Send to

Choose Destination
J Appl Bacteriol. 1996 Jul;81(1):73-7.

The lethal effects of biguanides on cysts and trophozoites of Acanthamoeba castellanii.

Author information

Welsh School of Pharmacy, University of Wales College of Cardiff, UK.


The effects of a range of biocides on trophozoite and encysted forms of Acanthamoeba castellanii were investigated. Viable acanthamoebae were enumerated by a plaque assay technique. The cyst form of Acanthamoeba castellanii was more resistant to all biocides tested than the trophozoite form. Of the biocides tested, chlorhexidine diacetate (CHA) and polyhexamethylene biguanide (PHMB) were the most effective. Their lethal effects were time- and concentration-dependent. CHA was very effective when formulated in 0.1% EDTA combined with Tris buffer pH 7.8 whereas PHMB activity was reduced by 0.1% EDTA. Three per cent dimethylsulphoxide (DMSO) enhanced the activity of CHA but not of PHMB.

[Indexed for MEDLINE]

Supplemental Content

Loading ...
Support Center