Lumen Dwelling Protozoa: Entamoeba, Trichomonads, And Giardia

This chapter considers protozoa are : Entamoeba histolytica, E. histo-lytica-like amebae (Laredo type), E. hartmanni, E. coli, E. gingivalis and E. invadens; Trichomonas vaginalis, T. tenax, T. gallinae, Tritrichomonas foetus and Pentatrichomonas hominis; Giardia lamblia, and G. duodenalis.. In vitro cultivation of protozoa, free-living or parasitic, is presently more an art than a science, and whether the reverse will be true some day is a moot point. The taxonomic scheme followed throughout this chapter is one recently adopted by the Committee on Systematics and Evolution of the Society of Protozoologists. The life cycle of E. histolytica is as follows: ingested mature cysts excyst in the lower ileum. Colonization occurs throughout the colon. Encystment takes place in the lower colon and the cysts leave the host via feces. The history of the cultivation of Entamoeba is dealt with in three sections: xenic, mon-oxenic, and axenic culture systems. Those studies considered influential in advancing the technology will receive most attention.