Jellyfish Gene Helps Scientists
Sleuth E. coli
By Marcia Wood
March 29, 2000
To discover the secrets of how a food
poisoning bacterium spreads, Agricultural
Research Service scientists are using a jellyfish gene in their laboratory
In nature, the gene cues the jellyfish to make a bright green fluorescent
protein. In the laboratory, ARS microbiologist Marian R. Wachtel has inserted
the gene into strains of the foodborne pathogen Escherichia coli
O157:H7. The fluorescence acts as a readily detectable marker.
Viewed with ultraviolet light, the E. coli fluoresces a bright green.
The fluorescence makes it easier for Wachtel to spy on E. coli bacteria
that she has used to artificially infect leaves of fresh lettuce for her
Outbreaks of E. coli O157:H7 linked to contaminated lettuce are
infrequent. But ARS scientists like Wachtel want to help ensure that the
popular vegetable remains safe to eat. Wachtel says eating fresh lettuce,
properly washed, should pose no significant health hazard.
Wachtel's fluorescence based assay enables researchers to quickly detect the
presence and quantity of the fluorescing E. coli within lettuce leaves.
That's how the assay can help scientists test the effectiveness of new tactics
designed to keep E. coli out of this veggie, and other foods, as well.
Though the idea of moving the fluorescence gene from Aequorea
victoria jellyfish into other organisms isn't new, Wachtel is among the
first to make a detailed study of plant tissue with fluorescent E. coli
Wachtel is with the
ARS Food Safety and
Health Research Unit at Albany, Calif. ARS is the
U. S. Department of Agriculture's chief
For details, see an article in the agency's Agricultural Research magazine.
Scientific contact: Marian R.
Wachtel, ARS Food Safety and Health Research Unit, Albany, Calif., phone
(510) 559-5957, fax (510) 559-5948, firstname.lastname@example.org.