title: Comparison of four commercial DNA extraction kits for the recovery of Bacillus spp. spore DNA from spiked powder samples.
abstract: Bacillus spp. include human pathogens such as Bacillus anthracis, the causative agent of anthrax and a biothreat agent. Bacillus spp. form spores that are physically highly resistant and may remain active over sample handling. We tested four commercial DNA extraction kits (QIAamp DNA Mini Kit, RTP Pathogen Kit, ZR Fungal/Bacterial DNA MiniPrep, and genesig Easy DNA/RNA Extraction kit) for sample inactivation and DNA recovery from two powders (icing sugar and potato flour) spiked with Bacillus thuringiensis spores. The DNA was analysed using a B. thuringiensis-specific real-time PCR assay. The detection limit was 3×10(1)CFU of spiked B. thuringiensis spores with the QIAamp DNA Mini, RTP Pathogen, and genesig Easy DNA/RNA Extraction kits, and 3×10(3)CFU with the ZR Fungal/Bacterial DNA MiniPrep kit. The results showed that manual extraction kits are effective and safe for fast and easy DNA extraction from powder samples even in field conditions. Adding a DNA filtration step to the extraction protocol ensures the removal of Bacillus spp. spores from DNA samples without affecting sensitivity.
authors.affiliation: Centres for Military Medicine and for Biological Threat Preparedness, Helsinki, Finland. Electronic address: markos.molsa@thl.fi.
authors.forename: Markos
authors.initials: M
authors.lastname: Mölsä
authors.affiliation: National Institute for Health and Welfare (THL), Helsinki, Finland.
authors.forename: Laura
authors.initials: L
authors.lastname: Kalin-Mänttäri
authors.affiliation: Centres for Military Medicine and for Biological Threat Preparedness, Helsinki, Finland.
authors.forename: Elina
authors.initials: E
authors.lastname: Tonteri
authors.affiliation: Centres for Military Medicine and for Biological Threat Preparedness, Helsinki, Finland.
authors.forename: Heidi
authors.initials: H
authors.lastname: Hemmilä
authors.affiliation: Centres for Military Medicine and for Biological Threat Preparedness, Helsinki, Finland.
authors.forename: Simo
authors.initials: S
authors.lastname: Nikkari
mesh_terms: D001413:Bacillus thuringiensis / Q000302:isolation & purification*; D004269:DNA, Bacterial / Q000302:isolation & purification*; D057230:Limit of Detection; D011208:Powders / Q000737:chemistry; D011933:Reagent Kits, Diagnostic; D013171:Spores, Bacterial / Q000302:isolation & purification*
chemical_list: D004269:DNA, Bacterial; D011208:Powders; D011933:Reagent Kits, Diagnostic
keywords: Bacillus anthracis; Bacillus spp.; Bacillus thuringiensis; Biothreat; DNA extraction; Powder; Spore; Spore inactivation