Weanling mice were infected with Trichuris muris and maintained for 8 weeks on either a solid diet containing 24% protein or on liquid diets containing 4 or 8% protein. No significant difference in growth attributable to diet was evidenced but a highly significant difference caused by did occur and was most marked during weeks 5 to 7 in the mice fed the low-protein liquid diets. The hematocrit levels reflected only normal changes commensurate with the gradual maturation of the mice. Significantly higher levels of the plasma alpha2 and total globulins occurred in all of the infected mice during weeks 4 to 6. The number of mice that developed patent infections not to have been influenced by diet. Significantly fewer male and female, and shorter female worms, were recovered from the mice fed the low-protein liquid diets than from those fed the 24% protein solid diet. Sex ratios of the worms were not affected by diet and were normal for the age of the infection. All 3 groups of infected mice ingested fewer calories, significantly so during weeks 4 and 5, than did the normal mice. Thus, in the course of the 8 weeks of the experiment Trichuris muris induced a state of anorexia in the host irrespective of the form and protein content of the diet. The interactions of nutrition and have been extensively presented (Scrimshaw et al., 1959, 1968) but documentation of the host-nutrition-parasite relationships of whipworms and their hosts is limited. Other helminths and host nutrition have been studied experimentally. When mice infected with Nematospiroides were fed a diet containing 10% protein they suffered a temporary weight loss and more severe blood changes than did those fed a 20% protein diet. Diet also appeared to have an appreciable effect on the survival and location of N. dubius (Ehrenford, 1954). Feeding a complete purified low-residue diet or powdered skim milk to mice infected with pinworms or with the tapeworm Hymenolepis nana resulted in loss of infection (DeWitt and Weinstein, 1964). On initial contact, before the development of acquired resistance, deficient diets increased the susceptibility of rats to Nippostrongylus brasiliensis. Later more parasites were lost by such rats than occurred in the controls. These findings were not related to changes in the rate of corticosteroid synthesis . . . but to the Received for publication 28 September 1971. * This study was supported in part by The Health Research Council of the City of New York, Contract No. U-1631. effect on susceptibility produced independently by severe dietary deficiency (Clarke, 1969). In human trichuriasis the presence of anorexia, failure to gain weight, and other clinical setbacks have been variously reported (Pike, 1969). In such cases the nature of the interplay between the host's nutrition, genetic endowment, other concomitant parasitoses and Trichuris trichiura is difficult to assess. Investigations were therefore undertaken to study trichuriasis in the genetically standardized mouse for which diet could be controlled. Nutritional studies using such mice have been reported (Hoag et al., 1966; Hoag and Dickie, 1962). Birbaum et al. (1958) and Greenstein et al. (1960) formulated chemically defined soluble diets. They showed that rats and mice fed those soluble diets were able to sustain normal growth curves. As they pointed out, such soluble diets have the advantage that food usage can be placed on a quantitative basis and can be measured volumetrically. This report concerns the effects of three diets, differing in composition and form, upon the mouse and T. muris and the interaction of these with the effects of the worm upon the host. The ability of mice to develop and maintain a patent infection, the size of the worms, measurement of the variations in food intake, body weight, plasma proteins, and hematocrits of the mice were recorded.
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Dec 1, 1981
John D Manwaring + 1
Open Access
