Press Release

TIGR Announces Completion of Cholera Genome Sequencing Project

August 3, 2000

ROCKVILLE, MD -- The Institute for Genomic Research (TIGR), a not-for-profit research institute, announced today publication of the genome sequence for the bacterium, Vibrio cholerae in the journal NATURE (Aug. 3, 2000). V. cholerae is the causative agent of cholera, an acute, diarrheal illness that most frequently occurs in epidemic form. The V. cholerae genome sequence will provide medical and environmental microbiologists a new starting point for the study of this organism—¹s pathobiological and environmental characteristics. Because this bacterium naturally occurs in many aquatic environments, the most comprehensive approach to cholera control will involve scientists from the fields of infectious disease and environmental microbiology working jointly on this problem, as was done on this project with collaborators representing the foremost researchers in microbial genomics, V. cholerae pathogenicity and ecology.

The V. cholerae sequencing project, lead by Dr. John Heidelberg at TIGR, was completed in collaboration with Dr. John Mekalanos, Chairman, Department of Microbiology and Molecular Genetics, Harvard Medical School and Dr. Rita R. Colwell, Director of the National Science Foundation, Inc., founder and former president of University of Maryland Biotechnology Institute, and a professor at the Center of Marine Biotechnology and Department of Cell and Molecular Biology at the University of Maryland. The National Institute of Allergy and Infectious Diseases (NIAID), a division of the National Institutes of Health (NIH) funded this project.

"The determination of the V. cholerae genome sequence represents a milestone in the history of cholera research. This information has begun to provide insights into how a free-living environmental organism has emerged to become a human pathogen and it will greatly accelerate our understanding of the disease and its control," said Claire M. Fraser, Ph.D., President of TIGR.

Cholera remains a global plague. In 1998, the Centers for Disease Control (CDC) reported an increase of nearly 100% in cholera cases on all continents. In 1999, approximately 222,475 cases, with 8,423 deaths were reported. Nearly 1000 deaths and 17,000 cases have been reported thus far this year. Of the 17 countries comprising the Americas, only two countries - the U.S., with 4 cases and Guatemala, with 59 cases -- have reported cases of cholera between January 1, 2000 and May 31, 2000. Other countries reporting outbreaks of cholera include: Australia, France, Singapore, Japan, Hong Kong, and the African nations of Zambia, Uganda, United Republic of Tanzania, Somalia, Mayote, Madagascar and Kenya. The CDC reports that cholera is rare in the U.S., nevertheless there is an on-going global pandemic over the last 40 years in Asia, Africa, and Latin America.

The genome sequence produced by TIGR provides a new starting point for the study of this unique bacterium that lives in the aquatic environment, yet is a human pathogen of major epidemiological significance. This new information will be useful in the development of vaccines to prevent cholera. The genomic sequence of V. cholerae provides a model for the study of multi-chromosomal prokaryotic organisms, and will also provide important clues to understanding the metabolic and regulatory networks represented by genes linked on one or both the chromosomes. V. cholerae represents a promising genetic system with stunning potential for learning how multiple horizontally acquired loci located on separate chromosomes can interact efficiently at the regulatory, cell biology, and biochemical levels of organization.

"If the disease is to be conquered, it will require a full understanding of its ecology and natural host relationships in the aquatic environment. While the bacterium probably and should not be completely eradicated, as it performs many important functions in nature, the disease surely can be controlled, but only with a complete comprehension of the environmental factors that influence epidemics (i.e., global warming, V. cholerae/zooplankton interactions, eutrophication of drinking water supplies due to poor sanitation, etc.). This genome data will allow a much more rapid and comprehensive understanding of this bacterium's ecology than previously imaginable," said Dr. Colwell.

"The determination of the Vibrio cholerae genome sequence represents a milestone of profound significance in the cholera field. This organism remains a formidable threat in much of the developing world, infecting millions and killing ten's of thousands globally," said Dr. Mekalanos. "This organism has so far resisted many conventional eradication efforts by acquiring new genes and rapidly evolving. Distinctly different strains have caused multiple pandemics in the past and novel strains will continue to emerge. The genome sequence will allow us to define new changes with perfect resolution and thus learn how this organism adapts to aquatic environments and becomes a more efficient pathogen of humans."

At the forefront of the emerging area of genomic science since its inception, TIGR is a not-for-profit research institute founded in 1992 with interests in structural, functional and comparative analysis of genomes and gene products in bacteria (pathogenic or disease causing and environmental) archaea and eukaryotes, both plant and animal.