Composition of Culturable Microorganisms in Dusts Collected from Sport Facilities in Finland during the COVID-19 Pandemic

Abstract

Sport facilities represent extreme indoor environments due to intense cleaning and disinfection. The aim of this study was to describe the composition of the cultivated microbiota in dust samples collected in sport facilities during the COVID-19 pandemic. A dust sample is defined as the airborne dust sedimented on 0.02 m2 within 28 d. The results show that the microbial viable counts in samples of airborne dust (n = 9) collected from seven Finnish sport facilities during the pandemic contained a high proportion of pathogenic filamentous fungi and a low proportion of bacteria. The microbial viable counts were between 14 CFU and 189 CFU per dust sample. In seven samples from sport facilities, 20–85% of the microbial viable counts were fungi. Out of 123 fungal colonies, 47 colonies belonged to the potentially pathogenic sections of Aspergillus (Sections Fumigati, Nigri, and Flavi). Representatives of each section were identified as Aspergillus fumigatus, A. flavus, A. niger and A. tubingensis. Six colonies belonged to the genus Paecilomyces. In six samples of dust, a high proportion (50–100%) of the total fungal viable counts consisted of these potentially pathogenic fungi. A total of 70 isolates were considered less likely to be pathogenic, and were identified as Aspergillus section Nidulantes, Chaetomium cochliodes and Penicillium sp. In the rural (n = 2) and urban (n = 7) control dust samples, the microbial viable counts were >2000 CFU and between 44 CFU and 215 CFU, respectively, and consisted mainly of bacteria. The low proportion of bacteria and the high proportion of stress tolerant, potentially pathogenic fungi in the dust samples from sport facilities may reflect the influence of disinfection on microbial communities.

Microbial occupational exposure in e-waste recycling: biological hazards, their sources, and potential toxic effects

“…Previous studies recommend the use of several sampling approaches allowing overcoming the limitations of each method and contributing to a more representative scenario of microbiologic exposure(Viegas et al 2022a;Whitby et al 2022). In previous studies protection devices worn by workers were used to predict exposure to microbial agents and metabolites, such as mycotoxins(Viegas et al 2021a(Viegas et al , 2020a.The use of 37ºC as incubation temperature allowed the identi cation of the fungal species/sections that can grow at that temperature unveiling the pathogenic potential(Andersson et al 2023). Additionally, it was also possible to overcome the limitation in recovering fungi with clinical relevance, such as Aspergillus section Fumigati isolates that, in this kind of setting, due to fungi with higher growth rates, such as Mucorales order, Trichoderma sp., and Chrysonilia sitophila are underestimated.…”

Recent Advances in the Detection of Indoor Fungi

“…In another study on the fungal composition of indoor dust, Andersson et al [ 9 ] focused on the cultivable microbiota in sport facilities subjected to intense cleaning and disinfection during the COVID-19 pandemic. Strains of Aspergillus flavus and A. fumigatus classified as risk group 2 (RG-2) and bio-safety level 2 (BSL-2) were detected in the samples.…”

“…The contributors to this Special Issue provided insights into current issues in indoor mycology, particularly from a methodological [ 6 , 7 , 8 , 11 , 13 ], metabolic/toxicological [ 10 , 11 , 12 , 14 , 15 ], and taxonomical [ 8 , 9 , 13 , 16 , 17 ] point of view. Overall, two key messages emerge: (i) the current detection methods appear to be shifting from air sampling [ 11 , 12 ] to dust sampling [ 6 , 8 , 9 , 10 , 13 ], as the latter provides information on longer exposure periods and a higher biodiversity; (ii) the microbial composition of buildings is still largely unknown [ 9 , 13 , 16 , 17 ]. Our authors demonstrated that the indoor environment should also be a focus of taxonomical research, especially with regard to wooden and cellulosic materials [ 14 , 15 , 16 , 17 ], which proved to have a relatively high biodiversity.…”

“…The contributors to this Special Issue provided insights into current issues in indoor mycology, particularly from a methodological [6][7][8]11,13], metabolic/toxicological [10][11][12]14,15], and taxonomical [8,9,13,16,17] point of view. Overall, two key messages emerge: (i) the current detection methods appear to be shifting from air sampling [11,12] to dust sampling [6,[8][9][10]13], as the latter provides information on longer exposure periods and a higher biodiversity; (ii) the microbial composition of buildings is still largely unknown [9,13,16,17].…”