Consideration of cysteine protease activity for serological M-typing of clinical Streptococcus pyogenes isolates

Microbiol Immunol. 2004;48(10):779-82. doi: 10.1111/j.1348-0421.2004.tb03594.x.

Abstract

Clinical isolates of Streptococcus pyogenes were classified by serological typing of their surface M protein. Non-M typeable strains with the emm1 gene were characterized as the degradation of M protein caused by overproduction of the extracellular cysteine protease, SpeB. These events are dependent on the growth phase. M protein produced prior to expression of SpeB is degraded in the stationary phase when the active form of SpeB is detected. The proteolytic degradation of M protein should be considered for precise M typing analysis.

MeSH terms

  • Antigens, Bacterial / genetics
  • Antigens, Bacterial / isolation & purification*
  • Bacterial Outer Membrane Proteins / genetics
  • Bacterial Outer Membrane Proteins / isolation & purification*
  • Bacterial Proteins
  • Carrier Proteins / genetics
  • Carrier Proteins / isolation & purification*
  • Cysteine Endopeptidases / analysis
  • Cysteine Endopeptidases / genetics
  • Cysteine Endopeptidases / metabolism*
  • Cysteine Endopeptidases / physiology
  • Humans
  • Serotyping
  • Streptococcus pyogenes / enzymology*
  • Streptococcus pyogenes / genetics
  • Streptococcus pyogenes / immunology
  • Streptococcus pyogenes / isolation & purification
  • Virulence

Substances

  • Antigens, Bacterial
  • Bacterial Outer Membrane Proteins
  • Bacterial Proteins
  • Carrier Proteins
  • streptococcal M protein
  • Cysteine Endopeptidases
  • streptopain