story to find out more.
Genomic analysis has revealed new information
about the nature of Listeria monocytogenes. Above, molecular biologist
Darrell Bayles (standing) and microbiologist Yanhong Liu analyze microarray
data from a microarray scanner. Image courtesy
Paul Pierlott, ARS.
Unraveling the Listeria Genome
October 24, 2006
If knowledge is power, researchers
are gaining the upper hand over Listeria monocytogenes, a pathogen that
Scientists at the Agricultural Research Service (ARS) Eastern Regional Research Center (ERRC)
in Wyndmoor, Pa., and The Institute for Genomic
Research in Rockville, Md., have sequenced the genomes of four L.
monocytogenes strains, representing three serotypesan important step
towards developing a management strategy for this deadly bacterium.
Researchers in the ERRC
Food Safety Research Unit and their colleagues have sequenced and analyzed
these genomes, according to research leader
With ERRC molecular biologist
Bayles and research associate
Uhlich, Luchansky found that Listeria strains, in addition to
sharing serotype-specific and strain-specific genome sequences, have largely
similar genetic content and organization.
The scientists also confirmed that Listeria strains have 15 genes in
the Crp/Fnr regulatory protein family, which is considerably more than most
bacteria. Luchansky and his colleagues are investigating whether these
sequences influence the bacteriums virulence or persistence.
The scientists have identified specific genes that warrant further
investigation. Theyre also pursuing proteomics and genomics studies. This
involves identifying phenotypes, or observable characteristics, understanding
the relationships between different strains and investigating different control
Knowing more about L. monocytogenes will help regulatory agencies and
members of the food industry make informed decisions about control strategies
and safety standards. In addition, uncovering the genetic information that
defines Listerias characteristics and behavior will help
scientists understand the bacteriums virulence and persistence.
This research will be useful in preventing Listeria contamination and
in reducing disease. It could also aid decisions about managing the threat of
more about this and other ARS food safety research in the October 2006
issue of Agricultural Research magazine.
ARS is the U.S. Department of
Agriculture's chief scientific research agency.