title: Prevalence of toxin-producing Clostridium botulinum associated with the macroalga Cladophora in three Great Lakes: growth and management.
abstract: The reemergence of avian botulism caused by Clostridium botulinum type E has been observed across the Great Lakes in recent years. Evidence suggests an association between the nuisance algae, Cladophora spp., and C. botulinum in nearshore areas of the Great Lakes. However, the nature of the association between Cladophora and C. botulinum is not fully understood due, in part, to the complex food web interactions in this disease etiology. In this study, we extensively evaluated their association by quantitatively examining population size and serotypes of C. botulinum in algal mats collected from wide geographic areas in lakes Michigan, Ontario, and Erie in 2011-2012 and comparing them with frequencies in other matrices such as sand and water. A high prevalence (96%) of C. botulinum type E was observed in Cladophora mats collected from shorelines of the Great Lakes in 2012. Among the algae samples containing detectable C. botulinum, the population size of C. Botulinum type E was 10(0)-10(4) MPN/g dried algae, which was much greater (up to 10(3) fold) than that found in sand or the water column, indicating that Cladophora mats are sources of this pathogen. Mouse toxinantitoxin bioassays confirmed that the putative C. botulinum belonged to the type E serotype. Steam treatment was effective in reducing or eliminating C. botulinum type E viable cells in Cladophora mats, thereby breaking the potential transmission route of toxin up to the food chain. Consequently, our data suggest that steam treatment incorporated with a beach cleaning machine may be an effective treatment of Cladophora-borne C. botulinum and may reduce bird mortality and human health risks.
authors.affiliation: BioTechnology Institute, University of Minnesota, St. Paul, MN 55108, United States.
authors.forename: Chan
authors.initials: C
authors.lastname: Lan Chun
authors.affiliation: BioTechnology Institute, University of Minnesota, St. Paul, MN 55108, United States.
authors.forename: Chase I
authors.initials: CI
authors.lastname: Kahn
authors.affiliation: BioTechnology Institute, University of Minnesota, St. Paul, MN 55108, United States.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Borchert
authors.affiliation: Lake Michigan Ecological Research Station, Great Lakes Science Center, U.S. Geological Survey, Porter, IN 46304, United States.
authors.forename: Muruleedhara N
authors.initials: MN
authors.lastname: Byappanahalli
authors.affiliation: Lake Michigan Ecological Research Station, Great Lakes Science Center, U.S. Geological Survey, Porter, IN 46304, United States.
authors.forename: Richard L
authors.initials: RL
authors.lastname: Whitman
authors.affiliation: Department of Chemistry, Physics and Astronomy, Indiana University Northwest, Gary, IN 46408, United States.
authors.forename: Julie
authors.initials: J
authors.lastname: Peller
authors.affiliation: Department of Bacteriology, University of Wisconsin, Madison, WI 53706, United States.
authors.forename: Christina
authors.initials: C
authors.lastname: Pier
authors.affiliation: Department of Bacteriology, University of Wisconsin, Madison, WI 53706, United States.
authors.forename: Guangyun
authors.initials: G
authors.lastname: Lin
authors.affiliation: Department of Bacteriology, University of Wisconsin, Madison, WI 53706, United States.
authors.forename: Eric A
authors.initials: EA
authors.lastname: Johnson
authors.affiliation: BioTechnology Institute, University of Minnesota, St. Paul, MN 55108, United States; Department of Soil, Water, and Climate, University of Minnesota, St. Paul, MN 55108, United States. Electronic address: sadowsky@umn.edu.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Sadowsky
mesh_terms: D000460:Chlorophyta / Q000382:microbiology*; D003014:Clostridium botulinum / Q000254:growth & development*; D004784:Environmental Monitoring; D020387:Food Chain; D060106:Lakes; D008824:Michigan; D009864:Ontario; D014871:Water Microbiology; D014876:Water Pollution / Q000032:analysis / Q000706:statistics & numerical data
keywords: Avian botulism; Cladophora; Clostridium botulinum; Great Lakes; Management practices; Neurotoxin genes