Bacterial and fungal communities in indoor aerosols from two Kuwaiti hospitals

Abstract

The airborne transmission of COVID-19 has drawn immense attention to bioaerosols. The topic is highly relevant in the indoor hospital environment where vulnerable patients are treated and healthcare workers are exposed to various pathogenic and non-pathogenic microbes. Knowledge of the microbial communities in such settings will enable precautionary measures to prevent any hospital-mediated outbreak and better assess occupational exposure of the healthcare workers. This study presents a baseline of the bacterial and fungal population of two major hospitals in Kuwait dealing with COVID patients, and in a non-hospital setting through targeted amplicon sequencing. The predominant bacteria of bioaerosols were Variovorax (9.44%), Parvibaculum (8.27%), Pseudonocardia (8.04%), Taonella (5.74%), Arthrospira (4.58%), Comamonas (3.84%), Methylibium (3.13%), Sphingobium (4.46%), Zoogloea (2.20%), and Sphingopyxis (2.56%). ESKAPEE pathogens, such as Pseudomonas, Acinetobacter, Staphylococcus, Enterococcus, and Escherichia, were also found in lower abundances. The fungi were represented by Wilcoxinia rehmii (64.38%), Aspergillus ruber (9.11%), Penicillium desertorum (3.89%), Leptobacillium leptobactrum (3.20%), Humicola grisea (2.99%), Ganoderma sichuanense (1.42%), Malassezia restricta (0.74%), Heterophoma sylvatica (0.49%), Fusarium proliferatum (0.46%), and Saccharomyces cerevisiae (0.23%). Some common and unique operational taxonomic units (OTUs) of bacteria and fungi were also recorded at each site; this inter-site variability shows that exhaled air can be a source of this variation. The alpha-diversity indices suggested variance in species richness and abundance in hospitals than in non-hospital sites. The community structure of bacteria varied spatially (ANOSIM r2 = 0.181–0.243; p < 0.05) between the hospital and non-hospital sites, whereas fungi were more or less homogenous. Key taxa specific to the hospitals were Defluvicoccales, fungi, Ganodermataceae, Heterophoma, and H. sylvatica compared to Actinobacteria, Leptobacillium, L. leptobacillium, and Cordycipitaceae at the non-hospital site (LefSe, FDR q ≤ 0.05). The hospital/non-hospital MD index > 1 indicated shifts in the microbial communities of indoor air in hospitals. These findings highlight the need for regular surveillance of indoor hospital environments to prevent future outbreaks.

Antibiotic Resistance Genes in Aerosols: Baseline from Kuwait

“…Nucleic acid quantification was performed on a Qubit fluorometer employing the Qubit HS DNA/RNA assay kits (Thermo Scientific, Waltham, MA, USA). All the RNA samples (HI-1 and HI-2), were converted to complementary DNA (cDNA) before conducting the PCR [ 20 , 21 ]. K-O and K-I samples collected in a month ( n = 4; one sample per week) were pooled due to their low biological yields.…”

“…Air as a medium for ARG dissemination is less explored [ 16 ]. Aerosols are known carriers of many pathogenic microbes [ 17 , 18 , 19 , 20 , 21 ]; it is, therefore, legitimate to speculate that they can be transmitters of ARGs. A study in China has reported the rate of ARG inhalation ranging from 10 3 to 10 4 copies per day by an adult [ 22 ].…”

A Molecular Approach for Detecting Bacteria and Fungi in Healthcare Environment Aerosols: A Systematic Review

“…In total, 16 articles were subjected to a full-text analysis, from which 3 were excluded due to not meeting the inclusion criteria (measurements of the exhaled air or non-English papers). In total, 13 articles were qualified for analysis in this systematic review [3,26,[34][35][36][37][38][39][40][41][42][43][44].…”

“…Most of the studies examined the aerosols present in different hospital areas such as wards, operating rooms, nursing stations, waiting rooms, textile rooms, corridors, etc. [3,26,[34][35][36][37][38][39][40][41][42][43]. Among all included studies, one focused on aerosols produced during dental prophylaxis with an ultrasonic scaler [44].…”

Spatial Variations in the Nasal Microbiota of Staff Working in a Healthcare-Associated Research Core Facility

“…Workers in the healthcare sector are exposed to microbial contaminants via several routes [1]. Indoor air circulating within hospitals, laboratories, and ancillary areas contains a variety of microbial communities and is considered the most viable channel to transmit them to human occupants via inhalation [2][3][4][5]. The anterior nasal cavity is the primary point of entry of these bacteria into the respiratory system of humans [6].…”