•Exposure to microbial contaminants should be considered.•In vitro toxicology provides relevant data on the potential health effects.•Interior layers exhibited higher cytotoxicity effect than ...exhalation valves.•Higher cytotoxicity among exhalation valves correlated with bacteria.•Training and education on the proper use of FRPD is needed.
Filtering respiratory protection devices (FRPD) are mandatory for workers to wear in the Portuguese waste-sorting industry. Previous results regarding microbial contamination found on FRPD interior layer raised the question of whether microbial contamination from the exhalation valve would also have cytotoxicity effects. Since the FRPD exhalation valves are very close to workers’ nose and mouth, they represent a source of exposure to bioburden by inhalation. This study aimed to evaluate the cytotoxicity of the microbial contamination present in the FRPD exhalation valves. For this purpose, the cytotoxicity effects were determined through the MTT assay in two different cell lines (human A549 epithelial lung cells, and swine kidney cells) and compared with previous results obtained with FRPD interior layers. The contamination present in the FRPD exhalation valves presented some cytotoxicity on epithelial lung cells, suggesting the inhalation route as a potential route of exposure through the use of FRPD in the waste-sorting industry. Half-maximal (50%) inhibitory concentration (IC50) values were lower for FRPD interior layer than exhalation valves in lung cells, with overall cytotoxicity lower in exhalation valves when compared to interior layer (z = −4.455, p = 0.000). Higher bacterial counts in TSA were correlated with lower IC50 values, thus, higher cytotoxicity effect in lung cells. No statistically significant differences were detected among different workplaces.
Exposure to Aspergillus conidia is an increased risk factor for the development of respiratory symptoms. The emergence of azole resistance in Aspergillus fumigatus is a major concern for the ...scientific community. The aim of this study was to perform the molecular identification of Aspergillus species collected from different occupational and non-occupational indoor settings and to study the azole susceptibility profile of the collected Fumigati isolates. The selected Aspergillus isolates were identified as belonging to the sections Fumigati, Nigri Versicolores, Terrei, Clavati and Nidulantes. All the Aspergillus fumigatus were screened for azole resistance using an agar media supplemented with itraconazole, voriconazole and posaconazole. None of the tested isolates showed resistance to those azoles. Knowledge of Aspergillus epidemiology in specific indoor environments allows a better risk characterization regarding Aspergillus burden. This study allowed the analysis of the molecular epidemiology and the determination of the susceptibility pattern of Aspergillus section Fumigati found in the studied indoor settings.
Safe working conditions must be guaranteed during waste sorting, which is crucial to maximizing recycling and reuse, in order to minimize workers' exposure to chemical and biological hazards. This ...study determines the contribution of
section
to the overall cytotoxicity of filtering respiratory protection devices (FRPD) and mechanic protection gloves (MPG) collected in 2019 from different workstations in one waste sorting industry in Portugal. The cytotoxicity of 133
section
isolates was determined as IC50 in human A549 epithelial lung cells and swine kidney cells, using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay.
section
cytotoxicity results were compared with previous total cytotoxicity data from FRPD and MPG samples. A significant correlation was detected between the total cytotoxicity of samples and cytotoxicity of
section
isolates in A549 cells (rS = -0.339,
= 0.030). The cytotoxicity of
section
isolates explained 10.7% of the total cytotoxicity of the sample. On the basis of the comparison of cytotoxicity levels, it was possible to determine the contribution of
section
isolates for the total cytotoxicity of protection devices used in the waste sorting industry. The results support in vitro toxicology as a relevant approach in risk assessments regarding cytotoxicity in passive sampling, and thus, useful in determining the contribution of relevant microbial contaminants to overall cytotoxicity. This approach can provide valuable answers in dose/response studies, and support innovations in risk characterization and their translation into occupational policies.
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.
The collection and analysis of settled dust samples from indoor environments has become one of several environmental sampling methods used to assess bioburden indoors. The aim of the study was to ...characterize the bioburden in vacuumed settled dust from 10 Primary Health Care Centers by culture based and molecular methods. Results for bacterial load ranged from 1 to 12 CFU.g
−1
of dust and Gram-negative bacteria ranged between 1 to 344 CFU.g
−1
of dust. Fungal load ranged from 0 CFU.g
−1
of dust to uncountable. Aspergillus section Fumigati was detected in 4 sampling sites where culture base-methods could not identify this section. Mucorales (Rhizopus sp.) was observed on 1 mg/L voriconazole. Three out of 10 settled dust samples were contaminated by mycotoxins. Settled dust sampling coupled with air sampling in a routine way might provide useful information about bioburden exposure.
Organic dust is widespread in the environment including occupational settings, such as bakeries. Recently, a new collection device—the electrostatic dust cloth (EDC)—has been described for the ...assessment of occupational exposures. The aim of this study was to investigate the suitability of EDC for identifying the distribution patterns and exposure concentrations of particulate matter and microbial contaminants such as fungi and bacteria in bakeries. Twelve bakeries were selected, and dust was allowed to settle for 13 to 16 days on EDCs (a total of 33 samples). Particle counts and size distribution (0.3 µm, 0.5 µm, 1 µm, 2.5 µm, 5 µm and 10 µm) were measured with direct-reading equipment. Higher EDC mass was significantly correlated (p values < 0.05) with higher fungal load on dichloran glycerol (DG18) and with particle size distribution in the 0.3 µm, 0.5 µm, 1.0 µm and 10.0 µm range. Fungal levels on malt extract agar (MEA) ranged from 0 to 2886 CFU/m2 EDC in the warehouse setting, 0 to 500 CFU/m2 EDC in the production setting, and 0 to 3135 CFU/m2 EDC in the store. Penicillium sp. (42.56%) was the most frequent fungi. Total bacterial load ranged from 0 to 18,859 CFU/m2 EDC in the warehouse, 0 to 71,656 CFU/m2 EDC in production, and 0 to 21,746 CFU/m2 EDC in the store. EDC assessment provided a longer-term integrated sample of organic dust, useful for identifying critical worksites in which particulate matter and bio-burden exposures are elevated. These findings suggest that EDC can be applied as a screening method for particulate matter-exposure assessment and as a complementary method to quantify exposures in occupational environments.
The higher education sector represents a unique environment and it acts as a work environment, a learning environment for students, and frequently, also a home environment. The aim of this study was ...to determine the microbial contamination (SARS-CoV-2, fungi, and bacteria) in Higher Education Facilities (HEI) by using active and passive sampling methods and combining culture-based methods with molecular tools targeting Aspergillus section Fumigati. In addition, the resistance to azole profile was also assessed. Surface samples showed a range of total bacterial contamination between 1 × 103 to 3.1 × 106 CFU·m−2, while Gram-negative bacteria ranged from 0 to 1.9 × 104 CFU·m−2. Fungal contamination ranged from 2 × 103 to 1.8 × 105 CFU·m−2 on MEA, and from 5 × 103 to 1.7 × 105 CFU·m−2 on DG18. The most prevalent species found on both media was Cladosporium sp. (47.36% MEA; 32.33% DG18). Aspergillus genera was observed on MEA (3.21%) and DG18 (14.66%), but not in the supplemented media used for the azole screening. Aspergillus section Fumigati was detected in 2 air samples (2.22%, 2 out of 90 samples) by qPCR. When testing for SARS-CoV-2 all results were negative. The present study showed that although cleaning and disinfection procedures are done regularly due to the COVID-19 pandemic, being effective in eliminating SARS-CoV-2, surfaces were often contaminated with microorganisms other than SARS-CoV-2. This can be a result of increasing resistance to biocides, and to the wide range of environmental factors that can contribute to the dissemination of microbial contamination indoors.
Respiratory abnormalities among workers at coffee roasting and packaging facilities have already been reported; however, little is known about microbiological contamination inside coffee production ...facilities. This study intends to assess the microbial contamination (fungi and bacteria) in two coffee industries from Brazil with a multi-approach protocol for sampling and for subsequent analyses using four main sources of samples: filtering respiratory protection devices (FRPD) used by workers, settled dust, electrostatic dust cloths (EDC) and coffee beans. The fungal contamination in the assessed industries was also characterized through the molecular detection of toxigenic species and antifungal resistance. Total bacteria contamination presented the highest values in FRPD collected from both industries (7.45 × 104 CFU·m
; 1.09 × 104 CFU·m
).
genera was widespread in all the environmental samples collected and sections with clinical relevance (
) and with toxigenic potential (
and
) were recovered from FRPD.
section was observed in 4 mg/mL itraconazole. Sections
(EDC, coffee beans and settled dust) and
(EDC, coffee beans and FRPD) were detected by qPCR. Some of the targeted
sections that have been identified microscopically were not detected by qPCR and vice-versa. Overall, this study revealed that microbial contamination is a potential occupational risk in the milling stage and should be tackled when assessing exposure and performing risk assessment. In addition, a multi-sampling campaign should be the approach to follow when assessing microbial contamination and FRPD should be included in this campaign. Occupational exposure to mycotoxins should be considered due to high fungal diversity and contamination. A One Health approach should address these issues in order to prevent consumption of coffee crops and beans infected by fungi and, more specifically, to avoid widespread azole resistance.
This study intends to assess the bioburden in ten Portuguese health care centers (PHCC) with a multi-approach protocol using active (air sampling by impaction and impinger) and passive (surface swabs ...and air-conditioning filters) sampling methods, and compare the results with compliance levels of IAQ Portuguese legislation for the assessment of bioburden. The fungal burden in the PHCC was also characterized through molecular detection of toxigenic species, antifungal resistance and mycotoxins profile. Concerning legal compliance criteria for bacteriota the first criteria indoor + 350 CFU. m−3 < outdoor was not complied in all PHCC analyzed. Regarding fungal load, 60% did not comply with the quantitative guideline (I/O < 1). Growth of four fungal genera (Chrysosporium, Cladosporium, Mucor and Penicillium) was observed in HVAC filter samples collected from 6 out of 10 assessed PHCC when using azole-supplemented SDA media. Overall, Aspergillus/Penicillium/Paecilomyces levels were above the detection limits, except in one PHCC. The presence of mycotoxins was found both in air and HVAC filter samples. From the air samples analyzed, nine were contaminated (ng/ml) with 1–5 different mycotoxins within the same sample, whereas in HVAC filters, four samples contained 1 or 2 mycotoxins in the same filter. Overall, it was possible to conclude that Portuguese legislation is not enough to ensure IAQ in health care settings. The multi-approach sampling protocol used in this study allowed to unveil a more real scenario regarding exposure to bioburden. Detection of mycotoxins reinforces the relevance of studying mycotoxins in the clinical environment.
•Portuguese legal criteria for bacteriota was not complied in all PHCC and for fungal load 60% did not comply.•The presence of mycotoxins was found both in air and HVAC filter samples.•Fungal biomass results have shown to be good predictors for bacterial and fungal counts in HVAC filters.•The multi-approach sampling protocol used allowed to unveil a more real scenario regarding exposure to bioburden.
The bioburden in a Hospital building originates not only from patients, visitors and staff, but is also disseminated by several indoor hospital characteristics and outdoor environmental sources. This ...study intends to assess the exposure to bioburden in one central Hospital with a multi-approach protocol using active and passive sampling methods. The microbial contamination was also characterized through molecular tools for toxigenic species, antifungal resistance and mycotoxins and endotoxins profile. Two cytotoxicity assays (MTT and resazurin) were conducted with two cell lines (Calu-3 and THP-1), and in vitro pro-inflammatory potential was assessed in THP-1 cell line. Out of the 15 sampling locations 33.3% did not comply with Portuguese legislation regarding bacterial contamination, whereas concerning fungal contamination 60% presented I/O > 1. Toxigenic fungal species were observed in 27% of the sampled rooms (4 out of 15) and qPCR analysis successfully amplified DNA from the Aspergillus sections Flavi and Fumigati, although mycotoxins were not detected. Growth of distinct fungal species was observed on Sabouraud dextrose agar with triazole drugs, such as Aspergillus section Versicolores on 1 mg/L VORI. The highest concentrations of endotoxins were found in settled dust samples and ranged from 5.72 to 23.0 EU.mg−1. While a considerable cytotoxic effect (cell viability < 30%) was observed in one HVAC filter sample with Calu-3 cell line, it was not observed with THP-1 cell line. In air samples a medium cytotoxic effect (61–68% cell viability) was observed in 3 out of 15 samples. The cytokine responses produced a more potent average cell response (46.8 ± 12.3 ρg/mL IL-1β; 90.8 ± 58.5 ρg/mL TNF-α) on passive samples than air samples (25.5 ± 5.2 ρg/mL IL-1β and of 19.4 ± 5.2 ρg/mL TNF-α).
A multi-approach regarding parameters to assess, sampling and analysis methods should be followed to characterize the biorburden in the Hospital indoor environment. This study supports the importance of considering exposure to complex mixtures in indoor environments.
•The multi-parameter approach on sampling methods and assays allowed to assess the biorburden.•Toxigenic fungal species were identified by culture based-methods and detected by qPCR.•Aspergillus section Versicolores was identified in the resistance to azoles screening.•Low levels of endotoxins were observed in the environmental matrices.•Low to moderate cytotoxic and pro-inflammatory effects were found.
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