B. anthracis genome sequence: Questions and Answers
Q. How can I access the data concerning the B. anthracis
genome?
The publication regarding the genome sequence of Bacillus anthracis
is:
Nature Vol. 423 pg 81-86 on
May 1, 2003.
The genome sequence can be accessed at the GenBank database under GenBank Accession Number AE016879.
The comparative genomic hybridization data can be accessed at the
National Center for Biotechnology Information Gene Omnibus Expression site under the data series
GSE341.
The underlying sequence can be accessed using the NCBI Trace Archive
.
Q. Have our results shed any new light on how and why anthrax
is such a virulent pathogen?
Many of the core virulence factors of B. anthracis have
been identified over time and most of them are encoded on the plasmids,
ie lethal toxin, and capsule. We have identified a number of genes
and proteins that may play accessory roles in virulence, such as
genes that allow increased survival in the human macrophage including
catalases and dismutases that mitigate damage by free-oxygen radicals,
an increased number of iron acquisition complexes (a common feature
of human pathogens), hemolysins and phospholipases. All of these
factors could play a role in the virulence of this organism by allowing
the evasion of the human immune system and survival in the human
host resulting in an increased moratility.
Q. What do the comparisons with the Bacillus cereus
and Bacillus thuringiensis genomes reveal, with respect
to virulence?
Comparison of the genomes of this group of pathogens is interesting
as it gives some insight into the development of a pathogen in a
specific host. Much of the core chromosomally encoded metabolic
pathways as well as some virulence factors are similar among these
organisms. Thus the genes that are responsible for the host specific
pathogenicity can be examined, such as the macrophage evasion genes
in B. anthracis, the insect-specific toxin in B. thuringiensis and
the toxins in B. cereus.
Q. Do the results offer any leads into improved treatments
or vaccines for
anthrax?
We have identified a number of potential targets for improved treatment
by identification of potential surface proteins that are unique
to B. anthracis as well as those conserved among this group
of pathogens. Additionally, the identification of potential unique
intracellular targets that currently show no similarity to other
proteins allows for the rational design of drugs to unique pathways
of these pathogens. Obviously, much more work will have to go into
the characterization of these potential therapeutic targets.
Q. How might your findings contribute to the search for
an improved treatment or vaccine? What research pathways should
you or others consider right now?
There are a significant number of genes that have no similar protein
in the database or are similar to other proteins in the database
that have no function. The concept that these genes and proteins
are conserved among this group of pathogens as well as other pathogens
in general indicates that there is most likely a function for them.
Identifying the function of this group of proteins in these organisms
will most likely be the best route of identification of novel targets
for drugs and vaccines.
Q. What are the differences between the previous B.
anthracis genome (Florida) sequenced by TIGR and the present
(B. anthracis Ames) isolate sequenced?
Both genome are Ames strains. B. anthracis Ames sequence
release here is of high quality and represent the complete high
quality (13x coverage) sequence of the chromosome without plasmids.
On the other hand B. anthracis Florida isolate was sequenced
to 8x coverage for the rapid identification of polymorphism between
the genomes (Read
et. al 2001) Additionally, B. anthracis Florida was
isolated form a patient and was sequenced in relation to the Federal
Bureau of Investigation's enquiry into the 2001 bioterror attacks,
whereas B. anthracis Ames is a laboratory strain that is
not virulent. For additional information on the TIGR B. anthracis
Florida sequencing click here
Q. What if my question has not been answered on this page?
Please contact us with further B. anthracis related questions
or queries by emailing us.
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