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Grahamphoto23 | Getty Images. Toxins from household fungi can easily become airborne and cause health problems, a new study has found. Toxins from household fungi can easily become airborne and cause health problems, a new study has found. A group of researchers found that three types of fungus that can grow on ordinary household wallpaper can spread into the air. They said the effects of the airborne transmission on human health are understudied. Fungal toxins, also called mycotoxins, should be taken seriously as a source of indoor air pollution, and so-called sick building syndrome, the researchers said. "We demonstrated that mycotoxins could be transferred from a moldy material to air, under conditions that may be encountered in buildings," said study co-author Jean-Denis Bailly, a professor of food hygiene at the National Veterinary School of Toulouse in France, in a release. "Thus, mycotoxins can be inhaled and should be investigated as parameters of indoor air quality, especially in homes with visible fungal contamination." They published the results Friday in the American Society for Microbiology's journal Applied and Environmental Microbiology. The researchers said far less research exists on the dangers of airborne fungal toxins than on fungal toxins in foods. Thus, they focused on three fungi commonly found in contaminated food: Penicillium brevicompactum, Aspergillus versicolor and Stachybotrys chartarum. The team created a flowing stream of air over a piece of wallpaper contaminated with the three fungi and analyzed samples of the air. They found that some toxins were present on tiny particles of dust, that people or animals could easily inhale. They also found the different species sent different amounts of fungal toxins into the air, which might allow future researchers to prioritize efforts. Very little research has been done on the effect of such toxins once they have been inhaled, the researchers said in the release. Scientists have highlighted the dangers of indoor air pollution before. While much attention is focused on airborne pollutants from car emissions, factories and power plants, others such as household mold, chemical fumes and smoke can pose dangers within the home. Bailly said energy efficiency efforts may even be exacerbating the problem, as houses are increasingly insulated to save on heating and cooling. These kinds of environments may worsen the development of fungus in moist areas, such as in bathrooms, or appliances that use water, like coffee makers. "The presence of mycotoxins in indoors should be taken into consideration as an important parameter of air quality," Bailly said.


News Article | June 23, 2017
Site: www.sciencedaily.com

Toxins produced by three different species of fungus growing indoors on wallpaper may become aerosolized, and easily inhaled. The findings, which likely have implications for "sick building syndrome," were published in Applied and Environmental Microbiology, a journal of the American Society for Microbiology. "We demonstrated that mycotoxins could be transferred from a moldy material to air, under conditions that may be encountered in buildings," said corresponding author Jean-Denis Bailly, DVM, PhD, Professor of Food Hygiene, National Veterinary School of Toulouse, France. "Thus, mycotoxins can be inhaled and should be investigated as parameters of indoor air quality, especially in homes with visible fungal contamination." The impetus for the study was the dearth of data on the health risk from mycotoxins produced by fungi growing indoors. (image: microscopic view of a sporulating Aspergillus, showing numerous light spores that can be easily aerosolized and inhaled together with mycotoxins. credit: Sylviane Bailly.) In the study, the investigators built an experimental bench that can simulate an airflow over a piece of contaminated wall paper, controlling speed and direction of the air. Then they analyzed the resulting bioaerosol. "Most of the airborne toxins are likely to be located on fungal spores, but we also demonstrated that part of the toxic load was found on very small particles -- dust or tiny fragments of wallpaper, that could be easily inhaled," said Bailly.. The researchers used three fungal species in their study: Penicillium brevicompactum, Aspergillus versicolor, and Stachybotrys chartarum. These species, long studied as sources of food contaminants, also "are frequent indoor contaminants," said Bailly. He noted that they produce different mycotoxins, and their mycelia are different from one another, likely leading to differences in the quantity of mycotoxins they loft into the air. (Mycelia are the thread-like projections of fungi that seek nutrition and water from the environment.) The findings raised two new scientific questions, said Bailly. First, "There is almost no data on toxicity of mycotoxins following inhalation," he said, noting that most research has focused on such toxins as food contaminants. Second, the different fungal species put different quantities of mycotoxins in the air, "probably related to mycelium organization," but also possibly related to the mechanisms by which mycotoxins from different fungi become airborne -- for example via droplets of exudate versus accumulation in spores. Such knowledge could help in prioritizing those species that may be of real importance in wafting mycotoxins, he said. Bailly noted that the push for increasingly energy efficient homes may aggravate the problem of mycotoxins indoors. Such homes "are strongly isolated from the outside to save energy," but various water-using appliances such as coffee makers "could lead to favorable conditions for fungal growth," he said. "The presence of mycotoxins in indoors should be taken into consideration as an important parameter of air quality," Bailly concluded.


"We demonstrated that mycotoxins could be transferred from a moldy material to air, under conditions that may be encountered in buildings," said corresponding author Jean-Denis Bailly, DVM, PhD, Professor of Food Hygiene, National Veterinary School of Toulouse, France. "Thus, mycotoxins can be inhaled and should be investigated as parameters of indoor air quality, especially in homes with visible fungal contamination." The impetus for the study was the dearth of data on the health risk from mycotoxins produced by fungi growing indoors. (image: microscopic view of a sporulating Aspergillus, showing numerous light spores that can be easily aerosolized and inhaled together with mycotoxins. credit: Sylviane Bailly.) In the study, the investigators built an experimental bench that can simulate an airflow over a piece of contaminated wall paper, controlling speed and direction of the air. Then they analyzed the resulting bioaerosol. "Most of the airborne toxins are likely to be located on fungal spores, but we also demonstrated that part of the toxic load was found on very small particles—dust or tiny fragments of wallpaper, that could be easily inhaled," said Bailly.. The researchers used three fungal species in their study: Penicillium brevicompactum, Aspergillus versicolor, and Stachybotrys chartarum. These species, long studied as sources of food contaminants, also "are frequent indoor contaminants," said Bailly. He noted that they produce different mycotoxins, and their mycelia are different from one another, likely leading to differences in the quantity of mycotoxins they loft into the air. (Mycelia are the thread-like projections of fungi that seek nutrition and water from the environment.) The findings raised two new scientific questions, said Bailly. First, "There is almost no data on toxicity of mycotoxins following inhalation," he said, noting that most research has focused on such toxins as food contaminants. Second, the different fungal species put different quantities of mycotoxins in the air, "probably related to mycelium organization," but also possibly related to the mechanisms by which mycotoxins from different fungi become airborne—for example via droplets of exudate versus accumulation in spores. Such knowledge could help in prioritizing those species that may be of real importance in wafting mycotoxins, he said. Bailly noted that the push for increasingly energy efficient homes may aggravate the problem of mycotoxins indoors. Such homes "are strongly isolated from the outside to save energy," but various water-using appliances such as coffee makers "could lead to favorable conditions for fungal growth," he said. "The presence of mycotoxins in indoors should be taken into consideration as an important parameter of air quality," Bailly concluded. Explore further: Food contaminants under the spotlight


News Article | June 23, 2017
Site: www.eurekalert.org

Washington, DC - June 23, 2017 - Toxins produced by three different species of fungus growing indoors on wallpaper may become aerosolized, and easily inhaled. The findings, which likely have implications for "sick building syndrome," were published in Applied and Environmental Microbiology, a journal of the American Society for Microbiology. "We demonstrated that mycotoxins could be transferred from a moldy material to air, under conditions that may be encountered in buildings," said corresponding author Jean-Denis Bailly, DVM, PhD, Professor of Food Hygiene, National Veterinary School of Toulouse, France. "Thus, mycotoxins can be inhaled and should be investigated as parameters of indoor air quality, especially in homes with visible fungal contamination." The impetus for the study was the dearth of data on the health risk from mycotoxins produced by fungi growing indoors. (image: microscopic view of a sporulating Aspergillus, showing numerous light spores that can be easily aerosolized and inhaled together with mycotoxins. credit: Sylviane Bailly.) In the study, the investigators built an experimental bench that can simulate an airflow over a piece of contaminated wall paper, controlling speed and direction of the air. Then they analyzed the resulting bioaerosol. "Most of the airborne toxins are likely to be located on fungal spores, but we also demonstrated that part of the toxic load was found on very small particles -- dust or tiny fragments of wallpaper, that could be easily inhaled," said Bailly.. The researchers used three fungal species in their study: Penicillium brevicompactum, Aspergillus versicolor, and Stachybotrys chartarum. These species, long studied as sources of food contaminants, also "are frequent indoor contaminants," said Bailly. He noted that they produce different mycotoxins, and their mycelia are different from one another, likely leading to differences in the quantity of mycotoxins they loft into the air. (Mycelia are the thread-like projections of fungi that seek nutrition and water from the environment.) The findings raised two new scientific questions, said Bailly. First, "There is almost no data on toxicity of mycotoxins following inhalation," he said, noting that most research has focused on such toxins as food contaminants. Second, the different fungal species put different quantities of mycotoxins in the air, "probably related to mycelium organization," but also possibly related to the mechanisms by which mycotoxins from different fungi become airborne -- for example via droplets of exudate versus accumulation in spores. Such knowledge could help in prioritizing those species that may be of real importance in wafting mycotoxins, he said. Bailly noted that the push for increasingly energy efficient homes may aggravate the problem of mycotoxins indoors. Such homes "are strongly isolated from the outside to save energy," but various water-using appliances such as coffee makers "could lead to favorable conditions for fungal growth," he said. "The presence of mycotoxins in indoors should be taken into consideration as an important parameter of air quality," Bailly concluded. The American Society for Microbiology is the largest single life science society, composed of over 50,000 scientists and health professionals. ASM's mission is to promote and advance the microbial sciences. ASM advances the microbial sciences through conferences, publications, certifications and educational opportunities. It enhances laboratory capacity around the globe through training and resources. It provides a network for scientists in academia, industry and clinical settings. Additionally, ASM promotes a deeper understanding of the microbial sciences to diverse audiences.


Citti C.,National Veterinary School of Toulouse | Blanchard A.,University of Bordeaux 1 | Blanchard A.,French National Institute for Agricultural Research
Trends in Microbiology | Year: 2013

Commonly known as mycoplasmas, bacteria of the class Mollicutes include the smallest and simplest life forms capable of self replication outside of a host. Yet, this minimalism hides major human and animal pathogens whose prevalence and occurrence have long been underestimated. Owing to advances in sequencing methods, large data sets have become available for a number of mycoplasma species and strains, providing new diagnostic approaches, typing strategies, and means for comprehensive studies. A broader picture is thus emerging in which mycoplasmas are successful pathogens having evolved a number of mechanisms and strategies for surviving hostile environments and adapting to new niches or hosts. © 2013 Elsevier Ltd.


Lacroux C.,National Veterinary School of Toulouse
PloS one | Year: 2012

The identification in the UK of 4 v-CJD infected patients thought to be due to the use of transfused Red Blood Cell units prepared from blood of donors incubating v-CJD raised major concerns in transfusion medicine. The demonstration of leucocyte associated infectivity using various animal models of TSE infection led to the implementation of systematic leuco-depletion (LD) of Red Blood cells concentrates (RBCs) in a number of countries. In the same models, plasma also demonstrated a significant level of infectivity which raised questions on the impact of LD on the v-CJD transmission risk. The recent development of filters combining LD and the capture of non-leucocyte associated prion infectivity meant a comparison of the benefits of LD alone versus LD/prion-reduction filters (LD/PR) on blood-borne TSE transmission could be made. Due to the similarity of blood/plasma volumes to human transfusion medicine an experimental TSE sheep model was used to characterize the abilities of whole blood, RBCs, plasma and buffy-coat to transmit the disease through the transfusion route. The impact of a standard RBCs LD filter and of two different RBCs LD/PR prototype filters on the disease transmission was then measured. Homologous recipients transfused with whole-blood, buffy-coat and RBCs developed the disease with 100% efficiency. Conversely, plasma, when intravenously administered resulted in an inconstant infection of the recipients and no disease transmission was observed in sheep that received cryo-precipitated fraction or supernatant obtained from infectious plasma. Despite their high efficacy, LD and LD/PR filtration of the Red Blood Cells concentrate did not provide absolute protection from infection. These results support the view that leuco-depletion strongly mitigates the v-CJD blood borne transmission risk and provide information about the relative benefits of prion reduction filters.


Andreoletti O.,National Veterinary School of Toulouse
PLoS pathogens | Year: 2012

It is now clearly established that the transfusion of blood from variant CJD (v-CJD) infected individuals can transmit the disease. Since the number of asymptomatic infected donors remains unresolved, inter-individual v-CJD transmission through blood and blood derived products is a major public health concern. Current risk assessments for transmission of v-CJD by blood and blood derived products by transfusion rely on infectious titers measured in rodent models of Transmissible Spongiform Encephalopathies (TSE) using intra-cerebral (IC) inoculation of blood components. To address the biological relevance of this approach, we compared the efficiency of TSE transmission by blood and blood components when administrated either through transfusion in sheep or by intra-cerebral inoculation (IC) in transgenic mice (tg338) over-expressing ovine PrP. Transfusion of 200 μL of blood from asymptomatic infected donor sheep transmitted prion disease with 100% efficiency thereby displaying greater virulence than the transfusion of 200 mL of normal blood spiked with brain homogenate material containing 10 3ID 50 as measured by intracerebral inoculation of tg338 mice (ID 50 IC in tg338). This was consistent with a whole blood titer greater than 10 3· 6ID 50 IC in tg338 per mL. However, when the same blood samples were assayed by IC inoculation into tg338 the infectious titers were less than 32 ID per mL. Whereas the transfusion of crude plasma to sheep transmitted the disease with limited efficacy, White Blood Cells (WBC) displayed a similar ability to whole blood to infect recipients. Strikingly, fixation of WBC with paraformaldehyde did not affect the infectivity titer as measured in tg338 but dramatically impaired disease transmission by transfusion in sheep. These results demonstrate that TSE transmission by blood transfusion can be highly efficient and that this efficiency is more dependent on the viability of transfused cells than the level of infectivity measured by IC inoculation.


Toutain P.-L.,National Veterinary School of Toulouse
Handbook of Experimental Pharmacology | Year: 2010

In racing and other equine sports, it is possible to increase artificially both the physical capability and the presence of a competitive instinct, using drugs, such as anabolic steroids and agents stimulating the central nervous system. The word doping describes this illegitimate use of drugs and the primary motivation of an equine anti-doping policy is to prevent the use of these substances. However, an anti-doping policy must not impede the use of legitimate veterinary medications and most regulatory bodies in the world now distinguish the control of illicit substances (doping control) from the control of therapeutic substances (medication control). For doping drugs, the objective is to detect any trace of drug exposure (parent drug or metabolites) using the most powerful analytical methods (generally chromatographic/mass spectrometric techniques). This so-called "zero tolerance rule" is not suitable for medication control, because the high level of sensitivity of current screening methods allows the detection of totally irrelevant plasma or urine concentrations of legitimate drugs for long periods after their administration. Therefore, a new approach for these legitimate compounds, based upon pharmacokinetic/pharmacodynamic (PK/PD) principles, has been developed. It involves estimating the order of magnitude of the irrelevant plasma concentration (IPC) and of the irrelevant urine concentration (IUC) in order to limit the impact of the high sensitivity of analytical techniques used for medication control. The European Horserace Scientific Liaison Committee (EHSLC), which is the European scientific committee in charge of harmonising sample testing and policies for racehorses in Europe, is responsible for estimating the IPCs and IUCs in the framework of a Risk Analysis. A Risk Analysis approach for doping/medication control involves three sequential steps, namely risk assessment, risk management, and risk communication. For medication control, the main task of EHLSC in the risk management procedure is the establishment of harmonised screening limits (HSL).The HSL is a confidential instruction to laboratories from racing authorities to screen in plasma or urine for the presence of drugs commonly used in equine medication. The HSL is derived from the IPC (for plasma) or from the IUC (for urine), established during the risk assessment step. The EHSLC decided to keep HSL confidential and to inform stakeholders of the duration of the detection time (DT) of the main medications when screening is performed with the HSL. A DT is the time at which the urinary (or plasma) concentration of a drug, in all horses involved in a trial conducted according to the EHSLC guidance rules, is shown to be lower than the HSL when controls are performed using routine screening methods. These DTs, as issued by the EHSLC (and adopted by the Fédération Equestre Internationale or FEI) provide guidance to veterinarians enabling them to determine a withdrawal time (WT) for a given horse under treatment. A WT should always be longer than a DT because the WT takes into account the impact of all sources of animal variability as well as the variability associated with the medicinal product actually administered in order to avoid a positive test. The major current scientific challenges faced in horse doping control are those instances of the administration of recombinant biological substances (EPO, GH, growth factors etc.) having putative long-lasting effects while being difficult or impossible to detect for more than a few days. Innovative bioanalytical approaches are now addressing these challenges. Using molecular tools, it is expected in the near future that transcriptional profiling analysis will be able to identify some molecular "signatures" of exposure to doping substances. The application of proteomic (i.e. the large scale investigation of protein biomarkers) and metabolomic (i.e. the study of metabolite profiling in biological samples) techniques also deserve attention for establishing possible unique fingerprints of drug abuse. © 2010 Springer-Verlag Berlin Heidelberg.


Collet S.H.,National Veterinary School of Toulouse
Toxicological sciences : an official journal of the Society of Toxicology | Year: 2010

The model of the prepubertal ovariectomized lamb was selected as a sensitive model to characterize the estrogenic effects of bisphenol A (BPA) on the hypothalamo-pituitary axis (HPA). In a first experiment, the disrupting effect of BPA and of 17-beta estradiol (E2), administered as a constant 54-h iv infusion, on luteinizing hormone (LH) pulsatility was quantified. The results showed that the inhibitory effect of BPA and E2 on LH secretion appeared to follow a dual mechanism: a rapid (about 1 h) suppressive effect for high exposure and an effect observed with a period of latency (about 48 h) probably of genomic origin and observed for lower E2 and BPA levels. For E2, the disrupting dose was 0.14 microg/(kg x d), corresponding to a plasma concentration of 2 pg/ml; for BPA, the lowest observed disrupting plasma concentration was 38 ng/ml, a value only 10-fold higher than the human plasma concentration routinely reported in biomonitoring surveys. In a second experiment, we showed that after 7 weeks of BPA treatment, there was no BPA accumulation and no evidence of an alteration in the HPA responsiveness to BPA. Finally, our results showed that directly considering plasma concentrations, the ratio of the BPA disrupting plasma concentration in lambs over the observed human plasma concentration is only 10, whereas if the dose is considered, it could be concluded that the BPA disrupting dose in lamb is conservatively 50-fold higher than the currently recommended Tolerable Daily Intake of 50 microg/(kg x d).


Ducatez M.F.,National Veterinary School of Toulouse | Pelletier C.,National Veterinary School of Toulouse
Emerging Infectious Diseases | Year: 2015

A new influenza virus, genus D, isolated in US pigs and cattle, has also been circulating in cattle in France. It was first identified there in 2011, and an increase was detected in 2014. The virus genome in France is 94%–99% identical to its US counterpart, which suggests intercontinental spillover. © Centers for Disease Control and Prevention (CDC). All rights reserved.

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