AUTHOR=Ghosh Anup K. , Singh Ravinder , Reddy Snigdha , Singh Shreya , Rudramurthy Shivaprakash M. , Kaur Harsimran , Choudhary Hansraj , Chakrabarti Arunaloke 

TITLE=Evaluation of environmental Mucorales contamination in and around the residence of COVID-19-associated mucormycosis patients

JOURNAL=Frontiers in Cellular and Infection Microbiology

VOLUME=Volume 12 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/cellular-and-infection-microbiology/articles/10.3389/fcimb.2022.953750

DOI=10.3389/fcimb.2022.953750

ISSN=2235-2988

ABSTRACT=Introduction: Recently, India witnessed an unprecedented surge of COVID-19 associated mucormycosis (CAM) cases. Besides patient management issues, environmental Mucorales contamination possibly contributed in the outbreak. A recent study evaluated environment contamination by Mucorales in the hospital setting. However considerable number of CAM patients were never admitted in a hospital before development of the disease. The present study, therefore, planned to evaluate Mucorales contamination of patients’ residences. 
Methods: Residential environment of 25 patients with CAM living in north India were surveyed. Air samples were collected from indoor and immediate outdoor vicinity of the patient’s residence and cultured on Dichloran Rose Bengal Chloramphenicol (DRBC) agar with benomyl for selective isolation of Mucorales. Surface swab samples were also collected from the air-coolers fitted in those residence and cultured on DRBC agar. The isolates were identified by phenotypic and genotypic methods.  Amplified Fragment Length Polymorphism (AFLP) was employed to evaluate genetic relatedness of the environmental and patient’s clinical isolates. 
Results: The median spore count (Mean± SD) of Mucorales in air of patients’ bedroom was significantly higher than air in other rooms in those residences (3.55 versus 1.5, p:0.003) or air collected directly from the front of the air cooler (p<0.0001).  The Mucorale spore count in the environment did not correlate either with ventilation of the room or hygiene level of the patients’ residences. Rhizopus arrhizus was isolated from the environment of all patients’ residences (n=25); others Mucorales isolated were Cunninghamella bertholletiae (n=14), R. microsporus (n=6), R. delemar (n=6), Syncephalastrum racemosum (n=1), Lichtheimia corymbifera (n=1) and Mucor racemosus (n=1). Genetic relatedness was observed between eleven environmental isolates from patient’s bedroom and respective clinical isolates from patients.
Discussion: The study supported the view that the patients might have acquired Mucorales from home environment during post-COVID-19 convalescence period. Universal masking at home during patients’ convalescence period and environmental decontamination could minimize exposure in those susceptible patients.