Stem cell proliferation and differentiation during larval metamorphosis of the model tapeworm Hymenolepis microstoma.

Background: Tapeworm larvae cause important diseases in humans and domestic animals. During infection, the first larval stage undergoes a metamorphosis where tissues are formed de novo from a population of stem cells called germinative cells. This process is difficult to study for human pathogens, as these larvae are infectious and difficult to obtain in the laboratory. Methods: In this work, we analyzed cell proliferation and differentiation during larval metamorphosis in the model tapeworm Hymenolepis microstoma, by in vivo labelling of proliferating cells with the thymidine analogue 5-ethynyl-2'-deoxyuridine (EdU), tracing their differentiation with a suite of specific molecular markers for different cell types. Results: Proliferating cells are very abundant and fast-cycling during early metamorphosis: the total number of cells duplicates every ten hours, and the length of G2 is only 75 minutes. New tegumental, muscle and nerve cells differentiate from this pool of proliferating germinative cells, and these processes are very fast, as differentiation markers for neurons and muscle cells appear within 24 hours after exiting the cell cycle, and fusion of new cells to the tegumental syncytium can be detected after only 4 hours. Tegumental and muscle cells appear from early stages of metamorphosis (24 to 48 hours post-infection); in contrast, most markers for differentiating neurons appear later, and the detection of synapsin and neuropeptides correlates with scolex retraction. Finally, we identified populations of proliferating cells that express conserved genes associated with neuronal progenitors and precursors, suggesting the existence of tissue-specific lineages among germinative cells. Discussion: These results provide for the first time a comprehensive view of the development of new tissues during tapeworm larval metamorphosis, providing a framework for similar studies in human and veterinary pathogens.

Hymenolepis diminuta, phylogenetic analyses of nuclear rRNA + ITS and mitochondrial cox1 and its infections in non-human primates.

Hymenolepis diminuta is a tapeworm commonly found worldwide in small rodents such as rats with occasional reports in other definitive hosts such as primates including chimpanzees and humans. It has not been reported in African green monkey (AGM, Chlorocebus sabaeus), and the parasite's molecular phenotype and phylogeny remain primitively sketchy. The aims of the current study were to determine if H. diminuta infected AGMs, to molecularly characterize H. diminuta and to review its infection in non-human primates. Feces of AGMs were examined visually for adult helminths and microscopically for eggs using centrifugation flotation. Total DNA extracted from eggs was amplified by PCR followed by DNA sequencing of targeted sequences of nuclear rRNA + internal transcribed spacers (ITS) and mitochondrial cox1. Phylogenetic analyses were performed. The DNA sequences of both nuclear rRNA + ITS and mitochondrial cox1 showed more than 98% and 99% identity to the known sequences respectively. Hymenolepis diminuta has been reported in various non-human primates with the highest prevalence of 38.5% in the white-headed capuchin monkey. The study presented here confirms that this tapeworm is capable of infecting various species of non-human primates with the first report of infections in AGM. Phylogenetic analyses of rRNA + ITS and mitochondrial cox1 demonstrated three separated clades I, II and III with the newly described AGM1 isolate belonging to the clade I. Whether these differences are at species level remains to be confirmed.

Trans-splicing in the cestode Hymenolepis microstoma is constitutive across the life cycle and depends on gene structure and composition.

Spliced leader (SL) trans-splicing is a key process during mRNA maturation of many eukaryotes, in which a short sequence (SL) is transferred from a precursor SL-RNA into the 5' region of an immature mRNA. This mechanism is present in flatworms, in which it is known to participate in the resolution of polycistronic transcripts. However, most trans-spliced transcripts are not part of operons, and it is not clear if this process may participate in additional regulatory mechanisms in this group. In this work, we present a comprehensive analysis of SL trans-splicing in the model cestode Hymenolepis microstoma. We identified four different SL-RNAs which are indiscriminately trans-spliced to 622 gene models. SL trans-splicing is enriched in constitutively expressed genes and does not appear to be regulated throughout the life cycle. Operons represented at least 20% of all detected trans-spliced gene models, showed conservation to those of the cestode Echinococcus multilocularis, and included complex loci such as an alternative operon (processed as either a single gene through cis-splicing or as two genes of a polycistron). Most insertion sites were identified in the 5' untranslated region (UTR) of monocistronic genes. These genes frequently contained introns in the 5' UTR, in which trans-splicing used the same acceptor sites as cis-splicing. These results suggest that, unlike other eukaryotes, trans-splicing is associated with internal intronic promoters in the 5' UTR, resulting in transcripts with strong splicing acceptor sites without competing cis-donor sites, pointing towards a simple mechanism driving the evolution of novel SL insertion sites.

Hymenolepidid cestodes: Diversity, morphological and molecular characterization of a new species, and phylogeny of parasitic species of rodents from North and South America.

Rodents are hosts of a wide diversity of cestodes. Fifteen genera included in the family Hymenolepididae parasitize rodents, and only four of these genera have been recorded from the Neotropical region. The purpose of this paper is to update species of Hymenolepididae from rodents, describe a new species of Hymenolepis based on morphological and molecular characterization (ITS1 rDNA and cox1 mtDNA), comparing the features among the species from North and South American rodents, and provide phylogenetic inferences of Hymenolepididae from rodents based on sequences available in the GenBank. Rodents were collected in the Parque Provincial Ernesto Tornquist, Buenos Aires, Argentina. Hymenolepis ivanovae n. sp. differs from other Hymenolepis species registered from North and South American rodents by body size, scolex, suckers, cirrus sac, cirrus, testes, and eggs, among others. Comparative morphometric data for Hymenolepis species from North and South American rodents is provided. Molecular analyses place H. ivanovae n. sp. within the genus Hymenolepis with strong support, and show it close to species of zoonotic importance. The new species is the first species of Hymenolepis described from Sigmodontinae rodents.

Detection of enteroparasites in foliar vegetables commercialized in street- and supermarkets in Aparecida de Goiânia, Goiás, Brazil / Detecção de enteroparasitas em hortaliças comercializadas em feiras e supermercados em Aparecida de Goiânia, Goiás, Brasil

Foliar vegetables contaminated with fecal residues are an important route of transmission of intestinal parasites to humans. The aim of this study was to evaluate the presence of parasitic forms of protozoa and helminths on lettuces (Lactuca sativa) and collard greens (Brassica oleracea) sold in street- and supermarkets in the city of Aparecida de Goiânia, Goiás, Brazil. A total of 30 samples of each vegetable (15 samples from each supermarkets and street markets) was analyzed. All samples were processed by spontaneous sedimentation method and centrifugal flotation. In 45% of the samples, immature forms of intestinal parasites were identified with 66.7% helminths eggs and 33.3% protozoan cysts or oocysts. Significantly more lettuce samples were contaminated with eggs, cysts or oocyst of at least one parasite than collard green samples (U=216; Z=-3.45; P <0.001). The parasitic forms were identified morphologically up to the family level with eggs of Ancylostomatidae, Strongyloididae, Ascarididae and Taeniidae, or oocysts of Eimeriidae, to the genus with Cystoisospora sp. and Toxocara sp., and to the species level with Cystoisospora canis, Dipylidium caninum and Hymenolepis nana. The presence of these infective agents in lettuce and collard green from both street- and supermarkets highlights the high risk of spreading parasites by eating raw vegetables sold in Aparecida de Goiânia.

Hortaliças contaminadas com resíduos fecais são importantes vias de transmissão de parasitas intestinais ao homem. O objetivo deste estudo foi avaliar a presença de formas parasitárias de protozoários e helmintos em alface (Lactuca sativa) e couve (Brassica oleracea) vendidas em feiras e supermercados na cidade de Aparecida de Goiânia, Goiás, Brasil. Um total de 30 amostras de cada vegetal (15 amostras de supermercados e 15 de feiras livres) foi analisado. Todas as amostras foram processadas pelos métodos de sedimentação espontânea e centrífugo-flutuação. Em 45% das amostras foram identificadas formas imaturas de parasitas intestinais sendo 66,7% ovos de helmintos e 33,3% de cistos ou oocistos de protozoários. Significativamente, mais amostras de alface estavam contaminadas com ovos, cistos ou oocistos de pelo menos um parasita do que as amostras de couve (U = 216; Z = -3,45; P <0,001). As formas parasitárias foram identificadas morfologicamente ao nível de família com ovos de Ancylostomatidae, Strongyloididae, Ascarididae e Taeniidae ou oocistos de Eimeriidae, dos gêneros Cystoisospora sp. e Toxocara sp., e ao nível de espécies com Cystoisospora canis, Dipylidium caninum e Hymenolepis nana. A presença desses agentes infecciosos em alface e couve, provenientes tanto de feiras quanto de supermercados, ressalta o alto risco de veiculação de parasitas pela ingestão de hortaliças cruas comercializadas em Aparecida de Goiânia.

Prevalence of intestinal parasitic diseases in school children of rural areas of district Lower Dir, Pakistan / Prevalência de doenças parasitárias intestinais em escolares de áreas rurais do distrito de Lower Dir, Paquistão

Present study was conducted among school children to recognize the prevalence of IPIs in rural communities of district Dir Lower, Pakistan. A sum of 324 samples of stool were collected (210 boys and 114 girls). Used direct smear method and formol ether sedimentation concentration technique for processing the samples. The result shows that 82% (n=266) were found infected comprised 64.8% male and 35.1% females. Children of the age group 10 to 12 years were found extremely infected 94.2% while 4-6 year age group were having minimum ratio of infection 72%. Current study shows mono parasitism in 50.6% of the students while 22.2% were infected with 2 species and 7.40% were infected with three species of parasites. Seven species of intestinal parasites were reported include Ascaris lumbricoid in male (n=122) 58.0% and in female (n=65) 57.0% followed by Hook worm (n=88) 41.9% and (n=44) 38.5%; Tania saginata (n=44) 20.9% and (n=24) 21.0%; Entrobius vermicularis (n=32) 15.2% and (n=16) 14.0%; Trichuris trichura (n=25) 11.9% and (n=22) 19.2%; Hymenolepis nana (n=24) 11.4% and (n=18) 15.7% and Entameoba histolytica (n=16) 7.61% and (n=14) 12.2% in male and females respectively. The study indicates that most occurring intestinal parasite in the current study were Ascaris lumbricoides 58.0% (n=122) followed by hookworms 41.9% (n=88). Male students were more infected than females in the present study.

O presente estudo foi conduzido entre crianças em idade escolar para reconhecer a prevalência de IPIs em comunidades rurais do distrito de Dir Lower, Paquistão. Foram coletadas 324 amostras de fezes (210 meninos e 114 meninas). Método de esfregaço direto usado e técnica de concentração de sedimentação de formol éter para processar as amostras. O resultado mostra que 82% (n = 266) dos infectados eram 64,8% do sexo masculino e 35,1% do feminino. Crianças da faixa etária de 10 a 12 anos foram encontradas extremamente infectadas 94,2%, enquanto a faixa etária de 4 a 6 anos apresentava proporção mínima de infecção de 72%. O estudo atual mostra monoparasitismo em 50,6% dos alunos, enquanto 22,2% estavam infectados com 2 espécies e 7,40% estavam infectados com três espécies de parasitas. Sete espécies de parasitas intestinais foram relatadas incluindo Ascaris lumbricoid em machos (n = 122) 58,0% e em fêmeas (n = 65) 57,0% seguido por anzol (n = 88) 41,9% e (n = 44) 38,5%; Tania saginata (n = 44) 20,9% e (n = 24) 21,0%; Entrobius vermicularis (n = 32) 15,2% e (n = 16) 14,0%; Trichuris trichura (n = 25) 11,9% e (n = 22) 19,2%; Hymenolepis nana (n = 24) 11,4% e (n = 18) 15,7% e Entameoba histolytica (n = 16) 7,61% e (n = 14) 12,2% em homens e mulheres, respectivamente. O estudo indica que os parasitas intestinais que mais ocorreram no presente estudo foram Ascaris lumbricoides 58,0% (n = 122), seguidos por ancilóstomos 41,9% (n = 88). Estudantes do sexo masculino foram mais infectados do que do sexo feminino no presente estudo.

Prevalence of intestinal parasitic diseases in school children of rural areas of district Lower Dir, Pakistan / Prevalência de doenças parasitárias intestinais em escolares de áreas rurais do distrito de Lower Dir, Paquistão

Present study was conducted among school children to recognize the prevalence of IPIs in rural communities of district Dir Lower, Pakistan. A sum of 324 samples of stool were collected (210 boys and 114 girls). Used direct smear method and formol ether sedimentation concentration technique for processing the samples. The result shows that 82% (n=266) were found infected comprised 64.8% male and 35.1% females. Children of the age group 10 to 12 years were found extremely infected 94.2% while 4-6 year age group were having minimum ratio of infection 72%. Current study shows mono parasitism in 50.6% of the students while 22.2% were infected with 2 species and 7.40% were infected with three species of parasites. Seven species of intestinal parasites were reported include Ascaris lumbricoid in male (n=122) 58.0% and in female (n=65) 57.0% followed by Hook worm (n=88) 41.9% and (n=44) 38.5%; Tania saginata (n=44) 20.9% and (n=24) 21.0%; Entrobius vermicularis (n=32) 15.2% and (n=16) 14.0%; Trichuris trichura (n=25) 11.9% and (n=22) 19.2%; Hymenolepis nana (n=24) 11.4% and (n=18) 15.7% and Entameoba histolytica (n=16) 7.61% and (n=14) 12.2% in male and females respectively. The study indicates that most occurring intestinal parasite in the current study were Ascaris lumbricoides 58.0% (n=122) followed by hookworms 41.9% (n=88). Male students were more infected than females in the present study.(AU)

O presente estudo foi conduzido entre crianças em idade escolar para reconhecer a prevalência de IPIs em comunidades rurais do distrito de Dir Lower, Paquistão. Foram coletadas 324 amostras de fezes (210 meninos e 114 meninas). Método de esfregaço direto usado e técnica de concentração de sedimentação de formol éter para processar as amostras. O resultado mostra que 82% (n = 266) dos infectados eram 64,8% do sexo masculino e 35,1% do feminino. Crianças da faixa etária de 10 a 12 anos foram encontradas extremamente infectadas 94,2%, enquanto a faixa etária de 4 a 6 anos apresentava proporção mínima de infecção de 72%. O estudo atual mostra monoparasitismo em 50,6% dos alunos, enquanto 22,2% estavam infectados com 2 espécies e 7,40% estavam infectados com três espécies de parasitas. Sete espécies de parasitas intestinais foram relatadas incluindo Ascaris lumbricoid em machos (n = 122) 58,0% e em fêmeas (n = 65) 57,0% seguido por anzol (n = 88) 41,9% e (n = 44) 38,5%; Tania saginata (n = 44) 20,9% e (n = 24) 21,0%; Entrobius vermicularis (n = 32) 15,2% e (n = 16) 14,0%; Trichuris trichura (n = 25) 11,9% e (n = 22) 19,2%; Hymenolepis nana (n = 24) 11,4% e (n = 18) 15,7% e Entameoba histolytica (n = 16) 7,61% e (n = 14) 12,2% em homens e mulheres, respectivamente. O estudo indica que os parasitas intestinais que mais ocorreram no presente estudo foram Ascaris lumbricoides 58,0% (n = 122), seguidos por ancilóstomos 41,9% (n = 88). Estudantes do sexo masculino foram mais infectados do que do sexo feminino no presente estudo.(AU)

Detection of enteroparasites in foliar vegetables commercialized in street- and supermarkets in Aparecida de Goiânia, Goiás, Brazil / Detecção de enteroparasitas em hortaliças comercializadas em feiras e supermercados em Aparecida de Goiânia, Goiás, Brasil

Foliar vegetables contaminated with fecal residues are an important route of transmission of intestinal parasites to humans. The aim of this study was to evaluate the presence of parasitic forms of protozoa and helminths on lettuces (Lactuca sativa) and collard greens (Brassica oleracea) sold in street- and supermarkets in the city of Aparecida de Goiânia, Goiás, Brazil. A total of 30 samples of each vegetable (15 samples from each supermarkets and street markets) was analyzed. All samples were processed by spontaneous sedimentation method and centrifugal flotation. In 45% of the samples, immature forms of intestinal parasites were identified with 66.7% helminths eggs and 33.3% protozoan cysts or oocysts. Significantly more lettuce samples were contaminated with eggs, cysts or oocyst of at least one parasite than collard green samples (U=216; Z=-3.45; P <0.001). The parasitic forms were identified morphologically up to the family level with eggs of Ancylostomatidae, Strongyloididae, Ascarididae and Taeniidae, or oocysts of Eimeriidae, to the genus with Cystoisospora sp. and Toxocara sp., and to the species level with Cystoisospora canis, Dipylidium caninum and Hymenolepis nana. The presence of these infective agents in lettuce and collard green from both street- and supermarkets highlights the high risk of spreading parasites by eating raw vegetables sold in Aparecida de Goiânia.(AU)

Hortaliças contaminadas com resíduos fecais são importantes vias de transmissão de parasitas intestinais ao homem. O objetivo deste estudo foi avaliar a presença de formas parasitárias de protozoários e helmintos em alface (Lactuca sativa) e couve (Brassica oleracea) vendidas em feiras e supermercados na cidade de Aparecida de Goiânia, Goiás, Brasil. Um total de 30 amostras de cada vegetal (15 amostras de supermercados e 15 de feiras livres) foi analisado. Todas as amostras foram processadas pelos métodos de sedimentação espontânea e centrífugo-flutuação. Em 45% das amostras foram identificadas formas imaturas de parasitas intestinais sendo 66,7% ovos de helmintos e 33,3% de cistos ou oocistos de protozoários. Significativamente, mais amostras de alface estavam contaminadas com ovos, cistos ou oocistos de pelo menos um parasita do que as amostras de couve (U = 216; Z = -3,45; P <0,001). As formas parasitárias foram identificadas morfologicamente ao nível de família com ovos de Ancylostomatidae, Strongyloididae, Ascarididae e Taeniidae ou oocistos de Eimeriidae, dos gêneros Cystoisospora sp. e Toxocara sp., e ao nível de espécies com Cystoisospora canis, Dipylidium caninum e Hymenolepis nana. A presença desses agentes infecciosos em alface e couve, provenientes tanto de feiras quanto de supermercados, ressalta o alto risco de veiculação de parasitas pela ingestão de hortaliças cruas comercializadas em Aparecida de Goiânia.(AU)

Characterization of a new type of neuronal 5-HT G- protein coupled receptor in the cestode nervous system.

Cestodes are platyhelminth parasites with a wide range of hosts that cause neglected diseases. Neurotransmitter signaling is of critical importance for these parasites which lack circulatory, respiratory and digestive systems. For example, serotonin (5-HT) and serotonergic G-protein coupled receptors (5-HT GPCRs) play major roles in cestode motility, development and reproduction. In previous work, we deorphanized a group of 5-HT7 type GPCRs from cestodes. However, little is known about another type of 5-HT GPCR, the 5-HT1 clade, which has been studied in several invertebrate phyla but not in platyhelminthes. Three putative 5-HT GPCRs from Echinococcus canadensis, Mesocestoides vogae (syn. M. corti) and Hymenolepis microstoma were cloned, sequenced and bioinformatically analyzed. Evidence grouped these new sequences within the 5-HT1 clade of GPCRs but differences in highly conserved GPCR motifs were observed. Transcriptomic analysis, heterologous expression and immunolocalization studies were performed to characterize the E. canadensis receptor, called Eca-5-HT1a. Functional heterologous expression studies showed that Eca-5-HT1a is highly specific for serotonin. 5-Methoxytryptamine and α-methylserotonin, both known 5-HT GPCR agonists, give stimulatory responses whereas methysergide, a known 5-HT GPCR ligand, give an antagonist response in Eca-5-HT1a. Mutants obtained by the substitution of key predicted residues resulted in severe impairment of receptor activity, confirming that indeed, these residues have important roles in receptor function. Immunolocalization studies on the protoscolex stage from E. canadensis, showed that Eca-5-HT1a is localized in branched fibers which correspond to the nervous system of the parasite. The patterns of immunoreactive fibers for Eca-5-HT1a and for serotonin were intimately intertwined but not identical, suggesting that they are two separate groups of fibers. These data provide the first functional, pharmacological and localization report of a serotonergic receptor that putatively belongs to the 5-HT1 type of GPCRs in cestodes. The serotonergic GPCR characterized here may represent a new target for antiparasitic intervention.

Inhibitors of protein kinases A and C impair the motility of oncospheres of the model tapeworm Hymenolepis microstoma.

The oncosphere larvae of tapeworms cyclically extend and retract their hooks during the penetration of the intestine of their intermediate hosts. The mechanisms regulating these movements are essentially unknown, in part due to the biohazardous nature of oncospheres from human pathogens. In this work, we standardized a method for the analysis of motility of hatched oncospheres (hexacanths) of the model tapeworm Hymenolepis microstoma. We used this assay to explore the relevance of protein kinases C (PKC) and A (PKA) in these processes. Pharmacological inhibition of the PKC pathway resulted in impaired larval motility. On the other hand, the PKA inhibitor H-89 potently blocked larval motility, as well as the motility of other life stages, although other inhibitors of the PKA pathway were not effective. This work represents the first study of the mechanisms that regulate the motility of oncospheres, and provides a path for further exploration.

Stage-specific transcriptomic analysis of the model cestode Hymenolepis microstoma.

Most parasitic flatworms go through different life stages with important physiological and morphological changes. In this work, we used a transcriptomic approach to analyze the main life-stages of the model tapeworm Hymenolepis microstoma (eggs, cysticercoids, and adults). Our results showed massive transcriptomic changes in this life cycle, including key gene families that contribute substantially to the expression load in each stage. In particular, different members of the cestode-specific hydrophobic ligand-binding protein (HLBP) family are among the most highly expressed genes in each life stage. We also found the transcriptomic signature of major metabolic changes during the transition from cysticercoids to adult worms. Thus, this work contributes to uncovering the gene expression changes that accompany the development of this important cestode model species, and to the best of our knowledge represents the first transcriptomic study with robust replicates spanning all of the main life stages of a tapeworm.

Morphological and molecular identification of hymenolepidid cestodes in children and synanthropic rodents from rural Mexico.

Hymenolepidid cestodes of synanthropic rodents represent a risk for public health. In order to describe the occurrence of hymenolepidids in children and the role of rodents as a potential source of infection, we conducted a morphological and molecular survey on cestodes in two rural villages from Yucatan, Mexico. One hundred and thirty-five stool samples from children (64 from Paraíso and 71 from Xkalakdzonot), 233 Mus musculus (159 from Paraíso and 74 from Xkalakdzonot) and 125 Rattus rattus (7 from Paraíso and 118 from Xkalakdzonot) were analyzed for the presence of cestodes. Three hymenolepidid species were identified morphologically: Hymenolepis nana in 7.8% of children from Paraíso, Hymenolepis microstoma in 4.4% of M. musculus from Paraíso and Hymenolepis diminuta in 15.3% of R. rattus from Xkalakdzonot. The molecular characterization and phylogenetic analysis based on mitochondrial cytochrome c subunit 1 (CO1) gene and ribosomal internal transcribed spacer 1 (ITS1) region, confirmed the identity of the three cestodes isolated from Yucatan. Phylogeny of the CO1 gene identified intraspecific genetic differences within H. nana ranging from 0 to 5%, in H. microstoma from 0 to 0.4%, and in H. diminuta ranged from 0 to 6.5% which suggests, the presence of complex species within H. nana and H. diminuta infecting humans and rodents, as reported by other authors. Based on the morphological and molecular results, and the epidemiological evidence, infections with H. nana suggest a non-zoonotic transmission; however, the presence of H. microstoma and H. diminuta in synanthropic rodents serve as a possible source for human infection.

Divergent Axin and GSK-3 paralogs in the beta-catenin destruction complexes of tapeworms.

The Wnt/beta-catenin pathway has many key roles in the development of animals, including a conserved and central role in the specification of the primary (antero-posterior) body axis. The posterior expression of Wnt ligands and the anterior expression of secreted Wnt inhibitors are known to be conserved during the larval metamorphosis of tapeworms. However, their downstream signaling components for Wnt/beta-catenin signaling have not been characterized. In this work, we have studied the core components of the beta-catenin destruction complex of the human pathogen Echinococcus multilocularis, the causative agent of alveolar echinococcosis. We focused on two Axin paralogs that are conserved in tapeworms and other flatworm parasites. Despite their divergent sequences, both Axins could robustly interact with one E. multilocularis beta-catenin paralog and limited its accumulation in a heterologous mammalian expression system. Similarly to what has been described in planarians (free-living flatworms), other beta-catenin paralogs showed limited or no interaction with either Axin and are unlikely to function as effectors in Wnt signaling. Additionally, both Axins interacted with three divergent GSK-3 paralogs that are conserved in free-living and parasitic flatworms. Axin paralogs have highly segregated expression patterns along the antero-posterior axis in the tapeworms E. multilocularis and Hymenolepis microstoma, indicating that different beta-catenin destruction complexes may operate in different regions during their larval metamorphosis.

Identification and expression profiling of microRNAs in Hymenolepis.

Tapeworms (cestodes) of the genus Hymenolepis are the causative agents of hymenolepiasis, a neglected zoonotic disease. Hymenolepis nana is the most prevalent human tapeworm, especially affecting children. The genomes of Hymenolepis microstoma and H. nana have been recently sequenced and assembled. MicroRNAs (miRNAs), a class of small non-coding RNAs, are principle regulators of gene expression at the post-transcriptional level and are involved in many different biological processes. In previous work, we experimentally identified miRNA genes in the cestodes Echinococcus, Taenia and Mesocestoides. However, current knowledge about miRNAs in Hymenolepis is limited. In this work we described for the first known time the expression profile of the miRNA complement in H. microstoma, and discovered miRNAs in H. nana. We found a reduced complement of 37 evolutionarily conserved miRNAs, putatively reflecting their low morphological complexity and parasitic lifestyle. We found high expression of a few miRNAs in the larval stage of H. microstoma that are conserved in other cestodes, suggesting that these miRNAs may have important roles in development, survival and for host-parasite interplay. We performed a comparative analysis of the identified miRNAs across the Cestoda and showed that most of the miRNAs in Hymenolepis are located in intergenic regions, implying that they are independently transcribed. We found a Hymenolepis-specific cluster composed of three members of the mir-36 family. Also, we found that one of the neighboring genes of mir-10 was a Hox gene as in most bilaterial species. This study provides a valuable resource for further experimental research in cestode biology that might lead to improved detection and control of these neglected parasites. The comprehensive identification and expression analysis of Hymenolepis miRNAs can help to identify novel biomarkers for diagnosis and/or novel therapeutic targets for the control of hymenolepiasis.

Effect of Mass Stool Examination and Mass Treatment For Decreasing Intestinal Helminth and Protozoan Infection Rates in Bolivian Children: A Cross-Sectional Study.

Bolivia is one of the countries with a high intestinal helminth and protozoan infection rate. Despite the high prevalence of the parasitic infection, nationwide preventive measures for Bolivian children have not yet been implemented. We evaluated the effect of mass stool examination and treatment as a strategy for decreasing the infection rate. This study was conducted between 2013 and 2015 in children aged 2-18 years. A total of 2,033 stool samples (575 in 2013, 815 in 2014 and 642 in 2015) were collected and examined using the formalin-ether medical sedimentation method. As an anthelminthic medicine, nitazoxanide was given to all infected children within 2 months post-examination, each year. The effect of mass stool examination and treatment was evaluated based on the changes in the overall or individual parasitic infection rates during the study period. The overall parasitic infection rate decreased significantly from 65.2% in 2013 to 43.0% in 2015; a 22.2 percentage point decrease (P<0.001). Protozoan infection accounted for a large portion of the parasitic infections, in the following rates: 62.4% in 2013, 49.3% in 2014, and 41.0% in 2015. The rate of the most common helminth infection, Hymenolepis nana, decreased significantly from 9.0% in 2013 to 6.4% in 2014 to 3.4% in 2015 (P<0.001). Prevalence of the most common pathogenic protozoan infection, Entamoeba histolytica, decreased significantly from 19.0% in 2013 to 3.0% in 2015 (P<0.001). Conversely, the rate of Giardia intestinalis increased significantly from 16.5% in 2013 to 21.2% in 2015 (P<0.01). Mass stool examination and treatment for intestinal helminth and protozoan infections was effective for decreasing the overall parasitic infection rate in the study population, excluding Giardia intestinalis. Further studies on the long-term effect of mass stool examination and treatment for decreasing all intestinal parasitic infection rates in Bolivian children are needed.

Comparative analysis of Wnt expression identifies a highly conserved developmental transition in flatworms.

BACKGROUND: Early developmental patterns of flatworms are extremely diverse and difficult to compare between distant groups. In parasitic flatworms, such as tapeworms, this is confounded by highly derived life cycles involving indirect development, and even the true orientation of the tapeworm antero-posterior (AP) axis has been a matter of controversy. In planarians, and metazoans generally, the AP axis is specified by the canonical Wnt pathway, and we hypothesized that it could also underpin axial formation during larval metamorphosis in tapeworms. RESULTS: By comparative gene expression analysis of Wnt components and conserved AP markers in the tapeworms Echinococcus multilocularis and Hymenolepis microstoma, we found remarkable similarities between the early stages of larval metamorphosis in tapeworms and late embryonic and adult development in planarians. We demonstrate posterior expression of specific Wnt factors during larval metamorphosis and show that scolex formation is preceded by localized expression of Wnt inhibitors. In the highly derived larval form of E. multilocularis, which proliferates asexually within the mammalian host, we found ubiquitous expression of posterior Wnt factors combined with localized expression of Wnt inhibitors that correlates with the asexual budding of scoleces. As in planarians, muscle cells are shown to be a source of secreted Wnt ligands, providing an explanation for the retention of a muscle layer in the immotile E. multilocularis larva. CONCLUSIONS: The strong conservation of gene expression between larval metamorphosis in tapeworms and late embryonic development in planarians suggests, for the first time, a homologous developmental period across this diverse phylum. We postulate these to represent the phylotypic stages of these flatworm groups. Our results support the classical notion that the scolex is the true anterior end of tapeworms. Furthermore, the up-regulation of Wnt inhibitors during the specification of multiple anterior poles suggests a mechanism for the unique asexual reproduction of E. multilocularis larvae.

[Experimental evaluation of Ulomoides dermestoides (tenebrionidae) as an intermediate host of Hymenolepis diminuta]. / Evaluación experimental de Ulomoides dermestoides (Tenebrionidae) como hospedero intermediario de Hymenolepis diminuta.

The aim of the study was to determine if Ulomoides dermestoides behaves as an intermediate host of Hymenolepis diminuta, therefore one hundred of them were experimentally infected with tapeworm eggs. As a result, it was found that in 92% of the insects formed cysticercoids which, inoculated in laboratory rats, developed the adult stage. These adults produced eggs with which the infection process was repeated, obtaining the same results. Therefore it can be said that U. dermestoides experimentally acts as an intermediate host.

Pesquisa de ovos de helmintos e oocitos de protozoários em alfaces (Lactuca sativa) comercializadas em feiras livres e supermercados / A research about helminths eggs and protozoa oocytes found in lettuce (Lactuca sativa) marketed fairs and supermarket

The fresh consumption of vegetables is an important vehicle for parasitological contamination with helminths in Brazil, especially in low-income people with bad or any kind of sanitation. This study investigated and compared the infection with intestinal parasites eggs and Protozoa oocytes in lettuce sold in supermarkets and street markets of the conquered city of Vitória da Conquista BA. 48 samples of lettuces, by spontaneous sedimentation method (Hoffmann), 24 samples from supermarkets and 24 samples were analyzed fairs. The pellet was analyzed under a light microscope. The samples analyzed, 100% were contaminated. The main parasites found were: Ascaris sp, Taeniasp, Enterobius sp, Hymenolepis sp, Fasciola hepatica, Dipylidium sp., Hookworms, as well as the protozoan oocysts Entamoeba coli. These results indicate that the samples of lettuce are at odds with current law and stressed the need for implementation of a health education program directed at growers and handlers of vegetables.(AU)

O consumo in natura de hortaliças folhosas é um importante veículo de contaminação parasitológica por helmintos no Brasil, principalmente em população de baixa renda com péssimo ou nenhum tipo de saneamento básico. O estudo que segue teve como objetivo investigar e comparar a contaminação por ovos de enteroparasitas em alfaces comercializadas em supermercados e feiras livres do município de Vitória da Conquista BA. Foram analisadas 48 amostras de alfaces, pelo método de sedimentação espontânea (Hoffmann), sendo 24 amostras provenientes de supermercados e 24 amostras de feiras livres. O sedimento foi analisado por microscopia óptica que revelou 100% das amostras contaminadas, sendo os principais: Ascaris sp., Taenia sp., Enterobius sp., Hymenolepis sp., Fasciola hepatica, Entamoeba coli,  Dipilidium sp. e Ancilostomídeos. Esses resultados indicam que as amostras de alfaces estão em desacordo com a legislação vigente e salientam a necessidade de aplicação de um programa de educação sanitária direcionado a horticultores e manipuladores de hortaliças.(AU)

Pesquisa de ovos de helmintos e oocitos de protozoários em alfaces (Lactuca sativa) comercializadas em feiras livres e supermercados / A research about helminths eggs and protozoa oocytes found in lettuce (Lactuca sativa) marketed fairs and supermarket

The fresh consumption of vegetables is an important vehicle for parasitological contamination with helminths in Brazil, especially in low-income people with bad or any kind of sanitation. This study investigated and compared the infection with intestinal parasites eggs and Protozoa oocytes in lettuce sold in supermarkets and street markets of the conquered city of Vitória da Conquista BA. 48 samples of lettuces, by spontaneous sedimentation method (Hoffmann), 24 samples from supermarkets and 24 samples were analyzed fairs. The pellet was analyzed under a light microscope. The samples analyzed, 100% were contaminated. The main parasites found were: Ascaris sp, Taeniasp, Enterobius sp, Hymenolepis sp, Fasciola hepatica, Dipylidium sp., Hookworms, as well as the protozoan oocysts Entamoeba coli. These results indicate that the samples of lettuce are at odds with current law and stressed the need for implementation of a health education program directed at growers and handlers of vegetables.

O consumo in natura de hortaliças folhosas é um importante veículo de contaminação parasitológica por helmintos no Brasil, principalmente em população de baixa renda com péssimo ou nenhum tipo de saneamento básico. O estudo que segue teve como objetivo investigar e comparar a contaminação por ovos de enteroparasitas em alfaces comercializadas em supermercados e feiras livres do município de Vitória da Conquista BA. Foram analisadas 48 amostras de alfaces, pelo método de sedimentação espontânea (Hoffmann), sendo 24 amostras provenientes de supermercados e 24 amostras de feiras livres. O sedimento foi analisado por microscopia óptica que revelou 100% das amostras contaminadas, sendo os principais: Ascaris sp., Taenia sp., Enterobius sp., Hymenolepis sp., Fasciola hepatica, Entamoeba coli,  Dipilidium sp. e Ancilostomídeos. Esses resultados indicam que as amostras de alfaces estão em desacordo com a legislação vigente e salientam a necessidade de aplicação de um programa de educação sanitária direcionado a horticultores e manipuladores de hortaliças.