NEW YORK, Oct. 25 — An international coalition of researchers has sequenced the typhoid genome. The project was conducted by a coalition of researchers in Vietnam, Denmark, and the UK and funded by the Wellcome Trust’s Beowulf Genomics Initiative, which was established in 1998 to make microbial pathogen genome sequences widely available to researchers.
A paper describing the genome appears today in the journal Nature , and the annotated sequence data is available at the Sanger Centre’s website.
The typhoid bacterium, Salmonella typhi , causes a febrile illness that infects roughly 17 million and claims 600,000 lives worldwide each year. The organism that the group sequenced is of a highly pathogenic strain known as CT18 that was isolated several years ago from a patient in Cho Quan Hospital in Ho Chi Minh City and which is resistant to many common antibiotics. More than 90 percent of the strains of typhoid in Vietnam are known to be resistant to most available drugs, according to Jeremy Farrar of the University of Oxford-Wellcome Trust Clinical Research Unit in Vietnam.
Knowing the genome sequence would help in the effort to develop treatments or vaccines for typhoid, researchers said. The disease can also be hard to diagnose, and the genome sequence may enable development of improved diagnostic tools. The bacterium could also serve as a model for the study of how resistance develops.
Researchers have already discovered that the genome includes a significant amount of “pseudogenes.” Imperial College researcher Gordon Dougan said these provide a key to the evolutionary history of the bacterium, indicating that it may only be able to survive in humans and raising hopes that eradicating the disease may one day be possible.
To date, the Beowulf Genomics Initiative has supported the sequencing of 16 bacterial genomes and participated in the funding of two further bacterial genomes, 3 protozoan parasites, and one fungus.