[Amebicide activity of antiseptics and an antibiotic on 2 Acanthamoeba isolated from corneal ulcers].

PURPOSE: To study the in vitro amoebicidal activity of antiseptics and antibiotics.

METHODS

Antiseptics (hexamidine, chlorhexidine, picloxydine, PHMB, polyvidone iodine) and an antibiotic (colimycine) were tested on two Acanthamoeba isolates from corneal ulcers under soft contact lenses. The appearence of trophozoïts and the increase of the number of cysts show their viability.

RESULTS

Four antiseptics and colimycin proved to be active in vitro on the two Acanthamoeba isolates: hexamidin 0.1% after 3 to 6 hours incubation, picloxydin 0.05% after 1 to 3 hours incubation (Wilcoxon test, p < 0.05), chlorhexidin 0.02% after 3 hours (Wilcoxon test, p < 0.01), PHBM 0.02% after 3 hours (Wilcoxon test, p < 0.01) and colimycin 125,000 Ul/ml after 1 to 3 hours incubation. Polyvidone iodine proved ineffective.

CONCLUSION

Our results confirm that hexamidin, chlorhexidin and PHMB have an amoebicidal activity on the two stains, and show that colimycine, which has already been tested, has also an amoebicidal activity; picloxydine is effective after 1 to 3 hours; there is a considerable variability which exists between the isolates and the sensitivity of the isolates is time-dependent. Medical polytherapy is therefore necessary especially if the sensitivity of the Acanthamoeba has not been tested.