Identifying and validating the presence of Guanine-Quadruplexes (G4) within the blood fluke parasite Schistosoma mansoni

Schistosomiasis is a neglected tropical disease that currently affects over 250 million individuals worldwide. In the absence of an immunoprophylactic vaccine and the recognition that mono-chemotherapeutic control of schistosomiasis by praziquantel has limitations, new strategies for managing disease burden are urgently needed. A better understanding of schistosome biology could identify previously undocumented areas suitable for the development of novel interventions. Here, for the first time, we detail the presence of G-quadruplexes (G4) and putative quadruplex forming sequences (PQS) within the Schistosoma mansoni genome. We find that G4 are present in both intragenic and intergenic regions of the seven autosomes as well as the sex-defining allosome pair. Amongst intragenic regions, G4 are particularly enriched in 3´ UTR regions. Gene Ontology (GO) term analysis evidenced significant G4 enrichment in the wnt signalling pathway (p<0.05) and PQS oligonucleotides synthetically derived from wnt-related genes resolve into parallel and anti-parallel G4 motifs as elucidated by circular dichroism (CD) spectroscopy. Finally, utilising a single chain anti-G4 antibody called BG4, we confirm the in situ presence of G4 within both adult female and male worm nuclei. These results collectively suggest that G4-targeted compounds could be tested as novel anthelmintic agents and highlights the possibility that G4-stabilizing molecules could be progressed as candidates for the treatment of schistosomiasis.

Schistosome japonicum Proteins that Interact with the Gynecophoral Canal Protein Identified Using a Yeast Two-hybrid System

Background: The large amount of eggs produced by mature female worms not only induce major pathological damage to hosts of schistosomes but also lead to disease transmission. Mature female schistosome worms need constant pairing contact with a male partner as male signaling is indispensable to female growth, development, and reproduction. The gynecophoral canal protein (GCP), a cell-surface glycoprotein that is gender-specific to the male worm, plays a potential role in the interaction between males and females and in stimulating female development and maturation. Methods: In this study, a yeast two-hybrid cDNA library of Schistosome japonicum (Sj) parasites 18 days post-infection was constructed; the SjGCP gene was inserted into a pGBKT7-BD bait plasmid and used as a bait protein to screen for its molecular interactions using a yeast mating procedure.Results: Twenty-four prey proteins that interacted with the SjGCP were selected after excluding false positives; the interactions between two of these, SjLGL and SjColV, and SjGCP were verified by co-immunoprecipitation.Conclusions: The proteins that interacted with SjGCP were identified as being associated with growth, development, and reproductive functionality in S. japonicum.

Human serum activates the tegument of female schistosomes and supports recovery from Praziquantel

Schistosomiasis is one of the most devastating parasitic disease in the world. Schistosoma spp. survive for decades within the vasculature of their human hosts. They have evolved a vast array of mechanisms to avoid the immune reaction of the host. Due to their sexual dimorphism, with the female worm lying within the gynecophoric canal of the male worm, it is the male that is exposed to the immediate environment and the soluble parts of the host’s immune response. To understand how the worms are so successful in fending off the immune attacks of the host, comparative analyses of both worm sexes in human serum (with or without Praziquantel) were performed using scanning electron microscopy, transmission electron microscopy, and immunohistochemistry. Further, gene expression analyses of tegument-specific genes were performed. Following the incubation in human serum, males and females out of pairs show morphological changes such as an altered structure of the pits below the surface and an increased number of pits per area. In addition, female schistosomes presented a marked tuft-like repulsion of their opsonized surface. The observed resistance of females to Praziquantel seemed to depend on active proteins in the human serum. Moreover, different expression profiles of tegument-specific genes indicate different functions of female_single and male_single teguments in response to human serum. Our results indicate that female schistosomes developed different evasion strategies toward the host’s immune system in comparison to males that might lead to more robustness and has to be taken into account for the development of new anti-schistosomal drugs.

Prevalence of Oxyuriasis and its Relationship With Eosinophilia in Children Aged 1 to 6 Years in Marand City, East Azerbaijan Province, Iran

Introduction: Enterobius vermicularis, commonly known as pinworm, is one of the most prevalent intestinal nematodes of humankind belonging to the Oxyuridae family. It is a small, white or transparent, threadlike roundworm. The length of the male worm is 2 to 3 mm and the female worm is 3 to 8 mm in length. This study was performed to determine the prevalence of E. vermicularis and its relationship with disease symptoms, allergic disease symptoms, and eosinophilia in children aged one to six years in Marand city of East Azerbaijan province, Iran. Methods: In this descriptive-analytical study, 200 children were studied using systematic random sampling. Data collection method was based on a questionnaire, peripheral blood smear, and Scotch tape test. In the designed questionnaire, children’s characteristics such as gender and age and parents’ characteristics including job and level of education were recorded. Peripheral blood smear slides were obtained from each child and examined for eosinophilia by a hematologist. Scotch test samples were prepared by parents after providing the necessary training on its sampling method and then examined in the laboratory for the presence of E. vermicularis eggs by a parasitologist. Results: In this study, 64 (32%) children were diagnosed with oxyuriasis. The prevalence of oxyuriasis was 36.5% in boys and 43.7% in girls. There was no significant relationship between oxyuriasis and its symptoms. Additionally, there was no significant relationship between oxyuriasis and allergic disease symptoms. Fourteen children had eosinophilia (7%), of which 9 (64%) were infected with E. vermicularis. There was a significant relationship between E. vermicularis infection and eosinophilia (P ˂ 0.05). Conclusion: According to the results of the study and the importance of the issue for the control and prevention of this disease, it is suggested that people should be provided with the necessary information about the life cycle, ways of transmission, and especially ways to prevent E. vermicularis infestation, and basic measures should be taken to improve the economic situation of the people of the region and to promote public and personal health through public education. Finally, medical treatment of patients and their families should be considered at the same time.

Identifying and validating the presence of Guanine-Quadruplexes (G4) within the blood fluke parasite Schistosoma mansoni

BackgroundSchistosomiasis is a neglected tropical disease that currently affects over 250 million individuals worldwide. In the absence of an immunoprophylactic vaccine and the recognition that mono-chemotherapeutic control of schistosomiasis by praziquantel has limitations, new strategies for managing disease burden are urgently needed. A better understanding of schistosome biology could identify previously undocumented areas suitable for the development of novel interventions.Methodology/Principal findingsHere, for the first time, we detail the presence of G-quadruplexes (G4) and putative quadruplex forming sequences (PQS) within the Schistosoma mansoni genome. We find that G4 are present in both intragenic and intergenic regions of the seven autosomes as well as the sex- defining allosome pair. Amongst intragenic regions, G4 are particularly enriched in 3’ UTR regions. Gene Ontology (GO) term analysis evidenced significant G4 enrichment in the wnt signalling pathway (p<0.05) and PQS oligonucleotides synthetically derived from wnt-related genes resolve into parallel and hybrid G4 motifs as elucidated by circular dichroism (CD) spectroscopy. Finally, utilising a single chain anti-G4 antibody called BG4, we confirm the in situ presence of G4 within both adult female and male worm nuclei.Conclusion/SignificanceThese results collectively suggest that G4-targeted compounds could be tested as novel anthelmintic agents and highlights the possibility that G4-stabilizing molecules could be progressed as candidates for the treatment of schistosomiasis.Author SummarySchistosoma mansoni causes schistosomiasis, a parasitic disease that affects millions of people living in resource-deprived areas of developing countries. No vaccine exists and the current drug treatment has limitations, notably inefficacy against the larval stages of the parasite. New drugs are, therefore, needed to sustainably control schistosomiasis. A further understanding of parasite biology will uncover new targets and lead to the development of novel therapies. Here, we identify the presence of G-Quadruplexes (G4s) in S. mansoni. G4s are four-stranded DNA structures that can affect gene function and, to date, have not been previously found in any parasitic helminth. Computational analysis predicted potential G4 folding sequences within the S. mansoni genome, several of which were confirmed to fold by circular dichroism spectroscopy. Analysis of G4-containing protein coding genes found an enrichment within the wnt signalling pathway, a developmental pathway crucial for axial development in the parasite. Additionally, G4s could be detected within adult worms using a fluorescent antibody that selectively recognises quadruplex structures in nucleic acids. This research describes the presence of a previously unknown structure within the parasite, which could present a new target for developing novel treatments.

Prevalence of Nematodiasis in Omasum and Abomasum of Goats Slaughtered at Pegirian Surabaya Slaughter House Through Gatrointestinal Surgery Method

The purpose of this research is to determine the kind of nematodes and to determine the prevalence result. Thirtysix samples of omasum and abomasum were collected from RPH Pegirian from September-November 2017 then using gastrointestinal surgery to get fresh adult worm, afterwards using Semichen-Acetic Carmine stainning method to makes the object easy to microscopic identify. The result showed that species was found Haemonchus contortus, as an identify result show that adult worm has a character on a anterior part called cervical papilae, female worm has a barber’s pole on body also posterior part has a vulva flap, posterior part of male worm has a bursa copulatrix, spicula, gubernaculum and dorsal rays looks like Y shape. Seventeen positive samples and the prevalence rate was 47,2%, 273 adult worms and female worms 215 (78,75%) and the male worms 58 (21,25%). Chi-Square statistical test (P <0.05) showed that 13 positive samples of kambing kacang (65%) were higher infected Haemonchosis infection than 4 potitive samples of PE (25%).

Morphology and morphometry of adult nematodes on Sumatran elephants (Elephas maximus sumatranus) in Way Kambas National Park area, Indonesia

Background and Aim: Worms from nematodes are the most numerous and the most detrimental in elephants. Most adult worms are located in the digestive tract. Nematode infection is at higher risk in young elephants, which caused several cases such as anemia, hypoalbuminemia, enteritis, and even death. This study aimed to determine the morphology and morphometry of adult nematodes on Sumatran elephants in Way Kambas National Park area. Materials and Methods: Nematode samples were obtained from Sumatran elephants' feces (Elephas maximus sumatranus) in Way Kambas National Park, Lampung Province, after being given Kalbazen® containing albendazole 1000 mg at a dose of 10 mg/kg by the veterinarian in charge of the National Park area. For the morphological and morphometric examinations, we used an Olympus BX 51 microscope equipped with Olympus DP 12 camera and were conducted at the Parasitology Laboratory, Faculty of Veterinary Medicine, Universitas Gadjah Mada. The scanning electron microscopic (SEM) analysis was carried out at the Biology Research Center of the Indonesian Institute of Sciences (Lembaga Ilmu Pengetahuan Indonesia). Results: The results of macroscopic observations of the obtained nematodes showed that the nematodes which were found have the characteristics of round, slim, and white color. The size of a female worm was larger than a male worm. Microscopic examination in four anterior papillae indicated that the dorsal lobe in the copulatory bursa was longer than lateral lobe. The result of inspection with the SEM showed a leaf crown consisting of 10 elements, a pair of amphids laterally, and two pairs of papilla in a submedian region. Conclusion: Based on our morphology and morphometry examinations of adult nematodes in Sumatran elephant (E. maximus sumatranus) in Way Kambas National Park area, the adult nematodes which were found are species of Quilonia travancra.

Systematically improved in vitro culture conditions reveal new insights into the reproductive biology of the human parasite Schistosoma mansoni

ABSTRACTSchistosomes infect over 200 million people. The prodigious egg output of these parasites is the sole driver of pathology due to infection, yet our understanding of their sexual reproduction is limited because egg production is not sustained for more than a few days in vitro. Here, we describe culture conditions that support schistosome sexual development and sustained egg production in vitro. Female schistosomes rely on continuous pairing with male worms to fuel the maturation of their reproductive organs. Exploiting these new culture conditions, we explore the process of male-stimulated female maturation and demonstrate that physical contact with a male worm, and not insemination, is sufficient to induce female development and the production of viable parthenogenetic haploid embryos. We further report the characterization of a novel nuclear receptor, that we call vitellogenic factor 1, that is essential for female sexual development following pairing with a male worm. Taken together, these results provide a platform to study the fascinating sexual biology of these parasites on a molecular level, illuminating new strategies to control schistosome egg production.

Suppression of Schistosoma japonicum Acetylcholinesterase Affects Parasite Growth and Development

To further investigate the importance of Schistosoma japonicum acetylcholinesterase (SjAChE) in cholinergic signaling for parasite growth and development, we used RNA interference (RNAi) to knock-down its expression in adults and eggs in vitro. This resulted in its reduced transcription but also expression of other important genes involved both in cholinergic signaling and glucose uptake were impacted substantially. Significant decreases in AChE protein expression, AChE enzymatic activity, and glucose uptake were observed in the SjAChE-knockdown parasites compared with luciferase controls. In vaccine/challenge experiments, we found that immunization of mice with recombinant SjAChE (rSjAChE) expressed in Escherichia coli elicited reductions in male worm numbers (33%), liver granuloma density (41%), and reduced numbers of mature intestinal eggs (73%) in the vaccinated group compared with the control group. These results indicate AChE plays an important role in the metabolism of male worms, and impacts indirectly on female fecundity leading to increased numbers of immature eggs being released and reduced sizes of liver granulomas. Furthermore, cytokine analysis showed that immunization of mice with rSjAChE elicited a predominantly Th1-type immune response characterized by increased production of IFNγ in splenic CD4+ T cells of vaccinated mice. The study confirms the potential of SjAChE as a vaccine/drug candidate against zoonotic schistosomiasis japonica.