State Water Resources Research Institute Program
Project ID: 2010DE188B
Title: The Prevalence of Pathogenic Bacteria in Delmarva Waters from a Virus Point of View
Project Type: Research
Start Date: 6/01/2010
End Date: 2/28/2011
Congressional District: At large
Focus Categories: Ecology, Surface Water, Water Use
Keywords: viruses, bacteria, human health, surface waters
Principal Investigators: Wommack, Eric; Hyatt, Mara
Federal Funds: $ 1,500
Non-Federal Matching Funds: $ 3,000
Abstract: Viruses are ubiquitous and diverse in all aquatic environments including those in Delaware. In the nearby Chesapeake Bay, they range in abundance from 2.6 to 140 million per milliliter. Some bacteriophages are known to alter the phenotype of their hosts while in the lysogenic phase. While genes involved in the lytic cycle are not transcribed, other sections of the prophage can be active that could affect the antigens on the cell's surface or impart virulence factors. One mechanism of pathogenicity acquired this way is the production of proteins called exotoxins, which are secreted by the host cell. For example, CTXΦ produces cholera toxin through lysogenic conversion of previously non-toxigenic Vibrio cholera and Vibrio mimicus .
The prevalence of viruses carrying virulence genes within aquatic environments is largely unknown with the exception of a few studies that found exotoxin genes in environmental DNA and viral DNA isolated from several sites in the San Diego area. Currently, no study has examined the prevalence of exotoxin genes within any aquatic environments of the Delmarva Peninsula. Investigating the prevalence of these exotoxin genes in viruses and bacteria from local water samples will help elucidate the role of viruses in determining the possible load of pathogenic bacteria within Delaware aquatic environments. The major goal of this research is to characterize the prevalence and diversity of viral and bacterial samples, and the presence of exotoxins, in a range of fresh and coastal surface waters from the Mid-Atlantic USA.
Progress/Completion Report, 2010, PDF