title: Environmental Persistence of Bacillus anthracis and Bacillus subtilis Spores.
abstract: There is a lack of data for how the viability of biological agents may degrade over time in different environments. In this study, experiments were conducted to determine the persistence of Bacillus anthracis and Bacillus subtilis spores on outdoor materials with and without exposure to simulated sunlight, using ultraviolet (UV)-A/B radiation. Spores were inoculated onto glass, wood, concrete, and topsoil and recovered after periods of 2, 14, 28, and 56 days. Recovery and inactivation kinetics for the two species were assessed for each surface material and UV exposure condition. Results suggest that with exposure to UV, decay of spore viability for both Bacillus species occurs in two phases, with an initial rapid decay, followed by a slower inactivation period. The exception was with topsoil, in which there was minimal loss of spore viability in soil over 56 days, with or without UV exposure. The greatest loss in viable spore recovery occurred on glass with UV exposure, with nearly a four log10 reduction after just two days. In most cases, B. subtilis had a slower rate of decay than B. anthracis, although less B. subtilis was recovered initially.
authors.affiliation: United States Environmental Protection Agency, Office of Research and Development, National Homeland Security Research Center, Research Triangle Park, North Carolina, United States of America.
authors.forename: Joseph P
authors.initials: JP
authors.lastname: Wood
authors.affiliation: Oak Ridge Institute for Science and Education, Research Triangle Park, NC, United States of America.
authors.forename: Kathryn M
authors.initials: KM
authors.lastname: Meyer
authors.affiliation: Battelle Memorial Institute, Columbus, Ohio, United States of America.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Kelly
authors.affiliation: Battelle Memorial Institute, Columbus, Ohio, United States of America.
authors.forename: Young W
authors.initials: YW
authors.lastname: Choi
authors.affiliation: Battelle Memorial Institute, Columbus, Ohio, United States of America.
authors.forename: James V
authors.initials: JV
authors.lastname: Rogers
authors.affiliation: Battelle Memorial Institute, Columbus, Ohio, United States of America.
authors.forename: Karen B
authors.initials: KB
authors.lastname: Riggs
authors.affiliation: Battelle Memorial Institute, Columbus, Ohio, United States of America.
authors.forename: Zachary J
authors.initials: ZJ
authors.lastname: Willenberg
mesh_terms: D001408:Bacillus anthracis / Q000502:physiology* / Q000528:radiation effects*; D001412:Bacillus subtilis / Q000502:physiology* / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D007700:Kinetics; D050296:Microbial Viability / Q000528:radiation effects; D016062:Porosity; D013045:Species Specificity; D013171:Spores, Bacterial / Q000502:physiology / Q000528:radiation effects; D014466:Ultraviolet Rays