Agency Sequences Genome of Food-Borne Pathogen
By Marty Clark
June 7, 2001
WASHINGTON, June 7, 2001--The
U.S. Department of Agriculture today
announced that researchers now have important new information about the genetic
makeup of Listeria, a bacterium that is known to cause serious
food-borne illness. This new information will help in the research of ways to
reduce the incidence of food contamination and illness from this bacterium.
The project is a collaboration between USDAs
Agricultural Research Service and The
Institute for Genomic Research (TIGR) in
Rockville, Md. Similar to efforts to understand the structure of the human
genome, the researchers began examining the complete genetic makeup of a
Listeria monocytogenes serotype 4b strain in January. The researchers
have now finished the initial phase, in which individual fragments of the
genome have been examined. The next step is to assemble these fragments into a
complete genomic map of the bacterium.
A serotype 4b strain of Listeria monocytogenes was selected for the
project because most food-borne listeriosis outbreaks, and 50 percent of
sporadic cases, are caused by strains of this serotype.
The Listeria research is an example of ongoing USDA efforts to
improve the safety of the U.S. food supply. Sequencing the Listeria
genome will help researchers better understand how this bacterium persists in
animals, in and on foods and in food processing plants, and affects people.
This information is critical for regulatory agencies such as USDAs
Food Safety Inspection Service
for creating and implementing regulations for safe processing and handling of
USDA continues to make efforts to prevent contamination by Listeria,
and other harmful pathogens, in ready-to-eat meat and poultry products.
Recently, USDA proposed food safety measures applicable to all ready-to-eat and
all partially heat-treated meat and poultry products, as well as environmental
testing requirements intended to reduce the incidence of Listeria
monocytogenes in processed meat and poultry products. The comment period
has been extended until June 28.
In May, USDA's Food Safety and Inspection Service held a one-day technical
conference and two days of public meetings to discuss scientific research and
new technologies, and to gather public information and comments specific to
proposed regulatory requirements for ready-to-eat meat and poultry products.
Listeria is widespread in the environment and is associated with some
ready-to-eat food products such as hot dogs, lunch meats, smoked fish and
certain types of soft cheeses. Each year, there are about 2,500 food-borne
cases of listeriosis and about 500 deaths.
Scientists will be able to access the genetic sequence information through
the TIGR website at http://www.TIGR.org after
June 8. For additional food safety information, visit USDA's website at:
Scientific contact: John Luchansky,
ARS Microbial Food Safety Research
Unit, Wyndmoor, Pa., phone (215) 233-6620, fax (215) 233-6581,