Noble Judith A, Ahearn Donald G, Avery Simon V, Crow Sidney A
Department of Biology, Georgia State University, University Plaza, Atlanta, Georgia 30303, USA.
Antimicrob Agents Chemother. 2002 Jul;46(7):2069-76. doi: 10.1128/AAC.46.7.2069-2076.2002.
The incidence of Acanthamoeba keratitis, a disease associated with contact lens wear, has been in apparent decline with the advent of multipurpose contact lens solutions. The concentrations of the biguanides chlorhexidine digluconate (CHX) and particularly polyhexamethylene biguanide (PHMB) included in multipurpose solutions (MPSs) are sublethal for amoebae. We evaluated by flow cytometry the effects of these two biguanides on phagocytosis of particles and the survival of trophozoites of Acanthamoeba castellanii and A. polyphaga. Trophozoites of A. castellanii and A. polyphaga (10(6)/ml) were exposed to solutions of 5 and 50 microg of PHMB and CHX per ml in the presence and absence of particles (i.e., heat-killed yeasts and bacteria and latex beads). In addition, trophozoites were exposed to particles treated with these concentrations of the two biguanides. In the absence of particles, trophozoites of A. polyphaga appeared to be more resistant to the biguanides than those of A. castellanii. In the presence of particles, the rates of survival of both species were decreased. In most instances, particles treated with sublethal concentrations of both biguanides that were adsorbed onto the particles reduced the incidence of phagocytosis. Particles present in MPSs in contact lens cases may be involved in the decreased incidence of Acanthamoeba keratitis.
棘阿米巴角膜炎是一种与隐形眼镜佩戴相关的疾病，随着多功能隐形眼镜护理液的出现，其发病率明显下降。多功能护理液（MPS）中含有的双胍类化合物葡萄糖酸洗必泰（CHX），尤其是聚六亚甲基双胍（PHMB）的浓度对阿米巴原虫具有亚致死性。我们通过流式细胞术评估了这两种双胍类化合物对棘阿米巴和多食棘阿米巴吞噬颗粒及滋养体存活的影响。将棘阿米巴和多食棘阿米巴的滋养体（10⁶/ml）在有和没有颗粒（即热灭活的酵母、细菌和乳胶珠）存在的情况下，暴露于每毫升含5和50微克PHMB和CHX的溶液中。此外，滋养体还暴露于用这些浓度的两种双胍类化合物处理过的颗粒中。在没有颗粒的情况下，多食棘阿米巴的滋养体似乎比棘阿米巴的滋养体对双胍类化合物更具抗性。在有颗粒存在的情况下，两种物种的存活率均降低。在大多数情况下，吸附在颗粒上的经亚致死浓度的两种双胍类化合物处理过的颗粒降低了吞噬作用的发生率。隐形眼镜盒中MPS里存在的颗粒可能与棘阿米巴角膜炎发病率的降低有关。
