ABSTRACT
The human parasites Giardia lamblia and Trichomonas vaginalis parasitize sites where levels of nutrients, competing organisms and gaseous composition fluctuate with respect to time. In this chapter the influence of environmental variables on parameters such as metabolic flux and drug sensitivity are discussed. Particular attention is focussed on the effects of O2 and CO2 on metabolism, as techniques developed in this laboratory have allowed the monitoring of these gases in tandem with other parameters such as intracellular redox potential. The two stage life cycle of G. lamblia makes an understanding of the relationship between the parasite and its different environments more complex than for T. vaginalis. These studies have provided new insights into possible antiparasite strategies.
