Fasciolosis, a zoonotic infection in humans and livestock, is caused by fasciolid trematodes. The trematode lifecycle requires the infection of a molluscan intermediate host by motile miracidia which hatch from fluke eggs deposited in faeces of definitive host. The transmission of miracidia to snails is considered as the most vulnerable link in their life cycle, and hence has been the focus of considerable interest, in an attempt to reduce the transmission rate. This thesis explores factors involved in interaction between liver fluke miracidia and their snail intermediate host. The species of lymnaeid snails present on farms in Ireland where infected livestock with fasciolosis have been reported, have been identified and their genetic variability and population structure has been determined. The correlation between environmental characteristics and snail prevalence and fluke infection has been assessed (Results I and 11). Host finding and recognition abilities of the Fasciola hepatica miracidia have been studied. Chemotactic ability of the miracidia is found to be comprised and an alternate explanation for successful transmission of the fasciolosis, in which sna'ils were attracted towards the source of miracidia, has been discussed (Results Ill). The swimming patterns of miracidia, from three species of fasciolids, have been determined and analyzed and their responses to physical factors, such as, temperature and salt concentrations have been noted (Results IV). Responses to two anthelmintic drugs by the liver fluke miracidia have been studied, leading to the development of a new method of testing the efficiency of drugs on trematodes (Results IV). Immunofluorescent light microscopy, scanning and transmission electron microscopy have been used to study the structures involved in the movement of miracidia (Result V). The information derived from the experimental work in this thesis may help find an effective way to disrupt the snail-trematode interaction and thus prevent the transmission of fasciolosis
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:676711 |
| Date | January 2015 |
| Creators | Thiagarajan, Lalitha |
| Publisher | Queen's University Belfast |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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