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Akira Ito - One of the best experts on this subject based on the ideXlab platform.
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new insights on the Taenia solium tapeworm using molecular tools age based human definitive host prevalence and deliberation on parasite life span
Pathogens and Global Health, 2021Co-Authors: Xingwang Chen, Christine M Budke, Yuangui Zhou, Mianchuan Duan, Celine Wang, Bo Zhong, Yang Liu, Jianying Luo, Jingye Shang, Akira ItoAbstract:Information on age-based Taenia solium Taeniasis prevalence is crucial for control of cysticercosis. T. solium Taeniasis prevalence was determined for a village in Liangshan Prefecture, Sichuan Province, China that was co-endemic for T. solium, Taenia saginata asiatica, and Taenia saginata. Individuals who were Taenia egg-positive by stool microscopy and/or expelled tapeworms or proglottids post-treatment were diagnosed as having Taeniasis. Infecting species was identified via multiplex PCR on tapeworm specimens or coproPCR followed by sequencing. In addition, initial stool samples from 10 children with Taeniasis suspected of having spontaneous expulsion of tapeworms within the period between diagnosis and treatment were subject to species confirmation via coproPCR and sequencing. Of the 389 study subjects, 194 (49.9%) were diagnosed with Taeniasis. Children (< 16 years of age) had a higher T. solium Taeniasis prevalence (8.8%) than older individuals (2.5%) (P = 0.0127). Molecular analysis of initial stool samples from 7 of 10 children suspected of spontaneously passing tapeworms indicated 6 infections due to T. solium and 1 infection due to T. saginata. This study found that young children had a higher T. solium Taeniasis prevalence than older individuals, providing additional support for the belief that adult T. solium likely has a relatively short lifespan compared to other Taenia species with human definitive hosts.
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molecular phylogeny of the genus Taenia cestoda taeniidae proposals for the resurrection of hydatigera lamarck 1816 and the creation of a new genus versteria
International Journal for Parasitology, 2013Co-Authors: Minoru Nakao, Munehiro Okamoto, Antti Lavikainen, Voitto Haukisalmi, Takashi Iwaki, Sergey V Konyaev, Yuzaburo Oku, Akira ItoAbstract:The cestode family Taeniidae generally consists of two valid genera, Taenia and Echinococcus. The genus Echinococcus is monophyletic due to a remarkable similarity in morphology, features of development and genetic makeup. By contrast, Taenia is a highly diverse group formerly made up of different genera. Recent molecular phylogenetic analyses strongly suggest the paraphyly of Taenia. To clarify the genetic relationships among the representative members of Taenia, molecular phylogenies were constructed using nuclear and mitochondrial genes. The nuclear phylogenetic trees of 18S ribosomal DNA and concatenated exon regions of protein-coding genes (phosphoenolpyruvate carboxykinase and DNA polymerase delta) demonstrated that both Taenia mustelae and a clade formed by Taenia parva, Taenia krepkogorski and Taenia Taeniaeformis are only distantly related to the other members of Taenia. Similar topologies were recovered in mitochondrial genomic analyses using 12 complete protein-coding genes. A sister relationship between T. mustelae and Echinococcus spp. was supported, especially in protein-coding gene trees inferred from both nuclear and mitochondrial data sets. Based on these results, we propose the resurrection of Hydatigera Lamarck, 1816 for T. parva, T. krepkogorski and T. Taeniaeformis and the creation of a new genus, Versteria, for T. mustelae. Due to obvious morphological and ecological similarities, Taenia brachyacantha is also included in Versteria gen. nov., although molecular evidence is not available. Taenia Taeniaeformis has been historically regarded as a single species but the present data clearly demonstrate that it consists of two cryptic species.
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Recent hybridization between Taenia asiatica and Taenia saginata.
Parasitology International, 2012Co-Authors: Kanako Yamane, Suzuki Yumi, Eiko Tachi, Xingwang Chen, Minoru Nakao, Agathe Nkouawa, Testuya Yanagida, Yasuhito Sako, Akira ItoAbstract:Five Taenia tapeworms collected from humans in Tibetan Plateau, Sichuan, China, where three species of human Taenia are sympatrically endemic, were examined for the mitochondrial cox1 gene and two nuclear genes, ef1 and elp. Phylogenetic analyses of these genes revealed that two adult worms showed nuclear-mitochondrial discordance, suggesting that they originated from hybridization between Taenia saginata and Taenia asiatica. One of two worms had T. asiatica-type mtDNA, whereas another worm had T. saginata-type mtDNA, indicating that reciprocal hybridization between T. saginata and T. asiatica could occur. The worm having T. asiatica-type mtDNA was heterozygous at both nuclear loci with T. saginata-type alleles and T. asiatica-type alleles. In another worm, the ef1 locus was heterozygous with a T. saginata-type alleles and T. asiatica-type alleles, while the elp locus was homozygous with T. saginata-type alleles. Self-fertilization is the main reproductive method of the genus Taenia. Since self-fertilization represents a type of inbreeding, each locus in the offspring would become homozygous over generations with genetic drift. The fact that some nuclear loci are still heterozygous means that hybridization might have occurred recently. Hybridization between T. asiatica and T. saginata is probably an ongoing event in many areas in which they are sympatrically endemic.
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Loop-Mediated Isothermal Amplification Method for Differentiation and Rapid Detection of Taenia Species
Journal of Clinical Microbiology, 2008Co-Authors: Agathe Nkouawa, Minoru Nakao, Yasuhito Sako, Kazuhiro Nakaya, Akira ItoAbstract:Rapid detection and differentiation of Taenia species are required for the control and prevention of Taeniasis and cysticercosis in areas where these diseases are endemic. Because of the lower sensitivity and specificity of the conventional diagnosis based on microscopical examination, molecular tools are more reliable for differential diagnosis of these diseases. In this study, we developed and evaluated a loop-mediated isothermal amplification (LAMP) assay for differential diagnosis of infections with Taenia species with cathepsin L-like cysteine peptidase (clp) and cytochrome c oxidase subunit 1 (cox1) genes. LAMP with primer sets to the cox1 gene could differentiate between three species, and LAMP with primer sets to the clp gene could differentiate Taenia solium from Taenia saginata/Taenia asiatica. Restriction enzyme digestion of the LAMP products from primer set Tsag-clp allowed the differentiation of Taenia saginata from Taenia asiatica. We demonstrated the high specificity of LAMP by testing known parasite DNA samples extracted from proglottids (n = 100) and cysticerci (n = 68). LAMP could detect one copy of the target gene or five eggs of T. asiatica and T. saginata per gram of feces, showing sensitivity similar to that of PCR methods. Furthermore, LAMP could detect parasite DNA in all taeniid egg-positive fecal samples (n = 6). Due to the rapid, simple, specific, and sensitive detection of Taenia species, the LAMP assays are valuable tools which might be easily applicable for the control and prevention of Taeniasis and cysticercosis in countries where these diseases are endemic.
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Taeniasis cysticercosis in a tibetan population in sichuan province china
Acta Tropica, 2006Co-Authors: Akira Ito, Xingwang Chen, Marcello Otake Sato, Toni Wandra, Dongchuan Qiu, Jiamin Qiu, H Bradshaw, Yun YangAbstract:The results of a preliminary survey of Taeniasis/cysticercosis in Yajiang County, Ganze Tibetan Prefecture in southwest Sichuan Province, China, indicated a very high prevalence of Taeniasis (22.5%), with Taenia saginata as the dominant species. There was also a significant occurrence of late-onset epilepsy (8.5% prevalence and 16.4% seropositive for Taenia solium antibodies) attributable in large part to probable neurocysticercosis caused by T. solium. The poor sanitation and hygiene in this Tibetan community likely contributed to a high risk of human cysticercosis despite a low level of T. solium Taeniasis (actually no T. solium carriers were detected amongst the 21 proven Taenia carriers). In addition, three Taeniasis cases were confirmed by DNA genotyping as Taenia asiatica, which is the first report of this tapeworm in Tibetans, the first report for Sichuan Province and only the third report for mainland China.
Munehiro Okamoto - One of the best experts on this subject based on the ideXlab platform.
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risk factors and prevalence of Taeniasis among the karen people of tha song yang district tak province thailand
Parasite, 2021Co-Authors: Teera Kusolsuk, Tetsuya Yanagida, Munehiro Okamoto, Surapol Sanguankiat, Jitra Waikagul, Nirundorn Homsuwan, Kittipong Chaisiri, Akkarin Poodeepiyasawad, Dorn Watthanakulpanich, Paron DekumyoyAbstract:Taeniasis remains a prevalent public health problem in Thailand. National helminthiasis surveys report only the incidence of Taenia spp. eggs. The ability to differentiate Taenia species using morphological and molecular techniques is vital for epidemiological surveys. This study detected Taeniasis carriers and other helminthic infections by Kato’s thick smear technique and identified the Taenia species by multiplex PCR. The study subjects were the ethnic Karen people in Tha Song Yang District, Tak Province, Thailand, bordering Myanmar. In total, 983 faecal samples from villagers were examined for helminthiases. Interview-based questionnaires were used to gather information on possible risk factors for infection. The prevalence of helminth infections was 42.7% (420/983), including single (37.3%, 367/983) and mixed infections (5.4%, 53/983). The most common infection (19.23%, 189/983) was Ascaris lumbricoides , whereas Taeniasis carriers comprised 2.8% (28/983). Multiplex PCR of Cox1 was used for species identification of Taenia tapeworms, eggs, or both in 22 Taeniasis carriers. Most of the parasites (20 cases) were Taenia solium , with two cases of Taenia saginata . Taenia saginata asiatica was not found in the villagers examined. The analysis of 314 completed questionnaires showed that a statistically significant (p < 0.05) risk of Taeniasis was correlated with being male, a history of being allowed to forage during childhood, a history of seeing tapeworm proglottids, and a history of raw or undercooked pork consumption. Health education programmes must seek to reduce and prevent reinfection in these communities.
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phylogenetic characterisation of Taenia tapeworms in spotted hyenas and reconsideration of the out of africa hypothesis of Taenia in humans
International Journal for Parasitology, 2014Co-Authors: Yitagele Terefe, Minoru Nakao, Antti Lavikainen, Voitto Haukisalmi, Zerihun Hailemariam, Sissay Menkir, Takashi Iwaki, Munehiro OkamotoAbstract:Abstract The African origin of hominins suggests that Taenia spp. in African carnivores are evolutionarily related to the human-infecting tapeworms Taenia solium, Taenia saginata and Taenia asiatica. Nevertheless, the hypothesis has not been verified through molecular phylogenetics of Taenia. This study aimed to perform phylogenetic comparisons between Taenia spp. from African hyenas and the congeneric human parasites. During 2010–2013, 233 adult specimens of Taenia spp. were collected from 11 spotted hyenas in Ethiopia. A screening based on short DNA sequences of the cytochrome c oxidase subunit 1 gene classified the samples into four mitochondrial lineages designated as I–IV. DNA profiles of nuclear genes for DNA polymerase delta (pold) and phosphoenolpyruvate carboxykinase (pepck) showed that lineages II and III can be assigned as two independent species. Common haplotypes of pold and pepck were frequently found in lineages I and IV, suggesting that they constitute a single species. Morphological observations suggested that lineage II is Taenia crocutae, but the other lineages were morphologically inconsistent with known species, suggesting the involvement of two new species. A phylogenetic tree of Taenia spp. was reconstructed by the maximum likelihood method using all protein-coding genes of their mitochondrial genomes. The tree clearly demonstrated that T. crocutae is sister to T. saginata and T. asiatica, whereas T. solium was confirmed to be sister to the brown bear tapeworm, Taenia arctos. The tree also suggested that T. solium and T. arctos are related to two species of Taenia in hyenas, corresponding to lineages I + IV and III. These results may partially support the African origin of human-infecting Taenia spp., but there remains a possibility that host switching of Taenia to hominins was not confined to Africa. Additional taxa from African carnivores are needed for further testing of the “Out of Africa” hypothesis of Taenia in humans.
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molecular phylogeny of the genus Taenia cestoda taeniidae proposals for the resurrection of hydatigera lamarck 1816 and the creation of a new genus versteria
International Journal for Parasitology, 2013Co-Authors: Minoru Nakao, Munehiro Okamoto, Antti Lavikainen, Voitto Haukisalmi, Takashi Iwaki, Sergey V Konyaev, Yuzaburo Oku, Akira ItoAbstract:The cestode family Taeniidae generally consists of two valid genera, Taenia and Echinococcus. The genus Echinococcus is monophyletic due to a remarkable similarity in morphology, features of development and genetic makeup. By contrast, Taenia is a highly diverse group formerly made up of different genera. Recent molecular phylogenetic analyses strongly suggest the paraphyly of Taenia. To clarify the genetic relationships among the representative members of Taenia, molecular phylogenies were constructed using nuclear and mitochondrial genes. The nuclear phylogenetic trees of 18S ribosomal DNA and concatenated exon regions of protein-coding genes (phosphoenolpyruvate carboxykinase and DNA polymerase delta) demonstrated that both Taenia mustelae and a clade formed by Taenia parva, Taenia krepkogorski and Taenia Taeniaeformis are only distantly related to the other members of Taenia. Similar topologies were recovered in mitochondrial genomic analyses using 12 complete protein-coding genes. A sister relationship between T. mustelae and Echinococcus spp. was supported, especially in protein-coding gene trees inferred from both nuclear and mitochondrial data sets. Based on these results, we propose the resurrection of Hydatigera Lamarck, 1816 for T. parva, T. krepkogorski and T. Taeniaeformis and the creation of a new genus, Versteria, for T. mustelae. Due to obvious morphological and ecological similarities, Taenia brachyacantha is also included in Versteria gen. nov., although molecular evidence is not available. Taenia Taeniaeformis has been historically regarded as a single species but the present data clearly demonstrate that it consists of two cryptic species.
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a loop mediated isothermal amplification method for a differential identification of Taenia tapeworms from human application to a field survey
Parasitology International, 2012Co-Authors: Agathe Nkouawa, Xingwang Chen, Minoru Nakao, Yasuhito Sako, Tetsuya Yanagida, Munehiro Okamoto, Tiaoying Li, Patrick Giraudoux, Francis Raoul, Kazuhiro NakayaAbstract:In this study, we applied a loop-mediated isothermal amplification method for identification of human Taenia tapeworms in Tibetan communities in Sichuan, China. Out of 51 proglottids recovered from 35 carriers, 9, 1, and 41 samples were identified as Taenia solium, Taenia asiatica and Taenia saginata, respectively. Same results were obtained afterwards in the laboratory, except one sample. These results demonstrated that the LAMP method enabled rapid identification of parasites in the field surveys, which suggested that this method would contribute to the control of Taenia infections in endemic areas.
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molecular and serological survey on Taeniasis and cysticercosis in kanchanaburi province thailand
Parasitology International, 2010Co-Authors: Yasuhito Sako, Munehiro Okamoto, Marcello Otake Sato, Teera Kusolsuk, Malinee T Anantaphruti, Tippayarat Yoonuan, Surapol Saguankiat, Megumi Sato, Jitra WaikagulAbstract:A community-based field survey on Taeniasis and cysticercosis was performed in two villages in Thong Pha Phum District, Kanchanaburi Province, central Thailand, where 3 Taenia species, T. solium, T. saginata and T. asiatica, are sympatrically occurring. Four (0.6%) out of 667 stool samples were egg-positive for Taenia sp. by Kato-Katz technique. Three out of those four persons and other three persons who were Taenia egg-negative but having a recent ( 1 year) history of expelling proglottids in the stool.
Minoru Nakao - One of the best experts on this subject based on the ideXlab platform.
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Description and life-cycle of Taenia lynciscapreoli sp. n. (Cestoda, Cyclophyllidea)
ZooKeys, 2016Co-Authors: Voitto Haukisalmi, Antti Lavikainen, Marja Isomursu, Sergey V Konyaev, Minoru NakaoAbstract:A new species of tapeworm, Taenia lynciscapreoli sp. n. (Cestoda, Cyclophyllidea), is described from the Eurasian lynx (Lynx lynx), the main definitive host, and the roe deer (Capreolus capreolus and Capreolus pygargus), the main intermediate hosts, from Finland and Russia (Siberia and the Russian Far East). The new species was found once also in the wolf (Canis lupus) and the Eurasian elk/moose (Alces alces), representing accidental definitive and intermediate hosts, respectively. The conspecificity of adult specimens and metacestodes of Taenia lynciscapreoli sp. n. in various host species and regions, and their distinction from related species of Taenia, was confirmed by partial nucleotide sequences of the mitochondrial cytochrome c oxidase subunit 1 gene. Morphologically, Taenia lynciscapreoli sp. n. can be separated unambiguously from all other species of Taenia by the shape of its large rostellar hooks, particularly the characteristically short, wide and strongly curved blade. If the large rostellar hooks are missing, Taenia lynciscapreoli may be separated from related species by a combination of morphological features of mature proglottids. It is suggested that Taenia lynciscapreoli has been present in published materials concerning the tapeworms of Lynx lynx and Lynx pardinus in Europe, but has been misidentified as Taenia pisiformis (Bloch, 1780). Taenia lynciscapreoli sp. n. has not been found in lynx outside the range of roe deer, suggesting a transmission pathway based on a specific predator-prey relationship. The present study applies a novel, simple approach to compare qualitative interspecific differences in the shape of rostellar hooks.
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phylogenetic characterisation of Taenia tapeworms in spotted hyenas and reconsideration of the out of africa hypothesis of Taenia in humans
International Journal for Parasitology, 2014Co-Authors: Yitagele Terefe, Minoru Nakao, Antti Lavikainen, Voitto Haukisalmi, Zerihun Hailemariam, Sissay Menkir, Takashi Iwaki, Munehiro OkamotoAbstract:Abstract The African origin of hominins suggests that Taenia spp. in African carnivores are evolutionarily related to the human-infecting tapeworms Taenia solium, Taenia saginata and Taenia asiatica. Nevertheless, the hypothesis has not been verified through molecular phylogenetics of Taenia. This study aimed to perform phylogenetic comparisons between Taenia spp. from African hyenas and the congeneric human parasites. During 2010–2013, 233 adult specimens of Taenia spp. were collected from 11 spotted hyenas in Ethiopia. A screening based on short DNA sequences of the cytochrome c oxidase subunit 1 gene classified the samples into four mitochondrial lineages designated as I–IV. DNA profiles of nuclear genes for DNA polymerase delta (pold) and phosphoenolpyruvate carboxykinase (pepck) showed that lineages II and III can be assigned as two independent species. Common haplotypes of pold and pepck were frequently found in lineages I and IV, suggesting that they constitute a single species. Morphological observations suggested that lineage II is Taenia crocutae, but the other lineages were morphologically inconsistent with known species, suggesting the involvement of two new species. A phylogenetic tree of Taenia spp. was reconstructed by the maximum likelihood method using all protein-coding genes of their mitochondrial genomes. The tree clearly demonstrated that T. crocutae is sister to T. saginata and T. asiatica, whereas T. solium was confirmed to be sister to the brown bear tapeworm, Taenia arctos. The tree also suggested that T. solium and T. arctos are related to two species of Taenia in hyenas, corresponding to lineages I + IV and III. These results may partially support the African origin of human-infecting Taenia spp., but there remains a possibility that host switching of Taenia to hominins was not confined to Africa. Additional taxa from African carnivores are needed for further testing of the “Out of Africa” hypothesis of Taenia in humans.
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molecular phylogeny of the genus Taenia cestoda taeniidae proposals for the resurrection of hydatigera lamarck 1816 and the creation of a new genus versteria
International Journal for Parasitology, 2013Co-Authors: Minoru Nakao, Munehiro Okamoto, Antti Lavikainen, Voitto Haukisalmi, Takashi Iwaki, Sergey V Konyaev, Yuzaburo Oku, Akira ItoAbstract:The cestode family Taeniidae generally consists of two valid genera, Taenia and Echinococcus. The genus Echinococcus is monophyletic due to a remarkable similarity in morphology, features of development and genetic makeup. By contrast, Taenia is a highly diverse group formerly made up of different genera. Recent molecular phylogenetic analyses strongly suggest the paraphyly of Taenia. To clarify the genetic relationships among the representative members of Taenia, molecular phylogenies were constructed using nuclear and mitochondrial genes. The nuclear phylogenetic trees of 18S ribosomal DNA and concatenated exon regions of protein-coding genes (phosphoenolpyruvate carboxykinase and DNA polymerase delta) demonstrated that both Taenia mustelae and a clade formed by Taenia parva, Taenia krepkogorski and Taenia Taeniaeformis are only distantly related to the other members of Taenia. Similar topologies were recovered in mitochondrial genomic analyses using 12 complete protein-coding genes. A sister relationship between T. mustelae and Echinococcus spp. was supported, especially in protein-coding gene trees inferred from both nuclear and mitochondrial data sets. Based on these results, we propose the resurrection of Hydatigera Lamarck, 1816 for T. parva, T. krepkogorski and T. Taeniaeformis and the creation of a new genus, Versteria, for T. mustelae. Due to obvious morphological and ecological similarities, Taenia brachyacantha is also included in Versteria gen. nov., although molecular evidence is not available. Taenia Taeniaeformis has been historically regarded as a single species but the present data clearly demonstrate that it consists of two cryptic species.
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a loop mediated isothermal amplification method for a differential identification of Taenia tapeworms from human application to a field survey
Parasitology International, 2012Co-Authors: Agathe Nkouawa, Xingwang Chen, Minoru Nakao, Yasuhito Sako, Tetsuya Yanagida, Munehiro Okamoto, Tiaoying Li, Patrick Giraudoux, Francis Raoul, Kazuhiro NakayaAbstract:In this study, we applied a loop-mediated isothermal amplification method for identification of human Taenia tapeworms in Tibetan communities in Sichuan, China. Out of 51 proglottids recovered from 35 carriers, 9, 1, and 41 samples were identified as Taenia solium, Taenia asiatica and Taenia saginata, respectively. Same results were obtained afterwards in the laboratory, except one sample. These results demonstrated that the LAMP method enabled rapid identification of parasites in the field surveys, which suggested that this method would contribute to the control of Taenia infections in endemic areas.
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Recent hybridization between Taenia asiatica and Taenia saginata.
Parasitology International, 2012Co-Authors: Kanako Yamane, Suzuki Yumi, Eiko Tachi, Xingwang Chen, Minoru Nakao, Agathe Nkouawa, Testuya Yanagida, Yasuhito Sako, Akira ItoAbstract:Five Taenia tapeworms collected from humans in Tibetan Plateau, Sichuan, China, where three species of human Taenia are sympatrically endemic, were examined for the mitochondrial cox1 gene and two nuclear genes, ef1 and elp. Phylogenetic analyses of these genes revealed that two adult worms showed nuclear-mitochondrial discordance, suggesting that they originated from hybridization between Taenia saginata and Taenia asiatica. One of two worms had T. asiatica-type mtDNA, whereas another worm had T. saginata-type mtDNA, indicating that reciprocal hybridization between T. saginata and T. asiatica could occur. The worm having T. asiatica-type mtDNA was heterozygous at both nuclear loci with T. saginata-type alleles and T. asiatica-type alleles. In another worm, the ef1 locus was heterozygous with a T. saginata-type alleles and T. asiatica-type alleles, while the elp locus was homozygous with T. saginata-type alleles. Self-fertilization is the main reproductive method of the genus Taenia. Since self-fertilization represents a type of inbreeding, each locus in the offspring would become homozygous over generations with genetic drift. The fact that some nuclear loci are still heterozygous means that hybridization might have occurred recently. Hybridization between T. asiatica and T. saginata is probably an ongoing event in many areas in which they are sympatrically endemic.
Antti Lavikainen - One of the best experts on this subject based on the ideXlab platform.
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Description and life-cycle of Taenia lynciscapreoli sp. n. (Cestoda, Cyclophyllidea)
ZooKeys, 2016Co-Authors: Voitto Haukisalmi, Antti Lavikainen, Marja Isomursu, Sergey V Konyaev, Minoru NakaoAbstract:A new species of tapeworm, Taenia lynciscapreoli sp. n. (Cestoda, Cyclophyllidea), is described from the Eurasian lynx (Lynx lynx), the main definitive host, and the roe deer (Capreolus capreolus and Capreolus pygargus), the main intermediate hosts, from Finland and Russia (Siberia and the Russian Far East). The new species was found once also in the wolf (Canis lupus) and the Eurasian elk/moose (Alces alces), representing accidental definitive and intermediate hosts, respectively. The conspecificity of adult specimens and metacestodes of Taenia lynciscapreoli sp. n. in various host species and regions, and their distinction from related species of Taenia, was confirmed by partial nucleotide sequences of the mitochondrial cytochrome c oxidase subunit 1 gene. Morphologically, Taenia lynciscapreoli sp. n. can be separated unambiguously from all other species of Taenia by the shape of its large rostellar hooks, particularly the characteristically short, wide and strongly curved blade. If the large rostellar hooks are missing, Taenia lynciscapreoli may be separated from related species by a combination of morphological features of mature proglottids. It is suggested that Taenia lynciscapreoli has been present in published materials concerning the tapeworms of Lynx lynx and Lynx pardinus in Europe, but has been misidentified as Taenia pisiformis (Bloch, 1780). Taenia lynciscapreoli sp. n. has not been found in lynx outside the range of roe deer, suggesting a transmission pathway based on a specific predator-prey relationship. The present study applies a novel, simple approach to compare qualitative interspecific differences in the shape of rostellar hooks.
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phylogenetic characterisation of Taenia tapeworms in spotted hyenas and reconsideration of the out of africa hypothesis of Taenia in humans
International Journal for Parasitology, 2014Co-Authors: Yitagele Terefe, Minoru Nakao, Antti Lavikainen, Voitto Haukisalmi, Zerihun Hailemariam, Sissay Menkir, Takashi Iwaki, Munehiro OkamotoAbstract:Abstract The African origin of hominins suggests that Taenia spp. in African carnivores are evolutionarily related to the human-infecting tapeworms Taenia solium, Taenia saginata and Taenia asiatica. Nevertheless, the hypothesis has not been verified through molecular phylogenetics of Taenia. This study aimed to perform phylogenetic comparisons between Taenia spp. from African hyenas and the congeneric human parasites. During 2010–2013, 233 adult specimens of Taenia spp. were collected from 11 spotted hyenas in Ethiopia. A screening based on short DNA sequences of the cytochrome c oxidase subunit 1 gene classified the samples into four mitochondrial lineages designated as I–IV. DNA profiles of nuclear genes for DNA polymerase delta (pold) and phosphoenolpyruvate carboxykinase (pepck) showed that lineages II and III can be assigned as two independent species. Common haplotypes of pold and pepck were frequently found in lineages I and IV, suggesting that they constitute a single species. Morphological observations suggested that lineage II is Taenia crocutae, but the other lineages were morphologically inconsistent with known species, suggesting the involvement of two new species. A phylogenetic tree of Taenia spp. was reconstructed by the maximum likelihood method using all protein-coding genes of their mitochondrial genomes. The tree clearly demonstrated that T. crocutae is sister to T. saginata and T. asiatica, whereas T. solium was confirmed to be sister to the brown bear tapeworm, Taenia arctos. The tree also suggested that T. solium and T. arctos are related to two species of Taenia in hyenas, corresponding to lineages I + IV and III. These results may partially support the African origin of human-infecting Taenia spp., but there remains a possibility that host switching of Taenia to hominins was not confined to Africa. Additional taxa from African carnivores are needed for further testing of the “Out of Africa” hypothesis of Taenia in humans.
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molecular phylogeny of the genus Taenia cestoda taeniidae proposals for the resurrection of hydatigera lamarck 1816 and the creation of a new genus versteria
International Journal for Parasitology, 2013Co-Authors: Minoru Nakao, Munehiro Okamoto, Antti Lavikainen, Voitto Haukisalmi, Takashi Iwaki, Sergey V Konyaev, Yuzaburo Oku, Akira ItoAbstract:The cestode family Taeniidae generally consists of two valid genera, Taenia and Echinococcus. The genus Echinococcus is monophyletic due to a remarkable similarity in morphology, features of development and genetic makeup. By contrast, Taenia is a highly diverse group formerly made up of different genera. Recent molecular phylogenetic analyses strongly suggest the paraphyly of Taenia. To clarify the genetic relationships among the representative members of Taenia, molecular phylogenies were constructed using nuclear and mitochondrial genes. The nuclear phylogenetic trees of 18S ribosomal DNA and concatenated exon regions of protein-coding genes (phosphoenolpyruvate carboxykinase and DNA polymerase delta) demonstrated that both Taenia mustelae and a clade formed by Taenia parva, Taenia krepkogorski and Taenia Taeniaeformis are only distantly related to the other members of Taenia. Similar topologies were recovered in mitochondrial genomic analyses using 12 complete protein-coding genes. A sister relationship between T. mustelae and Echinococcus spp. was supported, especially in protein-coding gene trees inferred from both nuclear and mitochondrial data sets. Based on these results, we propose the resurrection of Hydatigera Lamarck, 1816 for T. parva, T. krepkogorski and T. Taeniaeformis and the creation of a new genus, Versteria, for T. mustelae. Due to obvious morphological and ecological similarities, Taenia brachyacantha is also included in Versteria gen. nov., although molecular evidence is not available. Taenia Taeniaeformis has been historically regarded as a single species but the present data clearly demonstrate that it consists of two cryptic species.
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Molecular identification of Taenia spp. in the Eurasian lynx ( Lynx lynx ) from Finland
Parasitology, 2013Co-Authors: Antti Lavikainen, Juha Laakkonen, Katja Holmala, Pikka Jokelainen, Gunita Deksne, Voitto Haukisalmi, Manigandan Lejeune, Marja Isomursu, Anu Näreaho, Eric P HobergAbstract:Cestodes of the genus Taenia are parasites of mammals, with mainly carnivores as definitive and herbivores as intermediate hosts. Various medium-sized cats, Lynx spp., are involved in the life cycles of several species of Taenia. The aim of the present study was to identify Taenia tapeworms in the Eurasian lynx (Lynx lynx) from Finland. In total, 135 tapeworms from 72 lynx were subjected to molecular identification based on sequences of 2 mtDNA regions, the cytochrome c oxidase subunit 1 and the NADH dehydrogenase subunit 1 genes. Available morphological characters of the rostellar hooks and strobila were compared. Two species of Taenia were found: T. laticollis (127 samples) and an unknown Taenia sp. (5 samples). The latter could not be identified to species based on mtDNA, and the rostellar hooks were short relative to those described among other Taenia spp. recorded in felids from the Holarctic region. In the phylogenetic analyses of mtDNA sequences, T. laticollis was placed as a sister species of T. macrocystis, and the unknown Taenia sp. was closely related to T. hydatigena and T. regis. Our analyses suggest that these distinct taeniid tapeworms represent a putative new species of Taenia. The only currently recognized definitive host is L. lynx and the intermediate host is unknown.
Diego Currò - One of the best experts on this subject based on the ideXlab platform.
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expression and motor functional roles of voltage dependent type 7 k channels in the human Taenia coli
European Journal of Pharmacology, 2013Co-Authors: Alice Adduci, Gianluca Rizzo, Claudio Coco, Maurizio Taglialatela, Maria Martire, Vincenzo Arena, Diego CurròAbstract:Abstract Voltage-dependent type 7 K + (K V 7 or KCNQ) channels modulate the excitability of neurons and muscle cells. The aims of the present study were to investigate the motor effects of K V 7 channel modulators and the expression of K V 7 channels in the human Taenia coli . The effects of K V 7 channel modulators on the muscle tone of human Taenia coli strips were investigated under nonadrenergic non-nitrergic conditions by organ bath studies. Gene expression and tissue localisation of channels were studied by real-time PCR and immunohistochemistry, respectively. Under basal conditions, the K V 7 channel blocker XE-991 induced concentration-dependent contractions, with mean EC 50 and E max of 18.7 μM and 30.5% respectively of the maximal bethanechol-induced contraction, respectively. The K V 7 channel activators retigabine and flupirtine concentration-dependently relaxed the Taenia coli , with mean EC 50 s of 19.2 μM and 29.9 μM, respectively. Retigabine also relaxed bethanechol-precontracted strips, with maximal relaxations of 79.2% of the bethanecol-induced precontraction. The motor effects induced by the K V 7 channel modulators were not affected by tetrodotoxin or ω-conotoxin GVIA. XE-991 greatly reduced retigabine- and flupirtine-induced relaxations. Transcripts encoded by all KCNQ genes were detected in the Taenia coli , with KCNQ4 showing the highest expression levels. K V 7.4 channels were clearly visualised by immunohistochemistry in colonic epithelium, circular muscle layer and Taenia coli . K V 7 channels appear to contribute to the resting muscle tone of the human Taenia coli . In addition, K V 7 channel activators significantly relax the Taenia coli . Thus, they could be useful therapeutic relaxant agents for colonic motor disorders.
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Expression and motor functional roles of voltage-dependent type 7 K(+) channels in the human Taenia coli.
European journal of pharmacology, 2013Co-Authors: Alice Adduci, Gianluca Rizzo, Claudio Coco, Maurizio Taglialatela, Maria Martire, Vincenzo Arena, Diego CurròAbstract:Voltage-dependent type 7 K(+) (KV7 or KCNQ) channels modulate the excitability of neurons and muscle cells. The aims of the present study were to investigate the motor effects of KV7 channel modulators and the expression of KV7 channels in the human Taenia coli. The effects of KV7 channel modulators on the muscle tone of human Taenia coli strips were investigated under nonadrenergic non-nitrergic conditions by organ bath studies. Gene expression and tissue localisation of channels were studied by real-time PCR and immunohistochemistry, respectively. Under basal conditions, the KV7 channel blocker XE-991 induced concentration-dependent contractions, with mean EC50 and Emax of 18.7 μM and 30.5% respectively of the maximal bethanechol-induced contraction, respectively. The KV7 channel activators retigabine and flupirtine concentration-dependently relaxed the Taenia coli, with mean EC50s of 19.2 μM and 29.9 μM, respectively. Retigabine also relaxed bethanechol-precontracted strips, with maximal relaxations of 79.2% of the bethanecol-induced precontraction. The motor effects induced by the KV7 channel modulators were not affected by tetrodotoxin or ω-conotoxin GVIA. XE-991 greatly reduced retigabine- and flupirtine-induced relaxations. Transcripts encoded by all KCNQ genes were detected in the Taenia coli, with KCNQ4 showing the highest expression levels. KV7.4 channels were clearly visualised by immunohistochemistry in colonic epithelium, circular muscle layer and Taenia coli. KV7 channels appear to contribute to the resting muscle tone of the human Taenia coli. In addition, KV7 channel activators significantly relax the Taenia coli. Thus, they could be useful therapeutic relaxant agents for colonic motor disorders.
