Browsing by Author "Viegas, C."
Now showing 1 - 10 of 36
Results Per Page
Sort Options
- Accessing indoor fungal contamination by Aspergillus fumigatus complex using conventional and molecular methods in portuguese poultriesPublication . Viegas, C.; Malta-Vacas, J.; Sabino, R.; Viegas, S.; Veríssimo, C.Epidemiological studies showed increased prevalence of respiratory symptoms and adverse changes in pulmonary function parameters in poultry workers, corroborating the increased exposure to risk factors, such as fungal load and their metabolites. This study aimed to determine the occupational exposure threat due to fungal contamination caused by the toxigenic isolates belonging to the complex of the species of Aspergillus flavus and also isolates from Aspergillus fumigatus species complex. The study was carried out in seven Portuguese poultries, using cultural and molecular methodologies. For conventional/cultural methods, air, surfaces, and litter samples were collected by impaction method using the Millipore Air Sampler. For the molecular analysis, air samples were collected by impinger method using the Coriolis μ air sampler. After DNA extraction, samples were analyzed by real-time PCR using specific primers and probes for toxigenic strains of the Aspergillus flavus complex and for detection of isolates from Aspergillus fumigatus complex. Through conventional methods, and among the Aspergillus genus, different prevalences were detected regarding the presence of Aspergillus flavus and Aspergillus fumigatus species complexes, namely: 74.5 versus 1.0 % in the air samples, 24.0 versus 16.0 % in the surfaces, 0 versus 32.6 % in new litter, and 9.9 versus 15.9 % in used litter. Through molecular biology, we were able to detect the presence of aflatoxigenic strains in pavilions in which Aspergillus flavus did not grow in culture. Aspergillus fumigatus was only found in one indoor air sample by conventional methods. Using molecular methodologies, however, Aspergillus fumigatus complex was detected in seven indoor samples from three different poultry units. The characterization of fungal contamination caused by Aspergillus flavus and Aspergillus fumigatus raises the concern of occupational threat not only due to the detected fungal load but also because of the toxigenic potential of these species.
- Accessing occupational exposure to fungi in a cork industryPublication . Viegas, C.; Clérigo, A.; Faria, T.; Sabino, Raquel; Veríssimo, Cristina; Quintal-Gomes, A.; Viegas, S.In this study we aimed to access fungal exposure in workers from one cork industry through the mycological analysis of their nasal exudate and the environmental fungal contamination of their surroundings as well. Nasal mucous samples from 127 workers were taken with sterilized cotton swabs.The fungal species identified in the collected nose swabs were shown to be correlated with the results obtained in the environment. Eighty workers (63.0%) presented contamination of their nose nostril with Chrysonilia sitophila, which number of colonies was countless. Within the Aspergillus genus, the complexes Fumigati, Circumdati, Versicolores and Candidi were isolated. No azole-resistant Aspergillus isolates grew in the selective media used (screened itraconazole and voriconazole resistance).This approach allowed us to estimate the risk associated with these tasks performance. Moreover, the cork industry is related to high dust contamination and this can promote exposure to fungi since dust particles can act as carriers of fungi to the worker’s nose. Assessment by molecular tools will ensure the specific targeting of DNA from P. glabrum complex in workers nose.
- Air contaminants in animal production – poultry casePublication . Viegas, C.; Viegas, S.; Monteiro, A.; Carolino, E.; Sabino, R.; Verissimo, C.A descriptive study was developed in order to assess air contamination caused by fungi and particles in seven poultry units. Twenty seven air samples of 25 litters were collected through impaction method. Air sampling and particle concentration measurement were performed in the pavilions’ interior and also outside premises, since this was the place regarded as reference. Simultaneously, temperature and relative humidity were also registered. Regarding fungal load in the air from the seven poultry farms, the highest value obtained was 24040 CFU/m3 and the lowest was 320 CFU/m3. Twenty eight species/genera of fungi were identified, being Scopulariopsis brevicaulis (39.0%) the most commonly isolated species and Rhizopus sp. (30.0%) the most commonly isolated genus. From the Aspergillus genus, Aspergillus flavus (74.5%) was the most frequently detected species. There was a significant correlation (r=0.487; p=0.014) between temperature and the level of fungal contamination (CFU/m3). Considering contamination caused by particles, in this study, particles with larger dimensions (PM5.0 and PM10) have higher concentrations. There was also a significant correlation between relative humidity and concentration of smaller particles namely, PM0.5 (r=0.438; p=0.025) and PM1.0 (r=0.537; p=0.005). Characterizing typical exposure levels to these contaminants in this specific occupational setting is required to allow a more detailed risk assessment analysis and to set exposure limits to protect workers’ health.
- Air fungal contamination in ten hospitals’ food units from LisbonPublication . Viegas, C.; Ramos, C.; Almeida, M.; Sabino, Raquel; Verissimo, Cristina; Rosado, L.A descriptive study was developed to monitor air fungal contamination in ten food units from hospitals. Fifty air samples of 250 litres were collected through impaction method. Samples were collected in food storage facilities, kitchen, food plating, canteen and also, outside premises, since this is the place regarded as reference. Simultaneously, environmental parameters were also monitored, including temperature and relative humidity through the equipment Babouc, LSI Sistems and according to the International Standard ISO 7726.
- Aspergillus flavus contamination in 2 Portuguese waste water treatment plants: an occupational threatPublication . Viegas, C.; Dias, R.; Gomes, A.Q.; Meneses, M.; Sabino, R.; Viegas, S.Filamentous fungi from genus Aspergillus were previously detected in wastewater treatment plants (WWTP) as being Aspergillus flavus (A. flavus), an important toxigenic fungus producing aflatoxins. This study aimed to determine occupational exposure adverse effects due to fungal contamination produced by A. flavus complex in two Portuguese WWTP using conventional and molecular methodologies. Air samples from two WWTP were collected at 1 m height through impaction method. Surface samples were collected by swabbing surfaces of the same indoor sites. After counting A. flavus and identification, detection of aflatoxin production was ensured through inoculation of seven inoculates in coconut-milk agar. Plates were examined under long-wave ultraviolet (UV; 365 nm) illumination to search for the presence of fluorescence in the growing colonies. To apply molecular methods, air samples were also collected using the impinger method. Samples were collected and collection liquid was subsequently used for DNA extraction. Molecular identification of A. flavus was achieved by real-time polymerase chain reaction (RT-PCR) using the Rotor-Gene 6000 qPCR detection system (Corbett). Among the Aspergillus genus, the species that were more abundant in air samples from both WWTP were Aspergillus versicolor (38%), Aspergillus candidus (29.1%), and Aspergillus sydowii (12.7%). However, the most commonly species found on surfaces were A. flavus (47.3%), Aspergillus fumigatus (34.4%), and Aspergillus sydowii (10.8%). Aspergillus flavus isolates that were inoculated in coconut agar medium were not identified as toxigenic strains and were not detected by RT-PCR in any of the analyzed samples from both plants. Data in this study indicate the need for monitoring fungal contamination in this setting. Although toxigenic strains were not detected from A. flavus complex, one cannot disregard the eventual presence and potential toxicity of aflatoxins.
- Aspergillus nosocomial infections Do cryptic species found in hospital environment matter?Publication . Sabino, Raquel; Viegas, C.; Francisco, M.; Martins, Carlos; Clemons, Karl; Stevens, DavidPurpose: Aspergillus is a major threat causing nosocomial infections in immunocompromised patients. Advances in molecular methods allowed species identification through sequencing of specific genes, allowing high discrimination amongst isolates. Different Aspergillus species have different susceptibilities to antifungals and several cryptic species have been described as less susceptible to specific antifungals. Therefore, we addressed the possible influence of hospital environmental isolates in the overall situation of Aspergillus antifungal resistance. Methods: During one year, 101 air and 99 surface samples were collected from the environment of a Portuguese central hospital of Lisbon. Aspergillus isolates were identified morphologically and by molecular methods. Genomic DNA was prepared from each isolate and then sequenced to achieve the correct species identification. Determination of the antifungal susceptibility of selected isolates was performed by microdilution (CLSI M38-A2). The antifungal agents studied were deoxycholate amphotericin B, itraconazole, voriconazole, and posaconazole. Results: From the 200 samples collected, 75 isolates of Aspergillus were obtained and identified to section by ITS sequence; cryptic species were identified by β-tubulin and calmodulin sequencing. Ten different sections within the Aspergillus genus were identified: Versicolores (N=20), Nigri (N=11), Flavi (N=10), Circumdati (N=10), Fumigati (N=8), Usti (N=4), Terrei (N=4), Nidulantes (N=4), Aspergilli (N=3) and Cremei (N=1). From these, 25 different Aspergillus species were identified by β-tubulin and calmodulin sequencing, and a high percentage of cryptic species (not sensu stricto) was found (59%). Sections Usti, Versicolores and Circumdati harbored the highest proportion of cryptic species [100% (4/4), 95% (19/20) and 90% (9/10), respectively]. From the 75 isolates, 22 were tested for their antifungal susceptibility. Of the 8 Fumigati isolates, there was 1 cryptic species. The Circumdati, Versicolores and Nigri complexes contained isolates of cryptic species with reduced susceptibility to some of the antifungals used in clinical therapeutics. In the Circumdati complex, 3/5 isolates hadMIC to amphotericin B >8μg/ml and 1/5MIC >8μg/ml to itraconazole; 1/6 isolates fromVersicolores complex hadMIC to itraconazole >8 μg/ml; all 4 isolates fromNigri complex hadMIC to itraconazole=4 μg/ml. Conclusion: Since Aspergillus infections aremainly nosocomial, knowledge of themolecular epidemiology and determinationof the susceptibility profile of environmental isolateswould suggestmeasures need to be considered.
- Assessment of exposure to the Penicillium glabrum complex in cork industry using complementing methodsPublication . Viegas, C.; Sabino, Raquel; Botelho, D.; Santos, M.; Gomes, A.Q.Cork oak is the second most dominant forest species in Portugal and makes this country the world leader in cork export. Occupational exposure to Chrysonilia sitophila and the Penicillium glabrum complex in cork industry is common, and the latter fungus is associated with suberosis. However, as conventional methods seem to underestimate its presence in occupational environments, the aim of our study was to see whether information obtained by polymerase chain reaction (PCR), a molecular-based method, can complement conventional findings and give a better insight into occupational exposure of cork industry workers. We assessed fungal contamination with the P. glabrum complex in three cork manufacturing plants in the outskirts of Lisbon using both conventional and molecular methods. Conventional culturing failed to detect the fungus at six sampling sites in which PCR did detect it. This confirms our assumption that the use of complementing methods can provide information for a more accurate assessment of occupational exposure to the P. glabrum complex in cork industry.
- Assessment of fungal contamination in a Portuguese maternity unitPublication . Viegas, C.; Sabino, R.; Veríssimo, C.; Rosado, L.A descriptive study was developed to monitor air fungal contamination in one Portuguese maternity. Sixty air samples were collected through impaction method. Air sampling was performed in food storage facilities, kitchen, food plating, canteen, pharmacy, sterilization areas, genecology wards, intensive care unit, operating rooms, urgency and also, outside premises, since this was the place regarded as reference. Besides air samples, forty three samples were collected by swabbing the surfaces using a 10 by 10 cm square stencil. Simultaneously, temperature, relative humidity and particles counting (PM10) were registered. Twenty three species of fungi were identified in air, being the two most commonly isolated the genera Penicillium (41,5%) and Cladosporium (28,4%). Regarding yeasts, only Rhodotorula sp. (45,2%), Trichosporon mucoides (51,6%) and Cryptococcus neoformans (3,2%) were found. Thirteen species of fungi were identified in surfaces, being the most frequent the Penicillium genus (91,6%). Concerning yeasts found in surfaces, four species were identified being Rhodotorula sp. (29,1%) the most frequent. There was no coincidence between prevailing genera indoors and outside premises. Moreover, some places presented fungal species different from the ones isolated outside. In the inside environment, Aspergillus species were isolated in air and surfaces. There was no significant relationship (p>0,05) between fungal contamination and the studied environmental variables. Keywords: air, surfaces, fungal contamination, environmental variables, maternity.
- Assessment of fungal contamination in waste sorting and incineration-case study in PortugalPublication . Viegas, C.; Gomes, Q.; Abegão, J.; Sabino, R.; Graça, T.; Viegas, S.Organic waste is a rich substrate for microbial growth, and because of that, workers from waste industry are at higher risk of exposure to bioaerosols. This study aimed to assess fungal contamination in two plants handling solid waste management. Air samples from the two plants were collected through an impaction method. Surface samples were also collected by swabbing surfaces of the same indoor sites. All collected samples were incubated at 27◦C for 5 to 7 d. After lab processing and incubation of collected samples, quantitative and qualitative results were obtained with identification of the isolated fungal species. Air samples were also subjected to molecular methods by real-time polymerase chain reaction (RT PCR) using an impinger method to measure DNA of Aspergillus flavus complex and Stachybotrys chartarum. Assessment of particulate matter (PM) was also conducted with portable direct-reading equipment. Particles concentration measurement was performed at five different sizes (PM0.5; PM1; PM2.5; PM5; PM10). With respect to the waste sorting plant, three species more frequently isolated in air and surfaces were A. niger (73.9%; 66.1%), A. fumigatus (16%; 13.8%), and A. flavus (8.7%; 14.2%). In the incineration plant, the most prevalent species detected in air samples were Penicillium sp. (62.9%), A. fumigatus (18%), and A. flavus (6%), while the most frequently isolated in surface samples were Penicillium sp. (57.5%), A. fumigatus (22.3%) and A. niger (12.8%). Stachybotrys chartarum and other toxinogenic strains from A. flavus complex were not detected. The most common PM sizes obtained were the PM10 and PM5 (inhalable fraction). Since waste is the main internal fungal source in the analyzed settings, preventive and protective measures need to be maintained to avoid worker exposure to fungi and their metabolites.
- Climate change and aflatoxins exposure in Portugal – could we expect a significant health risk?Publication . Assunção, R.; Martins, C.; Viegas, S.; Viegas, C.; Jakobsen, Lea S.; Pires, S.; Alvito, P.In recent decades, changes in climate have caused impacts on natural and human systems on all continents and across the oceans. Climate change (CC) has become one of the most critical issues for the sustainable development of human societies and the functioning of ecosystems on earth. Portugal is highly vulnerable to CC impacts due to its Europe south-western geographical situation, mainly through decreasing annual precipitation, more intense extreme weather and climate events. In fact, CC is considered as one of the biggest global threats to human health of the 21st century and its effects will undoubtedly influence agricultural systems and food safety. Due to the potential impact on the occurrence of food hazards, increased concern has being aroused. Mycotoxins, natural contaminants produced by fungi, are among the most important of such hazards, especially due to their potential to establish deleterious health conditions. From all known mycotoxins, aflatoxins stand to the most toxic for humans. Dietary aflatoxins exposure is considered a significant risk factor for hepatocellular carcinoma (HCC). Considering the impact of CC in mycotoxin contamination of food products available in Portugal, the present study aims to discuss the potential influence of CC in the health risk associated to aflatoxins dietary exposure of Portuguese population. To tackle this objective, the estimated number of hepatocellular carcinoma (HCC) and the associated burden of disease in terms of Disability Adjusted Life Years (DALYs) were derived. Results showed that the number of extra cases of HCC associated to Portuguese aflatoxin dietary exposure ranged from 0.52 and 2.00. The derived DALYs ranged between 8.0 and 30.9. It is expected that in the future the number of DALYs and the associated HCC due to aflatoxin exposure should increase due to CC. These results should represent an alert for the potential consequences of an incompletely explored perspective of CC – the health impact of the human exposure to aflatoxins. Politics and decision-makers should be involved and committed to implement effective measures to deal with CC issues and to reduce its possible consequences.