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Peter Nejsum - One of the best experts on this subject based on the ideXlab platform.
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Mebendazole treatment persistently alters the size profile and morphology of Trichuris trichiura eggs.
Acta Tropica, 2020Co-Authors: Peter Nejsum, Stig Milan Thamsborg, Kasper Lind Andersen, Sidsel D. Andersen, Ana Merino TejedorAbstract:Abstract The soil transmitted whipworm, Trichuris trichiura affects about half a billion people globally. Diagnosis is based on identification of characteristic lemon-shaped eggs in stool samples. Occasionally large Trichuris eggs have been reported and have been ascribed to variation within T. trichiura or zoonotic infection with T. vulpis from dogs. We observed that the egg size profile changed markedly after anthelmintic treatment, and remained so, in a human individual self-infected with T. trichiura. The large eggs were detected with two standard diagnostic methods, Kato-Katz thick smear and salt-flotation (McMaster) method. It is therefore important to bear in mind that the morphology of parasite eggs may vary, e.g. in response to previous drug treatment. Large Trichuris eggs in human stool samples should not be diagnosed as T. vulpis infection without confirmation by other means.
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Insights into the molecular systematics of Trichuris infecting captive primates based on mitochondrial DNA analysis.
Veterinary Parasitology, 2019Co-Authors: Serena Cavallero, Cristina Cutillas, Rocio Callejon, Peter Nejsum, Jana Doležalová, David Modrý, Stefano D'amelioAbstract:Abstract Nematodes belonging to the Trichuris genus are prevalent soil-transmitted helminths with a worldwide distribution in mammals, while humans are mainly affected in areas with insufficient sanitation such as in Africa, Asia and South America. Traditionally, whipworms infecting primates are referred to Trichuris trichiura, but recent molecular and morphological evidence suggests that more than one species may be able to infect humans and non-human primates. Here, we analyzed the genetic diversity and phylogeny of Trichuris infecting five different non-human primate species kept in captivity using sequencing of three mitochondrial genes (cox1, rrnL and cob). Phylogenetic analyses of both single and concatenated datasets suggested the presence of two main evolutionary lineages and several highly supported clades likely existing as separate taxa. The first lineage included Trichuris infecting the mantled guereza (Colobus guereza kikuyensis), the chacma baboon (Papio ursinus) and the green monkeys (Chlorocebus spp.), clustering together with Trichuris suis; the second lineage included Trichuris infecting the Japanese macaque (Macaca fuscata) and the hamadryas baboon (Papio hamadryas), clustering together with Trichuris spp. infecting humans. These results were supported by the genetic distance between samples, which suggested that at least two taxa are able to infect macaques, baboons and humans. The present study improves our understanding of the taxonomy and evolutionary relationships among Trichuris spp. infecting primates. It moreover suggests that multiple Trichuris spp. may circulate among host species and that Trichuris in non human primates (NHPs) may be zoonotic. Further studies are important to better understand the epidemiology of Trichuris in primates and for implementing appropriate control and/or conservation measures.
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Glucose Absorption by the Bacillary Band of Trichuris muris
PLOS Neglected Tropical Diseases, 2016Co-Authors: Tina Va Hansen, Peter Nejsum, Michael Hansen, Helena Mejer, Matthew Denwood, Stig M ThamsborgAbstract:Background A common characteristic of Trichuris spp. infections in humans and animals is the variable but low efficacy of single-dose benzimidazoles currently used in mass drug administration programmes against human trichuriasis. The bacillary band, a specialised morphological structure of Trichuris spp., as well as the unique partly intracellular habitat of adult Trichuris spp. may affect drug absorption and perhaps contribute to the low drug accumulation in the worm. However, the exact function of the bacillary band is still unknown. Methodology We studied the dependency of adult Trichuris muris on glucose and/or amino acids for survival in vitro and the absorptive function of the bacillary band. The viability of the worms was evaluated using a motility scale from 0 to 3, and the colorimetric assay Alamar Blue was utilised to measure the metabolic activity. The absorptive function of the bacillary band in living worms was explored using a fluorescent glucose analogue (6-NBDG) and confocal microscopy. To study the absorptive function of the bacillary band in relation to 6-NBDG, the oral uptake was minimised or excluded by sealing the oral cavity with glue and agarose. Principal Findings Glucose had a positive effect on both the motility (p < 0.001) and metabolic activity (p < 0.001) of T. muris in vitro, whereas this was not the case for amino acids. The 6-NBDG was observed in the pores of the bacillary band and within the stichocytes of the living worms, independent of oral sealing. Conclusions/Significance Trichuris muris is dependent on glucose for viability in vitro, and the bacillary band has an absorptive function in relation to 6-NBDG, which accumulates within the stichocytes. The absorptive function of the bacillary band calls for an exploration of its possible role in the uptake of anthelmintics, and as a potential anthelmintic target relevant for future drug development.
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mitochondrial genome analyses suggest multiple Trichuris species in humans baboons and pigs from different geographical regions
PLOS Neglected Tropical Diseases, 2015Co-Authors: Mohamed B F Hawash, Lee Obrien Andersen, Robin B Gasser, Christen Rune Stensvold, Peter NejsumAbstract:Background The whipworms Trichuris trichiura and Trichuris suis are two parasitic nematodes of humans and pigs, respectively. Although whipworms in human and non-human primates historically have been referred to as T. trichiura, recent reports suggest that several Trichuris spp. are found in primates. Methods and Findings We sequenced and annotated complete mitochondrial genomes of Trichuris recovered from a human in Uganda, an olive baboon in the US, a hamadryas baboon in Denmark, and two pigs from Denmark and Uganda. Comparative analyses using other published mitochondrial genomes of Trichuris recovered from a human and a porcine host in China and from a francois’ leaf-monkey (China) were performed, including phylogenetic analyses and pairwise genetic and amino acid distances. Genetic and protein distances between human Trichuris in Uganda and China were high (~19% and 15%, respectively) suggesting that they represented different species. Trichuris from the olive baboon in US was genetically related to human Trichuris in China, while the other from the hamadryas baboon in Denmark was nearly identical to human Trichuris from Uganda. Baboon-derived Trichuris was genetically distinct from Trichuris from francois’ leaf monkey, suggesting multiple whipworm species circulating among non-human primates. The genetic and protein distances between pig Trichuris from Denmark and other regions were roughly 9% and 6%, respectively, while Chinese and Ugandan whipworms were more closely related. Conclusion and Significance Our results indicate that Trichuris species infecting humans and pigs are phylogenetically distinct across geographical regions, which might have important implications for the implementation of suitable and effective control strategies in different regions. Moreover, we provide support for the hypothesis that Trichuris infecting primates represents a complex of cryptic species with some species being able to infect both humans and non-human primates.
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genome and transcriptome of the porcine whipworm Trichuris suis
Nature Genetics, 2014Co-Authors: Peter Nejsum, Erich M Schwarz, Li Hu, Neil D Young, Ross S Hall, Pasi K Korhonen, Shengguang Liao, S M Thamsborg, Pengwei XuAbstract:Trichuris (whipworm) infects 1 billion people worldwide and causes a disease (trichuriasis) that results in major socioeconomic losses in both humans and pigs. Trichuriasis relates to an inflammation of the large intestine manifested in bloody diarrhea, and chronic disease can cause malnourishment and stunting in children. Paradoxically, Trichuris of pigs has shown substantial promise as a treatment for human autoimmune disorders, including inflammatory bowel disease (IBD) and multiple sclerosis. Here we report whole-genome sequencing at ~140-fold coverage of adult male and female T. suis and ~80-Mb draft assemblies. We explore stage-, sex- and tissue-specific transcription of mRNAs and small noncoding RNAs.
Stig M Thamsborg - One of the best experts on this subject based on the ideXlab platform.
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Glucose Absorption by the Bacillary Band of Trichuris muris
PLOS Neglected Tropical Diseases, 2016Co-Authors: Tina Va Hansen, Peter Nejsum, Michael Hansen, Helena Mejer, Matthew Denwood, Stig M ThamsborgAbstract:Background A common characteristic of Trichuris spp. infections in humans and animals is the variable but low efficacy of single-dose benzimidazoles currently used in mass drug administration programmes against human trichuriasis. The bacillary band, a specialised morphological structure of Trichuris spp., as well as the unique partly intracellular habitat of adult Trichuris spp. may affect drug absorption and perhaps contribute to the low drug accumulation in the worm. However, the exact function of the bacillary band is still unknown. Methodology We studied the dependency of adult Trichuris muris on glucose and/or amino acids for survival in vitro and the absorptive function of the bacillary band. The viability of the worms was evaluated using a motility scale from 0 to 3, and the colorimetric assay Alamar Blue was utilised to measure the metabolic activity. The absorptive function of the bacillary band in living worms was explored using a fluorescent glucose analogue (6-NBDG) and confocal microscopy. To study the absorptive function of the bacillary band in relation to 6-NBDG, the oral uptake was minimised or excluded by sealing the oral cavity with glue and agarose. Principal Findings Glucose had a positive effect on both the motility (p < 0.001) and metabolic activity (p < 0.001) of T. muris in vitro, whereas this was not the case for amino acids. The 6-NBDG was observed in the pores of the bacillary band and within the stichocytes of the living worms, independent of oral sealing. Conclusions/Significance Trichuris muris is dependent on glucose for viability in vitro, and the bacillary band has an absorptive function in relation to 6-NBDG, which accumulates within the stichocytes. The absorptive function of the bacillary band calls for an exploration of its possible role in the uptake of anthelmintics, and as a potential anthelmintic target relevant for future drug development.
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genetic variations in the beta tubulin gene and the internal transcribed spacer 2 region of Trichuris species from man and baboons
Parasites & Vectors, 2013Co-Authors: Tina Va Hansen, Stig M Thamsborg, Annette Olsen, Roger K Prichard, Peter NejsumAbstract:The whipworm Trichuris trichiura has been estimated to infect 604 – 795 million people worldwide. The current control strategy against trichuriasis using the benzimidazoles (BZs) albendazole (400 mg) or mebendazole (500 mg) as single-dose treatment is not satisfactory. The occurrence of single nucleotide polymorphisms (SNPs) in codons 167, 198 or 200 of the beta-tubulin gene has been reported to convey BZ-resistance in intestinal nematodes of veterinary importance. It was hypothesised that the low susceptibility of T. trichiura to BZ could be due to a natural occurrence of such SNPs. The aim of this study was to investigate whether these SNPs were present in the beta-tubulin gene of Trichuris spp. from humans and baboons. As a secondary objective, the degree of identity between T. trichiura from humans and Trichuris spp. from baboons was evaluated based on the beta-tubulin gene and the internal transcribed spacer 2 region (ITS2). Nucleotide sequences of the beta-tubulin gene were generated by PCR using degenerate primers, specific primers and DNA from worms and eggs of T. trichiura and worms of Trichuris spp. from baboons. The ITS2 region was amplified using adult Trichuris spp. from baboons. PCR products were sequenced and analysed. The beta-tubulin fragments were studied for SNPs in codons 167, 198 or 200 and the ITS2 amplicons were compared with GenBank records of T. trichiura. No SNPs in codons 167, 198 or 200 were identified in any of the analysed Trichuris spp. from humans and baboons. Based on the ITS2 region, the similarity between Trichuris spp. from baboons and GenBank records of T. trichiura was found to be 98 – 99%. Single nucleotide polymorphisms in codon 167, 198 and 200, known to confer BZ-resistance in other nematodes, were absent in the studied material. This study does not provide data that could explain previous reports of poor BZ treatment efficacy in terms of polymorphism in these codons of beta-tubulin. Based on a fragment of the beta-tubulin gene and the ITS2 region sequenced, it was found that T. trichiura from humans and Trichuris spp. isolated from baboons are closely related and may be the same species.
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genetic variation in codons 167 198 and 200 of the beta tubulin gene in whipworms Trichuris spp from a range of domestic animals and wildlife
Veterinary Parasitology, 2013Co-Authors: Tina Va Hansen, Peter Nejsum, Annette Olsen, Stig M ThamsborgAbstract:Abstract A recurrent problem in the control of whipworm (Trichuris spp.) infections in many animal species and man is the relatively low efficacy of treatment with a single application of benzimidazoles (BZs). The presence of single nucleotide polymorphisms (SNPs) in codons 167, 198 and 200 in the beta-tubulin gene has been associated with BZ anthelmintic resistance in intestinal nematodes of veterinary importance. We hypothesized that the low susceptibility to BZ could be related to a natural tolerance or induced resistance caused by BZ-resistant associated SNPs. The aim of the present study was therefore to investigate the presence of these SNPs in the beta-tubulin gene of Trichuris spp. obtained from a range of animals. DNA was extracted from a total of 121 Trichuris spp. adult whipworm specimens obtained from 6 different host species. The number of worms from each host was pig: 31, deer: 21, sheep: 18, mouse: 17, dog: 19 and Arabian camels: 14. A pooled sample of Trichuris eggs from 3 moose was also used. In order to amplify the beta-tubulin fragments which covered codons 167, 198 and 200 of the gene, degenerate primers were designed. The sequences obtained were used to design species specific primers and used to amplify a ∼476 bp fragment of the beta-tubulin gene. The PCR products were sequenced, analysed and evaluated. We did not identify SNPs in codons 167, 198 or 200 that led to amino acid substitutions in any of the studied Trichuris spp., but genetic variation expected to be related to species differences was observed. The cluster analysis showed close evolutionary relationship between Trichuris spp. from ruminants and between mouse and dog whereas the pig-derived worms, T. suis, clustered with T. trichiura obtained from Genbank.
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genetic analysis of Trichuris suis and Trichuris trichiura recovered from humans and pigs in a sympatric setting in uganda
Veterinary Parasitology, 2012Co-Authors: Sofie Nissen, Tina Va Hansen, Stig M Thamsborg, Annette Olsen, Azmi Aljubury, Henrik Christensen, Peter NejsumAbstract:Abstract The whipworms Trichuris trichiura and Trichuris suis in humans and pigs, respectively, are believed to be two different species yet closely related. Morphologically, adult worms, eggs and larvae of the two species are indistinguishable. The aim of this study was to examine the genetic variation of Trichuris sp. mainly recovered from natural infected pigs and humans. Worm material isolated from humans and pigs living in the same geographical region in Uganda were analyzed by PCR, cloning and sequencing. Measurements of morphometric characters were also performed. The analysis of the ITS-2 (internal transcribed spacer) region showed a high genetic variation in the human-derived worms with two sequence types, designated type 1 and type 2, differing with up to 45%, the type 2 being identical to the sequence found in pig-derived worms. A single human-derived worm showed exclusively the type 2-genotype (T. suis-type) and three cases of ‘heterozygote’ worms in humans were identified. However, the analysis showed that sympatric Trichuris primarily assorted with host origin. Sequence analysis of a part of the genetically conserved β-tubulin gene confirmed two separate populations/species but also showed that the ‘heterozygote’ worms had a T. suis-like β-tubulin gene. A PCR-RFLP on the ITS-2 region was developed, that could distinguish between worms of the pig, human and ‘heterozygote’ type. The data suggest that Trichuris in pigs and humans belong to two different populations (i.e. are two different species). However, the data presented also suggest that cross-infections of humans with T. suis takes place. Further studies on sympatric Trichuris populations are highly warranted in order to explore transmission dynamics and unravel the zoonotic potential of T. suis.
Huiqun Song - One of the best experts on this subject based on the ideXlab platform.
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mitochondrial and nuclear ribosomal dna evidence supports the existence of a new Trichuris species in the endangered francois leaf monkey
PLOS ONE, 2013Co-Authors: Robin B Gasser, Peter Nejsum, Yanyan Wang, Qiang Chen, Huiqun SongAbstract:The whipworm of humans, Trichuris trichiura, is responsible for a neglected tropical disease (NTD) of major importance in tropical and subtropical countries of the world. Whipworms also infect animal hosts, including pigs, dogs and non-human primates, cause clinical disease (trichuriasis) similar to that of humans. Although Trichuris species are usually considered to be host specific, it is not clear whether non-human primates are infected with T. trichiura or other species. In the present study, we sequenced the complete mitochondrial (mt) genome as well as the first and second internal transcribed spacers (ITS-1 and ITS-2) of Trichuris from the Francois’ leaf-monkey (langur), and compared them with homologous sequences from human- and pig-derived Trichuris. In addition, sequence comparison of a conserved mt ribosomal gene among multiple individual whipworms revealed substantial nucleotide differences among these three host species but limited sequence variation within each of them. The molecular data indicate that the monkey-derived whipworm is a separate species from that of humans. Future work should focus on detailed population genetic and morphological studies (by electron microscopy) of whipworms from various non-humans primates and humans.
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characterization of the complete mitochondrial genomes of two whipworms Trichuris ovis and Trichuris discolor nematoda trichuridae
Infection Genetics and Evolution, 2012Co-Authors: Yan Wang, Minjun Xu, Donghui Zhou, Yonggang Ye, Jiayuan Li, Huiqun SongAbstract:Abstract For many years, whipworms ( Trichuris spp.) have been described with a relatively narrow range of both morphological and biometrical features. Moreover, there has been insufficient discrimination between congeners (or closely related species). In the present study, we determined the complete mitochondrial (mt) genomes of two whipworms Trichuris ovis and Trichuris discolor , compared them and then tested the hypothesis that T. ovis and T. discolor are distinct species by phylogenetic analyses using Bayesian inference, maximum likelihood and maximum parsimony) based on the deduced amino acid sequences of the mt protein-coding genes. The complete mt genomes of T. ovis and T. discolor were 13,946 bp and 13,904 bp in size, respectively. Both mt genomes are circular, and consist of 37 genes, including 13 genes coding for proteins, 2 genes for rRNA, and 22 genes for tRNA. The gene content and arrangement are identical to that of human and pig whipworms Trichuris trichiura and Trichuris suis . Taken together, these analyses showed genetic distinctiveness and strongly supported the recent proposal that T. ovis and T. discolor are distinct species using nuclear ribosomal DNA and a portion of the mtDNA sequence dataset. The availability of the complete mtDNA sequences of T. ovis and T. discolor provides novel genetic markers for studying the population genetics, diagnostics and molecular epidemiology of T. ovis and T. discolor .
Tina Va Hansen - One of the best experts on this subject based on the ideXlab platform.
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Glucose Absorption by the Bacillary Band of Trichuris muris
PLOS Neglected Tropical Diseases, 2016Co-Authors: Tina Va Hansen, Peter Nejsum, Michael Hansen, Helena Mejer, Matthew Denwood, Stig M ThamsborgAbstract:Background A common characteristic of Trichuris spp. infections in humans and animals is the variable but low efficacy of single-dose benzimidazoles currently used in mass drug administration programmes against human trichuriasis. The bacillary band, a specialised morphological structure of Trichuris spp., as well as the unique partly intracellular habitat of adult Trichuris spp. may affect drug absorption and perhaps contribute to the low drug accumulation in the worm. However, the exact function of the bacillary band is still unknown. Methodology We studied the dependency of adult Trichuris muris on glucose and/or amino acids for survival in vitro and the absorptive function of the bacillary band. The viability of the worms was evaluated using a motility scale from 0 to 3, and the colorimetric assay Alamar Blue was utilised to measure the metabolic activity. The absorptive function of the bacillary band in living worms was explored using a fluorescent glucose analogue (6-NBDG) and confocal microscopy. To study the absorptive function of the bacillary band in relation to 6-NBDG, the oral uptake was minimised or excluded by sealing the oral cavity with glue and agarose. Principal Findings Glucose had a positive effect on both the motility (p < 0.001) and metabolic activity (p < 0.001) of T. muris in vitro, whereas this was not the case for amino acids. The 6-NBDG was observed in the pores of the bacillary band and within the stichocytes of the living worms, independent of oral sealing. Conclusions/Significance Trichuris muris is dependent on glucose for viability in vitro, and the bacillary band has an absorptive function in relation to 6-NBDG, which accumulates within the stichocytes. The absorptive function of the bacillary band calls for an exploration of its possible role in the uptake of anthelmintics, and as a potential anthelmintic target relevant for future drug development.
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genetic variations in the beta tubulin gene and the internal transcribed spacer 2 region of Trichuris species from man and baboons
Parasites & Vectors, 2013Co-Authors: Tina Va Hansen, Stig M Thamsborg, Annette Olsen, Roger K Prichard, Peter NejsumAbstract:The whipworm Trichuris trichiura has been estimated to infect 604 – 795 million people worldwide. The current control strategy against trichuriasis using the benzimidazoles (BZs) albendazole (400 mg) or mebendazole (500 mg) as single-dose treatment is not satisfactory. The occurrence of single nucleotide polymorphisms (SNPs) in codons 167, 198 or 200 of the beta-tubulin gene has been reported to convey BZ-resistance in intestinal nematodes of veterinary importance. It was hypothesised that the low susceptibility of T. trichiura to BZ could be due to a natural occurrence of such SNPs. The aim of this study was to investigate whether these SNPs were present in the beta-tubulin gene of Trichuris spp. from humans and baboons. As a secondary objective, the degree of identity between T. trichiura from humans and Trichuris spp. from baboons was evaluated based on the beta-tubulin gene and the internal transcribed spacer 2 region (ITS2). Nucleotide sequences of the beta-tubulin gene were generated by PCR using degenerate primers, specific primers and DNA from worms and eggs of T. trichiura and worms of Trichuris spp. from baboons. The ITS2 region was amplified using adult Trichuris spp. from baboons. PCR products were sequenced and analysed. The beta-tubulin fragments were studied for SNPs in codons 167, 198 or 200 and the ITS2 amplicons were compared with GenBank records of T. trichiura. No SNPs in codons 167, 198 or 200 were identified in any of the analysed Trichuris spp. from humans and baboons. Based on the ITS2 region, the similarity between Trichuris spp. from baboons and GenBank records of T. trichiura was found to be 98 – 99%. Single nucleotide polymorphisms in codon 167, 198 and 200, known to confer BZ-resistance in other nematodes, were absent in the studied material. This study does not provide data that could explain previous reports of poor BZ treatment efficacy in terms of polymorphism in these codons of beta-tubulin. Based on a fragment of the beta-tubulin gene and the ITS2 region sequenced, it was found that T. trichiura from humans and Trichuris spp. isolated from baboons are closely related and may be the same species.
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genetic variation in codons 167 198 and 200 of the beta tubulin gene in whipworms Trichuris spp from a range of domestic animals and wildlife
Veterinary Parasitology, 2013Co-Authors: Tina Va Hansen, Peter Nejsum, Annette Olsen, Stig M ThamsborgAbstract:Abstract A recurrent problem in the control of whipworm (Trichuris spp.) infections in many animal species and man is the relatively low efficacy of treatment with a single application of benzimidazoles (BZs). The presence of single nucleotide polymorphisms (SNPs) in codons 167, 198 and 200 in the beta-tubulin gene has been associated with BZ anthelmintic resistance in intestinal nematodes of veterinary importance. We hypothesized that the low susceptibility to BZ could be related to a natural tolerance or induced resistance caused by BZ-resistant associated SNPs. The aim of the present study was therefore to investigate the presence of these SNPs in the beta-tubulin gene of Trichuris spp. obtained from a range of animals. DNA was extracted from a total of 121 Trichuris spp. adult whipworm specimens obtained from 6 different host species. The number of worms from each host was pig: 31, deer: 21, sheep: 18, mouse: 17, dog: 19 and Arabian camels: 14. A pooled sample of Trichuris eggs from 3 moose was also used. In order to amplify the beta-tubulin fragments which covered codons 167, 198 and 200 of the gene, degenerate primers were designed. The sequences obtained were used to design species specific primers and used to amplify a ∼476 bp fragment of the beta-tubulin gene. The PCR products were sequenced, analysed and evaluated. We did not identify SNPs in codons 167, 198 or 200 that led to amino acid substitutions in any of the studied Trichuris spp., but genetic variation expected to be related to species differences was observed. The cluster analysis showed close evolutionary relationship between Trichuris spp. from ruminants and between mouse and dog whereas the pig-derived worms, T. suis, clustered with T. trichiura obtained from Genbank.
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genetic analysis of Trichuris suis and Trichuris trichiura recovered from humans and pigs in a sympatric setting in uganda
Veterinary Parasitology, 2012Co-Authors: Sofie Nissen, Tina Va Hansen, Stig M Thamsborg, Annette Olsen, Azmi Aljubury, Henrik Christensen, Peter NejsumAbstract:Abstract The whipworms Trichuris trichiura and Trichuris suis in humans and pigs, respectively, are believed to be two different species yet closely related. Morphologically, adult worms, eggs and larvae of the two species are indistinguishable. The aim of this study was to examine the genetic variation of Trichuris sp. mainly recovered from natural infected pigs and humans. Worm material isolated from humans and pigs living in the same geographical region in Uganda were analyzed by PCR, cloning and sequencing. Measurements of morphometric characters were also performed. The analysis of the ITS-2 (internal transcribed spacer) region showed a high genetic variation in the human-derived worms with two sequence types, designated type 1 and type 2, differing with up to 45%, the type 2 being identical to the sequence found in pig-derived worms. A single human-derived worm showed exclusively the type 2-genotype (T. suis-type) and three cases of ‘heterozygote’ worms in humans were identified. However, the analysis showed that sympatric Trichuris primarily assorted with host origin. Sequence analysis of a part of the genetically conserved β-tubulin gene confirmed two separate populations/species but also showed that the ‘heterozygote’ worms had a T. suis-like β-tubulin gene. A PCR-RFLP on the ITS-2 region was developed, that could distinguish between worms of the pig, human and ‘heterozygote’ type. The data suggest that Trichuris in pigs and humans belong to two different populations (i.e. are two different species). However, the data presented also suggest that cross-infections of humans with T. suis takes place. Further studies on sympatric Trichuris populations are highly warranted in order to explore transmission dynamics and unravel the zoonotic potential of T. suis.
Rocio Callejon - One of the best experts on this subject based on the ideXlab platform.
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Insights into the molecular systematics of Trichuris infecting captive primates based on mitochondrial DNA analysis.
Veterinary Parasitology, 2019Co-Authors: Serena Cavallero, Cristina Cutillas, Rocio Callejon, Peter Nejsum, Jana Doležalová, David Modrý, Stefano D'amelioAbstract:Abstract Nematodes belonging to the Trichuris genus are prevalent soil-transmitted helminths with a worldwide distribution in mammals, while humans are mainly affected in areas with insufficient sanitation such as in Africa, Asia and South America. Traditionally, whipworms infecting primates are referred to Trichuris trichiura, but recent molecular and morphological evidence suggests that more than one species may be able to infect humans and non-human primates. Here, we analyzed the genetic diversity and phylogeny of Trichuris infecting five different non-human primate species kept in captivity using sequencing of three mitochondrial genes (cox1, rrnL and cob). Phylogenetic analyses of both single and concatenated datasets suggested the presence of two main evolutionary lineages and several highly supported clades likely existing as separate taxa. The first lineage included Trichuris infecting the mantled guereza (Colobus guereza kikuyensis), the chacma baboon (Papio ursinus) and the green monkeys (Chlorocebus spp.), clustering together with Trichuris suis; the second lineage included Trichuris infecting the Japanese macaque (Macaca fuscata) and the hamadryas baboon (Papio hamadryas), clustering together with Trichuris spp. infecting humans. These results were supported by the genetic distance between samples, which suggested that at least two taxa are able to infect macaques, baboons and humans. The present study improves our understanding of the taxonomy and evolutionary relationships among Trichuris spp. infecting primates. It moreover suggests that multiple Trichuris spp. may circulate among host species and that Trichuris in non human primates (NHPs) may be zoonotic. Further studies are important to better understand the epidemiology of Trichuris in primates and for implementing appropriate control and/or conservation measures.
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Differentiation of Trichuris species using a morphometric approach
International journal for parasitology. Parasites and wildlife, 2019Co-Authors: A. M. García-sánchez, Rocio Callejon, J. Rivero, Antonio Zurita, M. Reguera-gomez, M.a. Valero, Cristina CutillasAbstract:Abstract Trichuris trichiura is a nematode considered as the whipworm present in humans and primates. The systematics of the genus Trichuris is complex. Morphological studies of Trichuris isolated from primates and humans conclude that the species infecting these hosts is the same. Furthermore, numerous molecular studies have been carried out so far to discriminate parasite species from humans and Non-Human Primates using molecular techniques, but these studies were not performed in combination with a parallel morphological study. The hypothesised existence of more species of Trichuris in primates opens the possibility to revise the zoonotic potential and host specificity of T. trichiura and other putative new species of whipworms. In the present work, a study of Trichuris Roederer, 1761 (Nematoda:Trichuridae) parasitizing C. g. kikuyensis, P. ursinus, Macaca sylvanus, Pan troglodytes, and Sus scrofa domestica has been carried out using modern morphometric techniques in order to differentiate populations of Trichuris isolated from four species of captive NHP from different geographical regions, and swine, respectively. The results obtained revealed strong support for geometrical morphometrics as a useful tool to differentiate male Trichuris populations. Therefore, morphometrics in combination with other techniques, such as molecular biology analyses, ought to be applied to further the differentiation of male populations. On the other hand, morphometrics applied to female Trichuris species does not seem to contribute new information as all the measurements combinations of obtained from females always showed similar results.
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Nuclear and mitochondrial genes for inferring Trichuris phylogeny
Parasitology Research, 2015Co-Authors: Rocio Callejon, Cristina Cutillas, Steven A. NadlerAbstract:Nucleotide sequences of the triose phosphate isomerase (TPI) gene (624 bp) and mitochondrial cytochrome b (cob) gene (520 bp) were obtained by PCR and evaluated for utility in inferring the phylogenetic relationships among Trichuris species. Published sequences of one other nuclear gene (18S or SSU rRNA, 1816–1846 bp) and one additional mitochondrial (mtDNA) gene (cytochrome oxidase 1, cox1, 342 bp) were also analyzed. Maximum likelihood and Bayesian inference methods were used to infer phylogenies for each gene separately but also for the combined mitochondrial data (two genes), the combined nuclear data (two genes), and the total evidence (four gene) dataset. Few Trichuris clades were uniformly resolved across separate analyses of individual genes. For the mtDNA, the cob gene trees had greater phylogenetic resolution and tended to have higher support values than the cox1 analyses. For nuclear genes, the SSU gene trees had slightly greater resolution and support values than the TPI analyses, but TPI was the only gene with reliable support for the deepest nodes in the tree. Combined analyses of genes yielded strongly supported clades in most cases, with the exception of the relationship among Trichuris clades 1, 2, and 3, which showed conflicting results between nuclear and mitochondrial genes. Both the TPI and cob genes proved valuable for inferring Trichuris relationships, with greatest resolution and support values achieved through combined analysis of multiple genes. Based on the phylogeny of the combined analysis of nuclear and mitochondrial genes, parsimony mapping of definitive host utilization depicts artiodactyls as the ancestral hosts for these Trichuris, with host-shifts into primates, rodents, and Carnivora.
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Taxonomy and phylogeny of Trichuris globulosa Von Linstow, 1901 from camels. A review of Trichuris species parasitizing herbivorous.
Infection Genetics and Evolution, 2015Co-Authors: Rocio Callejon, Ali Halajian, M De Rojas, Antonio Zurita, L. Gutiérrez-avilés, Cristina CutillasAbstract:At the present work, we carried out a morph-biometrical and molecular study of Trichuris species isolated from Camelus dromedarius from Iran and from Ovis aries from South Africa comparatively with other species of Trichuris from different herbivorous hosts and geographical regions. The population from camels from Iran was identified as Trichuris globulosa. Two different morphometrically populations of Trichuris sp. from sheep from South Africa were identified: Trichuris ovis and Trichuris skrjabini. Ribosomal data did not reveal significate differences in the ITS2 sequences between T. ovis and T. globulosa to assess a specific determination. The mitochondrial data suggest that T. globulosa constitute a different genetic lineage to T. ovis. Cytochrome c-oxidase and cytochrome b partial gene sequences corroborated the existence of a different genetic lineage of T. ovis from sheep of South Africa that would be closely related to the populations of T. globulosa from camels from Iran. The cytochrome c-oxidase and cytochrome b partial gene sequences of T. globulosa have been reported for the first time.
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Morphological and molecular characterization of a new Trichuris species (Nematoda- Trichuridae), and phylogenetic relationships of Trichuris species of Cricetid rodents from Argentina.
PLOS ONE, 2014Co-Authors: María Del Rosario Robles, Cristina Cutillas, Carlos Javier Panei, Rocio CallejonAbstract:Populations of Trichuris spp. isolated from six species of sigmodontine rodents from Argentina were analyzed based on morphological characteristics and ITS2 (rDNA) region sequences. Molecular data provided an opportunity to discuss the phylogenetic relationships among the Trichuris spp. from Noth and South America (mainly from Argentina). Trichuris specimens were identified morphologically as Trichuris pardinasi, T. navonae, Trichuris sp. and Trichuris new species, described in this paper. Sequences analyzed by Maximum Parsimony, Maximum Likelihood and Bayesian inference methods showed four main clades corresponding with the four different species regardless of geographical origin and host species. These four species from sigmodontine rodents clustered together and separated from Trichuris species isolated from murine and arvicoline rodents (outgroup). Different genetic lineages observed among Trichuris species from sigmodontine rodents which supported the proposal of a new species. Moreover, host distribution showed correspondence with the different tribes within the subfamily Sigmodontinae.
