Research Of Taenia Pisiformis On Structural Characteristics And Pathogenesis At Different Developmental Stages

Rabbit cysticercus pisiformis poses a worldwide distribution and serious threat to thedevelopment of rabbit and canine keeping. It is important value on veterinary public health tostudy the disease. To clear structural characteristics and pathogenesis at different developmentalstages of taenia pisiformis, canine and rabbits models respectively artificial infected taeniapisiformis and cysticercus pisiformis were successfully developed to observe ultrastructure andhistological structure of taenia pisiformis, hexacanth and cysticercus pisiformis with electronmicroscope and histopathological techniques. Moreover, pathological changes of rabbit infectedcysticercus pisiformis was studied and discussed.1）Canine was dewormed before artificially infection with cysticercus pisiformis, andgravid proglottid was exerted and collected after42days. The infected canine was killed tocollect whole adult worm after70days, the scolex, collum segment, mature and gravid proglottidof adult worm were prepared for transmission electron microscopic eximination, and wereprepared as paraffin section, then stained with HE, Masson’s special staining and Langhan’sspecial staining respectiveluy for light microscopic eximination. The results showed that thebasic structure of taenia pisiformis was as simialr as that of taenia solium, but the hamulus coreof taenia pisiformis was heterogeneous, that was different from taenia solium.2）oncosphere were separated,activated in artificial intestinal juice and prepared fortransmission electron microscopic eximination. The results showed that oncosphere of taeniapisiformis included cortical, subcutaneous and stroma layers, the basic structure of taeniapisiformis oncosphere was as simialr as that of taenia solium oncosphere, but the diameter ofhamulus basal partof was smaller than that of its end part, and hamulus core was heterogeneousin taenia pisiformis oncosphere, that was different in taenia solium oncosphere. Syncytium with9nuclear was observed in stroma layer and its structure was as same as the aruond structure,which confirmed that the basic structure of taenia pisiformis oncosphere was comprised bysyncytium.3）Rabbits, identified serologically without cysticercus pisiformis antibody, were artificiallyinfected oncosphere and isolated for2months to collcet adult cysticercus pisiformis, of whichultrastructure and histological structure were observed with the above method. The results showed that the structure of cysticercus pisiformis was almost same as that of cysticercuscellulosa and sheep coenosis. However, cysticercus pisiformis parasitized the surface ofomentum majus and mesentery, and were not checked out in muscle. Microvillus was notobserved on cyst wall of cysticercus pisiformis. This indicated that the basic structure wasalomost same among cysticercus of taeniidae taenia.4) Rabbits, identified serologically without cysticercus pisiformis antibody, were artificiallyinfected oncosphere and divided into high dose group(6) and low dose group(6) according to theinfectious amount, the control group was arranged6rabbits. At7,30,and60days after infection,the liver, spleen and kidney of all groups were collected to prepared paraffin section and stainwith HE for light microscopic observation. At the same time, the blood was taken from ear veinper week for hematologic examination. The light microscopic results showed that the liver,spleen and kidney of experimetal groups presented a pathological change of acute hemorrhagicinflammation, hepatocellular showed vacuolar degeneration, oncosphere can be found onhepatocellular mesenchyme and granuloma had preliminarily formed at early stage; that thecysticercus migrating channels can be observed, hepatocellular showed serven vacuolardegeneration, immature cysticercus can be found on hepatocellular mesenchyme afer one months;and that hepatocellular showed vacuolar and flocular degeneration, and parasitic specialgranuloma can be observed at late stage. The results of hematologic examination showed thatperipheral blood neutrophilic granulocyte and lymphocyte of experimetal groups were obvioushigher than that of control group after one week, but began to decrease after one month and werealmost close to that of control group after two months. Compared with control group, monocyteand eosinophilic granulocyte of experimental groups increase obviously after one week, andcontinued to increase after one month, but decrease to the near normal level after two months.