Fluorescence amplified fragment length polymorphism for subtyping of genotypes of Acanthamoeba isolated from patients with keratitis

BACKGROUND & OBJECTIVES Acanthamoeba keratitis (AK) is a painful and vision-threatening ocular infection. The differentiation of Acanthamoeba at the species and subspecies level is complicated. Nearly all the AK isolates have been shown to belong to T4 genotype when analysed by ribosomal RNA gene sequences and there is no universally acceptable method for differentiation of different subtypes of T4. The purpose of this study was to attempt further discrimination of T4 genotypes. METHODS In the present investigation, 15 Acanthamoeba isolates obtained from cornea of keratitis patients were subjected to fluorescence amplified fragment length polymorphism (FAFLP) genotyping to differentiate T4 subtypes. RESULTS FAFLP profiles showed five distinct clusters (I to V) within T4 clonal complex which clearly depicted genetic differences among the isolates of T4 sequence type of Acanthamoeba. INTERPRETATION & CONCLUSIONS Our study demonstrated the usefulness of FAFLP for reliable differentiation of T4 clonal complex of Acanthamoeba.