P146 Penicillium-like mo ld: caught red-handed, but remained unidentified

Abstract

Abstract Poster session 2, September 22, 2022, 12:30 PM - 1:30 PM Objective This case highlights the presence of a self-limited respiratory mycosis in an immunocompetent host and need for fungal sequencing in diagnosis of such rare cases. Methods and Results Ms X, a 25-year-old, apparently healthy software engineer, had an overnight journey in an air-conditioned bus from Hyderabad to Pune. The next day, she developed throat irritation followed 3 days later by fever and cough without dyspnea nor wheezing. Her chest X-ray was found to be normal at the time. Three days later she was admitted to our hospital, wherein X-ray chest and CT chest showed bilateral randomly scattered nodular shadows (Fig. 1). She was referred to ID as a case of suspected tuberculosis, but her presenting symptom being sore throat, the acuteness of symptoms, presence of nodular lung shadows which were absent on the X-ray chest done just 3 days earlier were against the diagnosis of TB. Inhalational fungal or viral pneumonitis were hence considered. Transbronchial biopsy showed an intense alveolar inflammatory exudate, but GMS staining did not reveal any fungal hyphae. BAL Galactomannan, Xpert MTB/RIF were negative. Both BAL and CT guided lung nodule biopsy samples grew a mold. Red pigment formation in culture and its morphological appearance on LPCB mount (Fig. 2) led to a diagnosis of Penicillium species infection. MALDI TOF MS, which had only a few Penicillium spp in its 2018 database, failed to identify the organism, leading us to believe that it could be a different Penicillium species. Since the patient was showing clinical improvement, a self-limited infection was thought of and therapy was withheld with cautious follow-up. The patient was completely asymptomatic after 10 days and CT chest done 20 days later showed complete resolution of the nodules. We believe that this illness was due to inhalation of spores from the air-conditioning vent, eliciting a brisk inflammatory response in the alveoli. The organism grew from BAL and CT guided biopsy from viable spores, but it failed to germinate into hyphae in the human host and hence was not seen on histopathology and did not produce galactomannan which is only released from the tips of growing hyphae. Conclusion Fungi are often isolated from poorly maintained air conditioning vents. In this case, the Penicillium like organism failed to produce progressive disease in the immunocompetent host. If the same organism could be cultured from the AC vent, showed genetic relatedness with the clinical isolate; the source, transmission, and disease linkage could have been established in this case.