Indoor bacteria and asthma in adults: a multicentre case-control study within ECRHS II.

Both protective and adverse effects of indoor microbial exposure on asthma have been reported, but mostly in children. To date, no study in adults has used non-targeted methods for detection of indoor bacteria followed by quantitative confirmation.A cross-sectional study of 198 asthmatic and 199 controls was conducted within the European Community Respiratory Health Survey (ECRHS) II.

Comparison of methods for assessing temporal variation of growth of fungi on building materials.

Fungal growth on indoor surfaces can decay building materials and release hazardous substances that affect indoor air quality. Despite the numerous methods available for growth determination, there is no commonly accepted standard. The goal of this study was to compare five different assay methods for the measurement of fungal growth: cultivation, MS-based determination of ergosterol, beta-N-acetylhexosaminidase activity, quantitative PCR and microscopic spore counting.

Bacterial Exposures and Associations with Atopy and Asthma in Children.

Background: The increase in prevalence of asthma and atopic diseases in Western countries has been linked to aspects of microbial exposure patterns of people. It remains unclear which microbial aspects contribute to the protective farm effect.

Objective: The objective of this study was to identify bacterial groups associated with prevalence of asthma and atopy, and to quantify indoor exposure to some of these bacterial groups.

Role of microbial and chemical composition in toxicological properties of indoor and outdoor air particulate matter.

Background: Ambient air particulate matter (PM) is increasingly considered to be a causal factor evoking severe adverse health effects. People spend the majority of their time indoors, which should be taken into account especially in future risk assessments, when the role of outdoor air particles transported into indoor air is considered. Therefore, there is an urgent need for characterization of possible sources seasonally for harmful health outcomes both indoors and outdoors.

Comparison of culture and qPCR methods in detection of mycobacteria from drinking waters.

Environmental mycobacteria are common bacteria in man-made water systems and may cause infections and hypersensitivity pneumonitis via exposure to water. We compared a generally used cultivation method and a quantitative polymerase chain reaction (qPCR) method to detect mycobacteria in 3 types of drinking waters: surface water, ozone-treated surface water, and groundwater. There was a correlation between the numbers of mycobacteria obtained by cultivation and qPCR methods, but the ratio of the counts obtained by the 2 methods varied among the types of water.

High indoor microbial levels are associated with reduced Th1 cytokine secretion capacity in infancy.

Background: Exposure to microbes and their components may affect the maturation of the immune system. We examined the association of house dust microbial content with cytokine-producing capacity at birth and at the age of 1 year.

Methods: Production of TNF-α, IFN-γ, IL-5, IL-8 and IL-10 at birth (n = 228) and at the age of 1 year (n = 200) following 24- and 48-hour whole-blood stimulation with staphylococcal enterotoxin B (SEB), lipopolysaccharide and the combination of phorbol ester and ionomycin was measured.

Microbial communities associated with house dust.

House dust is a complex mixture of inorganic and organic material with microbes in abundance. Few microbial species are actually able to grow and proliferate in dust and only if enough moisture is provided. Hence, most of the microbial content originates from sources other than the dust itself.

Concentrations and diversity of microbes from four local bioaerosol emission sources in Finland.

Microbial particles can readily be released into the air from different types of man-made sources such as waste operations. Microbiological emissions from different biological sources and their dispersion may be an issue of concern for area planning and for nearby residents. This study was designed to determine the concentrations and diversity of microbiological emissions from four different man-made source environments: waste center with composting windrows, sewage treatment plant, farming environment, and cattle manure spreading.

Molecular profiling of fungal communities in moisture damaged buildings before and after remediation--a comparison of culture-dependent and culture-independent methods.

Background: Indoor microbial contamination due to excess moisture is an important contributor to human illness in both residential and occupational settings. However, the census of microorganisms in the indoor environment is limited by the use of selective, culture-based detection techniques. By using clone library sequencing of full-length internal transcribed spacer region combined with quantitative polymerase chain reaction (qPCR) for 69 fungal species or assay groups and cultivation, we have been able to generate a more comprehensive description of the total indoor mycoflora.

Actinobacteria in indoor environments: exposures and respiratory health effects.

Actinobacteria are a large group of Gram-positive bacteria common in the environment, especially in the soil. They are morphologically diverse and extremely versatile in their metabolic activities. They produce tens of thousands of secondary metabolites with different biological activities.

Determination of bacterial load in house dust using qPCR, chemical markers and culture.

In this study, we developed two novel qPCR-assays for the detection of bacteria in house dust; one that determines the total bacterial amount and another that detects Gram-positive and Gram-negative bacteria separately. The methods were tested in silico and in vitro with microbial strains and vacuum cleaner dust samples, and validated in relation to culture and chemical marker analysis. We also compared the results of these three types of methods (qPCR, culture and chemical marker analysis) in 211 house dust samples from farming and non-farming environments.

The occupant as a source of house dust bacteria.

Background: Markers for microbial groups are commonly measured in house dust samples to assess indoor exposure to microbes in studies on asthma and allergy. However, little is known about the sources of different microbes. A better understanding of the nature and origin of microbes present in the immediate environment of human beings is crucial if one wants to elucidate protective as well as adverse effects on human health.

Microbial content of house dust samples determined with qPCR.

This study was designed to produce information about microbial concentrations using qPCR and their variation in different seasons and home environments with analyses of two types of house dust samples. Also the correlations between the two types of samples and the reproducibility of the parallel subsamples were studied. Two types of vacuumed house dust samples, rug dust and vacuum cleaner bag dust, were collected in 5 normal urban homes in four different seasons (N=20+20).

Indoor air particles and bioaerosols before and after renovation of moisture-damaged buildings: the effect on biological activity and microbial flora.

Many building-related health problems coincide with moisture damage and mold growth within a building. Their elimination is assumed to improve indoor air quality. The aim of this study was to follow the success of remediation in two individual buildings by analyzing the microbial flora and immunotoxicological activity of filter samples.

Quantitative PCR analysis of fungi and bacteria in building materials and comparison to culture-based analysis.

Prolonged moisture on building materials can lead to microbial growth on them. Microbes can emit spores, metabolites and structural parts into the indoor air and thus, cause adverse health effects of people living and working in these buildings. So far, culture methods have been used for assessment of microbial contamination of building materials.

Diversity and seasonal dynamics of bacterial community in indoor environment.

Background: We spend most of our lives in indoor environments and are exposed to microbes present in these environments. Hence, knowledge about this exposure is important for understanding how it impacts on human health. However, the bacterial flora in indoor environments has been only fragmentarily explored and mostly using culture methods.

Effects of moisture damage and renovation on microbial conditions and pupils' health in two schools--a longitudinal analysis of five years.

Airborne microbes and pupils' symptoms were monitored in a moisture-damaged (index) school and a reference school for five consecutive years. These surveys were carried out in two separate years before the renovation of the index school, during the renovation, and one and two years after the renovation. Microbial concentrations were higher in the index school than those in the reference school before and during renovation, but afterwards, the levels decreased to the level of the reference school.

Quantitative measurement of streptomycetes using real-time PCR.

A quantitative real-time PCR method was developed and used for determination of streptomycetes in indoor dust samples of five homes collected during three years. The specificity of the method was tested with 14 Streptomyces and ten non-streptomycetous species, revealing a high specificity for mesophilic streptomycetes. Thermophilic species and S.

Characterisation of Streptomyces spp. isolated from water-damaged buildings.

Abstract Saprophytic Streptomyces spp. common in soil and producing biologically active compounds have been related to abnormal microbial growth in buildings where occupants may have health problems. We characterised 11 randomly selected water-damaged building isolates.