| Microsporidian are a group of ubiquitous and unicellular protaza, and obligate intracellular parasites lacking mitochondria. Microsporidian can infect a wide rage of the invertebrates and vertebrates, especially including the economic insect, fish, rabbits, fur animal, nibbling the teeth and primate. After the founding of Noseaa bombycis in silkworm by Nageli in 1857,an increasing number of other pathogenic microsporidia have been found and separated in the last 20 years research. Microsporidia which can cause opportunistic infections in immunicompromised humans such as the HIV-infected patient, can cause aggravate patient' s agony, and accelerates patient' s death. Therefore further investigation of microsporidia has much significant theory and realistic meaning in many respects such as health epidemic prevention, environmental ecology and so on. As a traditional industry of our country, the sericulture has been playing an economic important role in agriculture all the time. Nosema. bombycis can cause the destructive pebrine disease and can transmit through eggs. Because of this ,it is quarantined in the silkworm egg production.Thus, this field has always been the focus and keypoint of the research on silkworm pathology. This research regards the microsporidia from Cerace Stipatana Walker as material to infect silkworm and fish, and also research into it' biology and categorised status. The result is as fo11ows:一,Biological characteristic and taxonomy position of the microsporidia from Cerace Stipatana Walker1.The spores which are oval and have light-blue refracted light, tend to get together as a cluster including a matority of octosporous and a minority of 2 spores. Compared to Nosema Bombycis, it has a slightly smaller spore size. Our measurements indicate that the spores are ranging from 2.5-3.5um in length and 1.4-1. 8 um in width. The life cycle of the microsporidia indicates that they reproduce mainly in the manner of binary fission, and have a isofilar polar filament, singlycoiled with about 7 to 12 turns (monocyte 7 turns, binuclear 12 turns ), life cycle is 6 to 10 days.2.The microsporidia from Cerace Stipatana Walker shows their disporoustic and octosporoustic development during sporogenic development. Due to its disporoustic and octosporoustic development, according to biological system for class infication of the microsporidia(Sprague, 1992), the microsporidia from Cerace Stipatana Walker are placed or assigned in Vairimorpha and the species name needs further study before being established. So, the microsporidia from Cerace Stipatana Walker are classified as Vairimorpha. sp.二, The infectious test of Microsporidia from Cerace Stipatana Walker to the silkworm1. The microsporidia from Cerace Stipatana Walker can manly infect muscle of Cerace Stipatana Walker, while inoculating the silkworm , it can infect many tisses, such as midgut epithelial tissue , silkgland,muscle, and so on. When infected seriously, the silkgland turn milky white, still, it can be transmitted to their offsping , but has lower pathogenity than that of silkworm. Pathogenic strength is slightly lower than N. b, the quantity (IC50) is: 1.2×104.2.The microsporidia from Cerace Stipatana Walker can infect parasitic organization muscle mainly among Cerace Stipatana Walker. After infected the silkworm, the number of parasitic organization be infected is increasing, such as midgut epithelial tissue, silk gland, muscle of silkworm, horse organ of inning charge of etc. At one hand, the number of ocrosporoblast reduces sharply while the disporoblash increase, on the other hand, the sopre size is a bit bigger than that in the Cerace Stipatana Walker三,The infection test of the microsporidia from Cerace Stipatana Walker to the fish1.Mix the microporidia and food together and then feed the fish. After 40 days, all fish are dissected. Spot some fish body gonad have milky white phenomenon take place , ffe found milky white gonad and gill, the swelling intestines and totten liver pancreas. Though examinition.it... |
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