Tirado-Angel J, Gabriel M M, Wilson L A, Ahearn D G
Ophthalmology Department, Emory University School of Medicine, Atlanta, GA 30322, USA.
Curr Eye Res. 1996 Feb;15(2):225-8. doi: 10.3109/02713689608997418.
We determined the relative minimal inhibitory and minimal amoebicidal concentrations of chlorhexidine digluconate and polyhexamethylene biguanide for four species of Acanthamoeba. The amoebae were grown in peptone-glucose-yeast extract broth for 72 h in tissue culture flasks. Either washed trophozoites (approximately 10(5)) or cysts (approximately 10(5)) were incubated in the enrichment broth in 96 well microtiter trays. Antimicrobial concentrations of the biguanides were determined from microscopic examinations of methylene blue uptake and from subcultures. In general, killing was time dependent. Minimal amoebicidal concentrations at 24 h ranged from 50 to 100 mg/ml and to as low as 25 mg/ml by 72 h. Trophozoites were killed more rapidly than cysts. Both biguanides had similar levels of activity. A synergistic combination of chlorhexidine and polyhexamethylene biguanide (total concentration 25 mg/ml) was most evident for A. castellanii and A. polyphaga. Cysts of A. culbertsoni and A. hatchetti stained more rapidly after exposure to the combination of biguanides than to the single biguanides, but there were no statistically significant differences in the final numbers of dead or stained cysts after exposure to the combination or to the single biguanides.
我们测定了葡萄糖酸氯己定和聚六亚甲基双胍对四种棘阿米巴的相对最低抑菌浓度和最低杀阿米巴浓度。将阿米巴在蛋白胨 - 葡萄糖 - 酵母提取物肉汤中于组织培养瓶中培养72小时。将洗涤后的滋养体（约10⁵个）或包囊（约10⁵个）在96孔微量滴定板的富集肉汤中孵育。通过亚甲蓝摄取的显微镜检查和传代培养来确定双胍类药物的抗菌浓度。一般来说，杀灭作用是时间依赖性的。24小时时的最低杀阿米巴浓度范围为50至100毫克/毫升，到72小时时低至25毫克/毫升。滋养体比包囊被杀灭得更快。两种双胍类药物具有相似的活性水平。氯己定和聚六亚甲基双胍的协同组合（总浓度25毫克/毫升）对卡氏棘阿米巴和多食棘阿米巴最为明显。库氏棘阿米巴和哈氏棘阿米巴的包囊在暴露于双胍类药物组合后比暴露于单一双胍类药物时染色更快，但暴露于组合或单一双胍类药物后，死亡或染色包囊的最终数量没有统计学上的显著差异。
