Drug-resistant severe Acanthamoeba keratitis caused by rare T5 Acanthamoeba genotype

To describe a case of severe and drug-resistant Acanthamoeba keratitis in a contact lens wearer caused by atypical T5 Acanthamoeba genotype (Acanthamoeba lenticulata).

Report of a case, Acanthamoeba DNA amplification and sequencing.

A 61-year-old patient was referred to our clinic with a 2-week history of keratitis. Acanthamoeba keratitis (AK) was diagnosed using confocal microscopy and corneal scraping culture. Using polymerase chain reaction (PCR) and DNA sequencing, the organism was classified as a T5 genotype (A. lenticulata). The keratitis continued to progress despite topical antiamoebic therapy and ultimately led to enucleation of the affected eye.

T5 genotype Acanthamoeba can cause severe AK. Atypical Acanthamoeba genotypes could be associated with worse prognosis and resistance to therapy.