Isolation of Cryptosporidium parvum and Cyclospora cayetanensis from vegetables collected in markets of an endemic region in Peru
Isolation of Cryptosporidium parvum and Cyclospora cayetanensis from vegetables collected in markets of an endemic region in Peru
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DOI：
10.4269/ajtmh.1997.57.683
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发表时间：
1997-12-01
影响因子：
3.3
通讯作者：
Sterling, CR
中科院分区：
文献类型：
--
作者：
Ortega, YR;Roxas, CR;Sterling, CR
微小隐孢子虫和卡氏环孢子虫是原生动物病原体，在免疫活性和免疫功能低下的宿主中都会导致长期腹泻。微小隐孢子虫可以通过粪-口途径传播，而卡氏环孢子虫的确切传播机制尚未完全确定。人类似乎是后者的唯一宿主，在世界各地的流行地区观察到了明显的季节性。在高发季和低发季，在秘鲁郊区贫民窟的几个小市场采集了蔬菜样本。蔬菜洗净，收集上清液，离心，颗粒再悬浮在2.5%重铬酸钾溶液中。通过直接显微镜观察、抗酸染色和免疫荧光方法检测微小隐孢子虫和卡氏环孢子虫卵囊。在三个时间段采集样本：低发季节、高发季节开始和高发季节结束。在所有被检测的蔬菜中，14.5%含有微小弧菌卵囊，1.8%含有环孢子虫卵囊。因此，市场蔬菜可能提供了一条传播隐孢子虫和环孢子虫的途径。我们的研究还表明，清洗蔬菜并不能完全清除隐孢子虫和环孢子虫卵囊。
Cryptosporidium parvum and Cyclospora cayetanensis are protozoan pathogens that cause prolonged diarrhea in both immunocompetent and immunocompromised hosts. Cryptosporidium parvum can be transmitted via the fecal-oral route, while the exact mechanisms cf transmission of Cyclospora cayetanensis have not been fully determined. Humans appear to be the sole host for the latter and a distinct seasonality has been observed in endemic areas around the world. Samples of vegetables were collected at several small markets in a periurban slum in Peru during the seasons of high and low incidence. The vegetables were washed, the supernatants were collected and centrifuged, and the pellets were resuspended in a solution of 2.5% potassium dichromate. Pellets were examined using direct microscopic observation, acid-fast staining, and immunofluorescent assays for C. parvum and Cyclospora cayetanensis oocysts. Samples were collected during three time periods: the season of low incidence, the beginning of the season of high incidence, and end of the season of high incidence. Of the total vegetables examined, 14.5% contained C. parvum oocysts and 1.8% had Cyclospora oocysts. Thus, market vegetables may provide a route by which Cryptosporidium and Cyclospora can be transmitted. Our study also suggests that washing vegetables does not completely remove Cryptosporidium and Cyclospora oocysts.