Clinical presentations, genotypic diversity and phylogenetic analysis of species causing keratitis.

keratitis is a sight-threatening corneal infection that is commonly reported among contact lens users and those suffering from corneal trauma. The prevalence of species or genotypes in causing keratitis infection is not well known. This study was conducted to identify and genotype isolates from keratitis patients, targeting the ribosomal nuclear subunit () region, and describe the associated clinical presentation and treatment outcome. Thirty culture-confirmed patients with keratitis, identified in a tertiary eye care centre in South India during the period from December 2016 to December 2018, were included in this study. The data collected from patient records include demographic details, history of illness, mode of trauma, treatment history and follow-up status. The genotype and species were identified based on the sequence and phylogenetic tree analysis. was the most predominant keratitis-causing species, followed by and . Three major genotypes were identified (T4, T11 and T12), with the T4 genotype being the most predominant, with four subclusters, i.e. T4A, T4B, T4D and T4E. This is the first report on corneal infection by the T11 genotype and the T12 genotype. No significant correlation was observed between the clinical outcomes of corneal disease and the genotypes or species. genotyping is very effective in identifying the species and genotype in keratitis. Genotyping of spp. will help to advance our understanding of genotype-specific pathogenesis and geographical distribution.