Biological Characteristics Of The Fasciola In Tibetan Sheep In Qing Hai

Studied on the intermediate host--lymnaeidae snails of Fasciola and adult Fasciola. Using morphological method and molecular method to identify the species of Fasciola larvas and adults. By the method of tabletting microscopy, investigated on the main intermediate host of Fasciola and the infection rates. Simultaneously, studied on the killing effects on lymnaeidae snails by allicin and matrine. The results showed:1.Redia, cercaria and Metacercaria were collected. By the method of microscopy,they were idented as larvas of Fasciola hepatica preliminarily.Then 18 S r RNA of larvas of Fasciola was cloned. The 18 S r RNA sequence result was compared with sequences of Fasciola hepatica and Fasciola gigantica which have been published in Gen Bank by using DNAMAN. The similarity rates were 99.12% and 92.03% respectively. Based on the analysis of the results that the larvas collected from Lymnaeidae snails were larvas of Fasciola hepatica.2.Intermediate types between Fasciola hepatica and Fasciola gigantic couldn’t be classified and identified by traditional method,so the method of 18 S r RNA gene cloning and sequencing were used to identified the species,the results showed that: The length of the purpose fragment was 1834 bp. The amplificated 18 S r RNA sequence result was compared with sequences of Fasciola gigantica and Fasciola hepatica which had been published in Gen Bank by using DNAMAN. The sequence was 92.92% similar to the 18 S sequence of Fasciola gigantica,and 99.78% similar to the 18 S sequence of Fasciola hepatica. Thus it was identified as Fasciola hepatica.3.Three kinds of Radix swinhoei(Radix cucnnorica, Radix swinhoei and Radix lagotis)were found in this study. By the method of tabletting microscopy and cultivating in the lab,the results showed that there was no infection in Radix swinhoei.Redia of Fasciola was found in Radix lagotis,and the infection rate was low,10%. Redia and cercaria of Fasciola was also found in Radix cucnnorica,and the infection rate was higher than others, 41.33%.Metacercaria as well as found in the cultivation of the process,but it wasn’t found in other two kinds of Lymnaeidae snails.So the main intermediate host of Fasciola hepatica was Radix cucnnorica.4.By extract of Allium sativum L and Sophora flavescens Ait treated Lymnaeidae snails.Lymnaeidae snails were treated by extract of Allium sativum L, 48 th hour, 8mg/L,it was showed that the mortality rate of lymnaeidae snails was 70%, 96 th, 24mg/L the mortality rate was 100% Lymnaeidae snails were treated by extract of Sophora flavescens Ait.And the LC50 at 48 th hour of the two extracts were 6.02mg/L and 45.55mg/Lrespectively.Found that the killing effect of allicin was better than that of matrine,it meant that The resistance ability of Lymnaeidae snails against extract of the Allium sativum L was weaker than that against extract of Sophora flavescens Ait.