An aero mycological analysis of Mucormycetes in indoor and outdoor environments of northern India

Abstract

Mucormycosis is an angio-invasive infection, predominantly acquired by inhalation of sporangiospores from the environment. However, the burden of Mucormycetes sporangiospores in the air is not well studied. We aimed to estimate the burden of Mucormycetes spores in the outdoor and indoor (hospital) environment across different seasons in north India. A total of 380 air samples from outdoor (n = 180) and indoor (n = 200) environment were included in the study. Air samples were suctioned using air sampler (100 l/min) and cultured on Dichloran Rose Bengal Chloramphenicol (DRBC) with benomyl for selective isolation of Mucormycetes. The isolates were identified by phenotypic and genotypic methods. The mean spore count (±SD) of Mucormycetes (cfu/m3) in outdoor samples varied from 0.73 (±0.96) to 8.60 (±5.70) across different seasons. In hospital, the mean spore count varied from 0.68 (±1.07) to 1.12 (±1.07) and 0.88 (±1.01) to 1.72 (±2.17) for air-conditioned wards and non-air-conditioned wards, respectively. Rhizopus arrhizus was the predominant agent isolated from both indoor and outdoor environment followed by Cunninghamella species. We also report a single isolate of the rare mucormycete agent, Apophysomyces variabilis from outdoor environment. The present study highlights the presence of low spore burden of Mucormycetes in outdoor and hospital settings in north India. This study also reports the first isolation of A. variabilis from air samples in the Indian subcontinent.

ECMM/ISHAM recommendations for clinical management of COVID‐19 associated mucormycosis in low‐ and middle‐income countries

“…The mean spore count of Mucormycetes in outdoor samples ranged between 0.73 to 8.60 cfu/m 3 across different seasons. Within the hospital, the mean spore count was slightly higher in an airconditioned area (0.88–1.72 cfu/m 3 ) compared to a non‐airconditioned area (0.68–1.12 cfu/m 3 ) 21 . R arrhizus was the predominant Mucorales isolated in both indoor and outdoor air 21 …”

“…An ecological study conducted in India revealed the presence of many species of Mucorales in soil 20 . Mucorales are also present in indoor environments such as air conditioning filters 21,22 . A recent study from North India reported large numbers of Mucorales spores in both hospitals and outdoor air 21 .…”

“…Mucorales are also present in indoor environments such as air conditioning filters 21,22 . A recent study from North India reported large numbers of Mucorales spores in both hospitals and outdoor air 21 . The mean spore count of Mucormycetes in outdoor samples ranged between 0.73 to 8.60 cfu/m 3 across different seasons.…”

“…The major underlying disease noted in mucormycosis cases in LMICs such as India, Iran or Mexico is uncontrolled diabetes with or without ketoacidosis 14,21,22,24 . Among COVID‐19 patients, uncontrolled diabetes had been reported at 7%–21%.…”

Connecting the Dots: Interplay of Pathogenic Mechanisms between COVID-19 Disease and Mucormycosis

“…An environmental study on the ecology of Mucorales in Indian soils reported a high prevalence of clinically relevant Mucorales [ 2 ]. Mucorales spores are also highly prevalent in the indoor and outdoor air of the same country [ 10 ]. Patients acquire the infection by inhalation, ingestion or traumatic inoculation of the spores from the environment.…”