Abstract
To determine if a storm event (i.e., high winds, large volumes of precipitation) could alter concentrations of Vibrio vulnificus and V. parahaemolyticus in aquacultured oysters (Crassostrea virginica) and associated surface water and sediment, this study followed a sampling timeline before and after Hurricane Irene impacted the Chesapeake Bay estuary in late August 2011. Aquacultured oysters were sampled from two levels in the water column: surface (0.3 m) and near-bottom (just above the sediment). Concentrations of each Vibrio spp. and associated virulence genes were measured in oysters with a combination of real-time PCR and most probable number (MPN) enrichment methods, and in sediment and surface water with real-time PCR. While concentration shifts of each Vibrio species were apparent post-storm, statistical tests indicated no significant change in concentration for either Vibrio species by location (surface or near bottom oysters) or date sampled (oyster tissue, surface water, and sediment concentrations). V. vulnificus in oyster tissue was correlated with total suspended solids (r = 0.41, P = 0.04), and V. vulnificus in sediment was correlated with secchi depth (r = -0.93, P <0.01), salinity (r = -0.46, P = 0.02), tidal height (r = -0.45, P = 0.03), and surface water V. vulnificus (r = 0.98, P <0.01). V. parahaemolyticus in oyster tissue did not correlate with environmental measurements, but V. parahaemolyticus in sediment and surface water correlated with several measurements including secchi depth [r = -0.48, P = 0.02 (sediment); r = -0.97, P <0.01 (surface water)] and tidal height [r = -0.96, P <0.01 (sediment), r = -0.59, P <0.01 (surface water)]. The concentrations of Vibrio spp. were higher in oysters relative to other studies (average V. vulnificus 4 × 105 MPN g-1, V. parahaemolyticus 1 × 105 MPN g-1), and virulence-associated genes were detected in most oyster samples. This study provides a first estimate of storm-related Vibrio density changes in oyster tissues, sediment, and surface water at an aquaculture facility in the Chesapeake Bay.
Highlights
Storm events are thought to be important mechanisms for the distribution of benthic Vibrio populations into the water column via resuspension of sediments associated with high winds, and flushing due to large volumes of precipitation (Randa et al, 2004; Fries et al, 2008; Wetz et al, 2008; Johnson et al, 2010)
This study provides a first estimate of storm-related Vibrio density changes in oyster tissues, sediment, and surface water at an aquaculture facility in the Chesapeake Bay
Frequent storm events in the Chesapeake Bay are associated with the summer season, a time when Vibrio vulnificus and V. parahaemolyticus, autochthonous bacteria known to cause human illness, are at their highest densities in surface waters (Wright et al, 1996; Parveen et al, 2008; Jacobs et al, 2010; Johnson et al, 2012)
Summary
Storm events are thought to be important mechanisms for the distribution of benthic Vibrio populations into the water column via resuspension of sediments associated with high winds, and flushing due to large volumes of precipitation (Randa et al, 2004; Fries et al, 2008; Wetz et al, 2008; Johnson et al, 2010). Frequent storm events in the Chesapeake Bay are associated with the summer season, a time when Vibrio vulnificus and V. parahaemolyticus, autochthonous bacteria known to cause human illness, are at their highest densities in surface waters (Wright et al, 1996; Parveen et al, 2008; Jacobs et al, 2010; Johnson et al, 2012). The frequency and intensity of storm events are predicted to escalate in response to global climate change (Goldenberg et al, 2001), with increases in peak wind intensities and near-storm precipitation (Meehl et al, 2007) likely impacting mid-Atlantic areas such as the Chesapeake Bay. In the Chesapeake Bay, a shallow, partially mixed estuary prone to tidal circulation (average depth 6.5 m), storm events may be expected to increase the overall Vibrio density in surface waters with relatively moderate wind speed and associated wave action. Based on the reported increases in storm-related Vibriosis in other areas of the United States, it is conceivable that storm-induced increases in Chesapeake Bay Vibrio density may be linked to future Vibriosis outbreaks
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
