| 1. |
- Choi, H., et al.
(författare)
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Residential culturable fungi, (1-3,1-6)-beta-d-glucan, and ergosterol concentrations in dust are not associated with asthma, rhinitis, or eczema diagnoses in children
- 2014
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Ingår i: Indoor Air. - : Wiley-Blackwell. - 0905-6947 .- 1600-0668. ; 24:2, s. 158-170
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Tidskriftsartikel (refereegranskat)abstract
- Qualitative reporting of home indoor moisture problems predicts respiratory diseases. However, causal agents underlying such qualitative markers remain unknown. In the homes of 198 multiple allergic case children and 202 controls in Sweden, we cultivated culturable fungi by directly plating dust, and quantified (1-3, 1-6)-beta-d-glucan and ergosterol in dust samples from the child's bedroom. We examined the relationship between these fungal agents and degree of parent or inspector-reported home indoor dampness, and microbiological laboratory's mold index. We also compared the concentrations of these agents between multiple allergic cases and healthy controls, as well as IgE-sensitization among cases. The concentrations of culturable fungal agents were comparable between houses with parent and inspector-reported mold issues and those without. There were no differences in concentrations of the individual or the total summed culturable fungi, (1-3, 1-6)-beta-d-glucan, and ergosterol between the controls and the multiple allergic case children, or individual diagnosis of asthma, rhinitis, or eczema. Culturable fungi, (1-3, 1-6)-beta-d-glucan, and ergosterol in dust were not associated with qualitative markers of indoor dampness or mold or indoor humidity. Furthermore, these agents in dust samples were not associated with any health outcomes in the children.
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| 2. |
- Bloom, Erica, et al.
(författare)
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Molds and mycotoxins in indoor environments — a survey in water-damaged buildings
- 2009
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Ingår i: Journal of Occupational and Environmental Hygiene. - : Informa UK Limited. - 1545-9624 .- 1545-9632. ; 6:11, s. 671-678
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Tidskriftsartikel (refereegranskat)abstract
- Mycotoxins are toxic, secondary metabolites frequently produced by molds in water-damaged indoor environments. We studied the prevalence of selected, potent mycotoxins and levels of fungal biomass in samples collected from water-damaged indoor environments in Sweden during a 1- year period. One hundred samples of building materials, 18 samples of settled dust, and 37 samples of cultured dust were analyzed for: (a) mycoflora by microscopy and culture; (b) fungal chemical marker ergosterol and hydrolysis products of macrocyclic trichothecenes and trichodermin (verrucarol and trichodermol) by gas chromatography-tandem mass spectrometry; and (c) sterigmatocystin, gliotoxin, aflatoxin B1, and satratoxin G and H by high performance liquid chromatography-tandem mass spectrometry. Sixty-six percent of the analyzed building materials samples, 11% of the settled dust samples, and 51% of the cultured dust samples were positive for at least one of the studied mycotoxins. In addition, except in the case of gliotoxin, mycotoxin-positive building material samples contained 2,6 times more ergosterol than mycotoxin-negative samples. We show that (a) molds growing on a range of different materials indoors in water-damaged buildings generally produce mycotoxins, and (b) mycotoxincontaining particles in mold-contaminated environments may settle on surfaces above floor level. The mass spectrometry methods used in this study are valuable tools in further research to survey mycotoxin exposure and investigate potential links with health effects. © 2009 JOEH, LLC.
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| 3. |
- Täubel, M., et al.
(författare)
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Co-occurrence of toxic bacterial and fungal secondary metabolites in moisture-damaged indoor environments
- 2011
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Ingår i: Indoor Air. - : Hindawi Limited. - 0905-6947 .- 1600-0668. ; 21:5, s. 368-375
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Tidskriftsartikel (refereegranskat)abstract
- Toxic microbial secondary metabolites have been proposed to be related to adverse health effects observed in moisture-damaged buildings. Initial steps in assessing the actual risk include the characterization of the exposure. In our study, we applied a multi-analyte tandem mass spectrometry-based methodology on sample materials of severely moisture-damaged homes, aiming to qualitatively and quantitatively describe the variety of microbial metabolites occurring in building materials and different dust sample types. From 69 indoor samples, all were positive for at least one of the 186 analytes targeted and as many as 33 different microbial metabolites were found. For the first time, the presence of toxic bacterial metabolites and their co-occurrence with mycotoxins were shown for indoor samples. The bacterial compounds monactin, nonactin, staurosporin and valinomycin were exclusively detected in building materials from moist structures, while chloramphenicol was particularly prevalent in house dusts, including settled airborne dust. These bacterial metabolites are highly bioactive compounds produced by Streptomyces spp., a group of microbes that is considered a moisture damage indicator in indoor environments. We show that toxic bacterial metabolites need to be considered as being part of very complex and diverse microbial exposures in ’moldy’ buildings. Practical Implications: Bacterial toxins co-occur with mycotoxins in moisture-damaged indoor environments. These compounds are measurable also in settled airborne dust, indicating that inhalation exposure takes place. In attempts to characterize exposures to microbial metabolites not only mycotoxins but also bacterial metabolites have to be targeted by the analytical methods applied. We recommend including analysis of samples of outdoor air in the course of future indoor assessments, in an effort to better understand the outdoor contribution to the indoor presence of microbial toxins. There is a need for a sound risk assessment concerning the exposure to indoor microbial toxins at concentrations detectable in moisture-damaged indoor environments.
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| 4. |
- Nilsson, Anders, et al.
(författare)
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Microorganisms and volatile organic compounds in airborne dust from damp residences
- 2004
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Ingår i: Indoor Air. International Journal of Indoor Environment and Health. - : Hindawi Limited. - 0905-6947 .- 1600-0668. ; 14:2, s. 74-82
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Tidskriftsartikel (refereegranskat)abstract
- Airborne dust samples from damp (n = 9) and control (n = 9) residences were analyzed for microorganisms (molds and bacteria), bacterial markers (3-hydroxy fatty acids and muramic acid), and adsorbed volatile organic compounds (VOCs). The number of mold species was greater in the damp residences than in the controls (23 vs.18) and nine mold species were found only in damp residences. The levels of 3-hydroxy fatty acids and muramic acid correlated better in damp residences than in controls, indicating that damp conditions affect the bacterial flora of airborne dust. Identifications made by culture and microscopy of the major molds found, i.e. Aspergillus, Cladosporium, and Penicillum, coincided with the identification of VOCs known to be produced by these species. A number of additional VOCs irritating to the skin, eyes, or respiratory tract were also found. The results from this pilot study illustrate the diversity of microorganisms and VOCs present in the indoor environment and suggest that analysis of airborne dust may help to assess human exposure to microorganisms and chemical compounds.
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| 5. |
- Peitzsch, M., et al.
(författare)
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Remediation of mould damaged building materials - Efficiency of a broad spectrum of treatments
- 2012
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Ingår i: Journal of Environmental Monitoring. - : Royal Society of Chemistry (RSC). - 1464-0325 .- 1464-0333. ; 14:3, s. 908-915
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Tidskriftsartikel (refereegranskat)abstract
- We compared the efficiency of some commercially available products and methods used for remediation of mould-contaminated building materials. Samples of gypsum board and pinewood were artificially contaminated with toxin-producing isolates of Stachybotrys chartarum and Aspergillus versicolor, respectively, then, ten different remediation treatments were applied according to the manufacturers’ instructions. Microbial and chemical analyses of the infested materials were carried out both immediately before and after treatment, after six weeks of drying at room temperature, and after another six weeks of remoistening. The aim of the study was to determine whether the investigated methods could inhibit the mould growth and destroy some selected mycotoxins produced by the moulds. None of the decontamination methods tested could completely eliminate viable moulds. Some methods, especially boron based chemicals, ammonium based chemicals, and oxidation reduced the contents of mycotoxins produced by S. chartarum (satratoxin G and H, verrucarol), whereas the one which uses an ammonium based chemical reduced the amount of sterigmatocystin produced by A. versicolor with statistical significance. No remediation treatment eliminated all the toxins from the damaged materials. These results emphasize the importance to work preventively with moisture safety throughout the construction processes and management to prevent mould growth on building materials.
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| 6. |
- Sebastian, Aleksandra, et al.
(författare)
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Characterization of the microbial community in indoor environments by chemical marker analysis: an update and critical evaluation.
- 2005
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Ingår i: Indoor Air. - : Hindawi Limited. - 0905-6947 .- 1600-0668. ; 15 Suppl 9:9, s. 20-26
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Tidskriftsartikel (refereegranskat)abstract
- We published recently an integrated procedure for applying chemical marker analysis to characterize the microbiology of indoor environments comprising a scheme for extraction and analysis of markers of endotoxin, peptidoglycan/bacterial biomass, and fungal biomass. In the present paper, we report some significant improvements and also new possibilities of the described approach. We found that while 3-hydroxy fatty acids (3-OH FAs) of 10-14 carbon chain lengths are useful endotoxin markers, longer 3-OH FAs (i.e. with 16 carbon atoms and more) may rather serve as markers of Actinobacteria. We introduced C-13-labeled 3-hydroxytridecanoic acid, from labeled Pectinatus cerevisiiphilus, as an internal standard to improve quantification of the 3-OH FAs in the gas chromatography-mass spectrometry analysis. Finally, in experiments aiming to identify a suitable method for collection of house dust for chemical marker analysis, we found that the marker compositions of dusts sedimented on plexiglass plates that were spatially well-distributed in a studied room at different heights above floor level, were undistinguishable. This type of sampling thus appears to be well suited for use, e.g. in epidemiological studies. In summary, the presented work describes important new capabilities of chemical marker analysis in defining human exposure to microorganisms in indoor environments.
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| 7. |
- Christensson, Bertil, et al.
(författare)
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D-arabinitol--a marker for invasive candidiasis
- 1999
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Ingår i: Medical Mycology. - 1460-2709. ; 37:6, s. 391-396
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Tidskriftsartikel (refereegranskat)abstract
- The five-carbon sugar alcohol D-arabinitol (DA) is a metabolite of most pathogenic Candida species, in vitro as well as in vivo, and can be determined by gas chromatography or enzymatic analysis. Endogenous DA and L-arabinitol (LA) are present in human body fluids, and serum DA and LA increase in renal dysfunction. In prospective clinical studies, elevated DA/LA or DA/creatine ratios in serum or urine have been found in immunocompromised, usually neutropenic, patients with invasive candidiasis. In addition, positive DA results have been obtained several days to weeks before positive blood cultures, and the normalization of DA levels has been correlated with therapeutic response in both humans and animals. However, to date, only a few prospective studies have been conducted in which adequate analytical methods were used. Thus, further investigation of various patient groups is needed to establish the applicability of the 'arabinitol method' in the diagnostic battery for invasive Candida infections.
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| 8. |
- Eisen, DP, et al.
(författare)
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Urine D-arabinitol/L-arabinitol ratio in diagnosing Candida infection in patients with haematological malignancy and HIV infection
- 2002
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Ingår i: Diagnostic Microbiology and Infectious Disease. - 1879-0070. ; 42:1, s. 39-42
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Tidskriftsartikel (refereegranskat)abstract
- Adult patients with hematologic malignancies along with HIV infected patients were prospectively studied to determine the performance of urine D-arabinitol/L-arabinitol (DA/LA) ratio in diagnosing invasive candidiasis. Ten evaluable febrile neutropenic patients had proven invasive candidiasis and elevated DA/LA ratios were found in 5. Invasive candidiasis with normal DA/LA ratios was most frequently due to Candida krusei infection. This Candida species is a non-producer of arabinitol. Only 4 of 81 febrile neutropenic patients given either antifungal prophylaxis or empiric antifungal treatment had elevated DA/LA ratios. Only 1 of 15 HIV positive patients with either oropharyngeal or esophageal candidiasis had elevated DA/LA ratios. Widespread use of fluconazole prophylaxis in bone marrow transplantation patients at the study hospital has led to an increased prevalence of C. krusei infection. This is the likely reason for the low sensitivity of the test in proven and suspected invasive Candida infections reported here. (C) 2002 Elsevier Science Inc. All rights reserved.
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| 9. |
- Spaan, Suzanne, et al.
(författare)
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Endotoxin Exposure In Sewage Treatment Workers: Investigation Of Exposure Variability And Comparison Of Analytical Techniques
- 2008
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Ingår i: Annals of Agricultural and Environmental Medicine. - 1898-2263. ; 15:2, s. 251-261
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Objectives were to give an overview of endotoxin exposure and its determinants in sewage treatment workers, and to study exposure to culturable and non-culturable microorganisms and the applicability of the LAL assay in this work environment. Material and methods: In 43 Dutch sewage treatment plants 470 full-shift, 123 task-based personal and 54 stationary inhalable dust samples were collected. Endotoxin concentration was determined with the LAL-assay. Mixed effects models were used to investigate possible determinants of exposure. Simultaneous parallel filter Samples, impinger samples and viable total bacteria and Gram-negative bacterial samples were taken to compare analytical techniques. Filter and impinger samples were analyzed with the LAL-assay, gas chromatography-mass spectrometry (GC-MS) and fluorescence microscopy. Results: Endotoxin exposure levels were moderate to low (geometric mean personal exposure 27 EU/m(3), stationary 33 EU/m(3), task-based 64 EU/m(3)), yet differences between jobs and sources and some determinants of exposure were identified. Exposure varied more from day to day than between workers. Concentrations in filter samples were higher and more consistent than in impinger samples. Fungi and Gram-positive bacteria were found in higher levels than Gram-negative bacteria. The LAL assay and GC-MS showed comparable endotoxin levels. Discussion and conclusion: Endotoxin exposure in Dutch sewage treatment workers was relatively low,. Comparison of sampling and analytical techniques suggests that the LAL-assay did not result in much exposure misclassification. It thus seems justified to perform filter measurements in combination with the LAL-assay to measure endotoxin exposure in sewage treatment plants.
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| 10. |
- Bloom, Erica, et al.
(författare)
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Mass spectrometry-based strategy for direct detection and quantification of some mycotoxins produced by Stachybotrys and Aspergillus spp. in indoor environments
- 2007
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Ingår i: Applied and Environmental Microbiology. - 0099-2240 .- 1098-5336. ; 73:13, s. 4211-4217
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Tidskriftsartikel (refereegranskat)abstract
- Dampness in buildings has been linked to adverse health effects, but the specific causative agents are unknown. Mycotoxins are secondary metabolites produced by molds and toxic to higher vertebrates. In this study, mass spectrometry was used to demonstrate the presence of mycotoxins predominantly produced by Aspergillus spp. and Stachybotrys spp. in buildings with either ongoing dampness or a history of water damage. Verrucarol and trichodermol, hydrolysis products of macrocyclic trichothecenes (including satratoxins), and trichodermin, predominately produced by Stachybotrys chartarum, were analyzed by gas chromatography-tandem mass spectrometry, whereas sterigmatocystin (mainly produced by Aspergillus versicolor), satratoxin G, and satratoxin H were analyzed by high-performance liquid chromatography-tandem mass spectrometry. These mycotoxin analytes were demonstrated in 45 of 62 building material samples studied, in three of eight settled dust samples, and in five of eight cultures of airborne dust samples. This is the first report on the use of tandem mass spectrometry for demonstrating mycotoxins in dust settled on surfaces above floor level in damp buildings. The direct detection of the highly toxic sterigmatocystin and macrocyclic trichothecene mycotoxins in indoor environments is important due to their potential health impacts.
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