Maryland - US researchers have mapped the complete genome sequence of an infectious strain of streptococcus pneumoniae, a bacterium which causes millions of children and elderly people to die each year of pneumonia or meningitis, the Institute for Genomic Research said yesterday. "While this project was a long time coming, the availability of this information represents a tremendous milestone in helping to understand the virulence and pathogenicity of a highly-infectious bacterium," said Ms Claire Fraser, the institute's president.