Molecular detection of fungal agents responsible for COVID-19-associated mycosis directly from tissue specimens

Abstract Poster session 3, September 23, 2022, 12:30 PM - 1:30 PM Objective Due to the ongoing COVID-19 pandemic a new group of patients at risk emerged with COVID-19-associated mucormycosis (CAM) and other fungal infections. Molecular studies, evaluating the prevalence of CAM and other fungal infections are lacking. To assess CAM prevalence in a super-specialty healthcare hospital in North India, we applied direct microscopy, fungal culture, and qualitative real-time-PCR targeting Mucorales-specific fragments on tissue specimens of critically ill COVID-19 patients. Methods This was a hospital-based prospective study during second-wave of COVID-19 in India. All clinically suspected CAM patients with a history of COVID-19 were included in the study from March 2021 to June 2021 where tissue or biopsy specimens were collected under aseptic conditions. Conventional identification methods were performed for all isolates, speciation was done by MALDI-TOF, and comparative detection by RTPCR was also done. Results In the present study, among 67 samples received in the laboratory from clinically suspected CAM patients, 32 samples showed positive growth using the conventional method of identification. Rhizopus arrhizus was the commonest fungal isolate obtained followed by Aspergillus flavus from tissue samples. Use of molecular and automated machines helped in the early identification of these species 24-48 h less than the conventional methods. Polyfungal isolates are also reported from two tissue samples of patients in the post-COVID discharge stage. Almost 90% of patients with CAM and other fungal etiology agreed to steroid intake and diabetes condition during COVID-19 infection. Conclusion Considering the ever-evolving strains and variants of COVID-19, it is important to have a high index of suspicion for fungal coinfection in patients with COVID-19 presenting with comorbidities. Further, they should undergo immediate molecular studies with an emphasis on the requirement of medical or surgical intervention if the result comes positive. There is a need to stress on the judicious use of steroids to avoid flaring up of the fungal infection.