Slater A F
Department of Zoology, University of Oxford, U.K.
Proc R Soc Lond B Biol Sci. 1988 Jul 22;234(1275):239-54. doi: 10.1098/rspb.1988.0046.
The influence of dietary protein on the epidemiology of an intestinal helminth infection was investigated with an experimental system that allowed transmission of the nematode Heligmosomoides polygyrus to occur naturally between laboratory mice. Mortality of mice was greatly increased in infected populations that were fed ad libitum on synthetic diets containing 2% compared with 16% protein. Larger numbers of larval and adult H. polygyrus were found to infect mice in the low-protein cage compared with the high-protein cage. No evidence for density dependence in the fecundity of female worms was detected; on average the daily egg output per female worm was greater for parasites infecting mice in the low-protein cage. The rate at which naïve mice acquired infection was also higher in the low-protein cage. Pinworm (Aspiculuris tetraptera) became established in each cage, and average worm burdens were again greater in the low-protein cage. The acquisition of resistance to reinfection was not found to be an important factor influencing the survival of parasites infecting mice in either cage. The epidemiology of H. polygyrus and A. tetraptera was therefore characterized by low average worm burdens and high host survival in a well-nourished population of mice, and by a high intensity of infection and severe parasite-induced host mortality in a malnourished colony of mice. This reflects differences in the survival and fecundity of adult parasites between mice in the two cages, and suggests that malnourished mice are predisposed to acquire large numbers of several species of intestinal worm.
利用一种实验系统，研究了膳食蛋白质对肠道蠕虫感染流行病学的影响，该系统允许线虫多毛螺旋体在实验室小鼠之间自然传播。与喂食含16%蛋白质的合成饲料的感染群体相比，随意喂食含2%蛋白质合成饲料的感染群体中，小鼠的死亡率大大增加。与高蛋白笼子相比，在低蛋白笼子中发现感染多毛螺旋体幼虫和成虫的小鼠数量更多。未检测到雌虫繁殖力存在密度依赖性的证据；平均而言，感染低蛋白笼子中小鼠的寄生虫，每只雌虫的日产卵量更高。在低蛋白笼子中，未感染的小鼠获得感染的速率也更高。蛲虫（四翼无刺线虫）在每个笼子中都得以生存，低蛋白笼子中的平均虫负荷再次更高。未发现获得对再感染的抵抗力是影响任一笼子中感染小鼠的寄生虫存活的重要因素。因此，在营养良好的小鼠群体中，多毛螺旋体和四翼无刺线虫的流行病学特征是平均虫负荷低和宿主存活率高，而在营养不良的小鼠群体中，则是感染强度高和寄生虫引起的宿主死亡率高。这反映了两个笼子中小鼠体内成年寄生虫在存活率和繁殖力方面的差异，并表明营养不良的小鼠易感染大量几种肠道蠕虫。
