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Parasites & Vectors Nov 2019Accurate diagnosis of urogenital schistosomiasis is vital for surveillance and control programmes. While a number of diagnostic techniques are available there is a need...
BACKGROUND
Accurate diagnosis of urogenital schistosomiasis is vital for surveillance and control programmes. While a number of diagnostic techniques are available there is a need for simple, rapid and highly sensitive point-of-need (PON) tests in areas where infection prevalence and intensity are low. Recombinase Polymerase Amplification (RPA) is a sensitive isothermal molecular diagnostic technology that is rapid, portable and has been used at the PON for several pathogens.
RESULTS
A real time fluorescence RPA assay (RT-ShDra1-RPA) targeting the Schistosoma haematobium Dra1 genomic repeat region was developed and was able to detect 1 fg of S. haematobium gDNA. Results were obtained within 10 minutes using a small portable battery powered tube scanner device that incubated reactions at 40 °C, whilst detecting DNA amplification and fluorescence over time. The assay's performance was evaluated using 20 urine samples, with varying S. haematobium egg counts, from school children from Pemba Island, Zanzibar Archipelago, Tanzania. Prior to RPA analysis, samples were prepared using a quick crude field DNA extraction method, the Speed Extract Kit (Qiagen, Manchester, UK). Positive assay results were obtained from urine samples with egg counts of 1-926 eggs/10 ml, except for two samples, which had inconclusive results. These two samples had egg counts of two and three eggs/10 ml of urine.
CONCLUSIONS
The RT-ShDra1-RPA assay proved robust for S. haematobium gDNA detection and was able to amplify and detect S. haematobium DNA in urine samples from infected patients. The assay's speed and portability, together with the use of crude sample preparation methods, could advance the rapid molecular diagnosis of urogenital schistosomiasis at the PON within endemic countries.
Topics: Animals; Child; Fluorescence; Humans; Neglected Diseases; Point-of-Care Testing; Real-Time Polymerase Chain Reaction; Schistosoma haematobium; Schistosomiasis haematobia; Sensitivity and Specificity; Tanzania
PubMed: 31685024
DOI: 10.1186/s13071-019-3755-6 -
Parasitology Research 1998The development of five schistosome species was compared in mice by the recovery of schistosomula from chopped lung tissue and of adult worms by portal perfusion. Three... (Comparative Study)
Comparative Study
Schistosoma haematobium, S. intercalatum, S. japonicum, S. mansoni, and S. rodhaini in mice: relationship between patterns of lung migration by schistosomula and perfusion recovery of adult worms.
The development of five schistosome species was compared in mice by the recovery of schistosomula from chopped lung tissue and of adult worms by portal perfusion. Three developmental patterns appeared. (1) Schistosoma japonicum was unique in showing an early establishment of schistosomula in and a rapid departure from the lungs together with the highest worm recovery; (2) S. haematobium contrasted by establishing later and persisting in the lungs for at least 2 weeks while yielding the lowest adult worm recovery; and (3) S. intercalatum, S. mansoni, and S. rodhaini had an intermediate pattern--they resided in the lungs for several days, then disappeared and produced intermediate numbers of adults. Lung petechiae, known to accompany the migration of S. japonicum, were never detected after infection with the other species. We speculate that the three migration patterns of schistosomes are related to the size of the relative spectra of naturally infected definitive hosts.
Topics: Animals; Female; Host-Parasite Interactions; Lung; Lymph Nodes; Mesenteric Veins; Mice; Schistosoma; Schistosoma haematobium; Schistosoma japonicum; Schistosoma mansoni; Schistosomiasis; Species Specificity
PubMed: 9569102
DOI: 10.1007/s004360050407 -
Parasitology Research Nov 2015This study concerns the first urinary schistosomiasis case observed in Corsica (France, Europe) occurring in a 12-year-old German boy. The aim was to identify the...
This study concerns the first urinary schistosomiasis case observed in Corsica (France, Europe) occurring in a 12-year-old German boy. The aim was to identify the relationship between this Schistosoma haematobium infection and other schistosomes of the Schistosoma group with terminal-spined ova. Morphological and molecular analyses were conducted on the ova. The results showed that the schistosome responsible for the emergence of schistosomiasis in Corsica was due to S. haematobium introgressed by genes from S. bovis.
Topics: Animals; Child; France; Humans; Male; Molecular Sequence Data; Nucleic Acid Hybridization; Phylogeny; Schistosoma; Schistosoma haematobium; Schistosomiasis haematobia
PubMed: 26268566
DOI: 10.1007/s00436-015-4643-4 -
Infectious Diseases of Poverty Sep 2020Efforts to control and eliminate schistosomiasis have accelerated over the past decade. As parasite burden, associated morbidity and egg excretion decrease, diagnosis... (Clinical Trial)
Clinical Trial Comparative Study
BACKGROUND
Efforts to control and eliminate schistosomiasis have accelerated over the past decade. As parasite burden, associated morbidity and egg excretion decrease, diagnosis with standard parasitological methods becomes harder. We assessed the robustness and performance of a real-time PCR (qPCR) approach in comparison with urine filtration microscopy and reagent strip testing for the diagnosis of Schistosoma haematobium infections of different intensities.
METHODS
The robustness of DNA isolation and qPCR was validated in eight laboratories from Europe and Africa. Subsequently, 792 urine samples collected during cross-sectional surveys of the Zanzibar Elimination of Schistosomiasis Transmission (ZEST) project in 2012-2017 were examined with qPCR in 2018. Diagnostic sensitivity of the qPCR was calculated at different infection intensity categories, using urine filtration microscopy as reference test. Spearman's rank correlation between Ct-values and S. haematobium egg counts was assessed and Ct-value percentiles for infection intensity categories determined.
RESULTS
S. haematobium Dra1 DNA-positive samples were identified correctly in all eight laboratories. Examination of urine samples from Zanzibar revealed Dra1 DNA in 26.8% (212/792) by qPCR, S. haematobium eggs in 13.3% (105/792) by urine filtration, and microhaematuria in 13.8% (109/792) by reagent strips. Sensitivity of the qPCR increased with augmenting egg counts: 80.6% (29/36) for counts between 1 and 4 eggs, 83.3% (15/18) for counts between 5 and 9 eggs, 100% (23/23) for counts between 10 and 49 eggs, and 96.4% (27/28) for counts of 50+ eggs. There was a significant negative correlation between Ct-values and egg counts (Spearman's rho = - 0.49, P < 0.001). Seventy-five percent of the Ct-values were ≥ 33 in the egg-negative category, < 31 in the light intensity category, and < 24 in the heavy intensity category.
CONCLUSIONS
While the sensitivity of the qPCR was ~ 80% for very light intensity infections (egg counts < 10), in general, the Dra1 based qPCR assay detected twice as many S. haematobium infections compared with classical parasitological tests. The qPCR is hence a sensitive, urine-based approach for S. haematobium diagnosis that can be used for impact assessment of schistosomiasis elimination programmes, individual diagnosis, and in improved format also for verification and certification of elimination.
TRIAL REGISTRATION
ISRCTN, ISRCTN48837681 . Registered 05 September 2012 - Retrospectively registered.
Topics: Animals; Cross-Sectional Studies; DNA, Helminth; Europe; Female; Humans; Male; Parasite Egg Count; Reagent Strips; Real-Time Polymerase Chain Reaction; Schistosoma haematobium; Schistosomiasis haematobia; Sensitivity and Specificity; Specimen Handling; Tanzania
PubMed: 32887642
DOI: 10.1186/s40249-020-00726-y -
Parasitology Research Sep 2007Flame atomic absorption spectrometry was performed to determine the alteration of calcium concentration in the soft parts and shells of Biomphalaria alexandrina and...
Flame atomic absorption spectrometry was performed to determine the alteration of calcium concentration in the soft parts and shells of Biomphalaria alexandrina and Bulinus truncatus due to the infection with Schistosoma mansoni and S. haematobium, respectively. The results showed significant lowering in the calcium content of the shells of cercariae shedding B. alexandrina and B. truncatus relative to the calcium content in the shells of uninfected ones. In contrast, the calcium content in the soft parts of cercariae shedding snails was higher than in the soft parts of uninfected snails; the differences were statistically significant. Generally, calcium content was significantly higher in the shells than in the soft parts of the snails, regardless infected or uninfected. The results obtained and the hypothesis of hypercalcification in shells of infected snails were discussed.
Topics: Animals; Biomphalaria; Bulinus; Calcium; Host-Parasite Interactions; Schistosoma haematobium; Schistosoma mansoni
PubMed: 17497170
DOI: 10.1007/s00436-007-0566-z -
Journal of Helminthology Mar 1990Treatment of Schistosoma haematobium (Nigerian strain) in hamsters with a single dose of 40 mg/kg of Astiban caused a reduction in the number of S1, S2, and S3 vitelline...
Treatment of Schistosoma haematobium (Nigerian strain) in hamsters with a single dose of 40 mg/kg of Astiban caused a reduction in the number of S1, S2, and S3 vitelline cells and an increase in S4 cells. Following seven daily doses of the drug, a marked reduction in S1 cells and a complete loss of S2 and S3 cells occurred such that 95% of the cells were S4 cells, all of which were structurally abnormal. Coagulation and disintegration of the protein granules of the vitelline droplets occurred with increase in lipid droplets, swelling of the nuclear membrane and an increase in cytosegresomes. Blebbing of the tegument in both sexes occurred following a single treatment and vacuolation of the basal infolds and alterations to the mitochondria also resulted, but severe erosion of the tegument was rare even following repeated drug treatment. Damage to the gastrodermis was severe with the development of autophagic vacuoles containing whorls of myelin and sequestered portions of damaged tissue. The degree of damage increased with the number of drug treatments.
Topics: Animals; Cricetinae; Dose-Response Relationship, Drug; Female; Male; Microscopy, Electron; Organometallic Compounds; Schistosoma haematobium; Schistosomiasis haematobia; Schistosomicides; Succimer; Sulfhydryl Compounds
PubMed: 2159964
DOI: 10.1017/s0022149x00011901 -
Molecular and Biochemical Parasitology 2011We predicted, and provided evidence for, the existence of a schistosome tegument-associated Mg(2+)-dependent neutral sphingomyelinase (nSMase), which controls hydrolysis...
We predicted, and provided evidence for, the existence of a schistosome tegument-associated Mg(2+)-dependent neutral sphingomyelinase (nSMase), which controls hydrolysis of surface membrane sphingomyelin molecules, thus allowing nutrients, but not host antibodies, to access proteins at the host-parasite interface. While a putative nSMase was identified in a recent Schistosoma mansoni genome sequencing and analysis study, our report is the first to measure nSMase enzymatic activity in Triton X-100-solubilized surface membrane (Sup 1) and whole worm soluble (SWAP) molecules of male and female S. mansoni and Schistosoma haematobium. Neutral, but no acidic, sphingomyelinase activity was readily detectable by the amplex red sphingomyelinase assay, and increased with incubation time and protein amount. Like nSMase family members, the schistosome nSMase activity was significantly (P<0.05 to <0.0001) enhanced by unsaturated fatty acids and phosphatidyl serine and significantly (P<0.01) decreased following exposure to the nSMase specific inhibitor GW4869. Peptides based on the published sequence of S. mansoni putative nSMase and used in a multiple antigen peptide form induced the generation of specific antibodies, which readily bound to the immunogen and to the cognate protein in Sup 1 and SWAP. Immunofluorescence studies suggested the parasite nSMase is located in the worm tegument and gut lining. Studies using RNA interference are in progress to define nSMase role in larval and adult worm surface membrane antigen exposure and unsaturated fatty acid-mediated attrition.
Topics: Animal Structures; Animals; Coenzymes; Fatty Acids, Unsaturated; Larva; Magnesium; Microscopy, Fluorescence; Phosphatidylserines; Schistosoma haematobium; Schistosoma mansoni; Sphingomyelin Phosphodiesterase; Sphingomyelins
PubMed: 21524668
DOI: 10.1016/j.molbiopara.2011.04.003 -
Parasitology Research Aug 2016A comparison has been made for the first time between the cholinergic components of the nervous system of important human digeneans namely Schistosoma mansoni and...
A comparison has been made for the first time between the cholinergic components of the nervous system of important human digeneans namely Schistosoma mansoni and Schistosoma haematobium from infected hamster (Cricentus auratus) in Egypt. In each parasite, the central nervous system consists of two cerebral ganglia and three pairs of nerve cords (ventral, lateral, and dorsal) linked together by some transverse connectives and numerous ring commissures. Peripheral cholinergic innervation was detected in oral and ventral suckers and in some parts of female reproductive system in both species, but there were some differences. The possible functions of some of these nervous components are discussed.
Topics: Acetylcholine; Animals; Cholinergic Agents; Cholinesterases; Cricetinae; Egypt; Female; Humans; Nervous System; Nervous System Physiological Phenomena; Schistosoma haematobium; Schistosoma mansoni
PubMed: 27130318
DOI: 10.1007/s00436-016-5070-x -
Transactions of the Royal Society of... Apr 2012Genetic studies on Schistosoma haematobium are often carried out on DNA extracted from miracidia, cercariae or adult worms. This paper presents a method for extracting...
Genetic studies on Schistosoma haematobium are often carried out on DNA extracted from miracidia, cercariae or adult worms. This paper presents a method for extracting DNA from S. haematobium eggs collected from urine samples and stored on nylon filters at room temperature. DNA was extracted from dried S. haematobium eggs using the DNeasy Blood & Tissue Kit (QIAGEN Sample & Assay Technologies, Copenhagen, Denmark). Selected genes were amplified using PCR to verify that DNA extraction had been successful. DNA was extracted from 45 samples and 31 had a positive PCR reaction for either or both of the two selected genes.
Topics: Animals; Child; DNA, Helminth; Female; Filtration; Humans; Male; Mozambique; Parasite Egg Count; Polymerase Chain Reaction; Schistosoma haematobium; Schistosomiasis haematobia; Schools; Sensitivity and Specificity; Species Specificity; Students
PubMed: 22381628
DOI: 10.1016/j.trstmh.2011.12.002 -
PLoS Neglected Tropical Diseases 2012Schistosomiasis in one of the most prevalent parasitic diseases, affecting millions of people and animals in developing countries. Amongst the human-infective species S....
BACKGROUND
Schistosomiasis in one of the most prevalent parasitic diseases, affecting millions of people and animals in developing countries. Amongst the human-infective species S. haematobium is one of the most widespread causing urogenital schistosomiasis, a major human health problem across Africa, however in terms of research this human pathogen has been severely neglected.
METHODOLOGY/PRINCIPAL FINDINGS
To elucidate the genetic diversity of Schistosoma haematobium, a DNA 'barcoding' study was performed on parasite material collected from 41 localities representing 18 countries across Africa and the Indian Ocean Islands. Surprisingly low sequence variation was found within the mitochondrial cytochrome oxidase subunit I (cox1) and the NADH-dehydrogenase subunit 1 snad1). The 61 haplotypes found within 1978 individual samples split into two distinct groups; one (Group 1) that is predominately made up of parasites from the African mainland and the other (Group 2) that is made up of samples exclusively from the Indian Ocean Islands and the neighbouring African coastal regions. Within Group 1 there was a dominance of one particular haplotype (H1) representing 1574 (80%) of the samples analyzed. Population genetic diversity increased in samples collected from the East African coastal regions and the data suggest that there has been movement of parasites between these areas and the Indian Ocean Islands.
CONCLUSIONS/SIGNIFICANCE
The high occurrence of the haplotype (H1) suggests that at some point in the recent evolutionary history of S. haematobium in Africa the population may have passed through a genetic 'bottleneck' followed by a population expansion. This study provides novel and extremely interesting insights into the population genetics of S. haematobium on a large geographic scale, which may have consequence for control and monitoring of urogenital schistosomiasis.
Topics: Africa; Animals; Cluster Analysis; DNA Barcoding, Taxonomic; DNA, Helminth; Electron Transport Complex IV; Genetic Variation; Haplotypes; Humans; Indian Ocean Islands; Male; Mitochondrial Proteins; Molecular Sequence Data; NADH Dehydrogenase; Schistosoma haematobium; Sequence Analysis, DNA
PubMed: 23145200
DOI: 10.1371/journal.pntd.0001882