Fallon P G, Mubarak J S, Fookes R E, Niang M, Butterworth A E, Sturrock R F, Doenhoff M J
Department of Pathology, University of Cambridge, United Kingdom.
Exp Parasitol. 1997 May;86(1):29-36. doi: 10.1006/expr.1997.4149.
The fecundities and drug susceptibilities of Schistosoma mansoni isolates from Senegal, Puerto Rico, and Kenya have been examined in mice. The Senegal parasite, obtained from the field in 1993, was shown to have a longer prepatent period (eggs first recovered in the faeces on Day 46 after infection) than those of two isolates, from Puerto Rico and Kenya, that had been maintained for a long period in the laboratory (faecal eggs recovered on Days 38 and 36 after infection, respectively). A Kenyan isolate, also collected from the field in 1994, was shown to mature more slowly than the laboratory-maintained Kenyan isolate. Tissue egg counts confirmed that early in infection the fecundity of the recently collected isolates from Senegal and Kenya was significantly lower than that of the long-term laboratory-maintained Kenyan isolate. Praziquantel and oxamniquine treatment of 8-week-old infections caused a significant (P < 0.001) reduction in worm burden in all isolates tested. However, the reduction in worm burden after praziquantel treatment of infections of the Senegal isolate (50% reduction) was significantly lower than the > 90% reductions in worm burdens after praziquantel treatment of mice infected with either of the Kenyan isolates (P < 0.001). The study confirms that despite being tolerant to praziquantel, the Senegal isolate is fully susceptible to oxamniquine. The praziquantel tolerance of the Senegal parasite is not solely attributed to the state of maturation of the parasite at the time of drug administration.
已在小鼠体内检测了来自塞内加尔、波多黎各和肯尼亚的曼氏血吸虫分离株的繁殖力和药物敏感性。1993年从野外获得的塞内加尔寄生虫，其潜伏期（感染后第46天首次在粪便中发现虫卵）比在实验室长期保存的来自波多黎各和肯尼亚的两个分离株更长（分别在感染后第38天和第36天在粪便中发现虫卵）。1994年也从野外采集的肯尼亚分离株，其成熟速度比实验室保存的肯尼亚分离株更慢。组织虫卵计数证实，在感染早期，最近从塞内加尔和肯尼亚采集的分离株的繁殖力明显低于长期在实验室保存的肯尼亚分离株。对8周龄感染小鼠用吡喹酮和奥沙尼喹治疗，所有测试分离株的虫负荷均显著降低（P < 0.001）。然而，用吡喹酮治疗塞内加尔分离株感染后的虫负荷降低率（降低50%）明显低于用吡喹酮治疗感染肯尼亚任一分离株的小鼠后的虫负荷降低率> 90%（P < 0.001）。该研究证实，尽管塞内加尔分离株对吡喹酮耐药，但对奥沙尼喹完全敏感。塞内加尔寄生虫对吡喹酮的耐药性并非完全归因于给药时寄生虫的成熟状态。
