Advances in molecular biology
have led to remarkably fast and accurate methods for sequencing
the genomes of disease-causing microorganisms. Genome sequencing
reveals the lineup of paired chemical bases that make up the pathogen's
DNA, the language of life. The potential payoffs of sequencing
pathogens have begun stirring scientific excitement. Sequence
information can be exploited in many ways: to demarcate genes,
to locate therapeutic targets, to identify mutations that contribute
to drug resistance, and to compare the genomes of variant strains
to note differences that may affect the antigenicity or virulence
of the microbe.
When scientists identify genes that are unique to a particular
microbe, drugs can be targeted to these genes, and the products
of these genes can be incorporated into experimental vaccines.
Strategies can be devised to counteract genetic mutations that
cause a microbe to become drug resistant. Once virulence genes
are found, researchers can attempt to disable them. Genetic
variations detected in different strains of the same pathogen
can be used to study the population dynamics of these strains,
such as the spread of a virulent or drug-resistant form of a
pathogen in a susceptible population. Finally, understanding
the genetic basis for both virulence and drug resistance may
also help predict disease prognosis and influence the type and
extent of patient care and treatment. |
Recognizing the tremendous benefits of genome sequencing, NIAID
has funded projects to sequence the full genomes of a number
of medically important microbes, including the bacteria that
cause tuberculosis, gonorrhea, chlamydia and cholera (see Table).
In addition, NIAID collaborates with other funding agencies
to sequence the larger genomes of protozoan pathogens such as
that of the organism causing malaria. Many of these microbes
have been completely sequenced and are now being annotated and
analyzed. During annotation, each gene's position or placement
on the genome is determined. This information is further analyzed
to provide insight on important features of the genome that
may affect the biology of the microbe and its ability to cause
disease. Sequence information as well as annotation data are
continually being provided to the scientific community by means
of publicly accessible Websites.
The following table identifies the projects supported by NIAID
as well as the Web sites where the data and additional information
can be found.
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