Academic literature on the topic 'Parasitic flatworms; Blood flukes'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Parasitic flatworms; Blood flukes.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Journal articles on the topic "Parasitic flatworms; Blood flukes"
1
Pila, Emmanuel A., Michelle A. Gordy, Valerie K. Phillips, Alethe L. Kabore, Sydney P. Rudko, and Patrick C. Hanington. "Endogenous growth factor stimulation of hemocyte proliferation induces resistance to Schistosoma mansoni challenge in the snail host." Proceedings of the National Academy of Sciences 113, no. 19 (April 25, 2016): 5305–10. http://dx.doi.org/10.1073/pnas.1521239113.
Full textAbstract:
Digenean trematodes are a large, complex group of parasitic flatworms that infect an incredible diversity of organisms, including humans. Larval development of most digeneans takes place within a snail (Gastropoda). Compatibility between snails and digeneans is often very specific, such that suitable snail hosts define the geographical ranges of diseases caused by these worms. The immune cells (hemocytes) of a snail are sentinels that act as a crucial barrier to infection by larval digeneans. Hemocytes coordinate a robust and specific immunological response, participating directly in parasite killing by encapsulating and clearing the infection. Hemocyte proliferation and differentiation are influenced by unknown digenean-specific exogenous factors. However, we know nothing about the endogenous control of hemocyte development in any gastropod model. Here, we identify and functionally characterize a progranulin [Biomphalaria glabrata granulin (BgGRN)] from the snail B. glabrata, a natural host for the human blood fluke Schistosoma mansoni. Granulins are growth factors that drive proliferation of immune cells in organisms, spanning the animal kingdom. We demonstrate that BgGRN induces proliferation of B. glabrata hemocytes, and specifically drives the production of an adherent hemocyte subset that participates centrally in the anti-digenean defense response. Additionally, we demonstrate that susceptible B. glabrata snails can be made resistant to infection with S. mansoni by first inducing hemocyte proliferation with BgGRN. This marks the functional characterization of an endogenous growth factor of a gastropod mollusc, and provides direct evidence of gain of resistance in a snail-digenean infection model using a defined factor to induce snail resistance to infection.
2
SCHOLZ, TOMÁš. "Keys to the Trematoda. Volume II (ed. Jones, A., Bray, R. A. and Gibson, D. I.), pp. 768. Commonwealth Agricultural Bureau International (CABI Publishing), UK and The Natural History Museum, London, UK, 2005. ISBN 0 85199 587 X. £150.00." Parasitology 132, no. 1 (January 2006): 153–54. http://dx.doi.org/10.1017/s0031182005229670.
Full textAbstract:
Trematodes (flukes or digeneans) are by far the most abundant group of parasitic flatworms (Neodermata), and their importance for human and animal health is indisputable. In addition, they exhibit a variety of unique adaptations to parasitism and, probably most remarkably, possess extraordinarily complicated life-cycles. Classification of trematodes represents a very difficult task due to the huge number of existing species and variety of morphological forms, sites of infection within invertebrate and vertebrate hosts and ability to infect a wide spectrum of animals. Therefore, identification of any trematode may represent a problem even for an experienced specialist. This is the reason why I appreciated so much the publication of the first volume of the Keys to the Trematoda in 2002.
3
McManus, Donald P. "Recent Progress in the Development of Liver Fluke and Blood Fluke Vaccines." Vaccines 8, no. 3 (September 22, 2020): 553. http://dx.doi.org/10.3390/vaccines8030553.
Full textAbstract:
Liver flukes (Fasciola spp., Opisthorchis spp., Clonorchis sinensis) and blood flukes (Schistosoma spp.) are parasitic helminths causing neglected tropical diseases that result in substantial morbidity afflicting millions globally. Affecting the world’s poorest people, fasciolosis, opisthorchiasis, clonorchiasis and schistosomiasis cause severe disability; hinder growth, productivity and cognitive development; and can end in death. Children are often disproportionately affected. F. hepatica and F. gigantica are also the most important trematode flukes parasitising ruminants and cause substantial economic losses annually. Mass drug administration (MDA) programs for the control of these liver and blood fluke infections are in place in a number of countries but treatment coverage is often low, re-infection rates are high and drug compliance and effectiveness can vary. Furthermore, the spectre of drug resistance is ever-present, so MDA is not effective or sustainable long term. Vaccination would provide an invaluable tool to achieve lasting control leading to elimination. This review summarises the status currently of vaccine development, identifies some of the major scientific targets for progression and briefly discusses future innovations that may provide effective protective immunity against these helminth parasites and the diseases they cause.
4
OGAWA, K. "Diseases of cultured marine fishes caused by Platyhelminthes (Monogenea, Digenea, Cestoda)." Parasitology 142, no. 1 (July 7, 2014): 178–95. http://dx.doi.org/10.1017/s0031182014000808.
Full textAbstract:
SUMMARYMariculture is a rapidly developing industrial sector. Generally, fish are maintained in net cages with high density. Cage culture systems allow uncontrolled flow of sea water containing potentially infectious stages of fish parasites. In such culture conditions, prevention of such parasitic infections is difficult for parasites with life cycles that complete within culture sites, among which monogeneans and blood flukes are the most important platyhelminthes. Intense monogenean infections induce respiratory and osmo-regulatory dysfunctions. A variety of control measures have been developed, including freshwater bath treatment and chemotherapy. The potential to control monogenean infections through selective breeding, modified culture techniques to avoid infection, and general fish health management are discussed. It should be noted that mariculture conditions have provided some host-specific monogeneans with a chance to expand their host ranges. Blood flukes sometimes induce mass mortality among farmed fish. In-feed administration of praziquantel is the best solution to treat infected fish. Some cases are described that show how international trade in marine fish has resulted in the spread of hitherto unknown parasites into indigenous farmed and wild fish.
5
González-Miguel, J., M. A. Valero, M. Reguera-Gomez, C. Mas-Bargues, M. D. Bargues, F. Simón, and S. Mas-Coma. "NumerousFasciolaplasminogen-binding proteins may underlie blood-brain barrier leakage and explain neurological disorder complexity and heterogeneity in the acute and chronic phases of human fascioliasis." Parasitology 146, no. 3 (September 24, 2018): 284–98. http://dx.doi.org/10.1017/s0031182018001464.
Full textAbstract:
AbstractHuman fascioliasis is a worldwide, pathogenic food-borne trematodiasis. Impressive clinical pictures comprising puzzling polymorphisms, manifestation multifocality, disease evolution changes, sequelae and mortality, have been reported in patients presenting with neurological, meningeal, neuropsychic and ocular disorders caused at distance by flukes infecting the liver. Proteomic and mass spectrometry analyses of theFasciola hepaticaexcretome/secretome identified numerous, several new, plasminogen-binding proteins enhancing plasmin generation. This may underlie blood-brain barrier leakage whether by many simultaneously migrating, small-sized juvenile flukes in the acute phase, or by breakage of encapsulating formations triggered by single worm tracks in the chronic phase. Blood-brain barrier leakages may subsequently occur due to a fibrinolytic system-dependent mechanism involving plasmin-dependent generation of the proinflammatory peptide bradykinin and activation of bradykinin B2 receptors, after different plasminogen-binding protein agglomeration waves. Interactions between diverse parasitic situations and non-imbalancing fibrinolysis system alterations are for the first time proposed that explain the complexity, heterogeneity and timely variations of neurological disorders. Additionally, inflammation and dilation of blood vessels may be due to contact system–dependent generation bradykinin. This baseline allows for search of indicators to detect neurological risk in fascioliasis patients and experimental work on antifibrinolytic treatments or B2 receptor antagonists for preventing blood-brain barrier leakage.
6
JEDLIČKOVÁ, LUCIE, HANA DVOŘÁKOVÁ, MARTIN KAŠNÝ, JANA ILGOVÁ, DAVID POTĚŠIL, ZBYNĚK ZDRÁHAL, and LIBOR MIKEŠ. "Major acid endopeptidases of the blood-feeding monogenean Eudiplozoon nipponicum (Heteronchoinea: Diplozoidae)." Parasitology 143, no. 4 (February 18, 2016): 494–506. http://dx.doi.org/10.1017/s0031182015001808.
Full textAbstract:
SUMMARYIn parasitic flatworms, acid endopeptidases are involved in crucial processes, including digestion, invasion, interactions with the host immune system, etc. In haematophagous monogeneans, however, no solid information has been available about the occurrence of these enzymes. Here we aimed to identify major cysteine and aspartic endopeptidase activities in Eudiplozoon nipponicum, an invasive haematophagous parasite of common carp. Employing biochemical, proteomic and molecular tools, we found that cysteine peptidase activities prevailed in soluble protein extracts and excretory/secretory products (ESP) of E. nipponicum; the major part was cathepsin L-like in nature supplemented with cathepsin B-like activity. Significant activity of the aspartic cathepsin D also occurred in soluble protein extracts. The degradation of haemoglobin in the presence of ESP and worm protein extracts was completely inhibited by a combination of cysteine and aspartic peptidase inhibitors, and diminished by particular cathepsin L, B and D inhibitors. Mass spectrometry revealed several tryptic peptides in ESP matching to two translated sequences of cathepsin L genes, which were amplified from cDNA of E. nipponicum and bioinformatically annotated. The dominance of cysteine peptidases of cathepsin L type in E. nipponicum resembles the situation in, e.g. fasciolid trematodes.
7
Dalton, John P., Patrick Skelly, and David W. Halton. "Role of the tegument and gut in nutrient uptake by parasitic platyhelminths." Canadian Journal of Zoology 82, no. 2 (February 1, 2004): 211–32. http://dx.doi.org/10.1139/z03-213.
Full textAbstract:
The ease of procuring nutrient is probably the main selection pressure that drives and maintains the host–parasite relationship. The feeding activities of the ectoparasitic monogeneans exhibit similarities with the predatory turbellarians, with certain monopisthocotylean members feeding by means of a protrusible pharynx. These parasites degrade fish skin by secreting enzymes extracorporeally, but most of the digestion is carried out intracellularly in cells lining a well-differentiated gut. Some polyopisthocotylean monogeneans, however, living within the vascularized gill chamber, took advantage of the availability of a more highly nutritious, consistent, and renewable diet in the form of blood, and this represented a major step in the evolution of endoparasitism. Blood provides a rich source of carbohydrates for the production of energy and amino acids and fatty acids for the synthesis of parasite molecules and for egg production. The external surfaces of all parasitic flatworms depart from turbellarian character and are composed of a multifunctional syncytial tegument that is permeable to a variety of small organic solutes. Glucose and amino acid transporter molecules situated in the tegumental surface and basal membranes of trematodes and cestodes function in the uptake of these molecules and their distribution to the parasite tissues. Cestodes are bereft of any vestige of a gut, but their tegument has become elaborated into a highly efficient digestive–absorptive layer that competes with the vertebrate mucosa for nutrients. The patterns of energy metabolism in adult flatworm parasites are generally anaerobic and based on glycogen, with abbreviated metabolic pathways and the loss of biosynthetic capacities. In contrast to the tegument, the role of the gut is to digest host macromolecules and subsequently absorb the soluble products. However, the switch to blood as the major source of nutrient necessitated development of a means of overcoming the problems of blood clotting, attack by immune effector mechanisms, and the intracellular accumulations of haematin pigment. Digenean trematode, in contrast to monogeneans, digest blood extracellularly and their secretions include molecules capable of lysing erythrocytes and preventing blood clotting. Digestion of the ingested proteins is generally rapid, involving a range of cathepsin-like cysteine and aspartic proteases, which reduce the blood meal to absorbable peptides that are most likely further catabolized to amino acids by intracellular aminopeptidases. The parasites dispose of accumulated haematin by simply emptying the contents of their blind-ended gut.
8
Wilson, R. Alan, Xiao Hong Li, and William Castro-Borges. "Schistosome vaccines: problems, pitfalls and prospects." Emerging Topics in Life Sciences 1, no. 6 (December 22, 2017): 641–50. http://dx.doi.org/10.1042/etls20170094.
Full textAbstract:
Human schistosomiasis caused by parasitic flatworms of the genus Schistosoma remains an important public health problem in spite of concerted efforts at control. An effective vaccine would be a useful addition to control strategies that currently rely on chemotherapy, but such a product is not imminent. In this review, likely causes for the lack of progress are first considered. These include the strategies used by worms to evade the immune response, concepts that have misdirected the field, an emphasis on internal antigens, and the use of the laboratory mouse for vaccine testing. On a positive note, recent investigations on self-cure by the rhesus macaque offer the most promising context for vaccine development. The identification of proteins at the parasite–host interface, especially those of the esophageal glands involved in blood processing, has provided an entirely new category of vaccine candidates that merit evaluation.
9
Mughal, Mudassar, Qing Ye, Lu Zhao, Christoph Grevelding, Ying Li, Wenda Di, Xin He, Xuesong Li, Robin Gasser, and Min Hu. "First Evidence of Function for Schistosoma japonicum riok-1 and RIOK-1." Pathogens 10, no. 7 (July 8, 2021): 862. http://dx.doi.org/10.3390/pathogens10070862.
Full textAbstract:
Protein kinases are known as key molecules that regulate many biological processes in animals. The right open reading frame protein kinase (riok) genes are known to be essential regulators in model organisms such as the free-living nematode Caenorhabditis elegans. However, very little is known about their function in parasitic trematodes (flukes). In the present study, we characterized the riok-1 gene (Sj-riok-1) and the inferred protein (Sj-RIOK-1) in the parasitic blood fluke, Schistosoma japonicum. We gained a first insight into function of this gene/protein through double-stranded RNA interference (RNAi) and chemical inhibition. RNAi significantly reduced Sj-riok-1 transcription in both female and male worms compared with untreated control worms, and subtle morphological alterations were detected in the ovaries of female worms. Chemical knockdown of Sj-RIOK-1 with toyocamycin (a specific RIOK-1 inhibitor/probe) caused a substantial reduction in worm viability and a major accumulation of mature oocytes in the seminal receptacle (female worms), and of spermatozoa in the sperm vesicle (male worms). These phenotypic alterations indicate that the function of Sj-riok-1 is linked to developmental and/or reproductive processes in S. japonicum.
10
Fabiano, Marco, Alfonso Califano, Francesco Chiancone, Antonio D’Antonio, Francesco Maiorino, Davide Simeone, Gianmarco Silvestre, and Vincenzo Altieri. "Bladder schistosomiasis in Italy: A case report." Urologia Journal 87, no. 4 (March 5, 2020): 191–93. http://dx.doi.org/10.1177/0391560320910647.
Full textAbstract:
Introduction: Human schistosomiasis is a snail-borne disease caused by parasitic blood-dwelling flukes. A long-term infection can lead to the risk of liver damage, kidney failure, infertility, or bladder cancer. The most common sign is hematuria with the blood first seen in the terminal urine, but in severe cases the whole urine sample can be dark colored. We analyze the case of a healthy African child living in Italy since birth, harboring a hidden debilitating disease that was picked up during ultrasonography. Case Report: A 11-year-old African child was admitted to our emergency department with macroscopic hematuria, dysuria, and frequency for 2 months. Ultrasonography revealed a solid mass involving bladder’s right wall. Non-contrast and contrast-enhanced scans of computerized tomography showed a mass of 45 mm x 15 mm on the right bladder wall. A bipolar transurethral resection of bladder was performed. The pathological examination showed findings consistent with Schistosoma haematobium. Discussion: The clinical manifestations of schistosomiasis depend on the inflammatory response to the parasitic infection. In particular, it can manifest in the bladder as painless dysuria, urinary incontinence and urinary frequency, hematuria, or even urinary retention if the trigone is involved. Utilization of ultrasonography for diagnostic evaluation of schistosomiasis is mandatory. For treatment, the World Health Organization recommends praziquantel which has an efficacy of up to 90%.
Dissertations / Theses on the topic "Parasitic flatworms; Blood flukes"
1
Fulford, Anthony John Charles. "Analysis of the patterns of exposure to, and infection by, Schistosoma mansoni." Thesis, University of London, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.312466.
Full textBooks on the topic "Parasitic flatworms; Blood flukes"
1
Barsoum, Rashad S. Schistosomiasis. Edited by Neil Sheerin. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780199592548.003.0181_update_001.
Full textAbstract:
AbstractSchistosomes are blood flukes that parasitize humans, apes, cattle, and other animals. In these definitive hosts they are bisexual, and lay eggs which are shed to fresh water where they complete an asexual cycle in different snails, ending in the release of cercariae which infect the definitive hosts to complete the life cycle.Seven of over 100 species of schistosomes are human pathogens, causing disease in different organs depending on the parasite species. Racial and genetic factors are involved in susceptibility, severity, and sequelae of infection.Morbidity is induced by the host’s immune response to schistosomal antigens. The latter include tegument, microsomal, gut, and oval antigens. The former are important in the process of invasion and establishment of infection, oval antigens in formation of granulomata which lead to fibrosis in different sites, and the gut antigens constitute the main circulating antigens in established infection, leading to immune-complex disease, particularly in the kidneys. The host immunological response includes innate and adaptive mechanisms, the former being the front line responsible for removing 90% of the infecting cercarial load. Adaptive immunity includes a Th1 phase, dominated by activation of an acute inflammatory response, followed by a prolonged Th2 phase which is responsible for immunity to re-infection as well as progression of tissue injury. Switching from Th1 to Th2 phases is controlled by functional and morphological change in the antigen-presenting cells, which is achieved by molecules of host as well as parasitic origin.Many cells participate in parasite killing, but also in the induction of tissue injury. The most potent of these is the eosinophil, which by binding antibodies to the parasite, particularly immunoglobulin E, facilitates parasite elimination. However, this process is complex, including agonist as well as antagonist pathways, which provide escape mechanisms for the parasite to survive, thereby achieving a delicate balance that permits schistosomes to live for decades in the infected host.
Book chapters on the topic "Parasitic flatworms; Blood flukes"
1
Wani, Robert Serafino. "Parasites and Worms." In Tutorial Topics in Infection for the Combined Infection Training Programme. Oxford University Press, 2019. http://dx.doi.org/10.1093/oso/9780198801740.003.0010.
Full textAbstract:
A parasite is an organism that lives on or in a host and gets its food from or at the expense of its host. Worms or helminths either live as parasites or free of a host in aquatic and terrestrial environments. Parasites and worms are found worldwide but mainly in the tropics. It is estimated that 20% of immigrants from endemic countries may have helminthic infections at their arrival to the UK. These people could be asymptomatic, but tend to present with unexplained symptoms, especially gastrointestinal in nature or eosinophilia. Travellers to endemic countries tend to be newly infected and have greater immune response and pronounced eosinophilia in some but not all parasitic infections. Parasites that can cause disease in humans fall under three classes: protozoa, helminths, and Ectoparasites Protozoa are microscopic, one- celled organisms that can be free living or parasitic in nature. Transmission of protozoa that live in a human’s intestine to another human typically occurs through a faeco-oral route (for example, contaminated food or water, or person- to-person contact). Protozoa that live in the blood or tissue of humans are transmitted to other humans by an arthropod vector (for example, through the bite of a mosquito or sand fly). Helminths are large, multicellular organisms that are generally visible to the naked eye in their adult stages. Like protozoa, helminths can be either free living or parasitic. There are three main groups of helminths that parasitize humans: cestodes, trematodes, and nematodes. These are flat worms that comprise Echinococcus species: intestinal tapeworms and neurocysticercosis (Taenia solium) These are leaf- shaped, and they vary in length from a few millimetres to 8 cm. They include: ■ Liver fluke: Clonorchis sinensis, Fasciola hepatica ■ Intestinal fluke: Fasciola buski, Heterophyes heterophyes, ■ Lung fluke: Paragonimus westernmani ■ Blood flukes: Schistosoma species These are cylindrical in structure. Blood- sucking arthropods such as mosquitoes are considered as ectoparasites because they depend on blood meal for their survival. Narrowly speaking, ectoparasites include organisms like ticks, fleas, lice, and mites (scabies) that attach or burrow into the skin and remain there for relatively long periods of time (e.g. weeks to months).