Recent significant contributions have been made to the understanding of Gro
up A Streptococcus (GAS) pathogenesis. New regulatory pathways have been di
scovered, insight into the molecular basis of epidemics of serotype M1 dise
ase has been obtained, the crystal structures of four toxins have been repo
rted and a genome sequence of one GAS strain has been determined. Genome-sc
ale approaches to the study of GAS pathogenesis are now rapidly emerging an
d will advance our fundamental understanding of the molecular basis of host
-pathogen interactions.