Scientists believe that dog feces left at Dog Beach in Ocean Beach represents a health threat to humans. In general, this is a concern since bacteria capable of causing human disease can be found in animal feces.
With the hypothesis that a potential source of fecal bacteria in recreational waters is the canine feces left behind by owners who do not clean up after their pets, scientists recently screened the DNA that was isolated from canine feces. 20 samples were collected from the shoreline at Dog Beach, processed and screened.
In scientific terms, the screening studied DNA isolated from canine feces for the bacteriophage-encoded stx gene normally found in the virulent strains of the fecal bacterium Escherichia coli.
And the conclusions:
The bacteriophage-encoded stx gene was found in multiple species of bacteria cultivated from canine fecal samples gathered at the shoreline of the Dog Beach area of Ocean Beach in San Diego, California.
The canine fecal bacteria carrying the stx gene were not the typical E. coli host and were instead identified through phylogenetic analyses as Enterococcus.
This suggests a large degree of horizontal gene transfer of exotoxin genes in recreational waters.
See the full report at 7th Space
For background on phages, go here.