ACANTHAMOEBA-CASTELLANII - GROWTH, ENCYSTMENT, EXCYSTMENT AND BIOCIDESUSCEPTIBILITY

Stages in the encystment and excystment processes of Acanthamoeba cast ellanii have been studied, The kinetics of encystment involved measure ments of the three phases (pre-encystment, cyst initiation and cyst wa ll synthesis), Excystment, starting from a mature cyst, involved pre-e mergence, penetration outwards of the cyst wall and free trophozoite, The sensitivity to biocides of trophozoites in the exponential growth phase, pre-encystment trophozoites, mature cysts and pre-excystment cy sts has been investigated, Some differences in relative sensitivity to a bisbiguanide (chlorhexidine) and a polymeric biguanide (polyhexamet hylene biguanide) were observed, but mature cysts were always the most resistant cellular form.