title: Comparative evaluation of vacuum-based surface sampling methods for collection of Bacillus spores.
abstract: In this study, four commonly-used sampling devices (vacuum socks, 37 mm 0.8 μm mixed cellulose ester (MCE) filter cassettes, 37 mm 0.3 μm polytetrafluoroethylene (PTFE) filter cassettes, and 3M™ forensic filters) were comparatively evaluated for their ability to recover surface-associated spores. Aerosolized spores (~10(5)CFUcm(-2)) of a Bacillus anthracis surrogate were allowed to settle onto three material types (concrete, carpet, and upholstery). Ten replicate samples were collected using each vacuum method, from each material type. Stainless steel surfaces, inoculated simultaneously with test materials, were sampled with pre-moistened wipes. Wipe recoveries were utilized to normalize vacuum-based recoveries across trials. Recovery (CFUcm(-2)) and relative recovery (vacuum recovery/wipe recovery) were determined for each method and material type. Recoveries and relative recoveries ranged from 3.8 × 10(3) to 7.4 × 10(4)CFUcm(-2) and 0.035 to 1.242, respectively. ANOVA results indicated that the 37 mm MCE method exhibited higher relative recoveries than the other methods when used for sampling concrete or upholstery. While the vacuum sock resulted in the highest relative recoveries on carpet, no statistically significant difference was detected. The results of this study may be used to guide selection of sampling approaches following biological contamination incidents.
authors.affiliation: US Environmental Protection Agency, National Homeland Security Research Center, Research Triangle Park, NC, USA. Electronic address: calfee.worth@epa.gov.
authors.forename: M Worth
authors.initials: MW
authors.lastname: Calfee
authors.forename: Laura J
authors.initials: LJ
authors.lastname: Rose
authors.forename: Stephen
authors.initials: S
authors.lastname: Morse
authors.forename: Dino
authors.initials: D
authors.lastname: Mattorano
authors.forename: Matt
authors.initials: M
authors.lastname: Clayton
authors.forename: Abderrahmane
authors.initials: A
authors.lastname: Touati
authors.forename: Nicole
authors.initials: N
authors.lastname: Griffin-Gatchalian
authors.forename: Christina
authors.initials: C
authors.lastname: Slone
authors.forename: Neal
authors.initials: N
authors.lastname: McSweeney
mesh_terms: D001408:Bacillus anthracis / Q000302:isolation & purification*; D001431:Bacteriological Techniques / Q000379:methods*; D015169:Colony Count, Microbial; D004783:Environmental Microbiology; D013048:Specimen Handling / Q000379:methods*; D013171:Spores, Bacterial / Q000302:isolation & purification*; D014618:Vacuum
keywords: Anthrax; Bacillus anthracis; Bioterrorism agent; Surface sampling; Vacuum sampling