The major goals of the project are to experimentally explore possible biological effects of selected herbicides (Dalapon, Round-up, Cutrine-plus, Paraquat and 2,4-D Amine) on non-target host-parasite relationships of Fasciola hepatica and its snail intermediate hosts Fossaria cubensis and Pseudosuccinea columella; and, to use the information accrued from these biological effects of each of the herbicides to explore the possibility of ultimately developing biological and other measures of control of fascioliasis. It is hypothesized that the presence and persistence of herbicides at varying concentrations in the aquatic environment of these snails, could possibly relate to the propagation, maintenance and survival of the non-target Fasciola hepatica and the snail intermediate hosts. Specifically, the aims of this project are as follows: (1) to study the sublethal effects of each of the herbicide on (a) ability or inability of the herbicide exposed snail to support polyembryony of the fluke, (b) egg laying capacity and reproductive potential of the snails and possible mutagenic action of the herbicide in causing resistance or refractoriness in the snails, (c) metabolic activities e.g. oxygen uptake by respirometry. Lowery's colormetric method and electrophoretic methods, liquid and paper chromatography will be used for protein and glycogen analyses and characterization and amino acid profiles, (d) physiological characteristics of every stage in the life cycle of the snail and the parasite, (e) longevity, viability, survival and infectivity of metacercariae. Incubation at varying temperatures under treatments with varying concentrations of herbicides will shed some light on the effects of temperature changes on herbicidal activities on the snail and the cercariae and metacercariae of Fasciola hepatica. This project will extrapolate from the results of the aforementioned studies, to explain the possible roles that commonly used herbicides play in the propagation and maintenance of the liver fluke Fasciola hepatica as well as that of their snail intermediate hosts. These flukes are etiological-agents of human and animal fascioliasis in the United States and many other countries in the world. The ultimate goal of this project is to develop a biological and other control measures (models) against fascioliasis. Two undergraduate and one graduate students will be actively and fully involved stepwise in all aspects of experimental works through research training and application of knowledge accrued from such training.
