CHAPTER VIII 



THE CULTIVATION OF INTESTINAL PROTOZOA 



By 

 Harvey P. Barret and Nannie M. Smith 



Charlotte, N. C. 



PROBLEMS TO BE CONSIDERED IN CULTIVATION 



The first reports of cultivation of intestinal protozoa, other 

 than amoebse, are, in the main, instances of keeping organisms ahve 

 in various forms of culture medium. The numerous early reports of 

 the cultivation of parasitic amoebse were based on the use of 

 free-living amoebse, instead of parasitic amoebse. In attempting to 

 cultivate protozoa on artificial media, many problems present 

 themselves : 



(a) First of all, the medium should be one which has no harm- 

 ful effect on the organism. In other words, a medium in which 

 the organism will remain alive over a long period of time — a 

 medium in which an organism will live is not necessarily one in 

 which it will multiply. For example, many protozoa will live for 

 days, or even weeks, in different concentrations of salt solution, 

 although they do not multiply in this solution. 



(b) Another important consideration is the reaction otr 

 hydrogen-ion concentration of the medium. 



(c) Still another consideration is the oxygen tension, which is 

 controlled best, in many media, by the height of the column of 

 the medium in the tube, or other container used. 



(d) An important consideration, necessarily, is providing a con- 

 stituent in the medium which will furnish nourishment to the 

 organism under cultivation. The nourishing constituent of the 

 medium should be supplied in a form available to the organism. 



(e) A final consideration is the proper temperature not only 

 for maintaining the life of the organism, but a temperature in 

 which the organism will multiply. 



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