title: The presence of M protein in nontypeable group A streptococcal upper respiratory tract isolates from Southeast Asia.
abstract: Previous studies have suggested that group A streptococcal strains from southeast Asia, serotypically different from temporally related North American and European isolates, may represent unrecognized M serotypes. Sixty non-M typeable group A streptococcal upper respiratory tract isolates from Thailand were evaluated for the presence of M protein using a modification of the direct serum bactericidal test. Of them, 59 (98%) grew rapidly in human blood. Typeability by T agglutination and opacity factor production did not influence their growth in blood. It was concluded that these isolates produce M protein and likely represent previously uncharacterized M serotypes. Identification of such non-M typeable strains is important in understanding the epidemiology and pathogenesis of group A streptococcal infections and their sequelae in areas of the world where they remain a significant health problem and will also be necessary in the development of a vaccine with global efficacy.
authors.affiliation: Department of Pediatrics, University of Minnesota Medical School, Minneapolis 55455.
authors.forename: P O
authors.initials: PO
authors.lastname: Tran
authors.forename: D R
authors.initials: DR
authors.lastname: Johnson
authors.forename: E L
authors.initials: EL
authors.lastname: Kaplan
mesh_terms: D000942:Antigens, Bacterial / Q000032:analysis*; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins / Q000032:analysis*; D002352:Carrier Proteins; D002648:Child; D006801:Humans; D012137:Respiratory System / Q000382:microbiology; D012703:Serotyping; D013290:Streptococcal Infections / Q000145:classification / Q000276:immunology*; D013297:Streptococcus pyogenes / Q000145:classification* / Q000378:metabolism; D013785:Thailand
chemical_list: D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D002352:Carrier Proteins; C014689:streptococcal M protein