Clinical and mycological characteristics of keratitis caused by molecularly confirmed Alternaria alternata sensu stricto: A case series.

Alternaria species cause fungal keratitis, but species-level identification is difficult, limiting lineage-resolved clinical data. We report three cases caused by isolates assigned to the A. alternata lineage using ASA-10 and ASA-19 sequence analysis. Together with one previously reported case, we compared the clinical courses and antifungal susceptibility profiles of four molecularly characterized isolates. Two patients were successfully managed with topical antifungals alone, whereas two with compromised corneas required therapeutic keratoplasty. Three patients achieved favorable visual outcomes. These observations suggest that the pre-existing condition and structural integrity of the cornea may influence outcomes in keratitis caused by A. alternata sensu stricto.