This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Omaña-Molina, M. Articles by Shibayama, M. Search for Related Content PubMed PubMed Citation Articles by Omaña-Molina, M. Articles by Shibayama, M.

 Previous Article  |  Next Article 

Infection and Immunity, June 2004, p. 3245-3251, Vol. 72, No. 6
0019-9567/04/$08.00+0     DOI: 10.1128/IAI.72.6.3245-3251.2004
Copyright © 2004, American Society for Microbiology. All Rights Reserved.

Induction of Morphological and Electrophysiological Changes in Hamster Cornea after In Vitro Interaction with Trophozoites of Acanthamoeba spp.

Departments of Experimental Pathology,¹ Cell Biology, Center for Research and Advanced Studies,² Department of Biochemistry, School of Medicine, National Polytechnic Institute, Mexico City, Mexico³

Received 3 September 2003/ Returned for modification 8 October 2003/ Accepted 17 February 2004

Acanthamoeba castellani and Acanthamoeba polyphaga are free-living amebae that cause keratitis and granulomatous encephalitis in humans. We have analyzed the early morphological and electrophysiological changes occurring during the in vitro interaction of cultured amebae with intact or physically damaged corneas obtained from hamsters. Both species of Acanthamoeba produced similar cytopathic changes, as seen by light microscopy and scanning electron microscopy. After adhesion to the epithelial surface, trophozoites formed clumps and migrated toward the cell borders, causing the separation of adjacent cells at 1 h of coculture. At later stages (2 to 4 h), some amebae were found under desquamating epithelial cells whereas others were seen associated with damaged cells or forming amebostome-like structures to ingest detached epithelial cells. Control corneas incubated in culture medium conditioned with amebae showed a cytoplasmic vacuolization and blurring of the epithelial-stromal junction. The early stages of corneal epithelial damage caused by amebae were also analyzed by measuring the transepithelial resistance changes in corneas mounted in Ussing chambers. Both species of Acanthamoeba caused a rapid decrease in electrical resistance. The present observations demonstrate that under in vitro conditions, Acanthamoeba trophozoites rapidly cause significant damage to the corneal epithelium. Furthermore, in our experimental model, previous physical damage to the corneas was not a prerequisite for the development of amebic corneal ulcerations.

Editor: W. A. Petri, Jr.