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Microscopic fungi in dwellings and their health implications in humans.

The article reviews the quantitative and qualitative incidence of microscopic filamentous fungi in dwellings, methods for their detection, mycotoxins, glucans and volatile organic compounds produced by microscopic fungi in the indoor air of homes. Characteristics and properties of the most important species of fungi in dwellings (Alternaria spp., Aspergillus spp., Cladosporium spp., Fusarium spp., Penicillium spp., Stachybotrys spp., and Wallemia spp.) and the health problems of occupants of the "moldy homes are also discussed.

Adolescent↗

[Nature and frequency of the existence of mold fungi in garbage cans for biological waste and the resultant airborne spore pollution].

In organic waste, numerous mold fungi and other microorganisms develop sometimes within a few hours only which decompose the organic material already in the collecting containers generating heat and odor. With regard to the emission of mold fungus spores out of garbage cans for bio-waste and the potential environmental-hygienic danger connected with it, considerable worries have been expressed recently. A wide spectrum of mold fungi can be found in bio-waste in strongly varying concentrations. No noticeable difference could be ascertained between the settlement structure areas and the cities respectively as to the fungus concentration in the bio-waste substrate. A. fumigatus and A. niger can be recommended as leading spores for the behavior of the total concentration of fungi in the bio-waste due to their frequency of detection and their seasonal dynamism. The intensity of the air spore pollution through emission of mold fungus spores correlates closely with the climatic conditions, such as variations of temperature, relative humidity and solar radiation. The airborne release of mold fungus spores out of garbage cans for bio-waste and the formation of a respective exposure connected with it is judged as harmless for healthy persons. Risk patients and persons having a weakened immune system or assumed to have such a one due to an existent basic illness and/or other reasons should avoid any handling of bio-waste as well as any other waste if possible.

Air Microbiology↗

[MVOC of fungi--use as an indicator for exposure level].

The production of microbial volatile organic compounds (MVOC) by fungi derived from biowaste was studied on synthetic agar (YES), compost-extract media (CEA VAR 1-3) and compost. Exposure assessment was carried out in composting facilities and the occurrence of VOC/MVOC was related to the presence of airborne fungi. A number of non-specific MVOC was found at all sampling sites or in each season, some of which showed preferences for certain sampling sites (3-methyl-1-butanol, 3-octanone). They seemed to be correlated with a certain species composition or with microbial activity, and may thus be used to describe a certain state of decomposition. Correlations between single volatiles and certain fungi were found in situ, but these findings did not match with the species-specific volatiles obtained from pure cultures.

Air Pollutants, Occupational↗

[Health-toxicologic aspects of some fungi].

Recent findings of fungi in food products of such renomed companies as Coca-Cola and Danone resulted in society-wide alert in Poland. Humans have contact with fungi everywhere. Every food product covered with mould or having marks of it should be discarded. We should mention that cutting of or skimming the mould is totally ineffective and dangerous, because of the fact that rest of the product will contain products of fungal metabolism such as mikotoxins, which are, of course, invisible. Modern food producing technologies effected in microorganism-free products, but sporadically we can find dead fungi debris due to improper washing procedures of multi-use bottles, like it was observed in Coca-Cola products. As for mould-covered cottage cheese type products of Danone, most probably reason was improper handling of ready, sealed products during transport and storage. Even minimal physical injuries to air-tight containers resulted in sporae penetration to milk products and finally contamination with mikotoxins.

Food Contamination↗

Regulation of siderophore production by iron Fe(III) in certain fungi and fluorescent pseudomonads.

Regulation of siderophore production in response to iron concentration in the medium was examined. Threshold concentration was recorded for twenty fungi and three rhizobacterial pseudomonads. Organisms showed difference in threshold values at which they stopped siderophore elaboration. In nine fungi (3 aspergilli, 1 penicillium, N. crassa, F. dimerum and 3 mucors) siderophore production was repressed at 3 microM Fe(III). Siderophore production was repressed at 27 microM of Fe (III) in 3 aspergilli, 2 penicillia and 3 pseudomonads. Rest of the fungi had cut off values at 6, 9, 15, 21 microM of Fe(III) concentration.

Fungi↗

The effect of sewage sludge composting on the quantitative state of some groups of bacteria and fungi.

Analysis of the quantitative state of disease causing bacteria and of other microbic groups were done on the sewage sludge from a sewage treatment plant. The results of the analysis include the ammonifying bacteria, nitrifying and denitrifying bacteria. The general quantity of bacteria and fungi in a secondary dehydrated sludge, fermented secondary dehydrated sludge, and in composted secondary dehydrated sludge was deterinated. Composts were prepared from dehydrated secondary sludge with the addition of sawdust. Microbiological analysis of sewage sludge showed, that the quantities of the fecal coli bacteria were 6500; 220 and 150 cells per cm3 of the secondary dehydrated sludge, fermented secondary dehydrated sludge and composted dehydrated secondary sludge, respectively. The numbers of Salmonella were respectively 67.80; 6.48 and 6.60 cells per cm3. The general numbers of bacteria were 2.98 x 10(7); 2.79 x 10(7); 2.15 x 10(7) cells per cm3 of sludge. The cell numbers of fungi were: 6.20x 10(2); 19.60 x 10(2); 7.80 x 10(2) per cm3 of sludge. In the three types of sludge, the results show great numbers of the ammonifying, nitrifying and denitrifying bacteria. Of the analysed groups of bacteria, the highest numbers of cells were found for general bacteria; ammonifying and nitrifying bacteria were next in abundance; still fewer were the denitrifying bacteria. Fungi and pathogenic bacteria were the least numerous.

Ammonia↗

Oxidation of elemental sulfur by bacteria and fungi in soil.

Laboratory experiments were used to determine the effects of antibiotics, organic C and CaCO3 amendments of sterile reinoculated soil on S0 oxidation by bacteria and fungi. The rate of S0 oxidation in soil with nystatin added was higher than in soil amended with penicillin + streptomycin. This tells us that bacteria were more efficient than fungi in the S0 oxidation process. It was demonstrated that neutrophilic chemolithotrophs were more efficient in this process than heterotrophs. Glucose introduced to the soil had a negative effect and CaCO3 had a positive effect on S0 oxidation. In soil enriched with glucose the number of chemolithotrophs was very low in comparison with extremely numerous heterotrophic bacteria and fungi. It suggests that the role of heterotrophs in S0 oxidation could be important in habitats rich in organic C, e.g. rhizosphere. In soil containing S0, qualitative changes of fungal communities to genera with higher S0 oxidation ability was also noted. In the presented paper, after comparison of the own results with the data of others concerning the natural soils, the role of various microbial groups in S0 oxidation process in soils is discussed.

Anti-Bacterial Agents↗

[Saphrophytic life of opportunistic fungi].

Probably all pathogenic fungi can cause opportunistic infections in compromised hosts. This paper briefly reviews our knowledge on the saprophytic life - geographic distribution and habitat - of the most common pathogenic fungi. Some mycoses are of endogenous origin - e.g. Candida albicans is an endosaprophyte - others of epigenon origin - e.g. Pityrosporum ovale is an episaprophyte - but most mycoses are caused by fungi which have an exosaprophytic (or exosaprobic) life: one becomes infected after exposure to the saprobic source of the fungus. Nevertheless, it should be kept in mind that mycoses, e.g., cryptococcosis, coccidioidomycosis, and histoplasmosis, in compromised hosts are not necessarily the result of recent exposure but may be the result of the reactivation of latent or inactive forms.

Arthrodermataceae↗

Filamentous fungi and yeasts on mattresses covered with different encasings.

Besides mites, filamentous fungi and yeasts play an important role as domestic allergens. Among different allergen avoidance strategies the efficacy of synthetic mattress encasings has been demonstrated for the reduction of house dust mites. Whether these synthetic encasings are also able to reduce the growth of fungi on the mattress under domestic conditions has not been assessed so far. To determine if the fungal growth on mattresses can be reduced by the use of synthetic encasings we assessed the fungal colonisation of mattresses covered either by conventional cotton encasings or by polyurethane encasings impermeable to particles > 3 mum. Within a 12-month period dust samples were obtained from the mattresses. Fungal quantities were measured by counting colonies on agar plates incubated at 20 degrees C and 37 degrees C. The counts of fungi were significantly higher on mattresses with cotton encasings. Penicillium spp. and Aspergillus spp. were isolated most frequently. Therefore the application of synthetic encasings with similar properties to the encasings used in this investigation is recommended as part of an allergen avoidance strategy for patients sensitised to fungal allergens.

Adult↗

[Effect of AM fungi on water and nutrition status of corn plants under salt stress].

Under NaCl stress, the dry matter production of corn plants inoculated with or without arbuscular mycorrhizal (AM) fungus (Glomus mosseae) was decreased, but the decrement for non-mycorrhizal plants was 10% higher than that for mycorrhizal ones. Under salt stress condition, the dry weights of root system and aboveground part of mycorrhizal corn and its leaf water potential were higher than those of non-mycorrhizal corn, while the proline content of mycorrhizal corn was less than that of non-mycorrhizal corn. The contribution of hypha to P uptake of plants decreased from 45.3% to 42.6%, while the effect of AM fungi on plant growth increased from 30.9% to 63.5% under salt stress condition. The above-mentioned results indicated that the mechanism that AM fungi enhance the salt-resistance of corn is related with the improvements of water and P nutrition conditions. Meanwhile, it was found whether under salt stress or not, the ratio of P accumulation of root system to aboveground part of mycorrhizal corn was higher than that of non-mycorrhizal corn, indicating that the infection of AM fungi changed the P distribution pattern in plant bodies, which is beneficial to increase the salt-resistance of plants.

Ecosystem↗

Chitin synthesis in human pathogenic fungi.

In recent years it has become evident that the structural polysaccharide chitin is synthesized from a family of enzymes encoded by multiple CHS chitin synthase genes, and regulated by an array of ancillary gene products that influence CHS activation and localization. Considerable attention has therefore been given to elucidating the function of specific CHS gene products in individual fungi. In those fungi in which individual CHS genes have been deleted systematically, there is little evidence for redundancy of function in family members. Chs enzymes are now known that participate in lateral wall biosynthesis, septum synthesis and spore formation but the phenotype of some CHS gene mutations is subtle, and so the role of the corresponding isoenzymes remains obscure. Nonetheless, it has become clear that certain members of the CHS gene families of fungi are more important for growth, integrity and viability than others, and this knowledge has already led to the design of new classes of antifungal agents that are targeted against key enzyme activities. Future work in this area will help define how individual Chs enzymes are targeted to specific regions of the cell wall and at specific times of the cell cycle, and should facilitate the rational development of novel and highly specific antifungal agents.

Antifungal Agents↗

Identification of fungi based on the nucleotide sequence homology of their internal transcribed spacer 1 (ITS1) region.

In this study, we examined the identification of fungi based on the sequence homology of the internal transcribed spacer 1 (ITS1) region. A newly designed primer pair could amplify the target region of all 42 strains tested. The PCR products were sequenced and the sequence homologies were searched by BLAST. It was demonstrated that this method is a reliable identification method at the genus or species level. At present, available databases are still insufficient to identify some fungi, but with the accumulation of further data in the ITS1 database, this method will be available for the identification of fungi.

Base Sequence↗

Indoor fungi and their ciliostatic metabolites.

According to epidemiological studies, it is possible that some secondary metabolites of indoor airborne fungi could be responsible for health troubles which occupants suffer from. In our previous experiments, a model with tracheal rings of 1-day-old chicks in vitro was shown to be a very suitable method to study the ciliostatic chloroform-extractable endo- and/or exometabolites of filamentous fungi. In this study we isolated the filamentous fungi from walls of "mouldy" dwellings and schools (cultivation on dichloran 18% glycerol agar at 25 and 37 degrees C for 10 d) in Slovakia. We studied the ciliostatic effect of the chloroform-extractable endo- and exometabolites of 96 representative isolates (stationary cultivation on the liquid medium with 2% of yeast extract and 10% of sucrose at 25 degrees C for 10 days) on the cilia movement in tracheal organ cultures of 1-day-old chickens in vitro after 24, 48 and 72 hrs (incubation in the minimal essential medium according to Eagle with Earl s salts and 20 microg of extract of metabolites dissolved in dimethylsulfoxide per 1 mL). Strains of Penicillium Link: Fr. sp., Aspergillus versicolor (Vuill.) Tiraboschi, A. flavus Link, Cladosporium sphaerospermum Penzig and C. cladosporioides (Fres.) de Vries were isolated most frequently. Two A. flavus isolates were able to produce aflatoxins B1, B2, G1, G2 in vitro after cultivation on the liquid medium with 20% sucrose and 2% yeast extract. This is the first isolation of aflatoxigenic A. flavus strains from dwellings in Slovakia. All frequently isolated strains produced secondary metabolites with the strongest ciliostatic activity -- their exo- and endometabolites stopped tracheal ciliary movement in chicks till 24 h. There are some toxic fungal metabolites in the indoor air not only with the ability to destroy ciliary movement in the upper airways in vitro but, probably, during long-lasting exposure to cause general intoxication of macroorganism via lung tissue.

Aflatoxins↗

Taphonomic mycota: fungi with forensic potential.

Forensic archaeologists and criminal investigators employ many different techniques for the location, recovery, and analysis of clandestine graves. Many of these techniques are based upon the premise that a grave is an anomaly and therefore differs physically, biologically, or chemically from its surroundings. The work reviewed in this communication demonstrates how and why field mycology might provide a further tool towards the investigation of scenes of crime concealed in forest ecosystems. The fruiting structures of certain fungi, the ammonia and the postputrefaction fungi, have been recorded repeatedly in association with decomposed mammalian cadavers in disparate regions of the world. The ecology and physiology of these fungi are reviewed briefly with a view to their potential as a forensic tool. This application of mycology is at an interface with forensic archaeology and forensic taphonomy and may provide a means to detect graves and has the potential to estimate postburial interval.

Ammonia↗

[Detection of fungi from agricultural commodities with serological method].

The types of fungus antigen and the purification of fungus antigen, the purification of anti-fungus antibody, and the application of serology in detecting fungi from agricultural commodities are introduced. Fungi antigen are mainly from extra-cellular protein and extra-cellular polysaccharide. The method for antigen purification was the same as the common method used to separate and purify proteins and polysaccharides. The specificity of an antibody is the most important parameter for the quality of antibody. As long as the specificity of a antibody is high, the antibody could detect the target fungi from agricultural commodities.

Animals↗

Impedance method for rapid detection of total counts of bacteria and fungi in bottled purified water.

A study was conducted to compare the current conventional method and the impedance method for rapid detection of total counts of bacteria and fungi in bottled purified water. The results indicated that the corresponding detection rate for the 2 methods was 94.5 and 90.4%, respectively. The detection time was shortened from 48 h (bacteria) and 5 days (fungi) to 14.5 and 44 h, respectively. Moreover, for more serious contamination, less time was needed. The impedance method predicted a positive sample within 11.3 h (bacteria) and 27.1 h (fungi). Therefore, the impedance method was found to be a rapid, accurate method.

Bacteria↗

Effect of some natural pesticides on entomogenous muscardine fungi.

Five commercial preparations of natural pesticides were tested for in vitro compatibility with muscardine fungi, Beauveria brongniartii and Metarhizium anisopliae. Neemark (azadirachtin) was found compatible with both the fungi. Phytoallexin, the natural fungicide, significantly inhibited the growth of both the fungi, while other natural pesticides showed moderate to severe inhibition.

Fungi↗

Concentration and species diversity of airborne fungi near busy streets in Lithuanian urban areas.

The investigations on air pollution in industrial cities of Lithuania: Vilnius, Alytus, Kaunas, Marijampole and Elektrenai were aimed at detecting the presence of fungi and aerosol particles during different seasons of the year. Sampling of fungal spores was carried out at 20 sampling sites. Active air sampling was performed simultaneously with the use of passive sedimentation plates. Data on the spread of various micromycete species in the air of cities contaminated with various pollutants are presented. Micromycetes of 430 species belonging to 165 genera, 19 families, 13 orders, 4 classes, and 3 phylla were isolated and identified. We found 21 species, 11 genera, 7 families from Ascomycota, 6 species, 1 genus, 1 family from Oomycota, 45 species, 15 genera, 8 families from Zygomycota. Mitosporic fungi comprised 138 genera, 358 species, and comprised the vast majority of identified species: 358 out of 430 (83.25 %). Conditionally pathogenic species were also isolated. It was concluded that the abundance of such fungi as Aspergillus niger, A. fumigatus, Cladosporium herbarum, Alternaria alternata, Aureobasidium pullulans in the air can be a significant criterion for the evaluation of air pollution.

Air Microbiology↗