Surface properties related to concanavalin A-induced agglutination. A comparative study of several Entamoeba strains.

Abstract

Pathogenic strains of E. histolytica are more easily agglutinated with concanavalin A (Con A) than strains isolated from human asymptomatic carriers. All 3 pathogenic strains studied agglutinated with low concentrations of Con A in contrast to various nonpathogenic axenic strains of amebas, characterized by their ability to grow at room temperature. The extreme susceptibility of pathogenic strains of E. histolytica to agglutinate with Con A seems related to their higher capacity for lectin binding and to their lack of detectable repulsive charges at the cell surface. The amount of fluorescein-tagged Con A bound to the surface was much higher in pathogenic strains. Only nonpathogenic strains showed a detectable negative surface charge on cell microelectrophoresis and when labeled with cationized ferritin at 0.degree. C. Mobility of surface Con A receptors estimated as the percentage of caps was comparable in all strains. Results of 1 strain cultured in axenic and monoxenic conditions suggested that bacteria can modify the behavior of E. histolytica trophozoites by altering surface properties of the amebas.