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The American Journal of Tropical... Dec 2012In schistosomiasis elimination programs, successful discrimination of Schistosoma haematobium from the related animal Schistosoma parasites will be essential for...
In schistosomiasis elimination programs, successful discrimination of Schistosoma haematobium from the related animal Schistosoma parasites will be essential for accurate detection of human parasite transmission. Polymerase chain reaction assays employing primers from two newly selected repeated sequences, named Sh73 and Sh77, did not discriminate S. haematobium when amplifying Sh73-77 intra- or inter-repeats. However, amplification between Sh73 and the previously described DraI repeat exhibited discriminative banding patterns for S. haematobium and Schistosoma bovis (sensitivity 1 pg and 10 pg, respectively). It also enabled banding pattern discrimination of Schistosoma curassoni and Schistosoma intercalatum, but Schistosoma mattheei and Schistosoma margrebowiei did not yield amplicons. Similar inter-repeat amplification between Sh77 and DraI yielded amplicons with discriminative banding for S. haematobium, and S. bovis; however, S. mattheei was detected only at low sensitivity (1 ng). The Sh73/DraI assay detected snails infected with S. haematobium, S. bovis, or both, and should prove useful for screening snails where discrimination of S. haematobium from related schistosomes is required.
Topics: Animals; Bulinus; DNA, Protozoan; Genome; Polymerase Chain Reaction; Repetitive Sequences, Nucleic Acid; Schistosoma haematobium; Species Specificity
PubMed: 23109375
DOI: 10.4269/ajtmh.2012.12-0243 -
Structure (London, England : 1993) Sep 2005Glutathione S-transferases (GSTs) are involved in detoxification of xenobiotic compounds and in the biosynthesis of important metabolites. All GSTs activate glutathione... (Review)
Review
Glutathione S-transferases (GSTs) are involved in detoxification of xenobiotic compounds and in the biosynthesis of important metabolites. All GSTs activate glutathione (GSH) to GS(-); in many GSTs, this is accomplished by a Tyr at H-bonding distance from the sulfur of GSH. The high-resolution structure of GST from Schistosoma haematobium revealed that the catalytic Tyr occupies two alternative positions, one external, involving a pi-cation interaction with the conserved Arg21, and the other inside the GSH binding site. The interaction with Arg21 lowers the pK(a) of the catalytic Tyr10, as required for catalysis. Examination of several other GST structures revealed the presence of an external pocket that may accommodate the catalytic Tyr, and suggested that the change in conformation and acidic properties of the catalytic Tyr may be shared by other GSTs. Arginine and two other residues of the external pocket constitute a conserved structural motif, clearly identified by sequence comparison.
Topics: Animals; Arginine; Catalysis; Enzyme Activation; Glutathione Transferase; Hydrogen Bonding; Protein Conformation; Schistosoma haematobium; Tyrosine
PubMed: 16154081
DOI: 10.1016/j.str.2005.06.007 -
Acta Tropica Apr 2021Accurate diagnosis of urogenital schistosomiasis is vital for surveillance/control programs as well as achieving the WHO 2012-2020 road map for the total eradication of...
Accurate diagnosis of urogenital schistosomiasis is vital for surveillance/control programs as well as achieving the WHO 2012-2020 road map for the total eradication of schistosomiasis. Recombinase polymerase amplification (RPA) has emerged as a rapid and simple molecular tool adaptable for fewer resources with diagnostic accuracy similar to polymerase chain reaction (PCR). This rapid molecular assay employs the use of enzymes for the amplification of nucleic acid taget at a constant temperature. The aim of this study was to validate a real-time RPA assay targeting the Dra 1 repittitive sequence of Schistosoma (S.) haematobium and evaluate its use in urogenital schistosomiasis diagnosis. S. haematobium Dra 1 molecular DNA standard was applied to determine the assay's analytical sensitivity. DNA extracts of S. haematobium, other Schistosoma species, protozoa and bacteria species were used to determine the specificity of the RPA assay. Clinical performance of the assay was validated with a panel of 135 urine samples from volunteers of schistosomiasis endemic communities. The developed assay was evaluated with urine samples extracted by just boiling and with SpeedXtract® DNA extraction kit. A specific fragment of S. haematobium Dra 1 repetitive sequence was amplified within 15 minutes at a constant 42˚C using the developed S. haematobium RPA assay. The detection limit was 15 copies of Dra1 molecular DNA standard per reaction. There was no cross-reaction with other protozoan and bacterial species except Schistosoma species, S. mansoni and S. japonicum. Using 135 urine samples, Schistosoma RPA assay had a clinical sensitivity and specificity of 98.4% (95% CI, 91.6-100) and 100% (95% CI, 94.9-99) respectively when compared to S. haematobium Dra 1 qPCR assay. The diagnostic performance of S. haematobium real-time RPA assay was not affected by the use of crude DNA extracted samples. The S. haematobium RPA assay can serve as an alternative to PCR, especially in low resource settings.
Topics: Animals; Health Resources; Humans; Nucleic Acid Amplification Techniques; Recombinases; Schistosoma haematobium; Schistosomiasis haematobia
PubMed: 33497617
DOI: 10.1016/j.actatropica.2021.105847 -
Zhongguo Xue Xi Chong Bing Fang Zhi Za... Apr 2014Schistosomiasis is a neglected tropical disease that severely threatens human health and affects the socioeconomic development. The causative agent that parasitizes in... (Review)
Review
Schistosomiasis is a neglected tropical disease that severely threatens human health and affects the socioeconomic development. The causative agent that parasitizes in humans mainly involves Schistosoma japonicum, S. mansoni, S. haematobiurn, S. intercalatum and S. mekongi. As the firstly identified schistosome, S. haematobium infection is found to strongly correlate with bladder cancer. This paper mainly reviews the discovery, morphology and life cycle of S. haematobium.
Topics: Animals; Humans; Schistosoma haematobium; Schistosomiasis haematobia
PubMed: 25051845
DOI: No ID Found -
The American Journal of Medicine Mar 2018
Topics: Adolescent; Animals; Humans; Male; Schistosoma haematobium; Schistosomiasis haematobia
PubMed: 29032230
DOI: 10.1016/j.amjmed.2017.09.041 -
Parasitology Research Feb 2019Diagnosis of Schistosoma haematobium relies primarily on microscopical analysis of urine. The method is time consuming and requires some expertise. Genus-specific...
Diagnosis of Schistosoma haematobium relies primarily on microscopical analysis of urine. The method is time consuming and requires some expertise. Genus-specific real-time PCRs have been developed, but we still observed low sensitivity. In the present study, in order to achieve a more sensitive DNA detection of eggs of S. haematobium in urine samples, we wanted to develop a novel protocol of DNA extraction using mechanic disruption of eggs by bead beating as supplementary step. We tested Schistosoma spp. internal transcribed spacer 2 real-time PCR after both methods with and without bead beating. First, we preliminary assessed the DNA detection after bead beating using dilution of 2, 10, 50, and 90 eggs/10 mL, and the Ct value analysis showed significant improved DNA detection per each point of egg concentration using the novel supplementary step. Twenty microscopy positive and five microscopy negative urine samples were used to validate the procedure. All urines came from imported cases and admitted at center for tropical medicine, and were examined by microscopy. PCR results after novel method with bead beating showed 100% to be positive for S. haematobium, compared with 85% positive by our standard extraction procedure. Results confirmed mechanic disruption of eggs by bead beating before DNA extraction to be highly effective method for the detection of S. haematobium DNA in urine.
Topics: Animals; DNA, Helminth; Diagnostic Tests, Routine; Humans; Microscopy; Ovum; Real-Time Polymerase Chain Reaction; Schistosoma haematobium; Schistosomiasis haematobia; Sensitivity and Specificity
PubMed: 30417247
DOI: 10.1007/s00436-018-6137-7 -
Biomolecules Dec 2021Glutathione transferases (GSTs) are the main detoxification enzymes in schistosomes. These parasitic enzymes tend to be upregulated during drug treatment, with being...
Glutathione transferases (GSTs) are the main detoxification enzymes in schistosomes. These parasitic enzymes tend to be upregulated during drug treatment, with being one of the species that mainly affect humans. There is a lack of complete sequence information on the closely related and 26-kDa GST isoforms in any database. Consequently, we engineered a pseudo-26-kDa / GST (Sbh26GST) to understand structure-function relations and ligandin activity towards selected potential ligands. Sbh26GST was overexpressed in as an MBP-fusion protein, purified to homogeneity and catalyzed 1-chloro-2,4-dinitrobenzene-glutathione (CDNB-GSH) conjugation activity, with a specific activity of 13 μmol/min/mg. This activity decreased by ~95% in the presence of bromosulfophthalein (BSP), which showed an IC of 27 µM. Additionally, enzyme kinetics revealed that BSP acts as a non-competitive inhibitor relative to GSH. Spectroscopic studies affirmed that Sbh26GST adopts the canonical GST structure, which is predominantly α-helical. Further extrinsic 8-anilino-1-naphthalenesulfonate (ANS) spectroscopy illustrated that BSP, praziquantel (PZQ), and artemisinin (ART) might preferentially bind at the dimer interface or in proximity to the hydrophobic substrate-binding site of the enzyme. The Sbh26GST-BSP interaction is both enthalpically and entropically driven, with a stoichiometry of one BSP molecule per Sbh26GST dimer. Enzyme stability appeared enhanced in the presence of BSP and GSH. Induced fit ligand docking affirmed the spectroscopic, thermodynamic, and molecular modelling results. In conclusion, BSP is a potent inhibitor of Sbh26GST and could potentially be rationalized as a treatment for schistosomiasis.
Topics: Animals; Enzyme Stability; Escherichia coli; Glutathione Transferase; Helminth Proteins; Models, Molecular; Protein Engineering; Protein Structure, Secondary; Recombinant Proteins; Schistosoma haematobium; Sulfobromophthalein
PubMed: 34944488
DOI: 10.3390/biom11121844 -
Virulence 2010Schistosoma haematobium is a parasitic flatworm that infects millions of people, mostly in the developing world, and is associated with high incidence of bladder cancer...
Schistosoma haematobium is a parasitic flatworm that infects millions of people, mostly in the developing world, and is associated with high incidence of bladder cancer although why is not clear. But our group was able to define the mechanistic relationship for the first time between infection of S. haematobium and cancer. We used in vitro models to demonstrate the presence of informative carcinogenesis-associated phenotypes in CHO cells exposed to Sh total antigen, in which we showed increased cell proliferation, decreased apoptosis, up regulation of the anti-apoptotic molecule Bcl-2, down regulation of the tumor suppressor protein p27, and increased cell migration and invasion. We further discuss the molecular and cellular events that might be responsible for schistosomiasis-related bladder cancer.
Topics: Animals; Apoptosis; CHO Cells; Cell Proliferation; Cricetinae; Cricetulus; Gene Expression Regulation; Helminth Proteins; Humans; Mice; Mice, Nude; Proto-Oncogene Proteins c-bcl-2; Schistosoma haematobium; Schistosomiasis haematobia; Urinary Bladder Neoplasms
PubMed: 21178421
DOI: 10.4161/viru.1.2.10487 -
Parasitology Nov 2018Since the construction of the Diama Dam (1985), the epidemiology of schistosomiasis along the Senegal River Basin (SRB) has been extremely dynamic with outbreaks of both...
Since the construction of the Diama Dam (1985), the epidemiology of schistosomiasis along the Senegal River Basin (SRB) has been extremely dynamic with outbreaks of both intestinal and urogenital schistosomiasis. In the early 2000s, technicians reported cases of suspected urogenital schistosomiasis in adults from the local hospital in Richard-Toll, Lower SRB. The genetic analysis of schistosome miracidia isolated from 11 patients in 2012 from two neighbourhoods (Campement and Gaya) of Richard-Toll confirmed infection with Schistosoma haematobium but also S. haematobium/S. bovis hybrids. Thirty-seven per cent of the miracidia were S. bovis/S. haematobium hybrids and 63% were pure S. haematobium. The data are discussed in relation to the ongoing dynamic epidemiology of the schistosomes in Senegal and the need to treat non-target individuals.
Topics: Adult; Animals; Cyclooxygenase 1; Disease Outbreaks; Humans; Hybridization, Genetic; Polymerase Chain Reaction; Schistosoma; Schistosoma haematobium; Schistosomiasis haematobia; Senegal; Urinary Tract
PubMed: 30185248
DOI: 10.1017/S0031182018001415 -
Parasitology Apr 2018Hybridization events between Schistosoma species (Digenea, Platyhelminthes) are reported with increasing frequency, largely due to improved access to molecular tools....
Hybridization events between Schistosoma species (Digenea, Platyhelminthes) are reported with increasing frequency, largely due to improved access to molecular tools. Nevertheless, little is known about the distribution and frequency of hybrid schistosomes in nature. Screening for hybrids on a large scale is complicated by the need for nuclear and mitochondrial sequence information, precluding a 'simple' barcoding approach. Here we aimed to determine and understand the spatiotemporal distribution of Schistosoma haematobium × Schistosoma bovis hybrids in the Senegal River Basin. From ten villages, distributed over the four main water basins, we genotyped a total of 1236 schistosome larvae collected from human urine samples using a partial mitochondrial cox1 fragment; a subset of 268 parasites was also genotyped using ITS rDNA. Hybrid schistosomes were unevenly distributed, with substantially higher numbers in villages bordering Lac de Guiers than in villages from the Lampsar River and the Middle Valley of the Senegal River. The frequency of hybrids per village was not linked with the prevalence of urinary schistosomiasis in that village. However, we did find a significant positive association between the frequency of hybrids per village and the prevalence of Schistosoma mansoni. We discuss the potential consequences of adopting a barcoding approach when studying hybrids in nature.
Topics: Animals; DNA Barcoding, Taxonomic; DNA, Mitochondrial; DNA, Ribosomal Spacer; Genotype; Genotyping Techniques; Humans; Hybridization, Genetic; Prevalence; Schistosoma; Schistosoma haematobium; Schistosomiasis; Senegal
PubMed: 29667570
DOI: 10.1017/S0031182018000525