title: Environmental influences on the seasonal distribution of Vibrio parahaemolyticus in the Pacific Northwest of the USA.
abstract: Populations of Vibrio parahaemolyticus in the environment can be influenced by numerous factors. We assessed the correlation of total (tl+) and potentially virulent (tdh+) V. parahaemolyticus in water with three harmful algal bloom (HAB) genera (Pseudo-nitzschia, Alexandrium and Dinophysis), the abundance of diatoms and dinoflagellates, chlorophyll-a and temperature, salinity and macronutrients at five sites in Washington State from 2008-2009. The variability in V. parahaemolyticus density was explained predominantly by strong seasonal trends where maximum densities occurred in June, 2 months prior to the highest seasonal water temperature. In spite of large geographic differences in temperature, salinity and nutrients, there was little evidence of corresponding differences in V. parahaemolyticus density. In addition, there was no evident relationship between V. parahaemolyticus and indices of HAB genera, perhaps due to a lack of significant HAB events during the sampling period. The only nutrient significantly associated with V. parahaemolyticus density after accounting for the seasonal trend was silicate. This negative relationship may be caused by a shift in cell wall structure for some diatom species to a chitinous substrate preferred by V. parahaemolyticus. Results from our study differ from those in other regions corroborating previous findings that environmental factors that trigger vibrio and HAB events may differ depending on geographic locations. Therefore caution should be used when applying results from one region to another.
authors.affiliation: Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 2725 Montlake Boulevard E, Seattle, WA 98112, USA rohinee.paranjpye@noaa.gov.
authors.forename: Rohinee N
authors.initials: RN
authors.lastname: Paranjpye
authors.affiliation: Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 2725 Montlake Boulevard E, Seattle, WA 98112, USA.
authors.forename: William B
authors.initials: WB
authors.lastname: Nilsson
authors.affiliation: Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 2725 Montlake Boulevard E, Seattle, WA 98112, USA.
authors.forename: Martin
authors.initials: M
authors.lastname: Liermann
authors.affiliation: US Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Laboratory, Research Triangle Park, NC 27709, USA.
authors.forename: Elizabeth D
authors.initials: ED
authors.lastname: Hilborn
authors.affiliation: US Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Laboratory, Research Triangle Park, NC 27709, USA.
authors.forename: Barbara J
authors.initials: BJ
authors.lastname: George
authors.affiliation: Biostatistics and Bioinformatics Research Center, Samuel Oschin Comprehensive Cancer Institute, Cedars Sinai Medical Center, Los Angeles, CA, USA.
authors.forename: Quanlin
authors.initials: Q
authors.lastname: Li
authors.affiliation: Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 2725 Montlake Boulevard E, Seattle, WA 98112, USA.
authors.forename: Brian D
authors.initials: BD
authors.lastname: Bill
authors.affiliation: Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 2725 Montlake Boulevard E, Seattle, WA 98112, USA.
authors.forename: Vera L
authors.initials: VL
authors.lastname: Trainer
authors.affiliation: Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 2725 Montlake Boulevard E, Seattle, WA 98112, USA.
authors.forename: Mark S
authors.initials: MS
authors.lastname: Strom
authors.affiliation: Hollings Marine Laboratory, National Ocean Service, National Oceanic and Atmospheric Administration, 331 Fort Johnson Road, Charleston, SC 29412, USA.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Sandifer
mesh_terms: D000818:Animals; D017377:Diatoms / Q000302:isolation & purification / Q000382:microbiology; D004141:Dinoflagellida / Q000737:chemistry / Q000382:microbiology; D057097:Harmful Algal Bloom; D006801:Humans; D007608:Kainic Acid / Q000031:analogs & derivatives / Q000032:analysis; D010125:Ostreidae / Q000382:microbiology; D010839:Phytoplankton / Q000302:isolation & purification* / Q000472:pathogenicity; D054712:Salinity; D012621:Seasons; D012623:Seawater / Q000737:chemistry / Q000382:microbiology*; D017640:Silicates / Q000032:analysis / Q000737:chemistry; D013696:Temperature; D014735:Vibrio Infections / Q000453:epidemiology*; D014736:Vibrio parahaemolyticus / Q000302:isolation & purification* / Q000472:pathogenicity; D014861:Washington / Q000453:epidemiology; D014871:Water Microbiology
chemical_list: D017640:Silicates; C012301:domoic acid; D007608:Kainic Acid
keywords: HABS; Vibrio; microbial ecology; pathogens