Siripanth Chutatip, Punpoowong Benjanee, Amarapal Pornsawan, Thima Niramol, Eampokalap Boonchuay, Kaewkungwal Joranit
Department of Protozoology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
Southeast Asian J Trop Med Public Health. 2004 Sep;35(3):540-6.
This study describes the development of Cryptosporidium parvum in MDCK, MA-104, Hep-2 and Vero cell lines. Differences in susceptibility, infectivity, and the methodology of excystation were determined. Various solutions were considered to determine the factors which enhanced the excystation (eg with and without sodium hypochlorite, trypsin or sodium taurocholate). It was shown that the sporozoites could be excysted in media either with or without trypsin and sodium taurocholate, but the number of sporozoites in the latter solution was less than the former one. Only oocysts digested by sodium hypochlorite and trypsin can enter the culture cells. Numerous meronts and oocysts were demonstrated and persisted for 9 days. Asexual stages were not observed in MA-104. Only few oocysts could be detected 1-3 days post-inoculation. There was a significant difference between the number of oocysts, which invaded MDCK, MA-104, and Hep-2 cells. MDCK gave the highest susceptibility to oocyst invasion among the three cell lines and asexual stages were also found. Among the 25 isolates, which had been cultivated, 23 isolates could infect MDCK and Hep-2. Only 2 isolates could not infect the MDCK cell. These 2 isolates could infect the Vero cell and yielded high numbers of trophozoites. Praziquantel (PZQ), doxycycline, and paromomycin (PRM) were tested on the infecting parasites. The drugs were added either with the inoculum or 24 hours after inoculation. None of them was effective, including PRM, which had been previously reported as effective.
本研究描述了微小隐孢子虫在犬肾细胞(MDCK)、恒河猴肾细胞(MA - 104)、人喉癌细胞(Hep - 2)和非洲绿猴肾细胞(Vero)系中的发育情况。测定了易感性、感染性以及脱囊方法的差异。考虑了各种溶液以确定增强脱囊的因素(例如有无次氯酸钠、胰蛋白酶或牛磺胆酸钠)。结果表明,子孢子在有或无胰蛋白酶和牛磺胆酸钠的培养基中均可脱囊,但后一种溶液中的子孢子数量少于前一种。只有经次氯酸钠和胰蛋白酶消化的卵囊才能进入培养细胞。观察到大量裂殖体和卵囊,并持续了9天。在MA - 104中未观察到无性阶段。接种后1 - 3天仅能检测到少数卵囊。侵入MDCK、MA - 104和Hep - 2细胞的卵囊数量存在显著差异。在这三种细胞系中,MDCK对卵囊入侵的易感性最高,且也发现了无性阶段。在所培养的25株分离株中,23株可感染MDCK和Hep - 2。只有2株不能感染MDCK细胞。这2株可感染Vero细胞并产生大量滋养体。对感染的寄生虫进行了吡喹酮(PZQ)、强力霉素和巴龙霉素(PRM)的测试。药物在接种时或接种后24小时加入。它们均无效,包括先前报道有效的PRM。