title: Extension of the Lancefield classification for group A streptococci by addition of 22 new M protein gene sequence types from clinical isolates: emm103 to emm124.
abstract: Classic M protein serotyping has been invaluable during the past 60 years for the determination of relationships between different group A streptococci (GAS) strains and the varied clinical manifestations inflicted by these organisms worldwide. Nonetheless, during the past 20 years, the difficulties of continued expansion of the serology-based Lancefield classification scheme for GAS have become increasingly apparent. By use of a less demanding sequence-based methodology that closely adheres to previously established strain criteria while being predictive of known M protein serotypes, we recently added types emm94-emm102 to the Lancefield scheme. Continued expansion by the addition of types emm103 to emm124 are now proposed. As with types emm94-emm102, each of these new emm types was represented by multiple independent isolates recovered from serious disease manifestations, each was M protein nontypeable with all typing sera stocks available to international GAS reference laboratories, and each demonstrated antiphagocytic properties in vitro by multiplying in normal human blood.
authors.affiliation: Centers for Disease Control and Prevention, World Health Organization (WHO) Collaborating Center for Streptococci, Atlanta, GA 30333, USA.
authors.forename: Richard F
authors.initials: RF
authors.lastname: Facklam
authors.forename: Diana R
authors.initials: DR
authors.lastname: Martin
authors.forename: Marguerite
authors.initials: M
authors.lastname: Lovgren
authors.forename: Dwight R
authors.initials: DR
authors.lastname: Johnson
authors.forename: Androulla
authors.initials: A
authors.lastname: Efstratiou
authors.forename: Terry A
authors.initials: TA
authors.lastname: Thompson
authors.forename: Sonia
authors.initials: S
authors.lastname: Gowan
authors.forename: Paula
authors.initials: P
authors.lastname: Kriz
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Tyrrell
authors.forename: Edward
authors.initials: E
authors.lastname: Kaplan
authors.forename: Bernard
authors.initials: B
authors.lastname: Beall
mesh_terms: D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics*; D002352:Carrier Proteins / Q000235:genetics*; D004269:DNA, Bacterial / Q000032:analysis; D006801:Humans; D010802:Phylogeny; D012698:Serologic Tests; D012703:Serotyping; D013297:Streptococcus pyogenes / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification
chemical_list: D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D002352:Carrier Proteins; D004269:DNA, Bacterial; C014689:streptococcal M protein