Growth response of Vibrio cholerae and other Vibrio spp. to cyanobacterial dissolved organic matter and temperature in brackish water

Abstract

Environmental control of growth and persistence of vibrios in aquatic environments is poorly understood even though members of the genus Vibrio are globally important pathogens. To study how algal-derived organic matter and temperature influenced the abundance of different Vibrio spp., Baltic Sea microcosms inoculated with Vibrio cholerae, Vibrio vulnificus, Vibrio parahaemolyticus, Vibrio alginolyticus and native bacterioplankton, were exposed to different temperatures (12-25 degrees C) and amended with dissolved organic matter from Nodularia spumigena (0-4.2 mg C L(-1)). Vibrio abundance was monitored by culture-dependent and molecular methods. Results suggested that Vibrio populations entered a viable but nonculturable state during the incubations. Abundance of Vibrio spp. and total bacterioplankton were orders of magnitude higher in microcosms amended with organic matter compared with reference microcosms. Vibrio cholerae abundances ranged from 0.9 to 1.9 x 10(5) cells mL(-1) in treatments amended with 4.2 mg C L(-1). Vibrio cholerae abundance relative to total bacterioplankton and other Vibrio spp. also increased >10-fold. In addition, V. vulnificus abundance increased in mesocosms with the highest organic matter addition (0.9-1.8 x 10(4) cells mL(-1)). Temperature alone did not significantly affect abundances of total bacterioplankton, total Vibrio spp. or individual Vibrio populations. By contrast, cyanobacterial-derived organic matter represented an important factor regulating growth and abundance of V. cholerae and V. vulnificus in brackish waters.

Community-Level and Species-Specific Associations between Phytoplankton and Particle-Associated Vibrio Species in Delaware's Inland Bays

“…In previous studies, environmental factors such as temperature (4,48,(50)(51)(52) and salinity (51)(52)(53)(54) explained the majority of variance in total (free-living and particle-associated) Vibrio abundance compared to other physical parameters (reviewed in references 55 and 56). Temperature and salinity can also influence the formation of Vibrio biofilms in estuarine environments (55,57).…”

“…(44), while other bacterial species have been shown to have algicidal effects on phytoplankton (45)(46)(47). Furthermore, survival, growth, and abundance of particle-attached bacterioplankton, such as Vibrio, may be positively affected by the release of bioavailable dissolved organic matter (DOM) from phytoplankton (13,48). Increased growth of pathogenic members of the bacterioplankton due to organic matter from phytoplankton may have serious implications for human and ecosystem health.…”

Temporal and Spatial Variability in Culturable Pathogenic Vibrio spp. in Lake Pontchartrain, Louisiana, following Hurricanes Katrina and Rita

“…Phyto-and zooplankton can promote vibrio growth by serving as a source of organic matter (18,48) and providing surfaces for bacterial attachment (30,73). A study of phytoplankton in Lake Pontchartrain following Hurricanes Katrina and Rita did reveal gradients in chlorophyll a and other photosynthetic pigments over large spatial scales (56), but we observed no correlation between the concentrations of any of the photosynthetic pigments and vibrio abundance for the one date and among the stations where we had coincident data (data not shown).…”

Emerging health issues of cyanobacterial blooms

“…associated to cyanobacteria in Baltic Sea, were positive for at least one of several factors of virulence. Blooms of the toxic cyanobacterium Nodularia spumigena are an ideal growing medium for several pathogenic microorganisms, including the deadly serotypes of Vibrio cholerae O1 and O139, and V. vulnificus [112], exposing people also during bathing activities. Decaying blooms of Microcystis aeruginosa can increase the concentration of Vibrio spp.…”