Complete genome sequence of an M1 strain of Streptococcus pyogenes

The 1,852,442-bp sequence of an M1 strain of Streptococcus pyogenes, a Gram -positive pathogen, has been determined and contains 1,752 predicted protei n-encoding genes, Approximately one-third of these genes have no identifiab le function, with the remainder falling into previously characterized categ ories of known microbial function. Consistent with the observation that S, pyogenes is responsible for a wider variety of human disease than any other bacterial species, more than 40 putative virulence-associated genes have b een identified. Additional genes have been identified that encode proteins likely associated with microbial "molecular mimicry" of host characteristic s and involved in rheumatic fever or acute glomerulonephritis, The complete or partial sequence of four different bacteriophage genomes is also presen t, with each containing genes for one or more previously undiscovered super antigen-like proteins. These prophage-associated genes encode at least six potential virulence factors, emphasizing the importance of bacteriophages i n horizontal gene transfer and a possible mechanism for generating new stra ins with increased pathogenic potential.