目的 研究大鼠源肺孢子菌的增殖方式.方法 从10只肺孢子菌肺炎(PCP)大鼠模型肺脏灌洗液中分离肺孢子菌,用四胺银染色法确定感染情况.用扫描电镜观察灌洗液中肺孢子菌的增殖情况；用透射电镜观察大鼠肺组织内肺孢子菌的增殖情况.结果 PCP大鼠造模成功,GMS染色下肺孢子菌阳性.扫描电镜下观察到肺孢子菌滋养体的二分裂增殖及接合生殖.透射电镜下观察到肺孢子菌滋养体的二分裂增殖、接合生殖与外出芽生殖,同时观察到包囊的内出芽生殖.结论 肺孢子菌有性生殖、无性增殖方式同时存在.在本研究中无性增殖方式包括滋养体的二分裂增殖、外出芽生殖及包囊的内出芽生殖；有性生殖方式为滋养体的接合生殖.%Objective To study the reproduction mode of Pneumocystis from dexamethasone- treated Wistar rats. Methods Ten female Wistar rats were injected subcutaneously with 1 mg of dexamethasone acetate twice a week to establish the Pneumocystis pneumonia (PCP) model . The rats were sacrificed at 9 weeks after the initiation of treatment. The organisms of Pneumocystis (p.c) were obtained from the bronchoalveolar lavage fluid (BALF) of the ten rats with Pneumocystis pneumonia (PCP). The pellets of BALF were stained with Gomori methenamine silver stain (GMS) to ensure the presence of p.c. The reproduction of Pneumocystis organisms from bronchoalveolar lavage fluid (BALF) of rats was studied with scanning electron microscopy (SEM),and the reproduction of Pneumocystis organisms in rats' lungs was studied with the transmission electron microscopy (TEM). Results The PCP rat model was successfully established and the organisms were found on full of the visual fields. In addition to the observation of binary fission and the conjugation of the trophic forms from the BALF and the lung sections with SEM and TEM, the exogenous budding of the trophic form and the endogenous budding of the cyst were observed from the lung sections with TEM in present study. Conclusion Sexual and asexual reproduction coexist in the life cycle of Pneumocystis organisms. The trophic forms maybe reproduce themselves by binary fission,conjugation and exogenous budding,and the cysts by endogenous budding.
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