A 3D illustration of fungi Candida albicans, closely related to Candida africana. Credit: Dr_Microbe/ Getty Images Plus

Steroids and antibiotics alter the composition of microbial communities in the nasal passages of patients with severe COVID-19 and COVID-associated mucormycosis (CAM)1.

The nasal microbiome consists of bacteria, viruses and fungi that keep toxic chemicals and pathogens at bay. But little is known about how the microbial composition changes during COVID and CAM.

Scientists isolated fungal DNA from nasal swabs of patients with severe COVID-19 and CAM at the All India Institute of Medical Sciences in Delhi. They sequenced a specific region of fungal genomes to classify the fungi and compared them with those of healthy people.

The team led by Bhabatosh Das and Animesh Ray identified 71 unique fungal species in the CAM group, with an abundance of pathogenic fungi such as Candida africana, Candida haemuloni, Starmerella floris, and Starmerella lactiscondensi.

The researchers at the BRIC-Translational Health Science and Technology Institute in Faridabad found that nasal fungi from severe COVID-19 patients were different to those in healthy people even anti-COVID drug administration.

Besides steroids, antibiotics also modified the fungi population, reducing ‘friendly’ microbes in these patients.

The results may help design new treatment protocols, reducing antibiotic use and carefully selecting steroids and antifungals for patients with CAM and similar diseases.