Anti-Acanthamoeba efficacy in contact lens disinfecting systems

Hiti et al produced an interesting study investigating the susceptibility of three strains of Acanthamoeba to a PHMB (polyhexamethylene biguanide) based multipurpose solution (MPS), a one step peroxide system (3% H2O2), and a two step peroxide system (0.6% H2O2). However, no comment was made regarding the choice of strains tested, only one of which (A castellanii 4CL) was typical of those that cause keratitis in humans. Although testing of all three strains was of interest to the microbiologist, the only result that can be extrapolated to clinical practice and be of clinical relevance to the contact lens wearer is that for A castellanii (4CL).