TECH APPLICATION by Animal Model
TECH APPLICATION by Animal Model
Parasitic worms, such as nematodes and/or platyhelminthes, cause infections and diseases in humans and animals having a major adverse socioeconomic impact worldwide. Given the limited number of anthelmintic drugs on the market and the currently increasing drug resistance, there is an urgent need for novel anthelmintic.
The assessment of motility is considered to be the current gold standard for measuring drug effectiveness for helminth parasites in vitro. Most motility assays of anthelmintic activity for parasitic worms are laborious and low throughput, and therefore not suitable for screening large compound libraries. Therefore, WMicrotracker system has become a very useful tool for fast screenings and automated biological output readout.
Haemonchus contortus, also known as the barber’s pole worm, is arguably the most injurious helminth parasite for small ruminants (cattle, sheep, and goat). It was estimated that the annual economic losses caused by H. contortus to the livestock industry accounted for up to 300 million globally. The widespread resistance to most of the commercially available antiparasitic drugs requires an urgent development of new and more effective compounds.
Cestode parasites cause neglected diseases, such as echinococcosis and cysticercosis, which represent a significant problem in human and animal health. Echinococcosis is a zoonotic disease caused by infection with tiny tapeworms of the genus Echinocococcus. The two most important forms of the disease in humans are cystic echinococcosis (hydatidosis – E. granulosus) and alveolar echinococcosis (E. multilocularis). Echinococcosis is often expensive and complicated to treat and may require extensive surgery and/or prolonged drug therapy. Prevention programs might focus on the deworming of dogs and sheep, which are the definitive hosts.
Cooperia oncophora is one of the most common intestinal nematodes in cattle in temperate regions. Infections with C. oncophora may result in mild clinical symptoms, but can lead to weight loss and damage of the small intestine. Infections are usually treated with broad-spectrum anthelmintics such as benzimidazole, but resistance to these drugs has developed in the last decades and is now very common.
Ostertagia ostertagi is a common roundworm that causes parasitic gastroenteritis in cattle. It is found worldwide and is economically important to cattle industries, particularly those found in temperate climates. This small brown worm has a direct life cycle with no intermediate hosts, and it is associated with poor weight gain, poor body condition, scour and potentially death if very heavy worm burdens are present.
Teladorsagia circumcincta is one of the most economically important gastrointestinal nematode parasites of sheep and goats in cool temperate regions. This parasite is transmitted through the faecal-oral route, affecting the abomasum and small intestine, cause clinical and economic disease. T. circumcincta resistance to anthelmintics is widespread, thus making control of this parasite highly challenging.
Cestodes (tapeworms) in the genus Mesocestoides are common in carnivores but only very rarely infect humans. M. vogae exhibits much potential as a model for the study of the biochemistry, physiology and differentiation of cestodes. Its larval form (tetrathyridium) is readily maintained in the laboratory by intraperitoneal passage through mice, providing a continuous availability of biological material. Also, it is easily cultured and is regarded as non-infective for humans
Brugia pahangi is a filarial parasite that is transmitted to domestic cats and dogs in South East Asia when infected mosquitoes take a blood meal. It is used as a model for filarial infections because it is relatively easy to maintain the laboratory. It is closely related to the human parasite Brugia malayi.
Schistosomiasis is infection with blood flukes of the genus Schistosoma, which are acquired transcutaneously by swimming or wading in contaminated freshwater.. It is found primarily across sub-Saharan Africa and some South American countries (Brazil, Venezuela, Suriname) and the Caribbean, with sporadic reports in the Arabian Peninsula. It is classified as a neglected tropical disease.
Angiostrongylus cantonensis, which is also known as the rat lungworm, causes eosinophilic meningitis and is prevalent in Southeast Asia and tropical Pacific islands. The recognized distribution of the parasite has been increasing over time and infections have been identified in other areas, including Africa, the Caribbean, and the United States. The limited number of anthelmintics available is concerning, especially because of increasing drug resistance.
Heligmosomoides polygyrus is a natural murine gastrointestinal helminth that is closely related to highly-prevalent human nematode parasites. H. polygyrus is able to survive long-term in the murine host, establishing chronic infections in rodents and altering host immune responses. This nematode is widely used as a gastrointestinal parasitic model in immunological, pharmacological, and toxicological studies.