Aspergillus Section Fumigati in Firefighter Headquarters

Abstract

Background: Aspergillus section Fumigati is one of the Aspergillus sections more frequently related to respiratory symptoms and by other health outcomes. This study aimed to characterize Aspergillus section Fumigati distribution in eleven firefighter headquarters (FFHs) to obtain an accurate occupational exposure assessment. Methods: A sampling approach protocol was performed using active (impaction method) and passive sampling methods (floor surfaces swabs, electrostatic dust collectors (EDCs), and settled dust). All samples were analysed by culture-based methods and passive sampling was used for molecular detection of Aspergillus section Fumigati. Results: Of all the matrices, the highest counts of Aspergillus sp. were obtained on settled dust filters (3.37% malt extract agar—MEA, 19.09% dichloran glycerol—DG18) followed by cleaning cloths (1.67% MEA; 7.07% DG18). Among the Aspergillus genus, the Fumigati section was predominant in Millipore and EDC samples in MEA (79.77% and 28.57%, respectively), and in swabs and settled dust filters in DG18 (44.76% and 30%, respectively). The Fumigati section was detected more frequently in DG18 (33.01%) compared to MEA (0.33%). The Fumigati section was observed in azole supplemented media (itraconazole and voriconazole) in several passive sampling methods employed and detected by qPCR in almost all passive samples, with EDCs being the matrix with the highest prevalence (n = 61; 67.8%). Conclusion: This study confirms that Aspergillus sp. is widespread and the Fumigati section is present in all FFHs. The presence of fungi potentially resistant to azoles in the FFHs was also observed. Further studies are needed to identify the best corrective and preventive measures to avoid this section contamination in this specific occupational environment.

Electrostatic Dust Cloth: A Useful Passive Sampling Method When Assessing Exposure to Fungi Demonstrated in Studies Developed in Portugal (2018–2021)

“…In the assessed dwellings, some constraints were faced due to the occupant’s availability when the sampling period ended, and although 30 days of sampling was to be followed, an extended period of sampling was performed in some cases. This difficulty was overcome by applying a different formula, (CFU.m-2.day =(1 x/(3.14*EDC area))/days of sampling) where the sampling days were considered, to obtain fungal densities [ 21 ]. This different approach for the fungal density’s quantification was the one followed after the first study performed in dwellings [ 16 ].…”

“…This sampling method is appropriate for large-scale epidemiological studies intending to measure microbial exposure, and to complement exposure information collected by building inspections dedicated to spotting dampness and mold [ 3 , 4 ]. EDC is also being used to assess microbial contamination using molecular tools as stand-alone analyses [ 4 , 5 , 6 , 7 , 8 ], even the most refined ones such as sequencing [ 2 ], or using side by side, culture-dependent, and independent methods [ 3 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 ]. In fact, the use of qPCR analyses from EDC is a promising tool to accurately measure microbial contamination in dwellings [ 4 , 8 , 24 ].…”

“…In fact, the use of qPCR analyses from EDC is a promising tool to accurately measure microbial contamination in dwellings [ 4 , 8 , 24 ]. Additionally, it has also been used to perform the fungal azole resistance screening in different indoor environments [ 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 ] and to identify MRSA presence and level of contamination in specific occupational environments [ 7 ]. Further, aside from microbial contamination, this sampling method has been applied to assess microbial metabolites, such as endotoxins [ 27 , 28 , 29 ] and mycotoxins [ 18 , 22 ].…”

Microbial Occupational Exposure Assessments in Sawmills—A Review

“…Several researchers [67,[73][74][75][76][77][78] have begun to collect and analyze from indoor environments a similar matrix (settled dust) as part of their microbial contamination exposure assessments. Settled dust reservoirs have been described as having the ability to anticipate microbial levels in indoor air, as well as being more repeatable than active sampling approaches [67].…”

Cytotoxicity of Aspergillus Section Fumigati Isolates Recovered from Protection Devices Used on Waste Sorting Industry

“…Furthermore, a microorganism's viability is associated with the potential of inflammatory and cytotoxic responses and, consequently, the infection potential. Therefore, molecular tools must be used in parallel with classic methods [18][19][20]. In addition, in exposure assessment studies, where the exposure is mainly occurring by inhalation, the outcomes of respiratory diseases may vary significantly with fungal viability, and thus, it is of utmost importance to apply cultures for the fungal assessment or isolates recovery [21].…”