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Host Defense and Parasite Evasion
Published in Eric S. Loker, Bruce V. Hofkin, Parasitology, 2023
Eric S. Loker, Bruce V. Hofkin
Helminths have also evolved novel means to avoid complement-mediated damage. Trichinella spiralis, for instance, causes the disease trichinosis. Certain developmental stages of this nematode, notably the adult, which lives in the small intestine, and the encysted larvae, surviving in mammalian striated muscle cells, express calreticulin on their surfaces and secrete it into the surrounding environment. This protein can bind to and inhibit the activity of C1q, the first component in the mammalian classical complement pathway. By inactivating C1q, T. spiralis thus suppresses various complement effector functions, including chemotaxis, cell lysis and inflammation.
The Parasitic Protozoa and Helminth Worms
Published in Julius P. Kreier, Infection, Resistance, and Immunity, 2022
Trichinosis is caused by infection with the nematode worm, Trichinella spiralis. The adult worms, which can infect virtually any carnivorous mammal, are quite small, about 1.5 mm by 0.04 mm for the male, and 3.5 mm by 0.06 mm for the female. The life cycle is simple with the same individual serving as both the intermediate host and definitive host. When infected muscle (containing encysted larvae) is ingested, the larvae are released in the small intestine and invade the mucosa where the worms mature. The females then migrate deeper into the mucosa to deposit larvae that gain access to the lymphatics and the blood. The larvae burrow into the fibers of striated muscle and then encyst (Figure 17.8). The symptoms produced depend on the number of worms ingested and may occur in phases corresponding to the periods of intestinal invasion, migration of larvae, and encystment in muscle. Clinical findings usually consist of diarrhea, muscle pain, fever, weakness, and eosinophilia, and death may result In severe infections. As for most other nematode infections, the mechanisms involved in immunity to T. spiralis in humans is unclear. The migrating larvae secrete a number of antigens that elicit both cellular and antibody responses, and some of these are responsible for the formation of granulomas, consisting of macrophages, lymphocytes, eosinophils, and neutrophils that eventually encapsulate the worm. Adult worms in the gut may be affected by IgE-mediated changes in gut physiology that result in the dislodgement of the worms but not in their death.
Artemisia Species
Published in Mahendra Rai, Shandesh Bhattarai, Chistiane M. Feitosa, Wild Plants, 2020
Suroowan Shanoo, Jugreet B. Sharmeen, Mahomoodally M. Fawzi
Clinical studies conducted on the plant have demonstrated that it is a good antiparasitic agent and reduces the number of Toxocara cati or Toxocara canis eggs in rat feces (Tariq et al. 2009). It is also lethal against Trichinella spiralis, and hence offers protection against roundworm infection, as shown in a study conducted on rats. It protects the liver and restores the potential of its enzymes, such as catalase, glutathione, and superoxide dismutase. It may also be of benefit in Crohn’s disease and against yeast infection (Omer et al. 2007, Juteau et al. 2003).
Nano-crystallization of flubendazole for enhanced dissolution rate and improved in vivo efficacy against Trichinella spiralis
Published in Pharmaceutical Development and Technology, 2023
Ahmed S. Kamel, Soha M. El-Masry, Haidy Abbas, Fatma Mkh Ibrahim, Hager S. Zoghroban, Gamal M. El Maghraby
Flubendazole is one of the most widely prescribed antiparasitic agents. It showed promising activity against Trichinella spiralis. However, its activity depended on the time of administration post infection with early administration being essential. This means that the drug will be effective on the intestinal phase of the disease but not on the migrating larvae or encysted phases. This can be attributed to its poor bioavailability which is dissolution limited and is also affected by first pass effect (El-Temsahi and El-Mansoury 1995). Authors tried to enhance oral absorption of flubendazole through amorphization approaches or adsorption on mesoporous silica (Vialpando et al. 2016), formation of nanofibrous solid dispersion in presence of hydroxylpropyl β − cyclodextrin and polyvinyl pyrrolidone (Vigh et al. 2017) and finally, extrusion with copovidone by hot melting (de Assis et al. 2022). Another study studied co-crystals with maleic acid through solvent assisted milling (de Araujo et al. 2018). Formulation of biodegradable nanoparticles (Farhadi et al. 2018) and nano-emulsion were also studied (Yukuyama et al. 2021). To the best of our knowledge, Anti-solvent precipitation technique to enhance dissolution rate of flubendazole through nanocrystal formation and evaluate its in vivo efficacy through oral administration was not investigated before.
Correlates of Immune Response in Trichinella spiralis Infection
Published in Immunological Investigations, 2018
Eun-Kyung Moon, Su-Hwa Lee, Yunsoo Soh, Yuan-Ri Guo, Ying Piao, Fu-Shi Quan
Trichinella spiralis is distributed worldwide. It has been found in rodents, pigs, horses, bears, and humans, causing a disease called trichinellosis (Franssen et al., 2011). Infection in animals or humans occurs after ingestion of Trichinella larvae that are encysted in muscle tissues of domestic or wild animal meat. Upon infection, T. spiralis larvae will reach the host’s intestinal tract and become adults. Each adult female produces batches of live larvae. These larvae can bore through the intestinal wall and enter the blood and lymphatic system. They are then carried to the striated muscle (Chu et al., 2014). T. spiralis infection induces host immune responses, including antibodies, T cells, mast cells, eosinophils, and neutrophils as immune reaction to this nematode (Bruschi and Chiumiento, 2012). Antibody response against T. spiralis in infected rats has been reported to be dose dependent. A positive correlation between the number of recovered muscle larvae and serum antibody levels has been found (Franssen et al., 2011). However, whether serum antibody level is positively correlated with infective stage is currently unclear. Serum antibody response is a useful tool for detecting T. spiralis in rats, mice, and humans for diagnosis purpose (Chu et al., 2016; Franssen et al., 2011; Kim et al., 2011). Without detecting T. spiralis-specific antibody response in serum, it is difficult to make a clinical diagnosis of trichinellosis because signs and symptoms of trichinellosis in humans are nonspecific, mimicking many other illnesses. Increased levels of eosinophils in blood or tissue have been historically recognized as a distinctive feature of helminth infections in mammals (Behm and Ovington, 2000). T. spiralis-specific serum antibody response, blood eosinophil response, and a history of consuming potentially contaminated meat are needed to support its clinical diagnosis.
Introduction to the special issue on gastroenterology
Published in Paediatrics and International Child Health, 2019
Strongyloides stercoralis can persist in the body for years. Clinical features include larva currens (skin disease), malabsorption and hyperinfection syndrome. Trichinella spiralis is contracted by eating undercooked pork. The small intestine phase (enteric) is associated with vomiting and abdominal pain and is followed by the migratory phase associated with severe local and systemic symptoms including cardiac and neurological disorders.