W. Khunkitti et al., ASPECTS OF THE MECHANISMS OF ACTION OF BIGUANIDES ON TROPHOZOITES ANDCYSTS OF ACANTHAMOEBA-CASTELLANII, Journal of applied microbiology, 82(1), 1997, pp. 107-114
A non-radioactive method was used to investigate the uptake by Acantha
moeba castellanii of chlorhexidine diacetate (CHA) and polyhexamethyle
ne biguanide (PHMB). Based on the Giles et al. (1974) hypothesis, the
uptake of CHA by trophozoites appeared to be of the L3 pattern whereas
that of cysts was C2. Unlike CHA, trophozoites took up PHMB with an L
2 pattern at low concentrations followed by a C-type pattern at higher
concentrations, the uptake by cysts was found to be of the C2 pattern
with a plateau effect at high concentrations. A diphasic leakage effe
ct was found in trophozoites whereas a relatively low peak of maximal
leakage occurred from cysts treated with high biocide concentrations.
The amount of pentose release depended on the formulation ingredients.
No correlation between pentose leakage and trophozoicidal or cysticid
al activity was found.