive coproantigen levels were detected at 1-2 DPI in both hosts, and the values remained positive until the end of the experiment in hamsters; in rats, the coproantigen levels reverted to negative values, coinciding with the loss of infection. High levels of circulating antigens were detected in hamsters from 21 DPI to the end of the study. In contrast, low levels of E. caproni seroantigens were detected in rats only. These observations may reflect the differences in local inflammatory responses induced by E. caproni in each host species. Infections with intestinal trematodes are widespread. Despite the frequency of these infections, the relationships between in- testinal trematodes and their final hosts have received little at- tention. Echinostoma caproni(Trematoda: Echinostomatidae) is an intestinal trematode that does not undergo tissue migration in its definitive host. After infection of the definitive host with E. caproni, the metacercariae excyst in the duodenum, and the juvenile parasites migrate to the posterior third of the small
Aneta Kostadinova - One of the best experts on this subject based on the ideXlab platform.
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A re-assessment of species diversity within the ‘revolutum’ group of Echinostoma Rudolphi, 1809 (Digenea: Echinostomatidae) in Europe
Systematic Parasitology, 2015Co-Authors: Anna Faltýnková, Simona Georgieva, Miroslava Soldánová, Aneta KostadinovaAbstract:Species of Echinostoma Rudolphi, 1809 (Digenea: Echinostomatidae) belonging to the ‘ revolutum ’ species complex were re-examined based on material gathered in an extensive sampling programme in eight countries in Europe. The morphology of the life-cycle stages was studied in naturally and experimentally infected snail and bird hosts. A review, with an updated synonymy, is presented for six European species, including one new to science, i.e. Echinostoma revolutum (Frölich, 1802) ( sensu stricto ) (type-species), E. bolschewense (Kotova, 1939), E. miyagawai Ishii, 1932, E. nasincovae n. sp., E. paraulum Dietz, 1909 and Echinostoma sp. IG), and keys to the identification of their cercariae and adults are provided.
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new cryptic species of the revolutum group of Echinostoma digenea Echinostomatidae revealed by molecular and morphological data
Parasites & Vectors, 2013Co-Authors: Simona Georgieva, Anna Faltýnková, Miroslava Soldánová, Aneta Kostadinova, Bernd Sures, Christian Selbach, Karl SkirnissonAbstract:The digenean species of Echinostoma (Echinostomatidae) with 37 collar spines that comprise the so-called ‘revolutum’ species complex, qualify as cryptic due to the interspecific homogeneity of characters used to differentiate species. Only five species were considered valid in the most recent revision of the group but recent molecular studies have demonstrated a higher diversity within the group. In a study of the digeneans parasitising molluscs in central and northern Europe we found that Radix auricularia, R. peregra and Stagnicola palustris were infected with larval stages of two cryptic species of the ‘revolutum’ complex, one resembling E. revolutum and one undescribed species, Echinostoma sp. IG. This paper provides morphological and molecular evidence for their delimitation. Totals of 2,030 R. auricularia, 357 R. peregra and 577 S. palustris were collected in seven reservoirs of the River Ruhr catchment area in Germany and a total of 573 R. peregra was collected in five lakes in Iceland. Cercariae were examined and identified live and fixed in molecular grade ethanol for DNA isolation and in hot/cold 4% formaldehyde solution for obtaining measurements from fixed materials. Partial fragments of the mitochondrial gene nicotinamide adenine dinucleotide dehydrogenase subunit 1 (nad 1) were amplified for 14 isolates. Detailed examination of cercarial morphology allowed us to differentiate the cercariae of the two Echinostoma spp. of the ‘revolutum’ species complex. A total of 14 partial nad 1 sequences was generated and aligned with selected published sequences for eight species of the ‘revolutum’ species complex. Both NJ and BI analyses resulted in consensus trees with similar topologies in which the isolates from Europe formed strongly supported reciprocally monophyletic lineages. The analyses also provided evidence that North American isolates identified as E. revolutum represent another cryptic species of the ‘revolutum’ species complex. Our findings highlight the need for further analyses of patterns of interspecific variation based on molecular and morphological evidence to enhance the re-evaluation of the species and advance our understanding of the relationships within the ‘revolutum’ group of Echinostoma.
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Phylogenetic relationships of Echinostoma Rudolphi, 1809 (Digenea: Echinostomatidae) and related genera re-assessed via DNA and morphological analyses
Systematic Parasitology, 2003Co-Authors: Aneta Kostadinova, E.a. Herniou, J. Barrett, D.t.j. LittlewoodAbstract:In order to investigate the relationships within the Echinostomatidae two data sets of gene sequences were analysed. The first consisted of all previously published ND1 sequences (20) together with 17 new sequences. The latter represented six species from the cosmopolitan genera Echinostoma, Echinoparyphium, Hypoderaeum and Isthmiophora . The second data-set of ITS sequences again included all previously published sequences (12) and three new sequences from species of Echinostoma, Echinoparyphium and Isthmiophora . All new isolates, as well as voucher material from five previously sequenced isolates, were identified on the basis of morphological characters. The phylogenetic trees inferred from the ND1 data set helped to clarify the generic affiliation of all isolates and confirmed the morphological identifications. The only exception was Echinoparyphium aconiatum , whose current position in the genus Echinoparyphium was not supported by the sequence data. Although the ITS data provided insufficient resolution for an unequivocal solution to the relationships within the genus Echinostoma , it supported the identification of Echinoparyphium ellisi and the distinct species status of three isolates of Echinostoma revolutum as predicted from the ND1 data.
Jong-yil Chai - One of the best experts on this subject based on the ideXlab platform.
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Morphology and Molecular Identification of Echinostoma revolutum and Echinostoma macrorchis in Freshwater Snails and Experimental Hamsters in Upper Northern Thailand
The Korean Journal of Parasitology, 2020Co-Authors: Preeyaporn Butboonchoo, Pheravut Wongsawad, Chalobol Wongsawad, Jong-yil ChaiAbstract:Echinostome metacercariae were investigated in freshwater snails from 26 districts in 7 provinces of upper northern Thailand. The species identification was carried out based on the morphologies of the metacercariae and adult flukes harvested from experimental hamsters, and on nucleotide sequences of internal transcribed spacer 2 (ITS2) and nicotinamide adenine dinucleotide dehydrogenase subunit 1 (nad1) genes. Twenty-four out of 26 districts were found to be infected with echinostome metacercariae in freshwater snails with the prevalence of 40.4%. The metacercariae were found in all 6 species of snails, including Filopaludina martensi martensi (21.9%), Filopaludina doliaris (50.8%), F. sumatrensis polygramma (61.3%), Bithynia siamensis siamensis (14.5%), Bithynia pulchella (38.0%), and Anenthome helena (4.9%). The echinostome metacercariae found in these snails were identified as Echinostoma revolutum (37-collar-spined) and Echinostoma macrorchis (45-collar-spined) morphologically and molecularly. The 2-week-old adult flukes of E. revolutum revealed unique features of the cirrus sac extending to middle of the ventral sucker and smooth testes. E. macrorchis adults revealed the cirrus sac close to the right lateral margin of the ventral sucker and 2 large and elliptical testes with slight indentations and pointed posterior end of the posterior testis. The ITS2 and nad1 sequences confirmed the species identification of E. revolutum, and the sequences of E. macrorchis have been deposited for the first time in Gen-Bank. The presence of the life cycle of E. macrorchis is a new record in Thailand and the snail F. doliaris as their second intermediate host seems to be new among the literature.
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Echinostoma mekongi n. sp. (Digenea: Echinostomatidae) from Riparian People along the Mekong River in Cambodia.
The Korean Journal of Parasitology, 2020Co-Authors: Jaeeun Cho, Woon-mok Sohn, Muth Sinuon, Bong-kwang Jung, Taehee Chang, Jong-yil ChaiAbstract:Echinostoma mekongi n. sp. (Digenea: Echinostomatidae) is described based on adult flukes collected from humans residing along the Mekong River in Cambodia. Total 256 flukes were collected from the diarrheic stool of 6 echinostome egg positive villagers in Kratie and Takeo Province after praziquantel treatment and purging. Adults of the new species were 9.0-13.1 (av. 11.3) mm in length and 1.3-2.5 (1.9) mm in maximum width and characterized by having a head collar armed with 37 collar spines (dorsal spines arranged in 2 alternative rows), including 5 end group spines. The eggs in feces and worm uterus were 98-132 (117) μm long and 62-90 (75) μm wide. These morphological features closely resembled those of Echinostoma revolutum, E. miyagawai, and several other 37-collar-spined Echinostoma species. However, sequencing of the nuclear ITS (ITS1-5.8S rRNA-ITS2) and 2 mitochondrial genes, cox1 and nad1, revealed unique features distinct from E. revolutum and also from other 37-collar-spined Echinostoma group available in GenBank (E. bolschewense, E. caproni, E. cinetorchis, E. deserticum, E. miyagawai, E. nasincovae, E. novaezealandense, E. paraensei, E. paraulum, E. robustum, E. trivolvis, and Echinostoma sp. IG). Thus, we assigned our flukes as a new species, E. mekongi. The new species revealed marked variation in the morphology of testes (globular or lobulated), and smaller head collar, collar spines, oral and ventral suckers, and cirrus sac compared to E. revolutum and E. miyagawai. Epidemiological studies regarding the geographical distribution and its life history, including the source of human infections, remain to be performed.
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Taxonomy of Echinostoma revolutum and 37-Collar-Spined Echinostoma spp.: A Historical Review.
The Korean Journal of Parasitology, 2020Co-Authors: Jong-yil Chai, Jaeeun Cho, Bong-kwang Jung, Taehee Chang, Woon-mok SohnAbstract:Echinostoma flukes armed with 37 collar spines on their head collar are called as 37-collar-spined Echinostoma spp. (group) or 'Echinostoma revolutum group'. At least 56 nominal species have been described in this group. However, many of them were morphologically close to and difficult to distinguish from the other, thus synonymized with the others. However, some of the synonymies were disagreed by other researchers, and taxonomic debates have been continued. Fortunately, recent development of molecular techniques, in particular, sequencing of the mitochondrial (nad1 and cox1) and nuclear genes (ITS region; ITS1-5.8S-ITS2), has enabled us to obtain highly useful data on phylogenetic relationships of these 37-collar-spined Echinostoma spp. Thus, 16 different species are currently acknowledged to be valid worldwide, which include E. revolutum, E. bolschewense, E. caproni, E. cinetorchis, E. deserticum, E. lindoense, E. luisreyi, E. mekongi, E. miyagawai, E. nasincovae, E. novaezealandense, E. paraensei, E. paraulum, E. robustum, E. trivolvis, and Echinostoma sp. IG of Georgieva et al., 2013. The validity of the other 10 species is retained until further evaluation, including molecular analyses; E. acuticauda, E. barbosai, E. chloephagae, E. echinatum, E. jurini, E. nudicaudatum, E. parvocirrus, E. pinnicaudatum, E. ralli, and E. rodriguesi. In this review, the history of discovery and taxonomic debates on these 26 valid or validity-retained species are briefly reviewed.
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Echinostoma aegyptica trematoda Echinostomatidae infection in five riparian people in savannakhet province lao pdr
Korean Journal of Parasitology, 2020Co-Authors: Jong-yil Chai, Bounlay Phammasack, Woon-mok Sohn, Tai-soon Yong, Keeseon S. Eom, Bong-kwang Jung, Taehee Chang, Hyejoo Shin, Duk Young Min, Bounnaloth InsisiengmayAbstract:Human infection with Echinostoma aegyptica Khalil and Abaza, 1924 (Trematoda: Echinostomatidae) is extremely rare. In this study, we confirmed E. aegyptica infection in 5 riparian residents living along the Mekong River in Savannakhet Province, Lao PDR. The patients revealed eggs of Opisthorchis viverrini/minute intestinal flukes, echinostomes, and other parasites in fecal examinations using the Kato-Katz technique. Following treatment with praziquantel 30-40 mg/kg and pyrantel pamoate 10-15 mg/kg in a single dose and purging with magnesium salts, adult specimens of various helminth species were collected. Among the trematodes, echinostome flukes of 4.5-7.6 mm in length (n = 134; av. 22.3 specimens per case) were of taxonomic interest and subjected in this study. The flukes were morphologically characterized by having total 43-45 collar spines arranged in 2 alternating rows (corner spines usually 5 on each side) and compatible with previous descriptions of E. aegyptica. The patients were mixed-infected with other helminths, so specific clinical manifestations due to this echinostome fluke were difficult to determine. The present paper describes for the first time human E. aegyptica infections in Lao PDR. This is the second report of human infection (2nd-6th cases) with E. aegyptica in the world following the first one from China.
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Echinostoma macrorchis metacercariae in cipangopaludina chinensis malleata from xiengkhuang province lao pdr and morphologies of adults from experimental animals
Korean Journal of Parasitology, 2019Co-Authors: Woon-mok Sohn, Tai-soon Yong, Jong-yil Chai, Keeseon S. Eom, Dongmin Lee, Duk Young MinAbstract:We identified the echinostome metacercariae in Chinese mystery snails, Cipangopaludina chinensis malleata, from Xiengkhuang Province, Lao PDR with morphologies of adult worms recovered. Total 20 snails were examined with artificial digestion method and then the collected metacercariae were orally infected to a mouse and a rat. Adult worms recovered from experimental animals were observed with a light microscope and a SEM. The metacercariae were round, 125×123 µm in average size, with a moderately thick cyst wall, collar spines distributed in the head collar and excretory granules in 2 canals of excretory tube. Adult flukes (3-week-old in a rat) were elongated, ventrally curved and 5.310×1.023 mm in average size. Head collar distinct, bearing 43 collar spines with 5 end group ones on each side. Oral sucker subterminal, prepharynx very short, pharynx well developed, and esophagus relatively short. Cirrus sac well developed, with a saccular seminal vesicle, and ventral sucker very large. Ovary round and on the median line of the body. Testes tandom and elongated. Eggs operculated, elliptical and 90×57 µm in average size. In the SEM observation, the head crown prominent, with 43 collar spines resembled with horns of younger stag. Scale-like tegumental spines were densely distributed on the surface between the head collar and ventral sucker, and their densities were decreased posteriorly. Conclusively, the metacercariae detected in C. chinensis malleata from Lao PDR were identified as those of Echinostoma macrorchis based on the morphological characteristics of adult worms.
G. Mitta - One of the best experts on this subject based on the ideXlab platform.
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Compatibility in the Biomphalaria glabrata/Echinostoma caproni model: new candidate genes evidenced by a suppressive subtractive hybridization approach.
Parasitology, 2007Co-Authors: A. Bouchut, C. Coustau, B. Gourbal, G. MittaAbstract:In order to elucidate mechanisms underlying snail/echinostome compatibility, numerous molecular studies comparing transcripts and proteins of Biomphalaria glabrata susceptible or resistant to Echinostoma caproni were undertaken. These studies focused on plasma and haemocytes of the two strains and revealed that some transcripts and/or proteins were differentially expressed between strains. The aim of the present study was to develop a complementary transcriptomic approach by constructing subtractive libraries. This work revealed some candidate transcripts already identified in previous studies (calcium-binding proteins and glycolytic enzymes) as well as novel candidate transcripts that were differentially represented between strains of B. glabrata. Among these newly identified genes, we revealed several genes potentially involved in immune processes encoding proteases, protease inhibitors, a lectin, an aplysianin-like molecule, and cell adhesion molecules.
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compatibility in the biomphalaria glabrata Echinostoma caproni model new candidate genes evidenced by a suppressive subtractive hybridization approach
Parasitology, 2007Co-Authors: A. Bouchut, Christine Coustau, B. Gourbal, G. MittaAbstract:In order to elucidate mechanisms underlying snail/echinostome compatibility, numerous molecular studies comparing transcripts and proteins of Biomphalaria glabrata susceptible or resistant to Echinostoma caproni were undertaken. These studies focused on plasma and haemocytes of the two strains and revealed that some transcripts and/or proteins were differentially expressed between strains. The aim of the present study was to develop a complementary transcriptomic approach by constructing subtractive libraries. This work revealed some candidate transcripts already identified in previous studies (calcium-binding proteins and glycolytic enzymes) as well as novel candidate transcripts that were differentially represented between strains of B. glabrata. Among these newly identified genes, we revealed several genes potentially involved in immune processes encoding proteases, protease inhibitors, a lectin, an aplysianin-like molecule, and cell adhesion molecules.
Woon-mok Sohn - One of the best experts on this subject based on the ideXlab platform.
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Echinostoma mekongi n. sp. (Digenea: Echinostomatidae) from Riparian People along the Mekong River in Cambodia.
The Korean Journal of Parasitology, 2020Co-Authors: Jaeeun Cho, Woon-mok Sohn, Muth Sinuon, Bong-kwang Jung, Taehee Chang, Jong-yil ChaiAbstract:Echinostoma mekongi n. sp. (Digenea: Echinostomatidae) is described based on adult flukes collected from humans residing along the Mekong River in Cambodia. Total 256 flukes were collected from the diarrheic stool of 6 echinostome egg positive villagers in Kratie and Takeo Province after praziquantel treatment and purging. Adults of the new species were 9.0-13.1 (av. 11.3) mm in length and 1.3-2.5 (1.9) mm in maximum width and characterized by having a head collar armed with 37 collar spines (dorsal spines arranged in 2 alternative rows), including 5 end group spines. The eggs in feces and worm uterus were 98-132 (117) μm long and 62-90 (75) μm wide. These morphological features closely resembled those of Echinostoma revolutum, E. miyagawai, and several other 37-collar-spined Echinostoma species. However, sequencing of the nuclear ITS (ITS1-5.8S rRNA-ITS2) and 2 mitochondrial genes, cox1 and nad1, revealed unique features distinct from E. revolutum and also from other 37-collar-spined Echinostoma group available in GenBank (E. bolschewense, E. caproni, E. cinetorchis, E. deserticum, E. miyagawai, E. nasincovae, E. novaezealandense, E. paraensei, E. paraulum, E. robustum, E. trivolvis, and Echinostoma sp. IG). Thus, we assigned our flukes as a new species, E. mekongi. The new species revealed marked variation in the morphology of testes (globular or lobulated), and smaller head collar, collar spines, oral and ventral suckers, and cirrus sac compared to E. revolutum and E. miyagawai. Epidemiological studies regarding the geographical distribution and its life history, including the source of human infections, remain to be performed.
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Taxonomy of Echinostoma revolutum and 37-Collar-Spined Echinostoma spp.: A Historical Review.
The Korean Journal of Parasitology, 2020Co-Authors: Jong-yil Chai, Jaeeun Cho, Bong-kwang Jung, Taehee Chang, Woon-mok SohnAbstract:Echinostoma flukes armed with 37 collar spines on their head collar are called as 37-collar-spined Echinostoma spp. (group) or 'Echinostoma revolutum group'. At least 56 nominal species have been described in this group. However, many of them were morphologically close to and difficult to distinguish from the other, thus synonymized with the others. However, some of the synonymies were disagreed by other researchers, and taxonomic debates have been continued. Fortunately, recent development of molecular techniques, in particular, sequencing of the mitochondrial (nad1 and cox1) and nuclear genes (ITS region; ITS1-5.8S-ITS2), has enabled us to obtain highly useful data on phylogenetic relationships of these 37-collar-spined Echinostoma spp. Thus, 16 different species are currently acknowledged to be valid worldwide, which include E. revolutum, E. bolschewense, E. caproni, E. cinetorchis, E. deserticum, E. lindoense, E. luisreyi, E. mekongi, E. miyagawai, E. nasincovae, E. novaezealandense, E. paraensei, E. paraulum, E. robustum, E. trivolvis, and Echinostoma sp. IG of Georgieva et al., 2013. The validity of the other 10 species is retained until further evaluation, including molecular analyses; E. acuticauda, E. barbosai, E. chloephagae, E. echinatum, E. jurini, E. nudicaudatum, E. parvocirrus, E. pinnicaudatum, E. ralli, and E. rodriguesi. In this review, the history of discovery and taxonomic debates on these 26 valid or validity-retained species are briefly reviewed.
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Echinostoma aegyptica trematoda Echinostomatidae infection in five riparian people in savannakhet province lao pdr
Korean Journal of Parasitology, 2020Co-Authors: Jong-yil Chai, Bounlay Phammasack, Woon-mok Sohn, Tai-soon Yong, Keeseon S. Eom, Bong-kwang Jung, Taehee Chang, Hyejoo Shin, Duk Young Min, Bounnaloth InsisiengmayAbstract:Human infection with Echinostoma aegyptica Khalil and Abaza, 1924 (Trematoda: Echinostomatidae) is extremely rare. In this study, we confirmed E. aegyptica infection in 5 riparian residents living along the Mekong River in Savannakhet Province, Lao PDR. The patients revealed eggs of Opisthorchis viverrini/minute intestinal flukes, echinostomes, and other parasites in fecal examinations using the Kato-Katz technique. Following treatment with praziquantel 30-40 mg/kg and pyrantel pamoate 10-15 mg/kg in a single dose and purging with magnesium salts, adult specimens of various helminth species were collected. Among the trematodes, echinostome flukes of 4.5-7.6 mm in length (n = 134; av. 22.3 specimens per case) were of taxonomic interest and subjected in this study. The flukes were morphologically characterized by having total 43-45 collar spines arranged in 2 alternating rows (corner spines usually 5 on each side) and compatible with previous descriptions of E. aegyptica. The patients were mixed-infected with other helminths, so specific clinical manifestations due to this echinostome fluke were difficult to determine. The present paper describes for the first time human E. aegyptica infections in Lao PDR. This is the second report of human infection (2nd-6th cases) with E. aegyptica in the world following the first one from China.
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Echinostoma macrorchis metacercariae in cipangopaludina chinensis malleata from xiengkhuang province lao pdr and morphologies of adults from experimental animals
Korean Journal of Parasitology, 2019Co-Authors: Woon-mok Sohn, Tai-soon Yong, Jong-yil Chai, Keeseon S. Eom, Dongmin Lee, Duk Young MinAbstract:We identified the echinostome metacercariae in Chinese mystery snails, Cipangopaludina chinensis malleata, from Xiengkhuang Province, Lao PDR with morphologies of adult worms recovered. Total 20 snails were examined with artificial digestion method and then the collected metacercariae were orally infected to a mouse and a rat. Adult worms recovered from experimental animals were observed with a light microscope and a SEM. The metacercariae were round, 125×123 µm in average size, with a moderately thick cyst wall, collar spines distributed in the head collar and excretory granules in 2 canals of excretory tube. Adult flukes (3-week-old in a rat) were elongated, ventrally curved and 5.310×1.023 mm in average size. Head collar distinct, bearing 43 collar spines with 5 end group ones on each side. Oral sucker subterminal, prepharynx very short, pharynx well developed, and esophagus relatively short. Cirrus sac well developed, with a saccular seminal vesicle, and ventral sucker very large. Ovary round and on the median line of the body. Testes tandom and elongated. Eggs operculated, elliptical and 90×57 µm in average size. In the SEM observation, the head crown prominent, with 43 collar spines resembled with horns of younger stag. Scale-like tegumental spines were densely distributed on the surface between the head collar and ventral sucker, and their densities were decreased posteriorly. Conclusively, the metacercariae detected in C. chinensis malleata from Lao PDR were identified as those of Echinostoma macrorchis based on the morphological characteristics of adult worms.
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Echinostoma ilocanum Infection in Two Residents of Savannakhet Province, Lao PDR.
Korean Journal of Parasitology, 2018Co-Authors: Jong-yil Chai, Bounlay Phommasack, Eui Hyug Hoang, Woon-mok Sohn, Tai-soon Yong, Bounnaloth InsisiengmayAbstract:: Adult specimens of Echinostoma ilocanum (Garrison, 1908) Odhner, 1911 (Trematoda: Echinostomatidae) were recovered from 2 riparian people who resided along the Mekong River in Savannakhet Province, Lao PDR. In fecal examinations done by the Kato-Katz technique, they revealed echinostome eggs together with eggs of Opisthorchis viverrini (and minute intestinal fluke eggs) and hookworms. To recover the adult flukes, they were treated with praziquantel 30-40 mg/kg in a single dose and purged with magnesium salts. A total of 658 adult fluke specimens were recovered from the 2 people; 456 from case 1 and 202 from case 2. Specimens from case 1 consisted of 335 echinostomes (301 E. ilocanum and 34 species undetermined), 120 O. viverrini, and 1 Haplorchis taichui, and those from case 2 consisted of 36 E. ilocanum, 134 O. viverrini, and 32 H. taichui. Thus, the number of E. ilocanum specimens was 337 in total (average per person, 168.5). From this study, it is suggested that foodborne intestinal flukes and liver flukes are highly prevalent along the Mekong River in Savannakhet Province. The present report describes for the first time human infections with E. ilocanum in Lao PDR.
