The Streptococcus pyogenes Genome Sequencing Project

Abstract

Advances in genome analysis have allowed unprecedented progress to be made in understanding the complete gene structure and organization of a pathogenic organism as evidenced by recent reports of the entire DNA sequence of organisms such as Haemophilus influenzae and Mycoplasma pneumoniae (4, 5). In this communication, we report on the progress to determine the complete nucleotide sequence of an M1 strain of Streptococcus pyogenes. Strain SF370 is a well characterized M1 strain that was originally isolated from a wound infection and possesses the same RFLP pattern found in strains associated with severe invasive disease. As a prelude to genomic sequencing, the nucleotide sequence of the SF370 emm gene was determined and found to be identical to that of Lancefield strain T1/19/8. This strain is lysogenic for a speC-containing, but not a speA-containing bacteriophage. The complete sequence of the T12 bacteriophage containing the speA gene has recently been determined and is reported elsewhere (6). No other extrachromosomal elements were known to exist in this strain, although sequencing has revealed that additional temperate phages or defective phages are probably present. A physical map of SF370 has been constructed utilizing three different restriction enzymes (SmaI, SfiI, and SgrAI), and its genome size has been estimated to be 1920 kb, with thirty six genes identified to date on the genetic map (7).