Diagnosis of Keratitis by Cultivation, Fluorescence Microscopy and PCR has Uncovered that Acanthamoeba Emits Auto Fluorescence

The amphizoic protozoa Acanthamoeba species are able to be free-living amoebae in environment or as parasites in humans and animals. These species comprise nearly 30 species and they have an increased role as human pathogens causing encephalitis in the nervous system or keratitis in the eyes. In diagnosis of a clinical sample of eye contact lens, light microscopy showed a heavy growth of amoeboid and Acanthamoeba trophozoites that occurred in agar plates and in cultivation flasks of patient sample and A. castellanii control as well. Fluorescence microscopy uncovered that visualised amoebae from patient and control samples emit fluorescence beforeand after glutaraldehyde fixation. Polymerase Chain Reaction (PCR) and Gel electrophoresis identified that the isolated amoebic microorganisms were Acanthamoeba species. In conclusion, we have diagnosed a case of keratitis that caused by Acanthamoeba species by cultivating the eye contact lens sample using glutaraldehyde as fluorescent dye for fluorescence microscopy and PCR. Acanthamoeba trophozoites and cysts emit autofluorescence and glutaraldehyde can be used as fluorescent dye to enhance the autofluorescence of Acanthamoeba trophozoites and cysts for diagnosis purposes.