Salim Abdel-Moneim, Al-Humiany Abdel-Rahman
Department of Medical Microbilogy, Taif University, Turaba, Saudi Arabia.
Turkiye Parazitol Derg. 2013;37(1):19-22. doi: 10.5152/tpd.2013.05.
The aim of the present study was to confirm observations on the concomitant immunity to Schistosoma mansoni in mice and assess its effects on the resistance of mice to a challenge infection.
Cercariae from infected Biomphalaria glabrata were used to infect mice. Twenty mice were infected with a single dose of S. mansoni cercariae. The animals were randomly divided into two groups: experimental group (Group A) and control group (Group B). Group A mice were challenged with the same number of cercariae six weeks after the primary infection. Perfusion of all mice was done 9 weeks after infection in order to obtain worm burdens in relation to their initial cercarial dose. The livers of all mice were obtained for parasitological and pathological assessments.
Our results showed that all the exposed animals became infected with S. mansoni. After a challenge infection, Group A mice had a 54.66% worm reduction rate, 41.45% liver egg reduction rate, and 51.76% granuloma size reduction rate compared to their respective controls. This study shows that mice with persistent adult S. mansoni infection are able to mount a very strong regulatory response to a challenge infection. It is concluded that concomitant immunity does occur in mice.
These results describe novel imaging methods that permit visualization of live schistosomes within their living hosts and may help to elucidate mechanisms of infection and also be of value not only for epidemiological investigations, but also in designing government control programs for schistosomiasis.
本研究的目的是证实对小鼠曼氏血吸虫伴随免疫的观察结果，并评估其对小鼠抵抗攻击感染的影响。
使用来自受感染光滑双脐螺的尾蚴感染小鼠。20只小鼠单次感染曼氏血吸虫尾蚴。动物被随机分为两组：实验组（A组）和对照组（B组）。A组小鼠在初次感染六周后用相同数量的尾蚴进行攻击感染。感染9周后对所有小鼠进行灌注，以获得与初始尾蚴剂量相关的虫负荷。获取所有小鼠的肝脏进行寄生虫学和病理学评估。
我们的结果表明，所有暴露的动物都感染了曼氏血吸虫。攻击感染后，与各自的对照组相比，A组小鼠的虫减少率为54.66%，肝卵减少率为41.45%，肉芽肿大小减少率为51.76%。本研究表明，持续感染曼氏血吸虫成虫的小鼠能够对攻击感染产生非常强烈的调节反应。得出结论，小鼠中确实存在伴随免疫。
这些结果描述了新的成像方法，可使活宿主体内的活血吸虫可视化，可能有助于阐明感染机制，不仅对流行病学调查有价值，而且在设计血吸虫病政府控制项目中也有价值。
