| 1. |
- Pekkanen, Juha, et al.
(författare)
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Indoor bacteria and asthma in adults : a multicentre case-control study within ECRHS II
- 2018
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Ingår i: European Respiratory Journal. - : European Respiratory Society (ERS). - 0903-1936 .- 1399-3003. ; 51:2
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Tidskriftsartikel (refereegranskat)abstract
- 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. DNA was extracted from mattress dust for bacterial analysis using denaturing gradient gel electrophoresis (DGGE). Selected bands were sequenced and associations with asthma confirmed with four quantitative PCR (qPCR) assays. 15 out of 37 bands detected with DGGE, which had at least a suggestive association (p<0.25) with asthma, were sequenced. Of the four targeted qPCRs, Clostridium cluster XI confirmed the protective association with asthma. The association was dose dependent (aOR 0.43 (95% CI 0.22-0.84) for the fourth versus first quartile, p for trend 0.009) and independent of other microbial markers. Few significant associations were observed for the three other qPCRs used. In this large international study, the level of Clostridium cluster XI was independently associated with a lower risk of prevalent asthma. Results suggest the importance of environmental bacteria also in adult asthma, but need to be confirmed in future studies.
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| 2. |
- Valkonen, Maria, et al.
(författare)
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Microbial characteristics in homes of asthmatic and non-asthmatic adults in the ECRHS cohort
- 2018
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Ingår i: Indoor Air. - : John Wiley & Sons. - 0905-6947 .- 1600-0668. ; 28:1, s. 16-27
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Tidskriftsartikel (refereegranskat)abstract
- Microbial exposures in homes of asthmatic adults have been rarely investigated; specificities and implications for respiratory health are not well understood. The objectives of this study were to investigate associations of microbial levels with asthma status, asthma symptoms, bronchial hyperresponsiveness (BHR), and atopy. Mattress dust samples of 199 asthmatics and 198 control subjects from 7 European countries participating in the European Community Respiratory Health Survey II study were analyzed for fungal and bacterial cell wall components and individual taxa. We observed trends for protective associations of higher levels of mostly bacterial markers. Increased levels of muramic acid, a cell wall component predominant in Gram-positive bacteria, tended to be inversely associated with asthma (OR's for different quartiles: II 0.71 [0.39-1.30], III 0.44 [0.23-0.82], and IV 0.60 [0.31-1.18] P for trend .07) and with asthma score (P for trend .06) and with atopy (P for trend .02). These associations were more pronounced in northern Europe. This study among adults across Europe supports a potential protective effect of Gram-positive bacteria in mattress dust and points out that this may be more pronounced in areas where microbial exposure levels are generally lower.
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