Fungal burden in waste industry: an occupational risk to be solved

Abstract

High loads of fungi have been reported in different types of waste management plants. This study intends to assess fungal contamination in one waste-sorting plant before and after cleaning procedures in order to analyze their effectiveness. Air samples of 50 L were collected through an impaction method, while surface samples, taken at the same time, were collected by the swabbing method and subject to further macro- and microscopic observations. In addition, we collected air samples of 250 L using the impinger Coriolis μ air sampler (Bertin Technologies) at 300 L/min airflow rate in order to perform real-time quantitative PCR (qPCR) amplification of genes from specific fungal species, namely Aspergillus fumigatus and Aspergillus flavus complexes, as well as Stachybotrys chartarum species. Fungal quantification in the air ranged from 180 to 5,280 CFU m(-3) before cleaning and from 220 to 2,460 CFU m(-3) after cleaning procedures. Surfaces presented results that ranged from 29×10(4) to 109×10(4) CFU m(-2) before cleaning and from 11×10(4) to 89×10(4) CFU m(-2) after cleaning. Statistically significant differences regarding fungal load were not detected between before and after cleaning procedures. Toxigenic strains from A. flavus complex and S. chartarum were not detected by qPCR. Conversely, the A. fumigatus species was successfully detected by qPCR and interestingly it was amplified in two samples where no detection by conventional methods was observed. Overall, these results reveal the inefficacy of the cleaning procedures and that it is important to determine fungal burden in order to carry out risk assessment.

Occupational exposure to bioburden in Portuguese bakeries: an approach to sampling viable microbial load

“…Culture based-methods not only affect the microbial loads but also their biodiversity (35). In contrast, quantitative polymerase chain reaction (qPCR)-based methods can not differentiate between live and dead microorganisms, which is not totally suitable for infectious microorganisms and mainly occupational settings (36). Therefore, cultureindependent methods do not overcome all the limitations of the culture-based ones.…”

“…Therefore, cultureindependent methods do not overcome all the limitations of the culture-based ones. While molecular tools such as next-generation sequencing (NGS) generally show greater biodiversity in aerosol samples than culture-based methods, more and more researchers recognise that culture-based and culture-independent methods are complementary (20,36). Given the complementarity of the culture basedmethods and molecular tools, we propose the following procedure: apply the impaction method to obtain information about the viable microbial load and the impinger method to target for specific microorganisms by later using molecular tools.…”

Collection efficiency of liquid‐based samplers for fungi in indoor air

“…In addition to fungal concentration, the CE of sampling devices is also affected by sampling locations (Table ). This is probably associated with the composition of mycobiota in air that likely varies in locations because of the differences in RH, temperature, and availability of nutrients . Various fungal species may have different susceptibilities to stresses inherent in bioaerosol sampling and different hydrophobicity properties associated with the potential of re‐aerosolization.…”

“…Indeed, fungal aerosols in homes, offices, hospitals, animal barns, and waste-associated facilities have been successfully detected and/ or quantified by liquid-based samplers, namely the BioSampler (SKC Inc, Eighty Four, PA, USA), 5,9 the all-glass impinger (AGI-30, Ace Glass Inc, Vineland, NJ, USA), 10,11 and the Coriolis sampler (Bertin Technologies, Montigny-le-Bretonneux, France). [1][2][3]7,13 A variety of fluids have been filled in bioaerosol samplers for fungal collection, including distilled water (DW), 5 phosphate-buffered saline (PBS), 9,10 and DW or PBS supplemented with surfactants (eg, Tween-20, Tween-80, and Triton X-100) [1][2][3]7,13,15 and antifoam agents. 12,17 The BioSampler is an improvement over the AGI-30 in terms of aerosol collection efficiency.…”

Antifungal-resistant Mucorales in different indoor environments

“…Mucorales isolates were obtained from samples collected at independent projects aiming for the assessment of occupational exposure and indoor air quality, focusing on exposure to bioburden. Indoor environmental samples were collected between 2013 and 2018 from four different occupational settings around Lisbon metropolitan area, and from dwellings in Aveiro region (Portugal) (Table 1), as follows: bakeries (Caetano, Faria, et al 2017;Caetano, Zegre, et al 2018;Viegas et al 2018c), swine farms (Viegas, Carolino, et al 2013;Viegas, Faria, Dos Santos, et al 2016b;Viegas, Faria, Monteiro, et al 2018b), taxis used for patient transportation (Viegas et al 2018d), waste-sorting plants (Viegas, Gomes, et al 2014;Viegas, Faria, Dos Santos, et al 2015;Viegas, Faria, Caetano, et al 2017a), and dwellings (data not published). In order to collect and assess total bioburden and resistant mycobiota, different sampling devices were used per setting that were better adapted to the activities developed in each environment: electrostatic dust collector (EDC) from dwellings and bakeries; filters from the air-conditioning system of vehicles (taxis and waste fork lifters); litter and feed from swine farms; raw materials from bakeries (Table 1).…”