Morphological changes and viability of Cryptosporidium parvum sporozoites after excystation in cell-free culture media
Morphological changes and viability of Cryptosporidium parvum sporozoites after excystation in cell-free culture media
复制标题
DOI：
10.1017/s0031182010000685
复制
发表时间：
2010-11-01
期刊：
影响因子：
2.4
通讯作者：
Sasai, K.
中科院分区：
文献类型：
--
作者：
Matsubayashi, M.;Ando, H.;Sasai, K.
隐孢子虫属顶复门，是世界范围内引起水传播性胃肠炎的主要病原。子孢子被认为是利用称为滑动运动的主动过程侵入宿主肠细胞。然而，在这一过程中，子孢子内的生物学和形态学变化尚未完全了解。在本研究中，C。在体外对小孢子进行了超微结构分析，并使用荧光染料评价了它们的活力。在培养液中培养3 h后，从卵囊中脱出的子孢子形态由香蕉形变为杆状，最后变为圆形。透射显微镜观察发现，顶端和核之间的距离显着减少，致密的颗粒存在接近棒状体在顶端区域，支链淀粉颗粒缺席，和圆形子孢子的膜不太清楚。荧光检测结果显示，0-3 h存活率从89%下降到56%（香蕉形子孢子为84.3%，杆状子孢子为49.2%）。因此，脱囊后的子孢子在体外经历了形态学变化和活力的迅速丧失。这种染色方法是有用的，廉价的，并提供了一种替代更昂贵和密集的流式细胞术测定或感染性测定与宿主细胞在体外。
Cryptosporidium parvum, belonging to the phylum Apicomplexa, is a major cause of waterborne gastroenteritis throughout the world. The sporozoites are thought to invade host enterocytes using an active process termed gliding motility. However, the biological and morphological changes within the sporozoites during this process are not fully understood. In the present study, excysted sporozoites of C. parvum were analysed ultrastructurally in vitro and their viability was evaluated using fluorescent dyes. The sporozoites excysted from oocysts changed morphologically from banana-shaped to rod-shaped and finally to a rounded shape, in culture media in 3 h. Transmission microscopy revealed that the distance between the apical end and the nucleus was markedly reduced, dense granules were present close to the rhoptry in the apical region, amylopectin granules were absent, and membranes of round sporozoites were less clear. A fluorescent assay showed that the rate of survival decreased from 89% to 56% at 0-3 h (84.3% for banana-shaped and 49.2% for rod-shaped sporozoites). Therefore, post-excysted sporozoites in vitro underwent morphological changes and a rapid loss of viability. This staining method is useful, inexpensive and provides an alternative to more costly and intensive flow cytometric assays or infectivity assays with host cells in vitro.