P205 Uncommon Aspergillus species encountered in human infections

Abstract

Poster session 2, September 22, 2022, 12:30 PM - 1:30 PM Objective Aspergillus species are ubiquitously found in environment and have propensity to infect both immunocompromised as well as immunocompetent individuals. Though the most common species implicated in human illness include Aspergillus fumigatus and A. flavus, many uncommon Aspergillus species are increasingly being reported. Moreover, these Aspergillus species have the potential to afflict varied organ systems and can thereby, be implicated in a wide array of infections. Here, we describe three patients infected by rare Aspergillus species viz. A. sclerotium, A. cristatus, and A. japonicum causing brain abscess, corneal ulcer and chronic dacrocystitis.MethodsUncommon Aspergillus species were isolated from clinical samples (nasal scraping, corneal scraping, and brain biopsy). Samples were inoculated on Sabouraud dextrose agar (incubated at 37°C and 25°C) and brain heart infusion agar (incubated at 25°C), followed by slide culture and lactophenol cotton blue (LCB) mount. The isolates were further subjected to molecular identification using polymerase chain reaction (PCR) targeting ITS region, followed by sequencing. Demographic details, clinical characteristics, risk factor, and management profile associated with these Aspergillus species were evaluated. We conducted systematic review using the search terms ‘A. sclerotium’ AND ‘humans’, ‘A. cristatus’ AND ‘humans’ and ‘A. japonicum’ AND ‘humans’.ResultsWe isolated three newer Aspergillus species from nasal scraping, corneal ulcer and brain biopsy. Direct microscopy using potassium hydroxide-calcofluor mount from all these clinical samples showed hyaline septate hyphae in background of pus cells. After 3-5 days of incubation, yellow-green mycelia were observed on the obverse in all the isolates. However, their microscopic features did not relate with the typical lactophenol cotton blue (LCB) picture of A. flavus, owing to which these were sub-cultured on Czapek Dox agar. After 4-5 days of incubation, LCB of these isolated again failed to divulge any specific picture and these isolates were subjected to molecular identification.Nasal scraping from 31-year-old immunocompetent male who presented with post-traumatic chronic dacrocystitis and recurrent orbital cellulitis yielded A. japonicum. He responded well with empirical antibiotics and oral voriconazole.Corneal scrapings from 56-year-old immunocompetent male who presented with post-traumatic blurring of vision yielded A. cristatus. He was treated with nystatin and voriconazole with good response.Brain biopsy from 45-year-old male with hypertension and subarachnoid hemorrhage, who presented with fever, headache, vomiting and periorbital swelling yielded A. sclerotium. He was treated with amphotericin B and had favorable outcome.The systematic literature review didn't yield any results of infection caused by these species in humans.ConclusionThis is the first report of isolation of A. sclerotium, A. japonicum, and A. cristatus from human tissue, though these fungi have been isolated from ambient air and environment. The present report highlights the emergence of uncommon Aspergillus species causing invasive infections even in immunocompetent patients and the requisite of molecular modalities to aid in identification of these rare, emerging species.