This story has been corrected from a previous version that ran on April 10, which indicated that David Roos led the effort to sequence the Plasmodium falciparum genome, in addition to directing the PlasmoDB database. In fact, Roos was not involved in the sequencing and served as a co-director of the database project.
NEW YORK, April 12 - Researchers have sequenced the genomes of two organisms relevant to malaria, strep throat, and scarlet fever, underscoring new information about virulence.
On Tuesday, a sequencing effort led by scientists at the University of Oklahoma published the sequence of Streptococcus pyogenes in the Proceedings of the National Academy of Sciences, and last Friday, researchers at the University of Pennsylvania released a searchable database of the Plasmodium falciparum genome.
David Roos, a biologist at the University of Pennsylvania, who co-directed the project to develop a database for the sequence P. falciparum , a pathogen responsible for the majority of malaria deaths, said that the organism is "one of mankind's great scourges," and that it is "by far the most complex pathogen that has been sequenced to date."
Sequencing the 30 million base pairs of the Plasmodium genome, about one hundreth the size of the human genome, began in 1996, and currently the sequence is about as accurate as that of the human sequence data released in February by the Human Genome Project, Roos said.
But Roos indicated that the "unusual" aspect of the project is the way the Plasmodium database handles sequence data not yet finished, or not yet determined beyond a certain degree of error. Rather than wait for scientists to completely finish and annotate the data before permitting others to analyze the sequence, the Plasmodium database, available online at http://PlasmoDB.org , allows researchers to search the database as is, using several different bioinformatics tools.
An analysis of the S. pyogenes genome, published in Tuesday's issue of PNAS, showed that more than 40 of the 1,752 genes identified by the University of Oklahoma research team were found to be associated with virulence, and that the genome contained four sections inserted by bacteriophages, viruses that infect bacteria and splice their genes into the bacterial DNA. The S. pyogenes sequence contains about 1.8 million base pairs in total, and researchers have yet to define a function for about a third of the genes.Fran Rubin, a respiratory disease officer at the National Institute of Allergy and Infectious Disease, said in a statement that sequencing the S. pyogenes genome should lead to potential vaccines for the diseases associated with the bacterium. "We expect the sequence will reveal new antigens, possibly proteins on the bacterium's surface, that would also be good vaccine candidates," he said.