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1.
对霉形体进入DK传代细胞内,并进行增殖的情况,作了详细的电镜观察.结果如下:(1)霉形体靠近传代细胞膜表面呈串珠样排列;霉形体与传代细胞膜表面接触部位融合增厚,电子密度增高,向内凹陷,将霉形体裹入细胞质,形成由膜结构包着的包涵体.(2)在传代细胞质中,除可见由膜结构包裹着的霉形体性包涵体外,还可见没有任何膜包着的散在的霉形体,并且均可见到霉形体的裂殖增殖相和出芽增殖相.(3)在传代细胞核的核周池和核质中,均见到典型的霉形体及其裂殖增殖相.(4)霉形体在传代细胞中大量的增殖,致使细胞崩解,霉形体即被释放出来.(5)霉形体使传代细胞出现严重的超微病变.本文还讨论了传代细胞培养污染霉形体后难以救治的根本原因是,霉形体在传代细胞内增殖,故仅仅着眼于消除培养液中的霉形体是不能达到预期结果的. 相似文献
2.
对猪细小病毒(PPV)、牛疱疹病毒2型(BHV2)和犬腺病毒1型(CAV1)3种动物DNA病毒在宿主细胞内的增殖、释放方式以及所致细胞结构的变化,通过电镜进行了观察比较.(1)这3种动物DNA病毒的复制和装配过程均发生在细胞核内,以毒浆结构(Viroplast)或核内包涵体为增殖场所和物质基础,但并非都形成结晶样结构.(2)有囊膜的BHV2,其核壳体在细胞核内装配完成后,从核内膜上以出芽方式获得囊膜,然后进入核周池,聚集的病毒使核外膜向胞质方向隆起,形成病毒性包涵体而脱离核外膜,并逐渐向细胞膜的方向移动,最后从细胞膜的破损处以病毒包涵体形式释放到细胞间隙.而无囊膜的CAV1,核壳体在细胞核内装配完成后,从细胞核膜破损处或细胞核崩解后进入细胞质,待整个细胞崩解后才能释放出来.无囊膜的PPV,在核壳体装配完成后,成堆地以病毒流的方式,从扩张的核孔释放到细胞质中,待细胞崩解后再释放出来.(3)3种病毒增殖时,宿主细胞的固有细胞器,如线粒体、内质网以及溶酶体等均出现不同程度的超微结构变化,并能诱导宿主细胞出现一些新的结构,除毒浆结构外,还有管状结构、细纤维样结构、周期性结构和髓膜样结构等,其中周期性结构仅见于BHV2感染. 相似文献
3.
将精氨酸霉形体和莱氏无（需）胆甾醇霉形体，分别接种于鸡胚细胞，电镜下观察结果如下：（１）此２种霉形体在形态、细胞内分布、增殖形式和吞噬功能以及对培养细胞的选择性等方面是相同的；（２）此２种霉形体引起培养细胞的病理学过程不同。接种ＭＡ的鸡胚细胞，早期即出现髓模样结构和脂质体等退行性变化，晚期在细胞质内才能见到空泡出现；而接种ＡＬ的鸡胚细胞，早期即可出现细胞质内的空泡化现象，晚期细菌质内才可见到髓膜样 相似文献
4.
将精氨酸霉形体（Ｍｙｃｏｐｌａｓｍａａｒｇｉｎｉｎｉ，简称ＭＡ）和莱氏无（需）胆甾醇霉形体（Ａｃｈｏｌｅｐｌａｓｍａｌａｉｄｅａｗｉｉ，简称ＡＬ），分别接种于鸡胚细胞，电镜下观察结果如下：（１）此２种霉形体在形态、细胞内分布、增殖形式和吞噬功能以及对培养细胞的选择性等方面是相同的；（２）此２种霉形体引起培养细胞的病理学过程不同。接种ＭＡ的鸡胚细胞，早期即出现髓膜样结构和脂质体等退行性变化，晚期在细胞质内才能见到空泡出现；而接种ＡＬ的鸡胚细胞，早期即可出现细胞质内的空泡化现象，晚期细胞质内才可见到髓膜样结构和脂质体。 相似文献
5.
本研究以伪狂犬病病毒(pseudorabies virus, PRV)Ra株体外感染ST细胞为生物模型,通过透射电镜对PRV的增殖规律和致细胞病变的显微结构进行观察。结果显示,PRV能诱导ST细胞发生明显病变,细胞的病变程度与PRV感染时间密切相关。PRV Ra株感染ST细胞,病毒吸附于ST细胞表面,以膜融合内陷的方式进入细胞和细胞核内,在细胞核内复制,出现包涵体结构,以出芽方式离开细胞核,在高尔基体等细胞内膜结构处完成病毒粒子的囊膜化过程。感染前期,病毒通过膜融合方式被释放到细胞外,完成细胞间病毒的传播;感染后期,细胞溶解,大量释放病毒粒子。感染细胞超微结构的变化主要体现为:线粒体肿胀、数目减少,嵴面积减少,核内出现包涵体,细胞融合,细胞内空泡化严重,溶细胞现象。 相似文献
6.
应用免疫金电子显微镜技术,研究了犬传染性肝炎病毒(ICHV)在犬肾传代细胞内的形态发生及抗原定位,发现ICHV除了在宿主细胞核内发生外,还有细胞质内发生途径.在细胞质内,病毒核壳体的装配以均质致密包涵体和副晶格包涵体为“基地”,这与细胞核内形态发生方式相似.免疫金标记显示,细胞质包涵体中含有大量的ICHV抗原成分,是核壳体在细胞质内装配的病毒结构蛋白来源.同时,在感染的细胞质内也观察到与细胞核内相同的病毒核心样结构. 相似文献
7.
将水泡性口炎病毒(VSV)接种于原代培养的犊牛口腔黏膜上皮细胞(CPMBCs),通过对不同时间收集的感染细胞制作超薄切片,观察病毒在该细胞上的形态发生。结果表明,VSV能导致CPMBCs出现典型的CPE和超微结构变化,主要表现为细胞圆缩、线粒体肿胀、胞浆空泡化,病毒游离于胞浆内或以出芽方式进入胞浆空泡内,病毒主要在细胞突起处进行出芽增殖,获得囊膜而成熟。感染24h后,细胞出现严重的纤维化,细胞骨架明显。该研究结果为VSV的嗜上皮机制研究提供了重要的依据。 相似文献
8.
9.
应用免疫金电子显微镜技术研究了犬传染性肝炎病毒(ICHV)在犬肾传代细胞内的增殖过程及其病毒抗原在感染细胞内外的定位.结果显示:(1)吸附在细胞膜表面的病毒粒子,主要通过细胞吞饮作用侵入细胞,而吸附在微绒毛膜表面的病毒粒子则可直接“渗入”细胞;(2)在病毒感染不同时用的细胞核内观察到均质型、微粒型、颗粒型、副晶格型、病毒包涵体型及致密型等6种类型包涵体,其中前5种能被免疫金标记,它们是尚未形成病毒粒子的抗原蛋白、病毒装配后剩余的抗原蛋白或ICHV的病毒粒子结晶,致密型包涵体未被免疫金标记,可能是病毒DNA;(3)感染细胞内出现的某些特殊结构均不具有病毒抗原性,其中纤维样结构和管状结构在病毒增殖过程中起支持作用. 相似文献
10.
1猪痘病 病原该病可由两种相似的病毒引起,一是猪痘病毒,它只引起猪发病,只在猪源组织细胞内增殖,并在细胞核内形成空泡和包涵体.第二是痘苗病毒,可以使猪和其他动物感染,能在牛、人、绵羊等动物的胚胎细胞内增殖,并在被感染的细胞内形成包涵体. 相似文献
11.
An ultrastructural study on the interaction of Mycoplasma gallisepticum with the chicken tracheal epithelium 总被引：3，自引：0，他引：3
Seven-day-old chickens wee intratracheally inoculated with Mycoplasma gallisepticum. The tracheas collected 6 and 14 days after chickens were inoculated were subjected to titration of mycoplasma and examination by light and electron microscopy. The mycoplasma organisms grew well; 10(7) to 10(8) color-changing units in a milligram of tissue were determined. Tracheal lesions occurred in close association with the presence of mycoplasmas and were characterized by degeneration of the epithelial cells and inflammatory cellular infiltration of the mucosa. Mycoplasmas were predominantly found extracellularly and only rarely in phagocytic vacuoles of the epithelial cells. Although the mycoplasmas exhibited considerable pleomorphism in size and shape, most of them were oval or round, and the largest diameters were between 300 and 700 mn. Elongated and irregular forms were also observed, particularly in those mycoplasmas adhering to the epithelial cells. The organism had a limiting unit membrane, the fibrillar nuclear area, the peripheral cytoplasmic area containing numerous ribosomes, and a terminal bleb structure. Mycoplasmas attached to the epithelial cells by their blebs close to the host cell membrane. At the attachment site, neither fusion of the membranes of the mycoplasma and host cell nor injury to the host cell membrane could be demonstrated. Nevertheless, seemingly, the intimate association between the adhering mycoplasmas and the epithelial cells might be an important factor in pathogenesis of the disease. 相似文献
12.
N F Friis 《Nordisk veterinaermedicin》1975,27(6):329-336
The mycoplasmas constitute a group of microorganisms placed between bacteria and virus. The name, Mycoplasma, is derived from the mycelial morphology of the organisms. The minimal reproductive unit, the elementary body, measures 0.2-0.5 mum. Unlike bacteria, mycoplasmas are not confined by a rigid cell wall, but just by a thin membrane. For their cultivation, though common bacteriological technique is adequate, especially enriched media are required. Antibiotics, as a rule penicillins, are added to the medium for inhibition of bacteria. Up to the present, 5 porcine species of mycoplasma are known: Mycoplasma suipneumoniae, Mycoplasma hyorhinis, Mycoplasma hyosynoviae, Mycoplasma flocculare, and Acholeplasma granularum. The 4 species first mentioned are very common among swine in Denmark. A. granularum has not been demonstrated so far. Occasionally, other species of mycoplasma are found in swine. M. suipneumoniae is by far the most important porcine mycoplasma, being to-day regarded as the primary etiologic agent in porcine enzootic pneumonia. A pure mycoplasma infection usually results in only weak clinical signs of pneumonia, but the disease may be aggravated by secondary factors as bacteria, parasites, and bad housing conditions. Enzootic pneumonia is usually prevalent only in fattening units, where it tends to persist indefinitely. The mycoplasma infection is practically incurable. Control of the disease is attempted by the SPF-program launched by the Danish Meat Research Institute, Roskilde. In this connexion the high sensitivity of mycoplasmas to physico-chemical influence is of advantage, because it results in a low rate of survival of the organisms outside the host. A further advantage is afforded by the fast that M. suipneumoniae is a definitely swine-specific organism. The rest of the porcine mycoplasmas are of far lesser importance. Yet, M. hyorhinis may produce a sero-fibrinous inflammation of serous cavities and joints in pigs less than 10 weeks old, and M. hyosynoviae may produce arthritis in fattening pigs. 相似文献
13.
Mycoplasmas are a diverse group of pathogens responsible for disease in a wide range of animal species. In recent years there have been considerable advances in knowledge of the proteins and structures involved in adherence in some mycoplasmas, but understanding of the biochemical functions and roles in virulence of another central feature of mycoplasmas, their lipoproteins, continues to develop. The aim of this review is to examine current knowledge of the roles of lipoproteins in the pathogenicity and the evolution of virulence in those mycoplasmas causing disease in domestic animals. Those lipoproteins that have been characterised have roles in adherence, in transport of nutrients into the mycoplasma cell, and in enzymatic interactions with the host. Furthermore they appear to play a prominent role in both inducing the host immune response to infection and in facilitating evasion of this response, particularly through the generation of dramatic levels of antigenic variation on the cell surface. Recent genomic comparisons of several pathogenic mycoplasmas have identified a further level of interaction between lipoproteins and pathogenicity. In several pathogens large scale horizontal gene transfer between distantly related mycoplasma species has resulted in the acquisition of a large number of genes, including those encoding lipoproteins thought to play a role in virulence, by one mycoplasma from another inhabiting the same host species. The interactions between these horizontally transferred genes, their new mycoplasma host and the animal that it infects may be an important contributing factor in the pathogenesis of some mycoplasmoses. 相似文献
14.
A virus isolated from a natural outbreak of canarypox was replicated on the chorioallantoic membranes of chicken embryos, and its ultrastructure and development were observed. Electron microscopy of thin sections of pocks produced on the chorioallantoic membranes revealed a variety of developmental forms which appear similar to those demonstrated in studies of vaccinia, ie, viroplasm or viral factories; immature, undifferentiated virions partially enclosed by membranes; completely enclosed nondifferentiated spherical or oval virions; immature virions with discrete nucleoids; and the more compact brick-shaped mature virions. Two types of A-type inclusions were noted: those with virions around the periphery, and those filled with virus particles. The appearance of mature viruses within the inclusion bodies and different stages of viruses outside the inclusion indicate that in a course of development, maturing poxvirus may enter the inclusion bodies as they acquire surface tubules on their envelopes. Mature virions also were seen budding out of the cell membrane, apparently enveloped in a portion of the membrane. Studies showing the entrance of poxvirus into inclusion bodies have not been reported. In this report, electron micrographs are shown of viruses entering inclusion bodies. 相似文献
15.
Electron microscopic observation of the respiratory tract of SPF piglets inoculated with Mycoplasma hyopneumoniae. 总被引：7，自引：0，他引：7
B atrice Blanchard Maria Marta Vena Annie Cavalier Joseph Le Lannic Jean Gouranton Maryl ne Kobisch 《Veterinary microbiology》1992,30(4):329-341
Seven hysterectomy derived piglets were repeatedly challenged with Mycoplasma hyoneumoniae during the first week of life. Samples of trachea, bronchi and lung tissue collected 2–11 weeks post-inoculation (p.i.) were examined using light and electron microscopy. Autoradiography was used to study in more detail the site of M. hyopneumoniae multiplication. Gross lesions were observed in lung tissue and were characterized by hyperplasia of the epithelium and an increased mononuclear cell accumulation in perivascular and peribronchiolar areas. Mild lesions of the trachea and the bronchi, including epithelial hyperplasia and infiltration of the lamina propria by inflammatory cells, were noted.
Electron microscopy showed that, 2–6 weeks p.i., changes in the mid-trachea and bronchi surface consisted of the loss of cilia. Mycoplasmas covered tufts of cilia remaining on the epithelial cell surface. Scanning and transmission electron micrographs showed that they were predominantly found closely associated with the top of cilia. No specialized terminal structure could be seen and no mycoplasma cells were identified lying free in the lumen nor in close contact with the plasma membrane of cells of microvilli. Some fine fibrils radiating from one mycoplasma to another or to cilia were seen at higher magnification by scanning electron microscopy. Six to eleven weeks p.i., a disrupted epithelial surface lacking cilia was observed. Cells were desquamated and shed into the lumen with cellular remains containing droplets of mucus.
Autoradiography revealed that label corresponded to the observed mycoplasma distribution. At the top of cilia, a high density of labeling was visible in the zone of high mycoplasma concentration. Therefore, incorporation of the label in the mycoplasma is proof or their multiplication in the trachea.
The intimate association between the mycoplasma and cilia may be an important factor in the pathogenesis of the disease caused by M. hyopneumoniae (swine enzootic pneumonia). 相似文献
16.
The incidence of Mycoplasma dispar, Ureaplasma and conventional Mycoplasma in the pneumonic calf lung. 总被引：1，自引：1，他引：0 
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下载免费PDF全文 This report describes the incidence of Mycoplasma dispar, ureaplasma and conventional (large colony) mycoplasma isolated from the pneumonic lungs of groups of young calves and the identification to species level of mycoplasmas in mixed populations with the aid of the indirect fluorescent antibody test. Pneumonic lung tissue yielded one or more mycoplasma species from 88% of the 153 calves cultured. The mycoplasmas identified and percent of the calves with lungs positive for each species were: M. dispar (56%), ureaplasma (44%), Mycoplasma bovis (37%), Mycoplasma arginini (33%) and Mycoplasma bovirhinis (23%). Conventional mycoplasmas isolated from two calves (1%) could not be identified using the antisera available. 相似文献
17.
抗猪支原体共同抗原单克隆抗体的制备与鉴定 总被引：4，自引：2，他引：2
以猪肺炎支原体（Mycoplasma hyopneumoniae,Mhp)168菌株F332作为抗原，免疫8周龄BALB/c小鼠，利用淋巴细胞杂交瘤技术，获得两株能稳定分泌特异单克隆抗体的杂交瘤细胞株。两株单抗与Mhp和猪鼻支原体（M.hyorhinis,Mh)等反应，而不与鸡支原体，对照血清等反应。结果表明两株单抗可能是针对猪支原体共同抗原的单抗，用SDS-PAGE电泳和Western-blot分析猪支原体的膜蛋白成分。结果显示，猪支原体的共同抗原是80kd和30kd蛋白，两株单抗均与Mhp和Mh的30kd蛋白条带反应，表明这两株单抗特异地针对猪支原体的共同抗原成分30kd蛋白，可以看出，这两株单抗在Mhp的抗原分析，血清学诊断和疫苗质量监测以及猪源支原体污染细胞检测等方面有重要应用价值。 相似文献