Jump to main content
Jump to site search

Issue 3, 2010
Previous Article Next Article

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

Author affiliations

Abstract

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. Microbial concentrations determined by the new qPCR assays (median 7.2 × 105 cell equivalents mg−1) were about two orders of magnitude higher than concentrations obtained by culture (median 6.7 × 103 cfu mg−1). The median concentration of muramic acid was 25.67 ng mg−1 and that of 3-hydroxy fatty acids, expressed as LPS10–16 was 26.14 pg mg−1. Correlations between qPCR and chemical markers were moderate, while correlations between culture and qPCR and chemical markers were low to moderate. All the methods used in this study showed that the microbial concentrations are statistically significantly higher (p < 0.001, Mann–Whitney) in farming than non-farming environments.

As a conclusion, all tested methods can be used for determining the bacterial load in dust samples, but none of the methods was superior to the others. The results obtained with these methods represent different aspects of bacterial exposure and therefore the results are not expected to be identical with each other.

Graphical abstract: Determination of bacterial load in house dust using qPCR, chemical markers and culture

Back to tab navigation
Please wait while Download options loads

Publication details

The article was received on 01 Sep 2009, accepted on 27 Nov 2009 and first published on 20 Jan 2010


Article type: Paper
DOI: 10.1039/B917937B
Citation: J. Environ. Monit., 2010,12, 759-768
  •   Request permissions

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

    P. M. Kärkkäinen, M. Valkonen, A. Hyvärinen, A. Nevalainen and H. Rintala, J. Environ. Monit., 2010, 12, 759
    DOI: 10.1039/B917937B

Search articles by author