Application of water-soluble nanofilters for collection of airborne Mycobacterium tuberculosis DNA in hospital wards

A simple inexpensive technique for collection of airborne biomarkers of nosocomial infections is described. Biomarkers were collected on water-soluble electrospun nanofilters attached to a household vacuum cleaner from 6-10 m3 of air in 10-15 min within several wards of a tuberculosis clinic. Filters were then dissolved in water and tested for the presence of the IS6110 and regX3 genes of Mycobacterium tuberculosis (MTB) using real-time polymerase chain reaction. It was demonstrated that trace amounts of airborne MTB DNA (>3 gene copies/m3) were always present in the air and on the surfaces in the wards occupied with tuberculosis patients having positive smear tests.