Anthrax virulence depends on the strain
strains of the bacterium that causes anthrax vary in their virulence,
and scientists are beginning to understand why. Six scientists from
Lawrence Livermore, Louisiana State University (LSU), and the U.S.
Army Medical Research Institute of Infectious Diseases published
findings in the Journal of Clinical Microbiology that could
lead to more effective vaccines against anthrax and better tools
for tracking the source of anthrax attacks. The papers lead
author was Pamala R. Coker, formerly of LSU and now at Livermore.
anthrax genome has one large chromosome and two small pieces of
DNA known as plasmids. The anthrax bacterium can contain not just
one set of plasmids but could have as many as 243 copies of one
plasmid and up to 32 copies of the other. That other plasmid, known
as pX02, is more capable of causing disease when more copies of
it are in a bacterial strain. In tests, the scientists found that
an anthrax strain with just one pX02 plasmid killed 25 percent of
the test animals, whereas a strain with 32 copies of the plasmid
killed all the animals.
suspect the pX02 plasmid carries genes that allow the anthrax bacterium
to develop an outer protein coat, and this coat shields it from
the immune system. The more pX02 copies, the thicker that coating,
and the more the anthrax bacterium can do its harm.
says the discovery may help forensics scientists track down the
country or laboratory that is the source of an anthrax strain used
as a biological weapon. The plasmid technique could reveal genetic
distinctions among varieties of anthrax, and that information could
be used to match an attack germ with its terrorist perpetrator.
She acknowledges that the research could also help others engineer
more deadly forms of anthrax. Therefore, the federal government
has urged scientists to carefully screen their work to prevent possible
harm to national security. Livermore put the scientific paper through
a careful security review before submitting it for publication.
Contact: Pamala Coker (925) 423-2817 (firstname.lastname@example.org).
Coming soon: more detection technologies
in Livermores newly created Radiation Detection Center are
investigating the application of more than a dozen advanced technologies
to detect clandestine nuclear materials or nuclear devices. Many
of the technologies were originally developed to search for black
holes and supernovas in space. Now, these technologies contribute
to fighting terrorism.
example, Ultra-Spec is an ultrahigh resolution gamma-ray spectrometer
that uses a detector at low temperatures to precisely measure gamma
rays from nuclear materials. It records the warming caused by a
single gamma ray hitting the detectors superconducting material
(usually tin). The temperature increase is measured to a precision
within 0.1 percent. Ultra-Spec users will be able to distinguish
emissions from different types of radioactive materials, thereby
allowing easier identification of the exact makeup of the materials.
example is the Gamma-Ray Imaging Spectrometer, one of five gamma-ray
imaging systems under development. It permits large-area pictures
to be taken of radioactivity emissions to determine the presence
and location of radioactive materials. The gamma-ray camera consists
of many gamma-ray sensors working together to take pictures, acting
like a digital camera for gamma rays. The spectrometer is the size
of a large-screen television and will provide a tenfold increase
in sensitivity for detecting nuclear materials or devices.
Contact: Simon Labov (925) 423-3818 (email@example.com).