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Yukifumi Nawa - One of the best experts on this subject based on the ideXlab platform.
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First intermediate hosts of Paragonimus spp. in Vietnam and identification of intramolluscan stages of different Paragonimus species
Parasites & vectors, 2018Co-Authors: Pham Ngoc Doanh, David Blair, Hoang Van Hien, Nguyen Van Duc, Yoichiro Horii, Yukifumi NawaAbstract:Members of the genus Paragonimus require at least three hosts in their life-cycles. The obligatory first intermediate hosts are freshwater snails. In Vietnam, although seven Paragonimus species have been recorded, the natural first intermediate hosts of almost all species have not been confirmed. The aim of this study was, therefore, to investigate snail hosts of Paragonimus species in Vietnam, and to identify Paragonimus species at intramolluscan stages. Freshwater snails were collected from streams in Yen Bai and Quang Tri Provinces, where high prevalences of Paragonimus metacercariae in crab hosts have been reported. Snails were morphologically identified and then examined individually for Paragonimus cercariae using shedding and crushing methods. Chaetomicrocercous cercariae, the morphological class to which Paragonimus cercariae belong, were collected for morphological description and molecular species identification by analyses of ITS2 sequences. The infected snail species were identified based on analyses of nucleotide sequences of the cox1 gene. Three snail species were found to be infected with Paragonimus cercariae at low infection rates, ranging between 0.07–1.0%. The molecular analyses identified them as Sulcospira quangtriensis and 2 species of subfamily Triculinae. In a phylogenetic tree, these two triculine snails were related to the genera Gammatricula and Tricula with low posterior probabilities. Thus we named them as Triculinae sp. 1 and Triculinae sp. 2. Cercariae from the three snail species, Sulcospira quangtriensis, Triculinae sp. 1 and Triculinae sp. 2, were molecularly identified as Paragonimus westermani, P. heterotremus and P. proliferus, respectively. The cercariae of the three species are morphologically similar to each other, but their daughter rediae can be distinguished by the length of the intestine and the number of cercariae per redia. The rediae of P. westermani have a long intestine and each contain 6–8 cercariae. In contrast, those of P. heterotremus and P. proliferus have a short intestine and each redia contain 10–12 and 5–6 cercariae, respectively. Three snail species, Sulcospira quangtriensis, Triculinae sp. 1 and Triculinae sp. 2, serve as the first intermediate hosts of P. westermani, P. heterotremus and P. proliferus, respectively, in Vietnam. The length of the intestine of rediae and the number of cercariae per redia are valuable characteristics for distinguishing between larvae of these Paragonimus species.
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First intermediate hosts of Paragonimus spp. in Vietnam and identification of intramolluscan stages of different Paragonimus species
BMC, 2018Co-Authors: Pham Ngoc Doanh, David Blair, Hoang Van Hien, Nguyen Van Duc, Yoichiro Horii, Yukifumi NawaAbstract:Abstract Background Members of the genus Paragonimus require at least three hosts in their life-cycles. The obligatory first intermediate hosts are freshwater snails. In Vietnam, although seven Paragonimus species have been recorded, the natural first intermediate hosts of almost all species have not been confirmed. The aim of this study was, therefore, to investigate snail hosts of Paragonimus species in Vietnam, and to identify Paragonimus species at intramolluscan stages. Methods Freshwater snails were collected from streams in Yen Bai and Quang Tri Provinces, where high prevalences of Paragonimus metacercariae in crab hosts have been reported. Snails were morphologically identified and then examined individually for Paragonimus cercariae using shedding and crushing methods. Chaetomicrocercous cercariae, the morphological class to which Paragonimus cercariae belong, were collected for morphological description and molecular species identification by analyses of ITS2 sequences. The infected snail species were identified based on analyses of nucleotide sequences of the cox1 gene. Results Three snail species were found to be infected with Paragonimus cercariae at low infection rates, ranging between 0.07–1.0%. The molecular analyses identified them as Sulcospira quangtriensis and 2 species of subfamily Triculinae. In a phylogenetic tree, these two triculine snails were related to the genera Gammatricula and Tricula with low posterior probabilities. Thus we named them as Triculinae sp. 1 and Triculinae sp. 2. Cercariae from the three snail species, Sulcospira quangtriensis, Triculinae sp. 1 and Triculinae sp. 2, were molecularly identified as Paragonimus westermani, P. heterotremus and P. proliferus, respectively. The cercariae of the three species are morphologically similar to each other, but their daughter rediae can be distinguished by the length of the intestine and the number of cercariae per redia. The rediae of P. westermani have a long intestine and each contain 6–8 cercariae. In contrast, those of P. heterotremus and P. proliferus have a short intestine and each redia contain 10–12 and 5–6 cercariae, respectively. Conclusions Three snail species, Sulcospira quangtriensis, Triculinae sp. 1 and Triculinae sp. 2, serve as the first intermediate hosts of P. westermani, P. heterotremus and P. proliferus, respectively, in Vietnam. The length of the intestine of rediae and the number of cercariae per redia are valuable characteristics for distinguishing between larvae of these Paragonimus species
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Paragonimus westermani and Paragonimus species
2014Co-Authors: Yukifumi Nawa, Ngoc P Doanh, Urusa Thaenkham, David BlairAbstract:Paragonimiasis is a zoonotic food-borne lung disease caused by lung flukes of the genus Paragonimus and acquired by consumption of raw/undercooked freshwater crabs/crayfish or wild boar meat. Paragonimus westermani is the best known species to infect humans in Asia, but several other species of human pathogens are also present. Molecular phylogenetic analyses assign most Asian Paragonimus species into four species complexes with some correlation to human pathogenesis. Paragonimus species exploit a range of mammalian definitive hosts and, as intermediate hosts, freshwater snails and crustaceans, eradication of which is not feasible. Avoidance of consumption of raw/undercooked foods and early diagnosis/treatment are recommended for the control of this disease.
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helminth trematode Paragonimus westermani and Paragonimus species
Reference Module in Food Science#R##N#Encyclopedia of Food Safety, 2014Co-Authors: Yukifumi Nawa, Ngoc P Doanh, Urusa Thaenkham, David BlairAbstract:Paragonimiasis is a zoonotic food-borne lung disease caused by lung flukes of the genus Paragonimus and acquired by consumption of raw/undercooked freshwater crabs/crayfish or wild boar meat. Paragonimus westermani is the best known species to infect humans in Asia, but several other species of human pathogens are also present. Molecular phylogenetic analyses assign most Asian Paragonimus species into four species complexes with some correlation to human pathogenesis. Paragonimus species exploit a range of mammalian definitive hosts and, as intermediate hosts, freshwater snails and crustaceans, eradication of which is not feasible. Avoidance of consumption of raw/undercooked foods and early diagnosis/treatment are recommended for the control of this disease.
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Paragonimus and Paragonimiasis in Vietnam: an Update
The Korean journal of parasitology, 2013Co-Authors: Pham Ngoc Doanh, Yoichiro Horii, Yukifumi NawaAbstract:Paragonimiasis is a food-borne parasitic zoonosis caused by infection with lung flukes of the genus Paragonimus. In Vietnam, research on Paragonimus and paragonimiasis has been conducted in northern and central regions of the country. Using a combination of morphological and molecular methods, 7 Paragonimus species, namely P. heterotremus, P. westermani, P. skrjabini, P. vietnamensis, P. proliferus, P. bangkokenis and P. harinasutai, have been identified in Vietnam. Of these, the first 3, P. heterotremus, P. westermani and P. skrjabini, are known to infect humans in other countries. However, in Vietnam, only P. heterotremus, found in some northern provinces, has been shown to infect humans. Even nowadays, local people in some northern provinces, such as Lai Chau and Yen Bai, are still suffering from P. heterotremus infection. In some provinces of central Vietnam, the prevalence and infection intensity of P. westermani metacercariae in freshwater crabs (the second intermediate hosts) are extremely high, but human cases have not been reported. Likewise, although P. skrjabini was found in Thanh Hoa Province, its pathogenicity to humans in Vietnam still remains uncertain. The results of molecular phylogenetic analyses of Vietnamese Paragonimus species provides new insights on the phylogeny and taxonomy of the genus Paragonimus. Comprehensive molecular epidemiological and geobiological studies on the genus in Vietnam and adjacent countries are needed to clarify the biodiversity and public health significance of the lung flukes.
Pham Ngoc Doanh - One of the best experts on this subject based on the ideXlab platform.
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Comparative genomics and transcriptomics of 4 Paragonimus species provide insights into lung fluke parasitism and pathogenesis.
GigaScience, 2020Co-Authors: Bruce A Rosa, Samantha N Mcnulty, Young Jun Choi, Hyeim Jung, John Martin, Takeshi Agatsuma, Hiromu Sugiyama, Pham Ngoc Doanh, Wanchai MaleewongAbstract:Background Paragonimus spp. (lung flukes) are among the most injurious foodborne helminths, infecting ∼23 million people and subjecting ∼292 million to infection risk. Paragonimiasis is acquired from infected undercooked crustaceans and primarily affects the lungs but often causes lesions elsewhere including the brain. The disease is easily mistaken for tuberculosis owing to similar pulmonary symptoms, and accordingly, diagnostics are in demand. Results We assembled, annotated, and compared draft genomes of 4 prevalent and distinct Paragonimus species: Paragonimus miyazakii, Paragonimus westermani, Paragonimus kellicotti, and Paragonimus heterotremus. Genomes ranged from 697 to 923 Mb, included 12,072-12,853 genes, and were 71.6-90.1% complete according to BUSCO. Orthologous group analysis spanning 21 species (lung, liver, and blood flukes, additional platyhelminths, and hosts) provided insights into lung fluke biology. We identified 256 lung fluke-specific and conserved orthologous groups with consistent transcriptional adult-stage Paragonimus expression profiles and enriched for iron acquisition, immune modulation, and other parasite functions. Previously identified Paragonimus diagnostic antigens were matched to genes, providing an opportunity to optimize and ensure pan-Paragonimus reactivity for diagnostic assays. Conclusions This report provides advances in molecular understanding of Paragonimus and underpins future studies into the biology, evolution, and pathogenesis of Paragonimus and related foodborne flukes. We anticipate that these novel genomic and transcriptomic resources will be invaluable for future lung fluke research.
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First intermediate hosts of Paragonimus spp. in Vietnam and identification of intramolluscan stages of different Paragonimus species
Parasites & vectors, 2018Co-Authors: Pham Ngoc Doanh, David Blair, Hoang Van Hien, Nguyen Van Duc, Yoichiro Horii, Yukifumi NawaAbstract:Members of the genus Paragonimus require at least three hosts in their life-cycles. The obligatory first intermediate hosts are freshwater snails. In Vietnam, although seven Paragonimus species have been recorded, the natural first intermediate hosts of almost all species have not been confirmed. The aim of this study was, therefore, to investigate snail hosts of Paragonimus species in Vietnam, and to identify Paragonimus species at intramolluscan stages. Freshwater snails were collected from streams in Yen Bai and Quang Tri Provinces, where high prevalences of Paragonimus metacercariae in crab hosts have been reported. Snails were morphologically identified and then examined individually for Paragonimus cercariae using shedding and crushing methods. Chaetomicrocercous cercariae, the morphological class to which Paragonimus cercariae belong, were collected for morphological description and molecular species identification by analyses of ITS2 sequences. The infected snail species were identified based on analyses of nucleotide sequences of the cox1 gene. Three snail species were found to be infected with Paragonimus cercariae at low infection rates, ranging between 0.07–1.0%. The molecular analyses identified them as Sulcospira quangtriensis and 2 species of subfamily Triculinae. In a phylogenetic tree, these two triculine snails were related to the genera Gammatricula and Tricula with low posterior probabilities. Thus we named them as Triculinae sp. 1 and Triculinae sp. 2. Cercariae from the three snail species, Sulcospira quangtriensis, Triculinae sp. 1 and Triculinae sp. 2, were molecularly identified as Paragonimus westermani, P. heterotremus and P. proliferus, respectively. The cercariae of the three species are morphologically similar to each other, but their daughter rediae can be distinguished by the length of the intestine and the number of cercariae per redia. The rediae of P. westermani have a long intestine and each contain 6–8 cercariae. In contrast, those of P. heterotremus and P. proliferus have a short intestine and each redia contain 10–12 and 5–6 cercariae, respectively. Three snail species, Sulcospira quangtriensis, Triculinae sp. 1 and Triculinae sp. 2, serve as the first intermediate hosts of P. westermani, P. heterotremus and P. proliferus, respectively, in Vietnam. The length of the intestine of rediae and the number of cercariae per redia are valuable characteristics for distinguishing between larvae of these Paragonimus species.
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First intermediate hosts of Paragonimus spp. in Vietnam and identification of intramolluscan stages of different Paragonimus species
BMC, 2018Co-Authors: Pham Ngoc Doanh, David Blair, Hoang Van Hien, Nguyen Van Duc, Yoichiro Horii, Yukifumi NawaAbstract:Abstract Background Members of the genus Paragonimus require at least three hosts in their life-cycles. The obligatory first intermediate hosts are freshwater snails. In Vietnam, although seven Paragonimus species have been recorded, the natural first intermediate hosts of almost all species have not been confirmed. The aim of this study was, therefore, to investigate snail hosts of Paragonimus species in Vietnam, and to identify Paragonimus species at intramolluscan stages. Methods Freshwater snails were collected from streams in Yen Bai and Quang Tri Provinces, where high prevalences of Paragonimus metacercariae in crab hosts have been reported. Snails were morphologically identified and then examined individually for Paragonimus cercariae using shedding and crushing methods. Chaetomicrocercous cercariae, the morphological class to which Paragonimus cercariae belong, were collected for morphological description and molecular species identification by analyses of ITS2 sequences. The infected snail species were identified based on analyses of nucleotide sequences of the cox1 gene. Results Three snail species were found to be infected with Paragonimus cercariae at low infection rates, ranging between 0.07–1.0%. The molecular analyses identified them as Sulcospira quangtriensis and 2 species of subfamily Triculinae. In a phylogenetic tree, these two triculine snails were related to the genera Gammatricula and Tricula with low posterior probabilities. Thus we named them as Triculinae sp. 1 and Triculinae sp. 2. Cercariae from the three snail species, Sulcospira quangtriensis, Triculinae sp. 1 and Triculinae sp. 2, were molecularly identified as Paragonimus westermani, P. heterotremus and P. proliferus, respectively. The cercariae of the three species are morphologically similar to each other, but their daughter rediae can be distinguished by the length of the intestine and the number of cercariae per redia. The rediae of P. westermani have a long intestine and each contain 6–8 cercariae. In contrast, those of P. heterotremus and P. proliferus have a short intestine and each redia contain 10–12 and 5–6 cercariae, respectively. Conclusions Three snail species, Sulcospira quangtriensis, Triculinae sp. 1 and Triculinae sp. 2, serve as the first intermediate hosts of P. westermani, P. heterotremus and P. proliferus, respectively, in Vietnam. The length of the intestine of rediae and the number of cercariae per redia are valuable characteristics for distinguishing between larvae of these Paragonimus species
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Paragonimus and Paragonimiasis in Vietnam: an Update
The Korean journal of parasitology, 2013Co-Authors: Pham Ngoc Doanh, Yoichiro Horii, Yukifumi NawaAbstract:Paragonimiasis is a food-borne parasitic zoonosis caused by infection with lung flukes of the genus Paragonimus. In Vietnam, research on Paragonimus and paragonimiasis has been conducted in northern and central regions of the country. Using a combination of morphological and molecular methods, 7 Paragonimus species, namely P. heterotremus, P. westermani, P. skrjabini, P. vietnamensis, P. proliferus, P. bangkokenis and P. harinasutai, have been identified in Vietnam. Of these, the first 3, P. heterotremus, P. westermani and P. skrjabini, are known to infect humans in other countries. However, in Vietnam, only P. heterotremus, found in some northern provinces, has been shown to infect humans. Even nowadays, local people in some northern provinces, such as Lai Chau and Yen Bai, are still suffering from P. heterotremus infection. In some provinces of central Vietnam, the prevalence and infection intensity of P. westermani metacercariae in freshwater crabs (the second intermediate hosts) are extremely high, but human cases have not been reported. Likewise, although P. skrjabini was found in Thanh Hoa Province, its pathogenicity to humans in Vietnam still remains uncertain. The results of molecular phylogenetic analyses of Vietnamese Paragonimus species provides new insights on the phylogeny and taxonomy of the genus Paragonimus. Comprehensive molecular epidemiological and geobiological studies on the genus in Vietnam and adjacent countries are needed to clarify the biodiversity and public health significance of the lung flukes.
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Natural hybridization between Paragonimus bangkokensis and Paragonimus harinasutai.
Parasitology international, 2013Co-Authors: Pham Ngoc Doanh, Yoichiro Horii, Nariaki Nonaka, Zhihong Guo, Yukifumi NawaAbstract:Paragonimus bangkokensis and Paragonimus harinasutai, which are morphologically distinguishable species, often co-infect in the same crab intermediate hosts. Recent molecular phylogenetic analyses revealed that these two species are genetically close to each other and are considered as the sister species. While we have been studying Paragonimus adult worms obtained from the lungs of a cat experimentally infected with Paragonimus metacercariae which were morphologically identified as P. harinasutai collected from central Viet Nam, one out of 6 adult worms has grouped cuticular spines, which is a feature of P. bangkokensis. By molecular analyses, the CO1 sequence of this specimen was identical with that of P. bangkokensis, but the ITS2 and the D2 region of 28S rDNA sequences showed a two peak pattern. Then, PCR products of the ITS2 and the D2 region of 28S rDNA sequences were ligated to TOPO vector and subcloned to determine the heterozygosity. Two types of sequences were obtained from each ITS2 and D2 region of 28S; one was identical with P. harinasutai and the other with P. bangkokensis. Taking all these morphological and molecular data together, we identified this adult worm as a hybrid specimen of P. bangkokensis and P. harinasutai.
Wanchai Maleewong - One of the best experts on this subject based on the ideXlab platform.
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Comparative genomics and transcriptomics of 4 Paragonimus species provide insights into lung fluke parasitism and pathogenesis.
GigaScience, 2020Co-Authors: Bruce A Rosa, Samantha N Mcnulty, Young Jun Choi, Hyeim Jung, John Martin, Takeshi Agatsuma, Hiromu Sugiyama, Pham Ngoc Doanh, Wanchai MaleewongAbstract:Background Paragonimus spp. (lung flukes) are among the most injurious foodborne helminths, infecting ∼23 million people and subjecting ∼292 million to infection risk. Paragonimiasis is acquired from infected undercooked crustaceans and primarily affects the lungs but often causes lesions elsewhere including the brain. The disease is easily mistaken for tuberculosis owing to similar pulmonary symptoms, and accordingly, diagnostics are in demand. Results We assembled, annotated, and compared draft genomes of 4 prevalent and distinct Paragonimus species: Paragonimus miyazakii, Paragonimus westermani, Paragonimus kellicotti, and Paragonimus heterotremus. Genomes ranged from 697 to 923 Mb, included 12,072-12,853 genes, and were 71.6-90.1% complete according to BUSCO. Orthologous group analysis spanning 21 species (lung, liver, and blood flukes, additional platyhelminths, and hosts) provided insights into lung fluke biology. We identified 256 lung fluke-specific and conserved orthologous groups with consistent transcriptional adult-stage Paragonimus expression profiles and enriched for iron acquisition, immune modulation, and other parasite functions. Previously identified Paragonimus diagnostic antigens were matched to genes, providing an opportunity to optimize and ensure pan-Paragonimus reactivity for diagnostic assays. Conclusions This report provides advances in molecular understanding of Paragonimus and underpins future studies into the biology, evolution, and pathogenesis of Paragonimus and related foodborne flukes. We anticipate that these novel genomic and transcriptomic resources will be invaluable for future lung fluke research.
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Evaluation of IgG4 Subclass Antibody Detection by Peptide-Based ELISA for the Diagnosis of Human
2016Co-Authors: Paragonimiasis Heterotrema, Yoon Kong, Pewpan M. Intapan, Penchom Janwan, Oranuch Sanpool, Porntip Laummaunwai, Nimit Morakote, Wanchai MaleewongAbstract:The lung flukes, Paragonimus species, cause paragonimiasis in humans and animals [1-3]. It is estimated that over 20 mil-lion people are infected worldwide [4] and approximately 292.8 million people are at risk of infection [5]. While Paragonimus westermani is the most important human pathogen in China, Korea, and Japan [1-3,6], Paragonimus heterotremus is the main etiological agent of human paragonimiasis in southern China, Southeast Asia (including Thailand and Vietnam), and India [1-3]. Diagnosis of paragonimiasis relies on demonstration of Par-agonimus eggs in the feces, sputum, or both [3]. However, mi-croscopic detection of Paragonimus eggs is not very sensitive because of irregular egg production and difficulties of process-ing sputum and fecal specimens and requirement for experi-enced microscopists. Furthermore, eggs are not detectable i
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Molecular identification of Paragonimus species by DNA pyrosequencing technology.
Parasitology international, 2012Co-Authors: Chairat Tantrawatpan, Pewpan M. Intapan, Penchom Janwan, Oranuch Sanpool, Viraphong Lulitanond, Chutatip Srichantaratsamee, Witthaya Anamnart, Wanchai MaleewongAbstract:DNA pyrosequencing for PCR amplicons is an attractive strategy for the identification of microorganisms because of its short time performance for large number of samples. In this study, the primers targeting the fragment of ITS2 region of nuclear ribosomal RNA gene were newly developed for pyrosequencing-based identification of 6 Paragonimus species, Paragonimus bangkokensis, Paragonimus harinasutai, Paragonimus heterotremus, Paragonimus macrorchis, Paragonimus siamensis and Paragonimus westermani. Pyrosequencing determination of 39 nucleotides of partial ITS2 region could discriminate 6 Paragonimus species, and could also detect intra-species genetic variation of P. macrorchis. This DNA pyrosequencing-based identification can be a valuable tool to improve species-level identification of Paragonimus in the endemic areas.
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Molecular identification of a case of Paragonimus pseudoheterotremus infection in Thailand.
The American journal of tropical medicine and hygiene, 2012Co-Authors: Pewpan M. Intapan, Yukifumi Nawa, Oranuch Sanpool, Kanokwan Imtawil, Tongjit Thanchomnang, Chatlert Pongchaiyakul, Wanchai MaleewongAbstract:Paragonimiasis is an important food-borne parasitic zoonosis caused by infection with lung flukes of the genus Paragonimus. In Southeast Asia, Paragonimus heterotremus is the only proven causative pathogen. Recently, a new Paragonimus species, P. pseudoheterotremus, was found in Thailand. This species is genetically similar to P. heterotremus and is considered as a sister species. However, infectivity or pathogenicity of P. pseudoheterotremus to humans remains unclear. We report the first confirmed human pulmonary paragonimiasis case caused by P. pseudoheterotremus infection. After polymerase chain reaction/sequencing of the DNA extracted from Paragonimus eggs in the sputum of the patient, partial internal transcribed spacer 2 and cytochrome c oxidase subunit 1 sequences were approximately identical (98–100%) with those of P. pseudoheterotremus. For P. heterotremus, the partial internal transcribed spacer 2 sequence was approximately identical (99–100%), but the partial mitochondrial cytochrome c oxidase subunit 1 sequence showed a similarity of 90–95%.
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Short Report: Molecular Identification of a Case of Paragonimus pseudoheterotremus Infection in Thailand
2012Co-Authors: Pewpan M. Intapan, Yukifumi Nawa, Oranuch Sanpool, Kanokwan Imtawil, Wanchai MaleewongAbstract:Paragonimiasis is an important food-borne parasitic zoonosis caused by infection with lung flukes of the genus Paragonimus. In Southeast Asia, Paragonimus heterotremus is the only proven causative pathogen. Recently, a new Paragonimus species, P. pseudoheterotremus, was found in Thailand. This species is genetically similar to P. heterotremus and is considered as a sister species. However, infectivity or pathogenicity of P. pseudoheterotremus to humans remains unclear. We report the first confirmed human pulmonary paragonimiasis case caused by P. pseudo- heterotremus infection. After polymerase chain reaction/sequencing of the DNA extracted from Paragonimus eggs in the sputum of the patient, partial internal transcribed spacer 2 and cytochrome c oxidase subunit 1 sequences were approx- imately identical (98-100%) with those of P. pseudoheterotremus. For P. heterotremus, the partial internal transcribed spacer 2 sequence was approximately identical (99-100%), but the partial mitochondrial cytochrome c oxidase subunit 1 sequence showed a similarity of 90-95%. Paragonimiasis is a food-borne zoonosis caused by infection with lung flukes of the genus Paragonimus .O nly 7o f approxi- mately 40 species can infect humans: 2 species (Paragonimus kelikotti and P. mexicanus) in the Western Hemisphere, 2( P. africanus and P. uterobilateralis )i n Africa, and 3( P. westeremani, P. skrjabini ,a ndP. heterotremus )i n Asia. 1-3
Yoichiro Horii - One of the best experts on this subject based on the ideXlab platform.
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First intermediate hosts of Paragonimus spp. in Vietnam and identification of intramolluscan stages of different Paragonimus species
Parasites & vectors, 2018Co-Authors: Pham Ngoc Doanh, David Blair, Hoang Van Hien, Nguyen Van Duc, Yoichiro Horii, Yukifumi NawaAbstract:Members of the genus Paragonimus require at least three hosts in their life-cycles. The obligatory first intermediate hosts are freshwater snails. In Vietnam, although seven Paragonimus species have been recorded, the natural first intermediate hosts of almost all species have not been confirmed. The aim of this study was, therefore, to investigate snail hosts of Paragonimus species in Vietnam, and to identify Paragonimus species at intramolluscan stages. Freshwater snails were collected from streams in Yen Bai and Quang Tri Provinces, where high prevalences of Paragonimus metacercariae in crab hosts have been reported. Snails were morphologically identified and then examined individually for Paragonimus cercariae using shedding and crushing methods. Chaetomicrocercous cercariae, the morphological class to which Paragonimus cercariae belong, were collected for morphological description and molecular species identification by analyses of ITS2 sequences. The infected snail species were identified based on analyses of nucleotide sequences of the cox1 gene. Three snail species were found to be infected with Paragonimus cercariae at low infection rates, ranging between 0.07–1.0%. The molecular analyses identified them as Sulcospira quangtriensis and 2 species of subfamily Triculinae. In a phylogenetic tree, these two triculine snails were related to the genera Gammatricula and Tricula with low posterior probabilities. Thus we named them as Triculinae sp. 1 and Triculinae sp. 2. Cercariae from the three snail species, Sulcospira quangtriensis, Triculinae sp. 1 and Triculinae sp. 2, were molecularly identified as Paragonimus westermani, P. heterotremus and P. proliferus, respectively. The cercariae of the three species are morphologically similar to each other, but their daughter rediae can be distinguished by the length of the intestine and the number of cercariae per redia. The rediae of P. westermani have a long intestine and each contain 6–8 cercariae. In contrast, those of P. heterotremus and P. proliferus have a short intestine and each redia contain 10–12 and 5–6 cercariae, respectively. Three snail species, Sulcospira quangtriensis, Triculinae sp. 1 and Triculinae sp. 2, serve as the first intermediate hosts of P. westermani, P. heterotremus and P. proliferus, respectively, in Vietnam. The length of the intestine of rediae and the number of cercariae per redia are valuable characteristics for distinguishing between larvae of these Paragonimus species.
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First intermediate hosts of Paragonimus spp. in Vietnam and identification of intramolluscan stages of different Paragonimus species
BMC, 2018Co-Authors: Pham Ngoc Doanh, David Blair, Hoang Van Hien, Nguyen Van Duc, Yoichiro Horii, Yukifumi NawaAbstract:Abstract Background Members of the genus Paragonimus require at least three hosts in their life-cycles. The obligatory first intermediate hosts are freshwater snails. In Vietnam, although seven Paragonimus species have been recorded, the natural first intermediate hosts of almost all species have not been confirmed. The aim of this study was, therefore, to investigate snail hosts of Paragonimus species in Vietnam, and to identify Paragonimus species at intramolluscan stages. Methods Freshwater snails were collected from streams in Yen Bai and Quang Tri Provinces, where high prevalences of Paragonimus metacercariae in crab hosts have been reported. Snails were morphologically identified and then examined individually for Paragonimus cercariae using shedding and crushing methods. Chaetomicrocercous cercariae, the morphological class to which Paragonimus cercariae belong, were collected for morphological description and molecular species identification by analyses of ITS2 sequences. The infected snail species were identified based on analyses of nucleotide sequences of the cox1 gene. Results Three snail species were found to be infected with Paragonimus cercariae at low infection rates, ranging between 0.07–1.0%. The molecular analyses identified them as Sulcospira quangtriensis and 2 species of subfamily Triculinae. In a phylogenetic tree, these two triculine snails were related to the genera Gammatricula and Tricula with low posterior probabilities. Thus we named them as Triculinae sp. 1 and Triculinae sp. 2. Cercariae from the three snail species, Sulcospira quangtriensis, Triculinae sp. 1 and Triculinae sp. 2, were molecularly identified as Paragonimus westermani, P. heterotremus and P. proliferus, respectively. The cercariae of the three species are morphologically similar to each other, but their daughter rediae can be distinguished by the length of the intestine and the number of cercariae per redia. The rediae of P. westermani have a long intestine and each contain 6–8 cercariae. In contrast, those of P. heterotremus and P. proliferus have a short intestine and each redia contain 10–12 and 5–6 cercariae, respectively. Conclusions Three snail species, Sulcospira quangtriensis, Triculinae sp. 1 and Triculinae sp. 2, serve as the first intermediate hosts of P. westermani, P. heterotremus and P. proliferus, respectively, in Vietnam. The length of the intestine of rediae and the number of cercariae per redia are valuable characteristics for distinguishing between larvae of these Paragonimus species
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Evaluation of the MGL method to detect Paragonimus eggs and its improvement
Parasitology Research, 2015Co-Authors: Takao Irie, Yoichiro Horii, Yohei Yamaguchi, Asako Sumen, Shigehisa Habe, Nariaki NonakaAbstract:Dog feces containing 500 Paragonimus westermani eggs per gram were examined by the Medical General Laboratory (MGL), the simple sedimentation (SS), and the Army Medical School III (AMS III) methods. The number of eggs per gram of feces (EPG) obtained by the MGL method was 17.2 and was significantly lower than those obtained by the SS method (324.0) and the AMS III method (505.6). When isolated P. westermani eggs were processed by the MGL method and four layers (ether, ether-fecal, formalin layers, and sediment) of the final centrifugation product were separately examined, almost 100 % of eggs were found at the ether-fecal layer. Similarly, when fecal samples containing P. westermani , Paragonimus skrjabini miyazakii , Paragonimus ohirai , or Paragonimus harinasutai eggs were processed by the MGL method, more than 95 % of the eggs were found in the supernatant layers. The formalin-ethyl acetate (FEA) method showed a similar tendency as the MGL method and over 90 % of eggs remained in the supernatant layers. Contrary to Paragonimus eggs, 63 and 96 % of Clonorchis and Metagonimus eggs were found in the sediment in the MGL method, respectively. When surfactant (Tween 80) was added to fecal solution, most of Paragonimus eggs spun down in the sediment in the MGL and FEA methods, suggesting that Paragonimus eggs have hydrophobic components on their surface. It is suggested that surfactant addition to the fecal solution should be considered when the MGL method is used for detection of Paragonimus eggs.
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Paragonimus and Paragonimiasis in Vietnam: an Update
The Korean journal of parasitology, 2013Co-Authors: Pham Ngoc Doanh, Yoichiro Horii, Yukifumi NawaAbstract:Paragonimiasis is a food-borne parasitic zoonosis caused by infection with lung flukes of the genus Paragonimus. In Vietnam, research on Paragonimus and paragonimiasis has been conducted in northern and central regions of the country. Using a combination of morphological and molecular methods, 7 Paragonimus species, namely P. heterotremus, P. westermani, P. skrjabini, P. vietnamensis, P. proliferus, P. bangkokenis and P. harinasutai, have been identified in Vietnam. Of these, the first 3, P. heterotremus, P. westermani and P. skrjabini, are known to infect humans in other countries. However, in Vietnam, only P. heterotremus, found in some northern provinces, has been shown to infect humans. Even nowadays, local people in some northern provinces, such as Lai Chau and Yen Bai, are still suffering from P. heterotremus infection. In some provinces of central Vietnam, the prevalence and infection intensity of P. westermani metacercariae in freshwater crabs (the second intermediate hosts) are extremely high, but human cases have not been reported. Likewise, although P. skrjabini was found in Thanh Hoa Province, its pathogenicity to humans in Vietnam still remains uncertain. The results of molecular phylogenetic analyses of Vietnamese Paragonimus species provides new insights on the phylogeny and taxonomy of the genus Paragonimus. Comprehensive molecular epidemiological and geobiological studies on the genus in Vietnam and adjacent countries are needed to clarify the biodiversity and public health significance of the lung flukes.
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Natural hybridization between Paragonimus bangkokensis and Paragonimus harinasutai.
Parasitology international, 2013Co-Authors: Pham Ngoc Doanh, Yoichiro Horii, Nariaki Nonaka, Zhihong Guo, Yukifumi NawaAbstract:Paragonimus bangkokensis and Paragonimus harinasutai, which are morphologically distinguishable species, often co-infect in the same crab intermediate hosts. Recent molecular phylogenetic analyses revealed that these two species are genetically close to each other and are considered as the sister species. While we have been studying Paragonimus adult worms obtained from the lungs of a cat experimentally infected with Paragonimus metacercariae which were morphologically identified as P. harinasutai collected from central Viet Nam, one out of 6 adult worms has grouped cuticular spines, which is a feature of P. bangkokensis. By molecular analyses, the CO1 sequence of this specimen was identical with that of P. bangkokensis, but the ITS2 and the D2 region of 28S rDNA sequences showed a two peak pattern. Then, PCR products of the ITS2 and the D2 region of 28S rDNA sequences were ligated to TOPO vector and subcloned to determine the heterozygosity. Two types of sequences were obtained from each ITS2 and D2 region of 28S; one was identical with P. harinasutai and the other with P. bangkokensis. Taking all these morphological and molecular data together, we identified this adult worm as a hybrid specimen of P. bangkokensis and P. harinasutai.
Pewpan M. Intapan - One of the best experts on this subject based on the ideXlab platform.
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Evaluation of IgG4 Subclass Antibody Detection by Peptide-Based ELISA for the Diagnosis of Human
2016Co-Authors: Paragonimiasis Heterotrema, Yoon Kong, Pewpan M. Intapan, Penchom Janwan, Oranuch Sanpool, Porntip Laummaunwai, Nimit Morakote, Wanchai MaleewongAbstract:The lung flukes, Paragonimus species, cause paragonimiasis in humans and animals [1-3]. It is estimated that over 20 mil-lion people are infected worldwide [4] and approximately 292.8 million people are at risk of infection [5]. While Paragonimus westermani is the most important human pathogen in China, Korea, and Japan [1-3,6], Paragonimus heterotremus is the main etiological agent of human paragonimiasis in southern China, Southeast Asia (including Thailand and Vietnam), and India [1-3]. Diagnosis of paragonimiasis relies on demonstration of Par-agonimus eggs in the feces, sputum, or both [3]. However, mi-croscopic detection of Paragonimus eggs is not very sensitive because of irregular egg production and difficulties of process-ing sputum and fecal specimens and requirement for experi-enced microscopists. Furthermore, eggs are not detectable i
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Molecular identification of Paragonimus species by DNA pyrosequencing technology.
Parasitology international, 2012Co-Authors: Chairat Tantrawatpan, Pewpan M. Intapan, Penchom Janwan, Oranuch Sanpool, Viraphong Lulitanond, Chutatip Srichantaratsamee, Witthaya Anamnart, Wanchai MaleewongAbstract:DNA pyrosequencing for PCR amplicons is an attractive strategy for the identification of microorganisms because of its short time performance for large number of samples. In this study, the primers targeting the fragment of ITS2 region of nuclear ribosomal RNA gene were newly developed for pyrosequencing-based identification of 6 Paragonimus species, Paragonimus bangkokensis, Paragonimus harinasutai, Paragonimus heterotremus, Paragonimus macrorchis, Paragonimus siamensis and Paragonimus westermani. Pyrosequencing determination of 39 nucleotides of partial ITS2 region could discriminate 6 Paragonimus species, and could also detect intra-species genetic variation of P. macrorchis. This DNA pyrosequencing-based identification can be a valuable tool to improve species-level identification of Paragonimus in the endemic areas.
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Molecular identification of a case of Paragonimus pseudoheterotremus infection in Thailand.
The American journal of tropical medicine and hygiene, 2012Co-Authors: Pewpan M. Intapan, Yukifumi Nawa, Oranuch Sanpool, Kanokwan Imtawil, Tongjit Thanchomnang, Chatlert Pongchaiyakul, Wanchai MaleewongAbstract:Paragonimiasis is an important food-borne parasitic zoonosis caused by infection with lung flukes of the genus Paragonimus. In Southeast Asia, Paragonimus heterotremus is the only proven causative pathogen. Recently, a new Paragonimus species, P. pseudoheterotremus, was found in Thailand. This species is genetically similar to P. heterotremus and is considered as a sister species. However, infectivity or pathogenicity of P. pseudoheterotremus to humans remains unclear. We report the first confirmed human pulmonary paragonimiasis case caused by P. pseudoheterotremus infection. After polymerase chain reaction/sequencing of the DNA extracted from Paragonimus eggs in the sputum of the patient, partial internal transcribed spacer 2 and cytochrome c oxidase subunit 1 sequences were approximately identical (98–100%) with those of P. pseudoheterotremus. For P. heterotremus, the partial internal transcribed spacer 2 sequence was approximately identical (99–100%), but the partial mitochondrial cytochrome c oxidase subunit 1 sequence showed a similarity of 90–95%.
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Short Report: Molecular Identification of a Case of Paragonimus pseudoheterotremus Infection in Thailand
2012Co-Authors: Pewpan M. Intapan, Yukifumi Nawa, Oranuch Sanpool, Kanokwan Imtawil, Wanchai MaleewongAbstract:Paragonimiasis is an important food-borne parasitic zoonosis caused by infection with lung flukes of the genus Paragonimus. In Southeast Asia, Paragonimus heterotremus is the only proven causative pathogen. Recently, a new Paragonimus species, P. pseudoheterotremus, was found in Thailand. This species is genetically similar to P. heterotremus and is considered as a sister species. However, infectivity or pathogenicity of P. pseudoheterotremus to humans remains unclear. We report the first confirmed human pulmonary paragonimiasis case caused by P. pseudo- heterotremus infection. After polymerase chain reaction/sequencing of the DNA extracted from Paragonimus eggs in the sputum of the patient, partial internal transcribed spacer 2 and cytochrome c oxidase subunit 1 sequences were approx- imately identical (98-100%) with those of P. pseudoheterotremus. For P. heterotremus, the partial internal transcribed spacer 2 sequence was approximately identical (99-100%), but the partial mitochondrial cytochrome c oxidase subunit 1 sequence showed a similarity of 90-95%. Paragonimiasis is a food-borne zoonosis caused by infection with lung flukes of the genus Paragonimus .O nly 7o f approxi- mately 40 species can infect humans: 2 species (Paragonimus kelikotti and P. mexicanus) in the Western Hemisphere, 2( P. africanus and P. uterobilateralis )i n Africa, and 3( P. westeremani, P. skrjabini ,a ndP. heterotremus )i n Asia. 1-3
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detection of Paragonimus heterotremus eggs in experimentally infected cats by a polymerase chain reaction based method
Journal of Parasitology, 2005Co-Authors: Pewpan M. Intapan, Kanokwan Imtawil, Chaisiri Wongkham, Wilawan Pumidonming, Thidarat K Prasongdee, Masanao Miwa, Wanchai MaleewongAbstract:A polymerase chain reaction (PCR) procedure for the detection of Paragonimus heterotremus eggs in stool samples was developed and compared with Stoll's egg count method. The primers were designed on the basis of a previously constructed pPH-13–specific DNA probe, which produced an approximate 0.5-kb amplified product. This PCR method could detect as few as 5 eggs in 0.6 g of artificially inoculated feces of a healthy control cat or as little as 1 × 10−4 ng of P. heterotremus genomic DNA. The assay had 100% sensitivity in all infected cats. The method did not yield an approximate 0.5-kb product with DNA from other parasites such as Gnathostoma spinigerum, Trichinella spiralis, Fasciola gigantica, Echinostoma malayanum, Opisthorchis viverrini, Dirofilaria immitis, and Taenia saginata; exceptions were Paragonimus siamensis and Paragonimus westermani. In addition, no genomic DNA from Escherichia coli, Burkholderia pseudomallei, Acinetobacter anitratus, Mycobacterium tuberculosis, Staphylococcus aureus, β-Stre...
