scholarly journals Settleable Dust and Bioburden in Portuguese Dwellings

2020 ◽  
Vol 8 (11) ◽  
pp. 1799
Author(s):  
Carla Viegas ◽  
Marta Dias ◽  
Beatriz Almeida ◽  
Estela Vicente ◽  
Liliana Aranha Caetano ◽  
...  
Keyword(s):  
Passive Sampling ◽  
Culture Media ◽  
Fungal Species ◽  
Winter Period ◽  
Azole Resistance ◽  
Resistance Screening ◽  
Molecular Tools ◽  
Fungal Contamination ◽  
Loading Rates ◽  
Dust Loading

Monitoring campaigns in several buildings have shown that occupants exposed to contaminated indoor air generally exhibit diverse health symptoms. This study intends to assess settleable dust loading rates and bioburden in Portuguese dwellings by passive sampling onto quartz fiber filters and electrostatic dust cloths (EDCs), respectively. Settled dust collected by EDCs was analyzed by culture-based methods (including azole-resistance screening) and qPCR, targeting four different toxigenic Aspergillus sections (Flavi, Fumigati, Circumdati, and Nidulantes). Dust loading rates and bioburden showed higher variability in the summer season. In both seasons, Penicillium sp. was the one with the highest prevalence (59.1% winter; 58.1% summer), followed by Aspergillus sp. in winter (13.0%). Fungal contamination increased in the winter period, while bacterial counts decreased. Aspergillus sections Circumdati and Nidulantes, detected in voriconazole supplemented media, and Aspergillus sections Fumigati and Nidulantes, detected by molecular tools, were found in the winter samples. This study reinforces the importance of applying: (a) Passive sampling methods in campaigns in dwellings; (b) two different culture media (MEA and DG18) to assess fungi; (c) in parallel, molecular tools targeting the most suitable indicators of fungal contamination; and (d) azole resistance screening to unveil azole resistance detection in fungal species.

scholarly journals Loading Rates of Dust and Bioburden in Dwellings in an Inland City of Southern Europe

Atmosphere ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 378
Author(s):  
Carla Viegas ◽  
Marta Dias ◽  
Beatriz Almeida ◽  
Estela Vicente ◽  
Carla Candeias ◽  
...  
Keyword(s):  
Indoor Air ◽  
Microbial Contamination ◽  
Fungal Species ◽  
Malt Extract ◽  
Gram Negative Bacteria ◽  
Fungal Contamination ◽  
Loading Rates ◽  
Colony Forming Units ◽  
Dust Loading ◽  
Total Bacteria

Sampling campaigns indoors have shown that occupants exposed to contaminated air generally exhibit diverse health outcomes. This study intends to assess the deposition rates of total settleable dust and bioburden in the indoor air of dwellings onto quartz fiber filters and electrostatic dust collectors (EDCs), respectively. EDC extracts were inoculated onto malt extract agar (MEA) and dichloran glycerol (DG18) agar-based media used for fungal contamination characterization, while tryptic soy agar (TSA) was applied for total bacteria assessment, and violet red bile agar (VRBA) for Gram-negative bacteria. Azole-resistance screening and molecular detection by qPCR was also performed. Dust loading rates ranged from 0.111 to 3.52, averaging 0.675 μg cm−2 day−1. Bacterial counts ranged from undetectable to 16.3 colony-forming units (CFU) m−2 day−1 and to 2.95 CFU m−2 day−1 in TSA and VRBA, respectively. Fungal contamination ranged from 1.97 to 35.4 CFU m−2 day−1 in MEA, and from undetectable to 48.8 CFU m−2 day−1 in DG18. Penicillium sp. presented the highest prevalence in MEA media (36.2%) and Cladosporium sp. in DG18 (39.2%). It was possible to observe: (a) settleable dust loadings and fungal contamination higher in dwellings with pets; (b) fungal species considered indicators of harmful fungal contamination; (c) Aspergillus section Candidi identified in supplemented media with voriconazole and posaconazole; (d) specific housing typologies and (e) specific housing characteristics influencing the microbial contamination.

scholarly journals Frequency of Aspergillus fumigatus fres.: A toxigenic and allergenic fungal species in milking cows feeds throughout one research year

2009 ◽  
pp. 101-112 ◽  
Author(s):  
Marija Skrinjar ◽  
Tibor Kenjves ◽  
Mira Ac
Keyword(s):  
Aspergillus Fumigatus ◽  
Fungal Species ◽  
Winter Period ◽  
Fungal Contamination ◽  
Autumn And Winter ◽  
Feed Samples

Fungal contamination of 92 feed samples used for milking cows feeding during one research year (in all seasons) in Vojvodina was examined. A special attention was paid to the frequency of A. fumigatus, a fungal species harmful to human and animals. As it was found out all feed samples in summer and spring were contaminated with fungi and about 95% in autumn and winter period. Aspergilli occurred as contaminants in all seasons. About 63% of feed samples in summer, 67% in autumn, 89% in winter and 48% in spring were contaminated with them. A. fumigatus was constantly present in feeds. It was isolated from 19% of feed samples investigated in summer, 33% in autumn, even 61% in winter and from 4% in spring.

scholarly journals Azole Resistance in Clinical and Environmental Aspergillus Isolates from the French West Indies (Martinique)

2021 ◽  
Vol 7 (5) ◽  
pp. 355
Author(s):  
Lorra Monpierre ◽  
Nicole Desbois-Nogard ◽  
Isabel Valsecchi ◽  
Marielle Bajal ◽  
Cécile Angebault ◽  
...  
Keyword(s):  
West Indies ◽  
Culture Media ◽  
Antifungal Susceptibility ◽  
Resistance Mechanisms ◽  
Clinical Samples ◽  
Azole Resistance ◽  
Environmental Isolates ◽  
French West Indies ◽  
First Time ◽  
Microdilution Broth

The emergence of azole resistant Aspergillus spp., especially Aspergillus fumigatus, has been described in several countries around the world with varying prevalence depending on the country. To our knowledge, azole resistance in Aspergillus spp. has not been reported in the West Indies yet. In this study, we investigated the antifungal susceptibility of clinical and environmental isolates of Aspergillus spp. from Martinique, and the potential resistance mechanisms associated with mutations in cyp51A gene. Overall, 208 Aspergillus isolates were recovered from clinical samples (n = 45) and environmental soil samples (n = 163). They were screened for resistance to azole drugs using selective culture media. The Minimum Inhibitory Concentrations (MIC) towards voriconazole, itraconazole, posaconazole and isavuconazole, as shown by the resistant isolates, were determined using the European Committee on Antimicrobial Susceptibility Testing (EUCAST) microdilution broth method. Eight isolates (A. fumigatus, n = 6 and A. terreus, n = 2) had high MIC for at least one azole drug. The sequencing of cyp51A gene revealed the mutations G54R and TR34/L98H in two A. fumigatus clinical isolates. Our study showed for the first time the presence of azole resistance in A. fumigatus and A. terreus isolates in the French West Indies.

scholarly journals In vitro culture as an aid to conservation of indigenous ferns: Diplazium proliferum

2015 ◽  
Vol 6 (1) ◽  
Author(s):  
Zubeir M. Golamaully ◽  
Vishwakalyan Bhoyroo ◽  
Nadeem Nazurally ◽  
Vineshwar Gopal
Keyword(s):  
Growth Rate ◽  
In Vitro Culture ◽  
Mercuric Chloride ◽  
Rare Species ◽  
Vascular Plants ◽  
Culture Media ◽  
Fungal Contamination ◽  
Increase Growth Rate ◽  
Growing Population

With the ever growing population and economic needs of Mauritius, the flora of Mauritius has never been in more danger and one group of vascular plants is even more in peril; ferns.<em> Diplazium proliferum</em> is indigenous to the Mascarene region and is considered as a rare species in Mauritius. The need to develop a tested <em>in vitro</em> propagation protocol is a must to protect the biodiversity of Mauritius. This experiment was geared towards the establishment of a proper sterilization technique and the effect of 6-benzylaminopurine (BAP) and light on <em>in vitro</em> culture of this fern. Sterilization with 0.05% Mercuric chloride was effective to eliminate fungal contamination and allow germination of spores. Culture media supplemented with BAP did not significantly increase growth rate of both gametophytes and sporophytes of<em> D. proliferum</em>. Present results suggest efficient sterilization methods to be a crucial stage for successful<em> in vitro r</em>egeneration of ferns. The established protocol will be used as an optimized baseline protocol for the propagation of other indigenous ferns.

scholarly journals Culture media selection for mass production of Isaria fumosorosea and Isaria farinosa

2010 ◽  
Vol 53 (4) ◽  
pp. 753-761 ◽  
Author(s):  
Gabriel Moura Mascarin ◽  
Sérgio Batista Alves ◽  
Rogério Biaggioni Lopes
Keyword(s):  
Mass Production ◽  
Culture Media ◽  
Fungal Species ◽  
Complete Medium ◽  
Sugarcane Molasses ◽  
Liquid Media ◽  
Isaria Fumosorosea ◽  
Isaria Farinosa ◽  
Selection For ◽  
Biphasic Fermentation

This work investigated the production of the fungi Isaria fumosorosea and Isaria farinosa in biphasic fermentation using agro-industrial products and residues. Combinations of natural liquid substrates, alternative to the complete medium and potato dextrose medium, were evaluated. The best liquid media were sugarcane molasses + rice broth, rice broth + yeast and sugarcane molasses + yeast + rice broth, which resulted in the highest viable propagule concentration. The molasses + rice broth medium was selected for the next phase of the study in which the production of both fungal isolates was evaluated in solid grain substrates. In solid-state fermentation, the best conidia production was achieved with the soybean meal and broken corn for I. farinosa, and whole rice and broken rice for I. fumosorosea. Results demonstrated that the two fungal species could be rapidly produced with higher yield of conidia on agro-industrial resources by using biphasic fermentation techniques.

scholarly journals Effective medium for in vitro sprouting of the buds and multiplication of the plantlets, and identification of the fungal contaminant associated with the explants of Gnetum

2021 ◽  
Vol 16 (2) ◽  
pp. 001-013
Author(s):  
Abwe Mercy Ngone ◽  
Lawrence Monah Ndam ◽  
Rita Mungfu Njilar ◽  
Doungous Oumar ◽  
Thomas Eku Njock
Keyword(s):  
Culture Medium ◽  
Culture Media ◽  
Fungal Growth ◽  
Growth Media ◽  
Fungal Contamination ◽  
Surface Sterilization ◽  
Pure Cultures ◽  
Nodal Cuttings ◽  
Baseline Information

Plant tissue culture requires the optimization of growth media. Gnetum, known locally in Cameroon as “Eru” is an indigenous gymnospermous vegetable with diverse medicinal, nutritional, cultural and socio-economic values. This resource is over-exploited and expected to neighboring countries, resulting to increased scarcity in the forest. Preliminary work on the in vitro culture of nodal cuttings was faced by the problem of fungal contamination. It was therefore necessary to isolate and identify the fungal contaminant, optimize the surface sterilization of field material and compose an appropriate medium for sprouting. Pure cultures of the fungus were obtained and grown on Potato Dextrose Agar (PDA) and Sabouraud Dextrose Agar (SDA). The identification was based on the appearance of the fungal growth on plates and also on the microscopic view. This was affected by the use of keys. Gnetum explants were disinfected with the various concentrations of disinfectants, preceded in some instances by pre-treatments, as well as incorporating fungicides in the culture medium. Two different culture media were employed: the Woody Plant Medium (WPM) and the Murashige and Skoog (MS) based establishment medium (Y-1). Gnetum was found to live in association with a complex of Microsporum species. The level of contamination of cultures was reduced from 100% to 40% when pre-treated before disinfection and even lower to 10% by incorporating fungicides in the medium. Sprouting was observed in WPM. This study provides baseline information on the in vitro propagation of Gnetum and thus opens up avenues for more research to be carried out in this field.

scholarly journals Culture Medium, Light Regime and Temperature Affect the Development of Sirosporium diffusum

2018 ◽  
Vol 10 (6) ◽  
pp. 310
Author(s):  
Tales Poletto ◽  
Marlove F. B. Muniz ◽  
Vinícius S. Fantinel ◽  
Renata F. Favaretto ◽  
Igor Poletto ◽  
...  
Keyword(s):  
Culture Medium ◽  
Culture Media ◽  
Fungal Species ◽  
Light Regime ◽  
Leaf Spot Disease ◽  
Light Regimes ◽  
Physical Conditions ◽  
Randomized Design ◽  
Brown Leaf Spot ◽  
Brown Leaf

Sirosporium diffusum is the causal agent of the brown leaf spot disease on pecan trees that seriously damages the foliage of adult plants and seedlings. This fungal species is difficult to grow satisfactorily in a culture medium. Therefore, the aim of this study was to evaluate the effects of different physical conditions on the development of S. diffusum. In the first assay, eight culture media and five light regimes were combined, while in the second, the three treatments that promoted highest sporulation were combined with three temperatures. The trials were conducted in a two-factorial arrangement in a fully randomized design with six replicates. V8, V8CaCO3, and CA media under a 24-h photoperiod produced the highest respective sporulations: 29 × 104, 35 × 104, and 41 × 104 conidia ml-1. The best temperature for sporulation was 20±1 °C for all culture media, especially V8CaCO3 and CA. The best artificial conditions for obtaining good mycelial growth and sporulation consisted of a photoperiod of 24 h, temperature of 20±1 °C and V8CaCO3 or CA culture medium.

scholarly journals Fungal Functional Genomics: Tunable Knockout-Knock-in Expression and Tagging Strategies

2009 ◽  
Vol 8 (5) ◽  
pp. 800-804 ◽  
Author(s):  
Luis F. Larrondo ◽  
Hildur V. Colot ◽  
Christopher L. Baker ◽  
Jennifer J. Loros ◽  
Jay C. Dunlap
Keyword(s):  
Functional Genomics ◽  
Target Gene ◽  
High Efficiency ◽  
Expression System ◽  
Gene Replacement ◽  
Fungal Species ◽  
Homologous Gene ◽  
Molecular Tools ◽  
Phenotypic Information ◽  
Endogenous Loci

ABSTRACT Strategies for promoting high-efficiency homologous gene replacement have been developed and adopted for many filamentous fungal species. The next generation of analysis requires the ability to manipulate gene expression and to tag genes expressed from their endogenous loci. Here we present a suite of molecular tools that provide versatile solutions for fungal high-throughput functional genomics studies based on locus-specific modification of any target gene. Additionally, case studies illustrate caveats to presumed overexpression constructs. A tunable expression system and different tagging strategies can provide valuable phenotypic information for uncharacterized genes and facilitate the analysis of essential loci, an emerging problem in systematic deletion studies of haploid organisms.

scholarly journals Occupational Exposures to Organic Dust in Irish Bakeries and a Pizzeria Restaurant

2020 ◽  
Vol 8 (1) ◽  
pp. 118 ◽  
Author(s):  
Carla Viegas ◽  
Gerard T. A. Fleming ◽  
Abdul Kadir ◽  
Beatriz Almeida ◽  
Liliana Aranha Caetano ◽  
...  
Keyword(s):  
Occupational Exposure ◽  
Microbial Contamination ◽  
Geometric Mean ◽  
Occupational Exposures ◽  
Azole Resistance ◽  
Resistance Screening ◽  
Settled Dust ◽  
Inhalable Dust ◽  
Flour Dust

For decades, occupational exposure to flour dust has been linked to a range of respiratory diseases, including occupational asthma, thought to result from exposure to fungi present in the flour. Antifungal resistance is of increasing prevalence in clinical settings, and the role of occupational and environmental exposures, particularly for specific fungal species, is of concern. Occupational exposure to flour dust can occur in a range of occupational settings, however, few studies have focused on restaurant workers. The objective of this study was to measure occupational exposure to flour and microbial contamination, including azole resistance screening, in two small commercial bakeries and in a pizzeria. Personal full shift inhalable dust measurements were collected from workers, and were analyzed for inhalable dust and fungi, bacteria, azole resistance, and mycotoxins. Samples of settled dust were collected, and electrostatic dust cloths (EDC) were deployed and analyzed for microbial contamination, including azole resistance screening, and mycotoxins. Geometric mean exposures of 6.5 mg m−3 were calculated for inhalable dust, however, exposures of up to 18.30 mg m−3 were measured—70% of personal exposure measurements exceeded the occupational exposure limit for flour dust of 1.0 mg m−3. The air and EDC fungal counts were similar to those reported in previous studies for similar occupational environments. The fungi were dominated by Penicillium genera, however Aspergillus genera, including Fumigati and Flavi sections, were observed using culture-based methods, and the Fumigati section was also observed by molecular tools. Both Aspergillus sections were identified on the azole resistance screening. Mycotoxins were also detected in the settled dust samples, dominated by deoxynivalenol (DON). The role of environmental exposure in both the development of antimicrobial resistance and the total mycotoxin body burden is a growing concern; therefore, the presence of azole-resistant fungi and mycotoxin contamination, although low in magnitude, is of concern and warrants further investigation.

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