Group A streptococcal cysteine protease degrades C3 (C3b) and contributes to evasion of innate immunity.

A relative lack of neutrophils around Streptococcus pyogenes is observed in streptococcal toxic shock syndrome (STSS). Because the bacteria spread rapidly into various organs in STSS, we speculated that S. pyogenes is equipped with molecules to evade the host innate immune system.

Dissemination of the phage-associated novel superantigen gene speL in recent invasive and noninvasive Streptococcus pyogenes M3/T3 isolates in Japan.

In Japan, more than 10% of streptococcal toxic shock-like syndrome (TSLS) cases have been caused by Streptococcus pyogenes M3/T3 isolates since the first reported TSLS case in 1992. Most M3/T3 isolates from TSLS or severe invasive infection cases during 1992 to 2001 and those from noninvasive cases during this period are indistinguishable in pulsed-field gel electropherograms. The longest fragments of these recent isolates were 300 kb in size, whereas those of isolates recovered during or before 1973 were 260 kb in size.