Abstract
Background Many species of coastal Vibrio spp. bacteria can infect humans, representing an emerging health threat linked to increasing seawater temperatures. Vibrio interactions with the planktonic community impact coastal ecology and human infection potential. In particular, interactions with eukaryotic and photosynthetic organism may provide attachment substrate and critical nutrients (e.g. chitin, phytoplankton exudates) that facilitate the persistence, diversification, and spread of pathogenic Vibrio spp. Vibrio interactions with these organisms in an environmental context are, however, poorly understood.Results We quantified pathogenic Vibrio species, including V. cholerae, V. parahaemolyticus, and V. vulnificus, and two virulence-associated genes for one year at five coastal sites in Southern California and used metabarcoding to profile associated prokaryotic and eukaryotic communities, including vibrio-specific communities. These Vibrio spp. reached high abundances, particularly during Summer months, and inhabited distinct species-specific environmental niches driven by temperature and salinity. Associated bacterial and eukaryotic taxa identified at fine-scale taxonomic resolution revealed genus and species-level relationships. For example, common Thalassiosira genera diatoms capable of exuding chitin were positively associated with V. cholerae and V. vulnificus in a species-specific manner, while the most abundant eukaryotic genus, the diatom Chaetoceros, was positively associated with V. parahaemolyticus. Associations were often linked to shared environmental preferences, and several copepod genera were linked to low-salinity environmental conditions and abundant V. cholerae and V. vulnificus.Conclusions This study clarifies ecological relationships between pathogenic Vibrio spp. and the planktonic community, elucidating new functionally relevant associations, establishing a workflow for examining environmental pathogen microbiomes, and highlighting prospective model systems for future mechanistic studies.
Coastal planktonic community unaffected by Boreal hydropower complex in Québec, Canada
