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1.
House dust contains bacteria, mycelial fungi, microarthropods, and yeasts. House dust samples collected in 25 apartments in Moscow and the Moscow region were found to contain yeasts belonging to the genera Candida, Cryptococcus, Debaryomyces, Rhodotorula, Sporobolomyces, and Trichosporon. The most frequently encountered microorganisms were typical epiphytic yeasts, such as Cryptococcus diffluens and Rhodotorula mucilaginosa, which are capable of long-term preservation in an inactive state. The direct source of epiphytic yeasts occurring in the house dust might be indoor plants, which were contaminated with these yeasts, albeit to a lesser degree than outdoor plants. Along with the typical epiphytic yeasts, the house dust contained the opportunistic yeast pathogens Candida catenulata, C. guillermondii, C. haemulonii, C. rugosa, and C. tropicalis, which are known as the causal agents of candidiases. We failed to reveal any correlation between the abundance of particular yeast species in the house dust, residential characteristics, and the atopic dermatitis of the inhabitants. 相似文献
2.
D. B. Hay B. J. Hart R. B. Pearce Z. Kozakiewicz A. E. Douglas 《Experimental & applied acarology》1992,16(1-2):37-47
Both house dust and house dust mitesDermatophagoides pteronyssinus contained a wider range of fungi than laboratory mite cultures. In total, nine species of fungi were isolated fromD. pteronyssinus in house dust, and these included three xerophilic species (Eurotium amstelodami, Aspergillus penicillioides andWallemia sebi) commonly found in laboratory cultures ofD. pteronyssinus. It is concluded that mites do interact with a similar range of fungi in natural dust and in laboratory culture, but that the diversity of fungal species in the laboratory is reduced and the density of individual fungal species in culture exceeds that of house dust. In a second experiment, dust samples were incubated at room temperature with 75% relative humidity. The diversity of fungi invariably declined from up to 13 genera to the few species recorded in laboratory culture. This suggests that the dominance of xerophilic fungi in laboratory mite rearings is mediated primarily by low relative humidity, and the exclusion of air-borne spores. 相似文献
3.
U. Lignell T. Meklin H. Rintala A. Hyvärinen A. Vepsäläinen J. Pekkanen A. Nevalainen 《Letters in applied microbiology》2008,47(4):303-308
Aims: Microbial concentrations in vacuumed house dust samples (n = 71) were analysed by culture and quantitative polymerase chain reaction (qPCR) methods and their association with extent of moisture damage in the house was studied. Methods and Results: Microbial concentrations measured by qPCR correlated with concentrations obtained by culture method, but were orders of magnitude higher. qPCR also had better sensitivity. Concentrations of several microbes in house dust, determined with qPCR, were associated with the extent of moisture damage in the house. This association was strongest for Penicillium brevicompactum, one of the fungi detected in highest concentrations by qPCR. Furthermore, house dust concentrations of Wallemia sebi, Trichoderma viride, Cladosporium sphaerospermum, Eurotium amstelodami and the combined assay group for Penicillium spp., Aspergillus spp. and Paecilomyces variotii were significantly associated with the extent of the moisture damage. Conclusion: These species or assay groups could probably be used as indicators of moisture damage in the house. Significance and Impact of the Study: This finding indicates the benefits of the qPCR method, which is sensitive enough to reveal the differences in microbial concentrations of house dust between moisture‐damaged and undamaged houses. 相似文献
4.
Isolation of ascomycetous microfungi from 58 house dust samples from detached and apartment dwellings around Kobe City revealed
that species ofTalaromyces, Eurotium andNeosartorya were common ascomycetous propagules in the house dust.Neosartorya species accounted for 8.3% of the total identified isolates, of whichN. pseudofischeri was the main constituent, indicating that it may be a common potential fungal pathogen in the dwelling environment. Based
on the specimens collected,N. pseudofischeri is described and illustrated as new to Japan. 相似文献
5.
Use of cereals as basal medium for the formulation of alternative culture media for fungi 总被引:1,自引:0,他引:1
Summary The feasibility of developing alternative media to different culture media particularly potato dextrose agar was assessed using local cereal species as the basal media. Three cereal meal extracts – corn, sorghum and millet – were prepared, using them as substitute for the potato in potato dextrose agar. Potato dextrose agar (PDA) was the standard set up with which the performances of the formulated media were compared. Eight genera of fungi (Aspergillus niger, Fusarium moniliforme, Penicillium sp., Cercospora sp., Curvularia palescens, Botryodiplopodia sp., Rhizopus sp. and Rhodotorula rubra) were isolated and pure cultures of each species aseptically inoculated onto the three different formulated media including PDA and allowed to grow. Their growths were measured at 24, 48, 72, and 96 h after inoculation, using diameter of growth as an index. The set up was repeated thrice for each species on the three formulated media and the control (PDA). Growth of all the fungal species were observed to be about the same or sometimes better in the formulated media relative to those on the standard set up, except for Rhodotorula rubra. The radius of growth of F. moniliformehad an average of 15 + 0.58 mm on corn-dextrose agar relative to 12 mm on PDA at 96 h while Cercospora sp. measured 30 + 0.58 mm on millet-meal dextrose agar relative to 37 + 1.16 mm at 48 h. Botryodiplopodia sp. grew through the whole diameter of the plate (covering the total length of the radius of 45 mm) in both sorghum-meal and PDA at 96 h. 相似文献
6.
B. v. d. Lustgraaf 《Oecologia》1978,33(3):351-359
Summary At. 75 and 80% relative humidity (RH), on a wheat germ flake medium, Aspergillus penicilloides grew abundantly and suppressed the population growth of Dermatophagoides pteronyssiunus. At 71% RH, A. penicilloides grew moderately and was only antagonistic to D. pteronyssinus when the fungus was previously incubated on the medium.On a human dander medium and on mattress dust, A. penicilloides grew moderately at 71% and 75% RH and stimulated the development of D. pteronyssinus populations. Also a moderate growth of Eurotium repens on human dander positively influenced D. pteronyssinus. Wallemia sebi and Penicillium brevicompactum grew slightly or did not grow at all at 75% RH. No effect was observed on D. pteronyssinus.It appears that xerophilic fungi may stimulate, and occasionally may reduce, the growth of house-dust mite populations in the natural environment. 相似文献
7.
Keratinophilic fungi include true fungi that vigorously degrade keratin as well as a number of important human pathogenic
dermatophytes. We identified 41 species and one variety belonging to 19 genera in 50 floor dust samples following culture
on Sabouraud’s dextrose agar medium at 28°C. Dermatophytes and closely related fungi were represented by six species—Aphanoascus fulvescens, Aphanoascus sp., Arthroderma cuniculi, Chrysosporium lucknowense, Gymnoascus uncinatus and Trichophyton rubrum. There were 35 species and one variety of other fungal species, with members of Aspergillus and Penicllium being the most prevalent. Twenty-seven species and 1 variety belonging to 14 genera were identified from 24 dust samples
gathered at 2-week intervals from male student housing at El-Kenose during January–December 2005 that had been cultured on
Sabauraud’s dextrose agar at 28°C. The monthly counts of keratinophilic fungi showed irregular fluctuations, with a peak in
April and the lowest point in November. Dermatophytes and closely related fungi were represented by Aphanoascus fulvescens, Aphanoascus sp., Chrysosporium lucknowense, Gymnoascus uncinatus, and Trichophyton rubrum. In conclusion, the study reports the incidences of some dermatophytes found in the floor dust of student houses of South
Valley University, Egypt. 相似文献
8.
The toxicity to adults of the American house dust mite, Dermatophagoides farinae, and the European house dust mite, Dermatophagoides pteronyssinus, of cassia bark and cassia and cinnamon oil compounds was examined using residual contact and vapour-phase toxicity bioassays.
Results were compared with those of the currently used acaricides: benzyl benzoate and dibutyl phthalate. The acaricidal principles
of cassia bark were identified as (E)-cinnamaldehyde and salicylaldehyde. In fabric-circle residual contact bioassays with adult D. farinae, salicylaldehyde (17.3 mg/m2) and (E)-cinnamaldehyde (25.8 mg/m2) were 2.5 and 1.7 times more toxic than benzyl benzoate (43.7 mg/m2), respectively, based on 24-h LD50 values. The acaricidal activity was more pronounced in benzaldehyde, menthol, α-terpineol, and thymol (70.8–234.3 mg/m2) than in dibutyl phthalate (281.0 mg/m2). Against adult D. pteronyssinus, salicylaldehyde (17.3 mg/m2) and (E)-cinnamaldehyde (19.3 mg/m2) were 2.4- and 2.2-fold more active than benzyl benzoate (41.9 mg/m2). The toxicity of benzaldehyde, menthol, α-terpineol, and thymol (75.3–179.2 mg/m2) was higher than that of dibutyl phthalate (285.1 mg/m2). In vapour-phase toxicity tests with adult D. farinae, the test compounds described were much more effective in closed—but not in open—containers, indicating that the effect of
these compounds was largely a result of action in the vapour phase. 相似文献
9.
The interaction of house dust mites(HDM)and microorganisms is the key factor in the survival of these mites in human-made environments.Spent growth medium(SPGM)provides the rest of the dict,along with dead mite bodies and microorganisms.SPGM represents a source of microorganisms for the recolonization of mite food and the mite digestive tract.An experiment was performed to observe how adding SPGM to the HDM diet affects HDM population growth,the microbiome composition and the microbial respiration in microcosms.We analyzed American house dust mite(Dermatophagoides farinae)and European house dust mite(Dermatophagoides pleronyssinus)originating from control diets and diets treated with an extract of SPGM from 1-and 3-month-old mite cultures.The microbiome was described using 16S and 18S barcode sequencing.The composition of the bacterial and fiungal microbiomes differed between the HDM species,but the SPGM treatment influenced only the bacterial profile of D.farinae.In the D.farinae microbiome of specimens on SPGM-treated dicts compared to those of the control situation,the Lactobacillus profile decreased,while the Candinium,Staphylococ-cus,Acinetobacter,and Sphingomonas profiles increased.The addition of SPGM extract decreased the microbial respiration in the microcosms with and without mites in almost all cascs.Adding SPGM did not influence the population growth of D.farinae,but it had a variable effect on D.pteronyssimus.The results indicated that the HDM are marginally influenced by the microorganisms in their feces. 相似文献
10.
Khan MA Jones I Loza-Reyes E Cameron MM Pickett JA Birkett MA 《Experimental & applied acarology》2012,57(1):65-74
The European and American house dust mites, Dermatophagoides pteronyssinus and D. farinae, have a huge impact upon human health worldwide due to being the most important indoor trigger of atopic diseases such as
asthma, rhinitis and atopic dermatitis. Preceding studies have shown that the behavioural response of house dust mites towards
volatile chemicals from food sources can be assessed using a Y-tube olfactometer assay. In the current study, we used this
assay to investigate, for the first time, the ability of the essential oil of the catmint plant, Nepeta cataria (Lamiaceae), known to repel other ectoparasites affecting human and animal health, to interfere with the attraction of D. pteronyssinus and D. farinae towards a standard food source (fish flakes). Two distinct chemotypes (A and B), enriched in the iridoid compounds (4aS,7S,7aR)-nepetalactone and (4aS,7S,7aS)-nepetalactone, and the sesquiterpene (E)-(1R,9S)-caryophyllene, were used. Initial assays with a hexane extract of fish flakes (FF extract) confirmed attraction of mites
to this positive control (P < 0.001 and P < 0.05 for D. pteronyssinus and D. farinae respectively), but when presented in combination with either N. cataria chemotype, tested across a range of doses (10, 1, 0.1 and 0.01 μg), decreasing attraction of mites to their food source was
observed as the dose augmented. Our study shows that N. cataria, enriched in iridoid nepetalactones and (E)-(1R,9S)-caryophyllene, exhibits potent repellent activity for house dust mites, and has the potential for deployment in control
programmes based on interference with normal house dust mite behaviour. 相似文献
11.
V. B. Ponizovskaya A. B. Antropova V. L. Mokeeva E. N. Bilanenko L. N. Chekunova 《Microbiology》2011,80(3):378-385
Original data on the growth parameters of the fungi Penicillium chrysogenum Thom, Aspergillus repens (Corda) Sacc., and Trichoderma viride Pers. isolated from living spaces in Moscow are presented. Spore germination, fungal growth, and the radial growth rate of
the colonies were investigated upon cultivation on agarized nutrient media with different water activity (aw) values. Spore germination and fungal growth were studied in house dust under laboratory conditions at different relative
air humidity (RH). It was shown that, at decreased aw and RH, the spore germination time increased, as did the period from germination to mycelium and conidia formation, while
the radial growth rate of colonies decreased. House dust was found to be a suitable growth substrate for A. repens and P. chrysogenum, supporting their complete life cycle. It was suggested that house dust is unsuitable as a substrate for the growth of T. viride. The aw and RH ranges for development of these micromycetes were determined. On this basis, the A. repens, P. chrysogenum, and T. viride strains isolated from living spaces were identified as xerophilic, xerotolerant, and hygrophilic ones, respectively. 相似文献
12.
Estrada-de Los Santos P Vacaseydel-Aceves NB Martínez-Aguilar L Cruz-Hernández MA Mendoza-Herrera A Caballero-Mellado J 《Journal of microbiology (Seoul, Korea)》2011,49(6):867-876
The presence of Burkholderia, Cupriavidus, and Ralstonia species in northeastern Mexico was investigated. An analysis of the root surrounding soil from different agricultural plants
led to the isolation of Burkholderia and Cupriavidus species but no Ralstonia strains. Most Cupriavidus species were unknown and grouped into two clusters according to ARDRA profiles. The 16S rRNA sequence analysis showed that
the Cupriavidus isolates were highly related among them and with different Cupriavidus species with validated names. However, SDS-PAGE profiles were distinct among the different ARDRA profiles and to other Cupriavidus species examined, suggesting new species in the genus. This shows that Cupriavidus is more widely associated with plants than previously appreciated. The BCC isolate was 99% similar to B. cenocepacia by recA sequence analysis. Additionally, most Cupriavidus strains from the two largest groups grew on media containing up to 0.1 mg/ml of copper, 10.0 mg/ml arsenic and 1.0 mg/ml
zinc. Burkholderia strains grew on media containing up to 10.0 mg/ml zinc, 5.0 mg/ml arsenic and 0.1 mg/ml copper. 相似文献
13.
Investigation of the phenotypic properties of three mixotrophic bacteria, strains Sb-K, Sb-F, and Sb-S, isolated from an aboriginal
thermoacidophilic microbial community participating in biooxidation of ore with high antimony content (26%) and ore concentrates
from the Olympiadinskoe deposit under semicontinuous cultivation conditions at 46 ± 1°C, revealed the differentiating characteristics
of these strains. The isolated cultures grew lithotrophically through different numbers of transfers: strains Sb-F and Sb-K
grew through seven and eight transfers, respectively, and strain Sb-S grew through two or three transfers. Strains Sb-K and
Sb-S utilized a wide range of organic substrates for active organotrophic growth during nine or ten transfers, while strain
Sb-F was less tolerant to organic compounds. Strain Sb-K grew on a medium with the ore and sulfide ore concentrates in the
pH range of 1.0–3.0. Growth of strains Sb-F and Sb-S occurred in the pH ranges of 1.0–2.5 and 1.5–5.5 on media with Fe2+ and S0, respectively.. The optimal initial pH values of the media, corresponding to the maximum specific growth rates, were 1.6–1.7,
1.9, and 2.0–3.0 for strains Sb-K, Sb-F, and Sb-S, respectively. All three strains were able to grow within a broad temperature
range, 20–65°C, with an optimum at 46°C (Sb-K), 40–46°C (Sb-F), and 48–50°C (Sb-S). According to the results of DNA-DNA hybridization
and phylogenetic analysis, as well as their phenotypic characteristics, the isolates can be classified as novel strains of
species of the genus Sulfobacillus. Strains Sb-K, Sb-F, and Sb-S, isolated as predominant cultures on the media with sulfide compounds, iron, or sulfur, respectively,
were affiliated to the species S. thermotolerans, S. sibiricus, and S. thermosulfidooxidans. 相似文献
14.
James W. Dalling T. R. H. Pearson J. Ballesteros E. Sanchez D. F. R. P. Burslem 《Oecologia》2009,161(2):361-370
Four species of fast-growing pioneer tree species in the genus Cecropia exist in the forests in central Panama. Cecropia insignis is dominant in old-growth forests but absent from nearby secondary forests; C. obtusifolia, and C.
peltata are abundant in secondary forests but rare in old-growth forest, and C. longipes is uncommon in both. To determine whether Cecropia habitat associations are a consequence of local dispersal or differences in recruitment success, we grew seedlings of these
species in common gardens in large treefall gaps in secondary and old-growth forest. In contrast to the observed adult distribution,
only C. insignis grew significantly over 16 months in secondary forests; remaining species were heavily browsed by herbivores. C. insignis also grew and survived best in old-growth forest. Differences in susceptibility to herbivory did not result from an ant defence
mutualism; none of the plants were colonised by ants during the experiment. To test whether C. insignis, the species least susceptible to herbivory, trades off investment in growth in favour of defence, we also grew the four
Cecropia species in a screened growing house under light conditions comparable to large forest gaps. Contrary to expectation, species
growth rates were similar; only C. peltata grew significantly faster than C. insignis. These results suggest that (1) conditions in ~40-year-old secondary forests no longer support the recruitment of Cecropia species, which are canopy dominants there; and (2) among congeners, differences in plant traits with little apparent cost
to growth can have large impacts on recruitment by affecting palatability to herbivores. 相似文献
15.
Sorokin DY Tourova TP Mussmann M Muyzer G 《Extremophiles : life under extreme conditions》2008,12(3):431-439
Anaerobic enrichments with H2 as electron donor and thiosulfate/polysulfide as electron acceptor at pH 10 and 0.6 M total Na+ yielded two non sulfate-reducing representatives of reductive sulfur cycle from soda lake sediments. Strain AHT 1 was isolated
with thiosulfate as the electron acceptor from north–eastern Mongolian soda lakes and strain AHT 2—with polysulfide as the
electron acceptor from Wadi al Natrun lakes in Egypt. Both isolates represented new phylogenetic lineages: AHT 1—within Clostridiales and AHT 2—within the Deltaproteobacteria. Both bacteria are obligate anaerobes with respiratory metabolism. Both grew chemolithoautotrophically with H2 as the electron donor and can use thiosulfate, elemental sulfur and polysulfide as the electron acceptors. AHT 2 also used
nitrate as acceptor, reducing it to ammonia. During thiosulfate reduction, AHT 1 excreted sulfite. dsrAB gene was not found in either strain. Both strains were moderate salt-tolerant (grow up to 2 M total Na+) true alkaliphiles (grow between pH 8.5 and 10.3). On the basis of the phenotypic and phylogenetic data, strains AHT 1 and
AHT 2 are proposed as new genera and species Dethiobacter alkaliphilus and Desulfurivibrio alkaliphilus, respectively.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.
Nucleotide sequence accession number: The GenBank/EMBL accession number of the 16S rRNA gene sequence of strains AHT 1T and
AHT 2T are EF422412 and EF422413. 相似文献
16.
During the past few decades, house dust mites have attracted worldwide interest among medical entomologists and acarologists
because of their importance in causing nasobronchial allergic disorders in human beings. House dust mites are present throughout
the year; however, their relative densities differ in different seasons and habitats. Because the prevalence of house dust
mite allergen is important epidemiologically and clinically, detailed knowledge on the seasonal abundance of important allergenic
mites is of great importance for better understanding of the pathogenesis of the disease. In view of this, a systematic survey
was carried out on the prevalence of total mites and four common allergenic mites in the city of Kolkata for two consecutive
years. Both bed and bedroom floor dust were collected separately from homes inhabited by asthmatic patients situated in different
corners of the city on monthly basis from January 2004 to December 2005. The population levels of total mites and four common
allergenic mites, namely Dermatophagoides pteronyssinus, D. farinae, Austroglycyphagus geniculatus, and Blomia tropicalis separately, were highest during the pre-monsoon period (March–May), irrespective of habitat, whereas densities were low in
all cases during winter (December–February). The study indicates that season had the most significant effect on the relative
abundance of house dust mites except Dermatophagoides farinae, irrespective of habitat. 相似文献
17.
18.
Denise Siew Hoong Tan Sheng Rong Ng Rudolf Meier 《Organisms Diversity & Evolution》2011,11(4):253-261
Here we describe the hitherto unknown details of the highly unusual mating behaviour of Saltella sphondylii—a widely cited model for male longevity costs caused by multiple copulations. When compared to the known mating behaviour
of 28 sepsid species, we find five unique behavioural elements based on frame-by-frame analyses of video-recordings. These
new behaviours are documented with video clips. We suggest that the male longevity costs could be due to copulation bouts
that involve multiple insertions of a comparatively membranous phallus into the female. We compare the phallus of the Saltella sphondylii to those from three other species (Themira putris, Parapaleosepsis plebeia, Sepsis punctum). 相似文献
19.
20.
Four ectomycorrhizal fungi were tested for their ability to grow (i.e., mycelial mat radial extension and fungal biomass) on nutrient media either supplemented with ammonium-nitrogen or nitrate-nitrogen or in the absence of an inorganic nitrogen source.Pisolithus tinctorius, Cenococcum geophilum andThelephora terrestris exhibited greater growth on ammonium-nitrogen.Suillus granulatus grew better on the nitrate-nitrogen nutrient medium. Regardless of inorganic nitrogen form preference (i.e., ammonium-nitrogen or nitrate-nitrogen), all 4 species showed some growth on each of the 3 nutrient media. Growth rate maxima varied by fungal species as well as by inorganic nitrogen source. Maximum growth rate forT. terrestris exceeded rates exhibited by the other 3 fungi by 2–5 times. 相似文献