【摘要】 目的　了解曼氏血吸虫吡喹酮抗性株对终宿主致病作用的强弱。方法　采用浸尾法以2 0 0尾蚴 /鼠逐只感染远交系 CD1 鼠 ,感染 5 7d后采集鼠粪便计数虫卵 ;78d后剖杀鼠收集成虫计数并摘取肝脏和肠做组织虫卵计数 ;95 d后取肝组织 ,切片、染色测量虫卵肉芽肿面积和周长。比较抗性株与敏感株对终宿主的易感性、产卵量和肝虫卵肉芽肿面积。结果　抗性株和敏感株感染鼠成虫回收数为 2 2 .5条 /鼠和 2 1.8条 /鼠 ;抗性株感染鼠粪便虫卵数为 6 8.6只 / 10 0 mg,敏感株为 31.7只 / 10 0 m g,两者间差异有非常显著性 ;感染第 78天 ,抗性株组织虫卵数为 836 4只 /对成虫 ,敏感株为 4 6 6 5只 /对成虫 ,两者间差异有非常显著性 ;敏感株产于肝和肠组织虫卵数为 15 4 0只 /对成虫和 312 4只 /对成虫 ,抗性株分别为 4 2 97只 /对成虫和 3887只 /对成虫 ;抗性株和敏感株感染鼠肝虫卵肉芽肿面积分别为 392 2 36 μm2和 5 2 32 6 3μm2 ,周长分别为 2 385 μm和 2 882 μm,两者间差异均无显著性。结论　抗性株在粪便与组织中产卵量均高于敏感株 ,故抗性株对终宿主的致病作用强于敏感株。更多还原

【Abstract】 Objective To investigate the change in the pathogenicity of Schistosoma mansoni associated with the development of the resistance to praziquantel in definitive hosts. Methods Outbred CD 1 albino mice were infected with five praziquantel-resistant isolates and five praziquantel-susceptible isolates of S. mansoni respectively. Faecal egg burdens were determined by using faecal samples collected on day 57 post-infection. Portal perfusions were performed on the infected mice after they had been sacrificed on day 78 post-infection. The entire gut and liver were removed and eggs in these tissues were counted. On day 95 other infected mice were sacrified and the egg-granulomas in the livers were measured. Results The number of worms recovered from the mice infected with the resistant and susceptible isolates were 22.5 / mouse and 21.5 / mouse respectively. The numbers of eggs presented in 100 mg of mouse faeces infected with the resistant and susceptible were 68.6 and 31.7 (P<0.01). On day 78 post-infection the numbers of eggs presented in the tissue per pair of worms in mice infected with the resistant and susceptible isolates were 8364 and 4665 (P<0.01). In the susceptible isolates the numbers of eggs presented in the liver and gut were 1540 and 3124,while in the resistant isolates the numbers of eggs presented in the liver and gut were 4297 and 3887. The areas and circumferences of egg granulomas in livers of mice infected with the five praziquantel-resistant isolates and five praziquantel-susceptible isolates of S. mansoni were 392236,523263 μm~2 (P>0.05) and 2385,2882 μm (P>0.05). Conclusion Although the infectivity and egg-granuloma sizes in livers were generally similar for all isolates,the praziquantel-resistant isolates may cause more severer morbidity in mammals than the susceptible ones because of their relatively high egg productions.更多还原