Nigro, O. D., University of Hawaii at Manoa, Honolulu, USA, onigro@hawaii.edu
Vithanage, G. ., University of Hawaii at Manoa, Honolulu, USA, gayatri@hawaii.edu
Fujioka, R. S., University of Hawaii at Manoa, Honolulu, USA, roger@hawaii.edu
Steward, G. F., University of Hawaii at Manoa, Honolulu, USA, grieg@hawaii.edu

WHERE STREAMS COMMINGLE WITH THE SEA: ENVIRONMENTAL CONTROLS ON PATHOGENIC VIBRIOS IN COASTAL WATERS

Human pathogens in the genus Vibrio (e.g. V. cholerae, parahaemolyticus, and vulnificus) thrive in warm brackish coastal waters. Because these pathogens are natural estuarine flora, rather than being simply washed into the coastal zone as pollutants, understanding the infection risk that they pose is complicated by myriad ecological interactions. Temperature and salinity tolerance appear to be major influences on the autecology of pathogenic Vibrio spp., but their relative importance is context dependent. In Lake Pontchartrain, Lousiana, for example, we found that V. vulnificus abundance was strongly correlated with lake temperature over a seasonal cycle. In coastal waters of Hawaii, on the other hand, variability in abundance was best explained by changes in salinity. Multiple strains of the same vibrio species were frequently isolated from a given sample, but what controls the balance of virulent and avirulent strains in the environment is not known. We propose that bacteriophages, which infect selectively, mediate horizontal gene transfer, and contribute to virulence through lysogenic conversion, will be key to better understanding the synecology, evolution, and changing virulence potential of pathogenic Vibrios in the environment.

Oral presentation

Presentation is given by student: No
Session #:120
Date: 03-03-2008
Time: 08:45