Entamoeba histolytica: the effect of different culture conditions on the components of amoebic movement

Abstract

The behaviour of trophozoites of Entamoeba histolytica, strain IP-106, were examined under three sets of culture conditions: various acid pH values, cysteine concentrations, and dilutions of bile. Changes in amoebic behaviour, as compared with controls, were evident under conditions of the lowest pH value tested (pH 5.1), at the highest cysteine concentration tested (17 mM), and at both dilutions of bile assayed. These changes in behaviour were due to a modulation of two components of amoebic movement, the rate of activity and (or) the rate of change of direction. These changes are thought to be the results of "metabolic" and "kinetic" effects, respectively, on these two parameters.