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PLoS Neglected Tropical Diseases Sep 2020China once suffered greatly from schistosomiasis japonica, a major zoonotic disease. Nearly 70 years of multidisciplinary efforts have achieved great progress in disease... (Meta-Analysis)
Meta-Analysis
China once suffered greatly from schistosomiasis japonica, a major zoonotic disease. Nearly 70 years of multidisciplinary efforts have achieved great progress in disease control, with infections in both humans and bovines significantly reduced to very low levels. However, reaching for the target of complete interruption of transmission at the country level by 2030 still faces great challenges, with areas of ongoing endemicity and/or re-emergence within previously 'eliminated' regions. The objectives of this study were, by using meta-analytical methods, to estimate the overall prevalence of Schistosoma japonicum infections in abundant commensal rodent species in mainland China after the introduction of praziquantel for schistosomiasis treatment in humans and bovines in 1980s. In doing so we thereby aimed to further assess the role of wild rodents as potential reservoirs in ongoing schistosome transmission. Published studies on infection prevalence of S. japonicum in wild rodents in mainland China since 1980 were searched across five electronic bibliographic databases and lists of article references. Eligible studies were selected based on inclusion and exclusion criteria. Risks of within and across study biases, and the variations in prevalence estimates attributable to heterogeneities were assessed. The pooled infection prevalence and its 95% confidence intervals (CIs) were calculated with the Freeman-Tukey double arcsine transformation. We identified a total of 37 relevant articles involving 61 field studies which contained eligible data on 8,795 wild rodents across mainland China. The overall pooled infection prevalence was 3.86% (95% CI: 2.16-5.93%). No significant change in the overall pooled prevalence was observed between 1980-2003 (n = 23 studies) and 2004-current (n = 38 studies). However, whilst the estimated prevalence decreased over time in the marshland and lake regions, there was an apparent increase in prevalence within hilly and mountainous regions. Among seven provinces, a significant prevalence reduction was only seen in Jiangsu where most endemic settings are classified as the marshland and lakes. These estimates changed over season, ranging from 0.58% in spring to 22.39% in winter, in association with increases in rodent density. This study systematically analyzed S. japonicum infections in wild rodents from the published literature over the last forty years after the introduction of praziquantel for schistosomiasis treatment in humans and bovines in 1980s. Although numbers of schistosomiasis cases in humans and bovines have been greatly reduced, no such comparable overall change of infection prevalence in rodents was detected. Furthermore, there appeared to be an increase in S. japonicum prevalence in rodents over time within hilly and mountainous regions. Rodents have been projected to become the dominant wildlife in human-driven environments and the main reservoir of zoonotic diseases in general within tropical zones. Our findings thus suggest that it is now necessary to include monitoring and evaluation of potential schistosome infection within rodents, particularly in hilly and mountainous regions, if we are ever to reach the new 2030 elimination goals and to maximize the impact of future public, and indeed One Health, interventions across, regional, national and international scales.
Topics: Animals; Animals, Wild; China; Humans; Praziquantel; Rodent Diseases; Rodentia; Schistosoma japonicum; Schistosomiasis japonica
PubMed: 32877407
DOI: 10.1371/journal.pntd.0008652 -
Experimental Parasitology Oct 1986Mercury labeled pepstatin was used to demonstrate the site of a pepstatin sensitive hemoglobinase in paraformaldehyde fixed adult Schistosoma japonicum. Pepstatin was...
Mercury labeled pepstatin was used to demonstrate the site of a pepstatin sensitive hemoglobinase in paraformaldehyde fixed adult Schistosoma japonicum. Pepstatin was covalently attached to glutathione using dicyclohexylcarbodiimide followed by addition to methyl mercury chloride. Deposition of mercury was observed in lipid-like globules and autophagic vacuoles in the gastrodermis. Control studies were negative in all instances. These results complement previous cytochemical studies on the distribution of other acid hydrolases in the gastrodermis of schistosomes. It is hypothesized that this pepstatin sensitive enzyme probably belongs to the carboxyl class of proteinases.
Topics: Animals; Aspartic Acid Endopeptidases; Endopeptidases; Hemoglobins; Histocytochemistry; Methylmercury Compounds; Pepstatins; Schistosoma japonicum
PubMed: 3527739
DOI: 10.1016/0014-4894(86)90025-1 -
Pharmacogenomics Dec 2016miRNAs play a significant role in pharmacogenomics and are likely to be important in the molecular mechanism of atesunate (ART) effects on Schistosoma japonicum.
AIM
miRNAs play a significant role in pharmacogenomics and are likely to be important in the molecular mechanism of atesunate (ART) effects on Schistosoma japonicum.
METHODS
We sequenced the RNAs using an Illumina (Solexa) DNA sequencer and compared the relative expression levels of the miRNAs in 10-day-old schistosomula from ART and the parallel control group.
RESULTS
We characterized 95 known miRNAs from S. japonicum schistosomula individuals, including 38 novel miRNA families. Among the detectable 134 miRNAs differentially expressed (>2.0-fold change, p < 0.01) after ART treatment in schistosomula, a total of seven known or novel 3p- or 5p- derived S. japonicum miRNAs were characterized. We propose that sja-miR-125b may regulate the expression of ART metabolizing enzymes, glutathione synthetase or heme-binding protein 2 to help S. japonicum resists or adapts to drug stress and also ART may significantly inhibit sexual maturation of female worms mediated by mir-71b/2 miRNA cluster.
CONCLUSION
This was the first comprehensive miRNAs expression profile analysis of S. japonicum in response to ART, and provides an overview of the complex network of the mechanism of action of ART on S. japonicum.
Topics: Animals; Artemisinins; Artesunate; Computational Biology; Gene Expression Profiling; Humans; MicroRNAs; Schistosoma japonicum; Schistosomicides
PubMed: 27918238
DOI: 10.2217/pgs.16.23 -
Acta Tropica Jul 2020Schistosomula antigens play an important role in the growth and development of Schistosoma japonicum. We investigated the role of S. japonicum adenylate kinase 1 (SjAK1)...
Schistosomula antigens play an important role in the growth and development of Schistosoma japonicum. We investigated the role of S. japonicum adenylate kinase 1 (SjAK1) in the growth and development of schistosomula. Quantitative real-time PCR showed that SjAK1 mRNA was expressed in all schistosomula stages, but increased gradually with the development of S. japonicum schistosomula. Using immunohistochemical techniques, the AK1 protein was found to be mainly distributed in the tegument and in some parenchymal tissues of the schistosomula. Double-stranded RNA-mediated knockdown of AK1 reduced AK1 mRNA transcripts by more than 90%; western blot analysis demonstrated that AK1 protein expression decreased by 66%. Scanning electron microscopy following RNA-mediated AK1 knockdown demonstrated that the sensory papillae degenerated significantly. Transmission electron microscopy demonstrated that the mean thickness of the tegument in the SjAK1 interference group was lower than that in the negative control group. Terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) suggested that, compared with the negative control group, apoptosis increased in the interference group. These results show that AK1 may be involved in the growth and development of S. japonicum schistosomula, and thus may be a target when developing treatments for schistosomiasis.
Topics: Adenylate Kinase; Animals; Female; Mice; Mice, Inbred ICR; Schistosoma japonicum
PubMed: 32277925
DOI: 10.1016/j.actatropica.2020.105467 -
Scientific Reports Oct 2016Schistosoma japonicum is a widespread human and animal parasite that causes intestinal and hepatosplenic schistosomiasis linked to colon, liver and bladder cancers, and...
Schistosoma japonicum is a widespread human and animal parasite that causes intestinal and hepatosplenic schistosomiasis linked to colon, liver and bladder cancers, and anemia. Estimated 230 million people are currently infected with Schistosoma spp, with 779 million people at risk of contracting the parasite. Infection occurs when a host comes into contact with cercariae, a planktonic larval stage of the parasite, and can be prevented by inactivating the larvae, commonly by chemical treatment. We investigated the use of physical non-equilibrium plasma generated at atmospheric pressure using custom-made dielectric barrier discharge reactor to kill S. japonicum cercariae. Survival rate decreased with treatment time and applied power. Plasmas generated in O and air gas discharges were more effective in killing S. japonicum cercariae than that generated in He, which is directly related to the mechanism by which cercariae are inactivated. Reactive oxygen species, such as O atoms, abundant in O plasma and NO in air plasma play a major role in killing of S. japonicum cercariae via oxidation mechanisms. Similar level of efficacy is also shown for a gliding arc discharge plasma jet generated in ambient air, a system that may be more appropriate for scale-up and integration into existing water treatment processes.
Topics: Animals; Cercaria; Humans; Larva; Liver; Physical Phenomena; Schistosoma japonicum; Schistosomiasis japonica
PubMed: 27739459
DOI: 10.1038/srep35353 -
Parasites & Vectors May 2019Schistosomiasis is a debilitating neglected tropical disease that affects approximately 190 million people around the world. Praziquantel (PZQ) is the only drug...
BACKGROUND
Schistosomiasis is a debilitating neglected tropical disease that affects approximately 190 million people around the world. Praziquantel (PZQ) is the only drug available for use against all Schistosoma species. Although PZQ has a high efficacy, recognized concerns have prompted the development of new, alternative drugs for repeated use in endemic areas where PZQ efficacy against strains of Schistosoma is reduced. A hybrid drug containing different pharmacophores within a single molecule is a promising strategy. Our earlier in vivo studies showed the significant antiparasitic activity of a praziquantel derivative, DW-3-15, against Schistosoma japonicum. In the present study, DW-3-15 was synthesized in large amounts by a pharmaceutical company and its schistosomicidal efficacy and stability were further confirmed. Parameters such as parasite viability, pairing and oviposition were evaluated in vitro. An in vivo study was conducted to assess the effect of commercial DW-3-15 on worm burden, egg production and diameter of granulomas. Additionally, to gain insight into the mechanism of action for DW-3-15, morphological changes in the tegument of S. japonicum were also examined.
RESULTS
The in vitro study showed the antiparasitic activity of DW-3-15 against S. japonicum, with significant reductions in viability of adult and juvenile worms, worm pairings and egg output. Compared to PZQ, DW-3-15 induced similar ultrastructural changes and evident destruction of the tegument surface in male worms. In vivo, the oral administration of DW-3-15 at a dose of 400 mg/kg per day for five consecutive days in mice significantly reduced the total worm burden and number of eggs in the liver. Histological analysis of the livers showed a marked reduction in the average diameter of the egg granuloma.
CONCLUSIONS
Our findings suggest that DW-3-15, a PZQ derivative with the prospect of commercial production, can be developed as a potential promising schistosomicide.
Topics: Administration, Oral; Animals; Female; Humans; Liver; Male; Mice, Inbred ICR; Parasite Egg Count; Praziquantel; Schistosoma japonicum; Schistosomiasis japonica; Schistosomicides
PubMed: 31053083
DOI: 10.1186/s13071-019-3442-7 -
Parasitology Research Feb 2005The migration of Schistosoma japonicum and S. mansoni through mouse skin epidermis and dermis was compared by immunofluorescence techniques from 4 to 22 h after... (Comparative Study)
Comparative Study
The migration of Schistosoma japonicum and S. mansoni through mouse skin epidermis and dermis was compared by immunofluorescence techniques from 4 to 22 h after infection. At all times, the percentage of parasites detected in the dermis was significantly higher for S. japonicum than for S. mansoni. Thus, S. japonicum migrates more rapidly very early after infection. This agrees with the quicker migration observed previously by this species for later times. Both species expressed antigens related to the cercarial glycocalyx on the parasite body and antigenically detectable elastase in the acetabular glands, at least until 22 h after infection. Bot sets of antigens were also left as "traces" in cercarial migration channels in the skin as well as in skin tissue in the absence of detectable worms or migration channels. The data further substantiate differences between schistosome species in the speed of migration, and suggest that glycocalyx-related antigens and cercarial elastase continue to be expressed for at least 1 day after infection.
Topics: Animals; Dermis; Epidermis; Fluorescent Antibody Technique; Histological Techniques; Host-Parasite Interactions; Mice; Rabbits; Schistosoma japonicum; Schistosoma mansoni; Schistosomiasis japonica; Schistosomiasis mansoni; Skin; Time Factors
PubMed: 15723270
DOI: 10.1007/s00436-004-1284-4 -
Experimental Parasitology Mar 1992The release pattern of excretory-secretory (E-S) products of Schistosoma japonicum eggs was investigated using eggs cultured in a chemically defined medium (MEMSE-J) for...
The release pattern of excretory-secretory (E-S) products of Schistosoma japonicum eggs was investigated using eggs cultured in a chemically defined medium (MEMSE-J) for 16 days. The amount of protein released in culture supernatants was greater in 0- to 4-day and 12- to 16-day cultures than in 4- to 12-day cultures. The protein composition of E-S products and soluble extracts of newly laid eggs (N-SEA) and in vitro matured eggs (M-SEA) was analyzed by SDS-PAGE. Silver staining patterns of N-SEA and M-SEA were found to be similar except for the band at approximately 66 kDa, which appeared in highest concentrations in N-SEA. Western blot analysis with human infected sera showed antibody recognition of a 140- to 160-kDa antigen present in E-S products from mature eggs, while E-S products from immature eggs were unreactive. When either [35S]methionine or [3H]glucosamine was added to the culture medium, newly synthesized proteins or glycoproteins of the SEA and E-S products were labeled. Incorporation of both isotopes into SEA appears to correlate with developmental activity of the eggs. In contrast, release of E-S proteins and glycoproteins is more apparent as the miracidium matures. These results suggested that the source of E-S products from immature eggs is likely to be the collapsing vitelline cells and that of E-S products from mature eggs to be mainly miracidial secretions.
Topics: Animals; Antigens, Helminth; Carbohydrates; Electrophoresis, Polyacrylamide Gel; Glucosamine; Glycoproteins; Helminth Proteins; Methionine; Molecular Weight; Ovum; Schistosoma japonicum; Silver Staining
PubMed: 1740176
DOI: 10.1016/0014-4894(92)90041-8 -
Gene Jan 2018Vasa, an enzyme belonging to the helicase family, contributes to the regulation of reproductive system development in many species. Thus, we hypothesized that the Vasa3...
Vasa, an enzyme belonging to the helicase family, contributes to the regulation of reproductive system development in many species. Thus, we hypothesized that the Vasa3 gene may function in the reproductive system of the parasite Schistosoma japonicum (S. japonicum), which is a major causative agent of schistosomiasis. It is a severe disease globally affecting humans and animals. To test this hypothesis, we firstly conducted whole mount in situ hybridization analyses and found that the S. japonicum Vasa3 (SjVasa3) gene was expressed mainly in the reproductive organs. We then explored the reproductive functions of Vasa3 in S. japonicum using RNA interference (RNAi) techniques. Coupled schistosomes collected from mice 28days post infection (dpi) were transfected three times with SjVasa3-specific small interfering RNA (siRNA) and cultured in vitro for up to 10days. As measured by quantitative PCR (qPCR) and Western blot analysis, levels of SjVasa3 mRNA and protein in Vasa siRNA treated worms were significantly reduced compared with untreated and scrambled siRNA treated worms. Confocal laser scanning microscopy (CLSM) images showed markedly siRNA induced changes in the morphology of the reproductive organs, especially in the female ovary, vitellarium and the male testes. SjVasa3 gene silencing also significantly reduced egg production. These data demonstrate that SjVasa3 is essential in reproductive organ development and egg production in S. japonicum, and could be a potential target for developing novel compounds to treat schistosomiasis.
Topics: Animals; DEAD-box RNA Helicases; Female; In Situ Hybridization; Male; Mice; Ovary; RNA Interference; Schistosoma japonicum; Schistosomiasis japonica; Testis
PubMed: 28964895
DOI: 10.1016/j.gene.2017.09.054 -
The Southeast Asian Journal of Tropical... Jun 1994The present paper deals with studies on the characteristics of Schistosoma japonicum isolated from five localities in the mainland of China. The following items were... (Comparative Study)
Comparative Study Review
The present paper deals with studies on the characteristics of Schistosoma japonicum isolated from five localities in the mainland of China. The following items were observed and compared including morphometric data, susceptibility of six mammalian hosts, prepatent period, compatibility between larvae and snail hosts, size of hepatic granuloma produced by eggs, immunoreactions in experimental animals, sensitivity to praziquantel, SDS-PAGE protein pattern and its antigenicity analysis, DNA hybridization and genetic variation and differentiation by analysis with multilocus enzyme electrophoresis. By means of these multidisciplinary methods, from morphological to molecular level, the following conclusions may be drawn from our results. The evidence indicates firstly that S. japonicum in the mainland of China comprises a strain complex with several components of geographically distributed strains. At least four distinct strains exist, ie Yunnan, Guangxi, Sichuan and Anhui-Hubei. Characteristics of each strain are distinct and the results of these studies lead to discussion on the problem of the intraspecific and interstrain differentiation of S. japonicum in the mainland of China.
Topics: Animals; China; Disease Vectors; Female; Host-Parasite Interactions; Male; Schistosoma japonicum; Schistosomiasis japonica
PubMed: 7855634
DOI: No ID Found