Cytopathic effect of 18 isolated Acanthamoeba trophozoites on human corneal epithelial cells. A, KA/MSG1; B, KA/MSG3; C, KA/MSG4; D, KA/MSG10; E, KA/MSG12; F, KA/MSG15; G, KA/MSG16; H, KA/MSG18; I, KA/MSG23; J, KA/MSG26; K, KA/MSG29; L, KA/MSS1; M, KA/MSS2; N, KA/MSS6; O, KA/MSS7; Q, KA/MSS8-1; R, KA/MSS8-2; S, control. The control was cultured without Acanthamoeba trophozoites.