Review of methods to collect settled dust and isolate culturable microorganisms
Macher, J. M.
2001 Indoor Air, 11(2): 99
Macher, J. M., (2001), "Review of methods to collect settled dust and isolate culturable microorganisms", Indoor Air, 11(2): 99.
Abstract:
Examination of settled dust is often included in investigations of indoor environments to identify the types and concentrations of particles to which building occupants may be exposed. Fungi and bacteria are among the many components in dust that have been studied. Isolation by culture is an established method that is used widely to quantify and identify microorganisms in environmental samples. However, no standard procedures for culturing fungi or bacteria from dust have been adopted widely to ensure the validity of comparing findings from different studies. This paper reviews methods various researchers have used to study surface particles and to isolate culturable microorganisms from dust. Factors that were found to differ included the method of sample collection, the ways dust was prepared for inoculation onto growth media, and the culture media chosen for specific categories of agents. The need for reference methods in environmental microbiology for use in the assessment of indoor environmental quality is discussed.
Practical Implications
A literature review revealed differences in the methods investigators use to collect settled dust from residential, office, and commercial buildings and to isolate culturable microorganisms from dust. No professional group has recommended detailed methods for the collection and processing of settled dust to measure the concentration of mesothermic and thermophilic bacteria, hydrophilic and xerophilic fungi, and specific genera and species. Consequently, investigators adopt procedures from the published literature or develop their own methods. Unless procedures have been demonstrated to give comparable results, the validity of comparisons across studies is questionable. Consensus on reference methods for the collection of settled dust and the isolation of culturable microorganisms from indoor environments would provide better assurance that results within and between groups are consistent and reliable and that observed differences are not artifacts of the analytical methods.