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1.
The formation of guttation droplets is a long-known property of various fungi. However, their composition, biological function and metabolism in fungi have hardly attracted deeper research interest. The highly toxic mould Stachybotrys (S.) chartarum chemotype S is supposed to play—amongst other factors such as endotoxins and microbial volatile organic compounds (MVOCs)—an important role in indoor air toxicity, mainly after water damage. The way of toxins becoming airborne and leading to exposure via inhalation, however, is still under discussion. We hypothesised that guttation may be a factor for exudation of toxins into the environment. Therefore, selected isolates (n?=?15) of our own culture collection of Stachybotrys spp. (S. chartarum chemotype S, S. chartarum chemotype A, S. chlorohalonta) originating from various habitats were cultivated on malt extract agar for 3 weeks. All strains but one produced different amounts of guttation droplets, which were collected quantitatively and subjected to various independent analytical techniques like ELISA, effect-based bioassay (MTT cell culture test) and tandem mass spectrometry (LC-MS/MS). Actually, the toxigenic isolates (n?=?5) produced highly toxic guttation droplets, which was confirmed by all methods. The concentration of macrocyclic trichothecenes, such as satratoxin G and H, ranged between the LOD and 7,160 ng/ml exudate and 280 and 4,610 ng/ml as determined by LC-MS/MS, respectively. According to our knowledge, the ability of S. chartarum to produce toxic exudates is reported for the first time, which possibly plays an important role regarding its toxic potential in indoor environments.  相似文献   

2.
Yike I  Rand T  Dearborn DG 《Mycopathologia》2007,164(4):171-181
The adverse health effects of Stachybotrys chartarum have often been linked to exposure to the trichothecene mycotoxins. Recent studies have shown that in addition to mycotoxins this fungus is capable of producing and secreting in vivo proteins such as hemolysins and proteinases. Spore extracts obtained from a high trichothecene producing isolate JS 58-17 exhibited a significantly lower proteolytic activity compared to the low trichothecene producer, JS 58-06. Growing isolates on rice or potato dextrose agar results in higher proteolytic activity of the spores compared to those grown on drywall. Proteinases in the spore extracts can hydrolyze gelatin and collagen I and IV. Analysis of zymograms shows the presence of several proteins with proteolytic activity in the spores of S. chartarum. Human tracheal epithelial cells exposed to spore extracts produced significantly higher levels of IL-6, IL-8, and TNF-α than control cells. This stimulation of cytokine production was completely abolished by Pefabloc, a serine protease inhibitor. Neutrophil numbers and proinflammatory cytokine (IL1-β and TNF-α) concentrations were highly elevated in the lungs of 7 day old rat pups exposed intratracheally to 4 × 104 spores/gm body weight compared to control. No significant differences in those inflammatory indices in vivo were noted between the treatments with the high trichothecene producer, isolate JS 58-17 and JS 58-06, which does not produce macrocyclic trichothecenes. Immunohistochemistry revealed reduced collagen IV labeling in spore-induced lung granulomas in rat pups exposed to both isolates. These results suggest that proteinases from S. chartarum spores significantly contribute to lung inflammation and injury.  相似文献   

3.
The existence of airborne mycotoxins in mold-contaminated buildings has long been hypothesized to be a potential occupant health risk. However, little work has been done to demonstrate the presence of these compounds in such environments. The presence of airborne macrocyclic trichothecene mycotoxins in indoor environments with known Stachybotrys chartarum contamination was therefore investigated. In seven buildings, air was collected using a high-volume liquid impaction bioaerosol sampler (SpinCon PAS 450-10) under static or disturbed conditions. An additional building was sampled using an Andersen GPS-1 PUF sampler modified to separate and collect particulates smaller than conidia. Four control buildings (i.e., no detectable S. chartarum growth or history of water damage) and outdoor air were also tested. Samples were analyzed using a macrocyclic trichothecene-specific enzyme-linked immunosorbent assay (ELISA). ELISA specificity was tested using phosphate-buffered saline extracts of the fungal genera Aspergillus, Chaetomium, Cladosporium, Fusarium, Memnoniella, Penicillium, Rhizopus, and Trichoderma, five Stachybotrys strains, and the indoor air allergens Can f 1, Der p 1, and Fel d 1. For test buildings, the results showed that detectable toxin concentrations increased with the sampling time and short periods of air disturbance. Trichothecene values ranged from <10 to >1,300 pg/m3 of sampled air. The control environments demonstrated statistically significantly (P < 0.001) lower levels of airborne trichothecenes. ELISA specificity experiments demonstrated a high specificity for the trichothecene-producing strain of S. chartarum. Our data indicate that airborne macrocyclic trichothecenes can exist in Stachybotrys-contaminated buildings, and this should be taken into consideration in future indoor air quality investigations.  相似文献   

4.
Highly respirable particles (diameter, <1 μm) constitute the majority of particulate matter found in indoor air. It is hypothesized that these particles serve as carriers for toxic compounds, specifically the compounds produced by molds in water-damaged buildings. The presence of airborne Stachybotrys chartarum trichothecene mycotoxins on particles smaller than conidia (e.g., fungal fragments) was therefore investigated. Cellulose ceiling tiles with confluent Stachybotrys growth were placed in gas-drying containers through which filtered air was passed. Exiting particulates were collected by using a series of polycarbonate membrane filters with decreasing pore sizes. Scanning electron microscopy was employed to determine the presence of conidia on the filters. A competitive enzyme-linked immunosorbent assay (ELISA) specific for macrocyclic trichothecenes was used to analyze filter extracts. Cross-reactivity to various mycotoxins was examined to confirm the specificity. Statistically significant (P < 0.05) ELISA binding was observed primarily for macrocyclic trichothecenes at concentrations of 50 and 5 ng/ml and 500 pg/ml (58.4 to 83.5% inhibition). Of the remaining toxins tested, only verrucarol and diacetylverrucarol (nonmacrocyclic trichothecenes) demonstrated significant binding (18.2 and 51.7% inhibition, respectively) and then only at high concentrations. The results showed that extracts from conidium-free filters demonstrated statistically significant (P < 0.05) antibody binding that increased with sampling time (38.4 to 71.9% inhibition, representing a range of 0.5 to 4.0 ng/ml). High-performance liquid chromatography analysis suggested the presence of satratoxin H in conidium-free filter extracts. These data show that S. chartarum trichothecene mycotoxins can become airborne in association with intact conidia or smaller particles. These findings may have important implications for indoor air quality assessment.  相似文献   

5.
Li S  Hartman GL  Jarvis BB  Tak H 《Mycopathologia》2002,154(1):41-49
As part of our effort to investigate fungi associated with soybean roots, Stachybotrys chartarum was isolated from soybean root lesions. Since this fungus has not been reported to cause a disease of soybean, the objectives were to identify and characterize this fungus using biological, chemical, and molecular approaches. Fungal morphology was examined using light and environmental scanning electron microscopy. Phialides bearing conidia arose from determinate, macronematous, dark olivaceous conidiophores. The phialides were obovate or ellipsoidal in whorls. Conidia were unicellular, round or ellipsoidal, 5–13 × 4–7 μm, initially hyaline with smooth walls then dark brown to black and rough-walled when mature. Radial growth of the fungus on cornmeal, oatmeal and potato dextrose agar was 38, 47, and 33 mm in diam., respectively, after 10 days at 25 °C. Pathogenicity was performed using sorghum grain colonized by S. chartarum placed below sown soybean seeds in a soil : sand (1 : 1) steam-pasteurized mix. Three weeks after inoculation, root lesions ranged from 7 to 25 mm long. The fungus was reisolated from soybean root lesions and was reidentified as S. chartarum. Biochemical analysis indicated that this soybean isolate produced satratoxins G and H along with roridin L-2, as well as the spircyclic lactones and lactams in rice culture. PCR using a S. chartarum-specific primer StacR3 and IT51 amplified a 198-bp DNA fragment from the total genomic DNA. The DNA sequence of the ITS region was 100% identical to the S. chartarum strain ATCC 9182, one nucleotide mismatch with S. chartarum strain UAMH 7900, and differed from all published sequences of 12 other species of Stachybotrys and 2 species of Memnoniella in GenBank with genetic divergence ranging from 5.26 to 9.98%. This molecular evidence further supports the identification of S. chartarum isolated from soybean root lesions. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

6.
Twenty seven isolates of Stachybotrys chartarum, S. albipes, S. kampalensis and S. microspora from Egypt and Eastern Europe were tested for production of macrocyclic trichothecenes. Twenty of the 27 isolates, grown on rice seeds, were toxic to brine shrimp larvae. Based on TLC and HPLC analyses, 5 macrocyclic trichothecenes (verrucarin J, roridin E, satratoxins F, G & H) as well as trichoverrols were identified. When grown in liquid culture on rice extract medium, only 3 isolates were toxic and produced verrucarin J, roridin E and satratoxins G & H. Extracts from mycelial mats were more toxic than culture filterates of two isolates grown on rice extract and both contained the same macrocyclic trichothecenes (285.5 mg/4 L), in addition to trichoverrols A & B (31 mg/4 L) found in mycelial mats only. When grown on 3% sucrose Czapek's medium supplemented with peptone and yeast extract (still cultures), all isolates were non-toxic to brine shrimp and no trichothecenes could be detected in the extracts.  相似文献   

7.
Twenty-five Stachybotrys isolates from two previous studies have been examined and compared, using morphological, chemical and phylogenetic methods. The results show that S. chartarum sensu lato can be segregated into two chemotypes and one new species. The new species, S. chlorohalonata, differs morphologically from S. chartarum by having smooth conidia, being more restricted in growth and producing a green extracellular pigment on the medium CYA. S. chlorohalonata and S. chartarum also have different tri5, chs1 and tub1 gene fragment sequences. The two chemotypes of S. chartarum, chemotype S and chemotype A, have similar morphology but differ in production of metabolites. Chemotype S produces macrocyclic trichothecenes, satratoxins and roridins, while chemotype A produces atranones and dolabellanes. There is no difference between the two chemotypes in the tub1 gene fragment, but there is a one nucleotide difference in each of the tri5 and the chs1 gene fragments.  相似文献   

8.
The pathogenicity of nine Fusarium graminearum isolates belonging to three different trichothecene-producing chemotypes, i.e. NIV + FUS, DON + 3-AcDON, and DON + 15-AcDON was tested on corn, wheat, triticale and rye. Although these compounds are known to have different toxicity, no difference in pathogenicity was observed among the mean values for chemotypes. However, within each chemotype there were isolates with different pathogenicity which was not correlated with the ability to produce trichothecenes in vitro. The pathogenicity of each isolate was almost the same for all tested cereals. The involvement of trichothecenes in pathogenesis was investigated in infected corn stalk tissues. All the expected trichothecenes were detected with the exception of NIV and FUS.  相似文献   

9.
Sections (8 cm2) of unused, nonsterile gypsum wallboard (dry wall) were inoculated with varying densities (104 to ∼108/ml) of conidia from 14- to 21-day cultures of Stachybotrys chartarum grown on cellulose agar. The sections were permitted to air dry and were placed into vessels with 86% or 92% RH and incubated at 22–25°C for up to 12 weeks. The moisture content of the dryboard increased from near 10% to over 35%. Selected sections with confluent surface growth, mainly of S. chartarum, were obtained within 3 weeks. Sections were cleaned with a quaternary or quaternary and chlorine dioxide or a concentrated oxygen-saline solution and treated, in some cases, with a preservative system and returned to humidity vessels. Reemergence of S. chartarum from inoculated and treated surfaces occurred within 5 weeks only with sections treated with the quaternary alone. Other fungi, mostly species of Aspergillus, Chaetomium and Penicillium, slowly colonized (between 9–12 weeks) at least some areas of most treated surfaces and most uninoculated control surfaces. Stachybotrys chartarum was also found on several sections of uninoculated controls. Sections treated with a quaternary/acrylic and placed in a dynamic challenging chamber remained visually free of colonized fungi for over 90 days. These studies indicate that control samples of uninstalled wallboard, available from local distributors, can contain a baseline bioburden, including S. chartarum, that will colonize surfaces under high humidity conditions. Sanitation and preservation treatment of the wallboard can markedly delay regrowth of these fungi, particularly of S. chartarum. Received: 8 January 1999 / Accepted: 22 February 1999  相似文献   

10.
This work deals with a comparative analysis of Stachybotrys chartarum strains isolated from various artificial cellulose-containing materials and natural substrates in geographically distant regions of Russia. The analysis included determination of the spore size; the strain toxicity to Paramecium caudatum; the strain resistance to the fungicides Benomil, Olilen, and Tilt; and the PCR study of the genome structure with the aid of a primer that was complementary to the core sequence of the SINE retrotransposon. It was found that some of the strains that were isolated from different areas and from different substrates differ in their toxicity, fungicide resistance, and genome structure. PCR analysis showed the absence of any correlation between the genome structure, the strain properties, the geographic area, and the substrates from which the strains were isolated. The pheno- and genotypic diversity of the strains and their different vegetative compatibility suggest the existence of an intraspecies diversity of the S. chartarum strains that were isolated in different geographic areas. The absence of any correlation between the pheno- and genotypic properties of the strains and the substrates from which they were isolated implies that the colonization of artificial substrates by S. chartarum occurred occasionally from natural habitats. The S. chartarum populations that live on artificial substrates are unlikely to have their own evolutionary history.  相似文献   

11.
Highly conserved regions are attractive targets for detection and quantitation by PCR, but designing species-specific primer sets can be difficult. Ultimately, almost all primer sets are designed based upon literature searches in public domain databases, such as the National Center for Biotechnology Information (NCBI). Prudence suggests that the researcher needs to evaluate as many sequences as available for designing species-specific PCR primers. In this report, we aligned 11, 9, and 16 DNA sequences entered for Stachybotrys spp. rRNA, tri5, and β-tubulin regions, respectively. Although we were able to align and determine consensus primer sets for the 9 tri5 and the 16 β-tubulin sequences, there was no consensus sequence that could be derived from alignment of the 11 rRNA sequences. However, by judicious clustering of the sequences that aligned well, we were able to design three sets of primers for the rRNA region of S. chartarum. The two primer sets for tri5 and β-tubulin produced satisfactory PCR results for all four strains of S. chartarum used in this study whereas only one rRNA primer set of three produced similar satisfactory results. Ultimately, we were able to show that rRNA copy number is approximately 2-log greater than for tri5 and β-tubulin in the four strains of S. chartarum tested.  相似文献   

12.
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.  相似文献   

13.
Observing that the conidia of Stachybotrys chartarum can germinate in the lung of infant rats, it became important to ascertain whether an infection can ensue. Viable conidia of S. chartarum were instilled into the lungs of 4 and 14 day-old rat pups. Germination was observed frequently in the lungs of 4 day-old but rarely in the 14 day-old pups. In the 4 day-old pups, pulmonary inflammation with hemorrhagic exudates was observed and resulted in about 15% mortality rate compared to 0% for the controls instilled with phosphate buffered saline. Acute neutrophilic inflammation and intense interstitial pneumonia with poorly formed granulomas observed three days following exposure were associated with fungal hyphae and conidia. The surviving experimental pups showed significantly slower weight gain for seven days. Dilution plating and quantitative PCR analysis were used to follow total fungal load in the rat pups lung homogenates. In the 4 day-old rat pups viable fungi decreased rapidly and were less than 1% by day seven. Similarly, fungal DNA decreased exponentially and was only 0.03% by fourteen days after exposure. However, 14 day-old rat pups showed neither the lethal effects of exposures to viable conidia of S. chartarum nor the slower weight gain, and the fungal load decreased even more rapidly. We conclude that S. chartarum conidia can initially germinate and form hyphae but even in the immature rat pups do not establish an effective infection, although a very limited persistence cannot be excluded.This revised version was published online in October 2005 with corrections to the Cover Date.  相似文献   

14.
Growth of Stachybotrys atra and its toxin production on some building materials and in animal fodder were studied at relative humidities ranging from 78 to 100%. Toxins were detected by biological assays and chemical methods. Strong growth of the fungus and presence of macrocyclic trichothecenes, mainly satratoxins G and H, were detected on wallpaper and gypsum boards and in hay and straw at saturation conditions. On pine panels, S. atra grew well, but neither biological toxicity nor production of macrocyclic trichothecenes was observed.  相似文献   

15.
A Phoma sp., known to produce the pharmaceutically active metabolites squalestatin 1 (S1) and squalestatin 2 (S2), was cultured on malt-extract/agar (MEA) over a range of water activities (a w, 0.995–0.90) and temperatures (10–35 °C) to investigate the influence on growth and metabolite production. Use of the ionic solute NaCl to adjust a w resulted in significantly lower (P < 0.01) squalestatin yields than when the Phoma sp. was grown on MEA amended with the non-ionic solute glycerol. Water activity and temperature and their interactions were highly significant factors (P < 0.001) affecting growth of the Phoma sp., with optimum conditions of 0.998–0.980 a w and 25 °C. Squalestatin production was similarly influenced by a w, temperature, time and their interactions (P < 0.001). S1 and S2 production occurred over a narrower a w and temperature range than growth, with a slightly lower optimum a w range of 0.995–0.980 a w. The optimum temperature for squalestatin production varied from 20 °C (S1) to 25 °C (S2) and yields of S2 were up to 1000 times lower than those of S1. The ratio of S1 and S2 produced by the Phoma sp. was influenced by a w and temperature, with highest values at 0.99–0.98 a w, and at 15 °C. Incubation times of 28 days gave highest yields of both S1 and S2. Up to 2000-fold increases in squalestatin yields were measured at optimum environmental conditions, compared to the unmodified MEA. This indicates the need to consider such factors in screening systems used to detect biologically active lead compounds produced by fungi. Received: 2 June 1997 / Received last revision: 6 November 1997 / Accepted: 7 November 1997  相似文献   

16.
Satureja montana and S. subspicata are used as spice, pepper substitute, for preparing tea, juice, and as a medicine. Fourteen populations (seven per species) of Satureja montana L. and S. subspicata Vis . growing in Croatia were examined to determine the chemical composition of the essential oil (analyzed by GC‐FID and GC/MS), the content of macroelements (Na, K, Ca, Mg) and trace elements (B, Fe, Cu, Mn, Zn, Al, Pb, Cr, Cd, Ni, Hg, As) analyzed by ICP‐AES, antioxidant compounds (analyzed by UV/VIS spectrophotometer), and the types and distribution of trichomes (analyzed by scanning electron microscopy). The main constituents of the essential oil were carvacrol and thymol in S. montana (all populations belong to one phenol chemotype), while α‐eudesmol, β‐eudesmol, and spathulenol dominated in S. subspicata (three chemotypes could be distinguished). Both species possess considerably higher quantities of Ca and Mg, and moderate concentrations of K and Na, while Hg and As levels were below the limit of quantification. Non‐glandular trichomes, peltate trichomes, and three types of capitate trichomes were observed on leaves, stem, calyx, and corolla.  相似文献   

17.
Stachybotrys occurring in mouldy indoor environments is associated with the so called “sick building syndrome” in humans or cases of idiopathic pulmonary hemorrhages. Samples of mouldy materials from indoor environments (n=15) were analysed for the occurrence of this fungus and its secondary metabolites by a sensitive LC-MS/MS method. In four samples,Stachybotrys and macrocyclic trichothecenes have been detected. Maximum values for Satratoxin G and H in wallpaper were determined with 9.7 μg/cm2 and 12.0 μg/cm2, respectively.  相似文献   

18.
Rand TG  White K  Logan A  Gregory L 《Mycopathologia》2003,156(2):119-131
Stachybotrys chartarum is an important toxigenic fungus often associated with chronically wet cellulose-based building materials. The purpose of this study was to evaluate some histological, immunohistochemical and morphometric changes in mouse lung tissues exposed intratracheally to either 50 l of 1.4 × 106 S. chartarum spores (35 ng toxin/kg BW), isosatratoxin-F (35ng/kg BW),50 l of 1.4 × 106 Cladosporium cladosporioides spores, or 50 l saline. Exposure of lung tissues to S. chartarum or C. cladosporioides spores resulted in granuloma formation at the sites of spore impaction. Some of the lung tissues impacted by S. chartarum spores also showed erythrocyte accumulation in the alveolar air space, dilated capillaries engorged with erythrocytes, and hemosiderin accumulation at spore impaction sites, which were features not noted in the C. cladosporioides-spore treated animals. Immunohistochemistry revealed reduced collagen IV distribution in lung granulomas in S. chartarum-treated animals especially at 48 and 72 hr post-exposure compared to that in lungs of mice with C. cladosporioides-spore induced granulomas. Quantitative analysis of pooled S. chartarum and C. cladosporioides spore impacted lungs revealed significant depression (P < 0.05) of alveolar air space from 71.4 ± 6.1 in untreated animals to 56.04 ± 6.1 in the S. chartarum- and 60.24 ± 5.5% in the C. cladosporioides-spore treated animals. It also revealed that alveolus air space in S. chartarum treated animals declined significantly from 63.74 ± 3.1% at12 hr post-exposure to 42.94 ± 7.9% at 72 hr post-exposure and was increased to 54.84 ± 5.2% at 96 hr post-exposure. Alveolus air space in C. cladosporioidestreated animals also decreased significantly from 64.84 ± 7.1% at 12 hr exposure to 54.94 ± 5.4% at 48 hr post-exposure and was increased to 64.64 ± 10.1% at 96 hr post-exposure. It also revealed significant (P <0.05) alveolar accumulation of erythrocytes from 1.24 ± 1.4% in the untreated animals to 3.44 ± 1.5% in the pooled S. chartarum spore treated animals. Erythrocyte abundance in S. chartarum treated animals increased significantly (P <0.001) from 2.14 ± 1. 7% at 12 hr post-exposure to 5.54 ± 1.5% at 72 hr and 4.94 ± 1.4% at 96 hr post-exposure. These results further reveal that exposure to S. chartarum spores elicit tissue responses in vivo significantly different from those associated with exposure to pure trichothecene toxin and to spores of a non-toxigenic fungus.This revised version was published online in October 2005 with corrections to the Cover Date.  相似文献   

19.
20.
A total of 676 isolates ofPithomyces chartarum, recovered from pasture at a single site, were examined for their ability to produce sporidesmin. Two isolates did not produce sporidesmin in levels detectable by HPLC despite their ability to spore profusely. This is the first report of sporulatingP. chartarum isolated from New Zealand pasture which does not produce sporidesmin.Abbreviations RCA rabbit chow agar  相似文献   

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