title: Consideration of cysteine protease activity for serological M-typing of clinical Streptococcus pyogenes isolates.
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.
authors.affiliation: Department of Bacteriology, National Institute of Infectious Diseases, Shinjuku-ku, Tokyo, Japan.
authors.forename: Masatomo
authors.initials: M
authors.lastname: Morita
authors.forename: Tadayoshi
authors.initials: T
authors.lastname: Ikebe
authors.forename: Haruo
authors.initials: H
authors.lastname: Watanabe
mesh_terms: D000942:Antigens, Bacterial / Q000235:genetics / Q000302:isolation & purification*; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000302:isolation & purification*; D001426:Bacterial Proteins; D002352:Carrier Proteins / Q000235:genetics / Q000302:isolation & purification*; D003546:Cysteine Endopeptidases / Q000032:analysis / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D006801:Humans; D012703:Serotyping; D013297:Streptococcus pyogenes / Q000201:enzymology* / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification; D014774:Virulence
chemical_list: D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D002352:Carrier Proteins; C014689:streptococcal M protein; D003546:Cysteine Endopeptidases; C042477:streptopain