Abstract

Background and Purpose: Polymicrobial keratitis involving emerging pathogens presents a significant diagnostic challenge for conventional microbiology. Inaccurate etiology identification often leads to inappropriate antimicrobial therapy and adverse clinical outcomes. To bridge these diagnostic gaps, molecular techniques are playing a vital role in culture-independent detection of coinfecting rare bacterial and fungal pathogens, facilitating early, targeted antimicrobial intervention.

Material and Methods: An 80-year-old woman with the history of traumatic implantation of soil presented with right eye conjunctival hyperaemia, photophobia, foreign body sensation, whitish lesion on the cornea with diminution of vision lasting for one month. A total of three corneal scrapping collected successively on different timeline and examined by Gram stain and potassium hydroxide (KOH) wet mount. Blood agar (BA), Sabouraud dextrose agar (SDA) and non-Nutrient agar (NNA) were used for isolation of etiological agents. The antibiotic susceptibility testing was done on BA by Kriby Bauer disc diffusion method.

Results: The culture-based isolation of two consecutive corneal scrapings and automated identification using the VITEK® 2 system, revealed Kocuria kristinae as the bacterial isolate. The fungal etiological agents such as Schizophyllum commune and Peroneutypa scoparia were confirmed by molecular characterization through Sanger sequencing. The underlying host-related factors, delayed identification of rare etiological agents, and the absence of definitive evidence-based treatment guidelines complicated the clinical course. There was a gradual regression of infection occurred after a protracted course of approximately 8 months and no recurrence documented.

Conclusion: The present case is the first documented report on concurrent triple infections involving Kocuria kristinae, Schizophyllum commune and Peroneutypa scoparia. To our knowledge, this represents the second reported global case of Peroneutypa scoparia keratitis. Importantly, complete clinical resolution was achieved through medical therapy alone without surgery, despite the challenge of treating an elderly patient with multiple comorbidities.

Key words: Polymicrobial keratitis, Kocuria kristinae, Schizophyllum commune, Peroneutypa scoparia, Vitek-2.