Dowd S E, Gerba C P, Pepper I L
Department of Microbiology and Immunology, Water and Environmental Science, University of Arizona, Tucson, Arizona 85721, USA. Scot
Appl Environ Microbiol. 1998 Sep;64(9):3332-5. doi: 10.1128/AEM.64.9.3332-3335.1998.
Microsporidia, as a group, cause a wide range of infections, though two species of microsporidia in particular, Enterocytozoon bieneusi and Encephalitozoon intestinalis, are associated with gastrointestinal disease in humans. To date, the mode of transmission and environmental occurrence of microsporidia have not been elucidated due to lack of sensitive and specific screening methods. The present study was undertaken with recently developed methods to screen several significant water sources. Water concentrates were subjected to community DNA extraction followed by microsporidium-specific PCR amplification, PCR sequencing, and database homology comparison. A total of 14 water concentrates were screened; 7 of these contained human-pathogenic microsporidia. The presence of Encephalitozoon intestinalis was confirmed in tertiary sewage effluent, surface water, and groundwater; the presence of Enterocytozoon bieneusi was confirmed in surface water; and the presence of Vittaforma corneae was confirmed in tertiary effluent. Thus, this study represents the first confirmation, to the species level, of human-pathogenic microsporidia in water, indicating that these human-pathogenic microsporidia may be waterborne pathogens.
微孢子虫作为一个群体，可引发多种感染，不过，尤其是微孢子虫的两个物种，即比氏肠微孢子虫和肠道脑炎微孢子虫，与人类胃肠道疾病有关。迄今为止，由于缺乏灵敏且特异的筛查方法，微孢子虫的传播模式和环境中的存在情况尚未阐明。本研究采用最近开发的方法对几种重要水源进行筛查。对水样浓缩物进行群落DNA提取，随后进行微孢子虫特异性PCR扩增、PCR测序以及数据库同源性比较。总共筛查了14份水样浓缩物；其中7份含有人类致病微孢子虫。在三级污水处理厂出水、地表水和地下水中证实存在肠道脑炎微孢子虫；在地表水中证实存在比氏肠微孢子虫；在三级污水处理厂出水中证实存在角膜维塔孢子虫。因此，本研究首次在物种水平上证实了水中存在人类致病微孢子虫，表明这些人类致病微孢子虫可能是水源性病原体。
