Human corneal buttons were exposed to trophozoites and cysts of Acanthamoeba castellanii for 12 hours. Examination of the buttons by scanning electron microscopy showed numerous trophozoites on the surface of the epithelium. Trophozoites examined by transmission electron microscopy had limited regions of attachment to the epithelium but extensive regions of attachment to each other. Attachment regions were characterized as plaque-like maculae of an incomplete desmosome junction. Firm attachment mechanisms may explain how penetration of the human cornea occurs.
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