title: Isolation ratio and T- serotyping of group A streptococci from pediatric upper respiratory tract infections in Turkey.
abstract: OBJECTIVE
  Acute rheumatic fever can follow throat infections with group A streptococci. Certain serotypes of group A streptococci such as M1, M3, M5, M6, M14, M18, M19, M24 are associated with this disorder. Immunity to streptococci and to rheumatic fever depends on antibodies to the M proteins. Due to current scarcity of M-typing sera, many laboratories use T typing and opacity factor production for serotype identification of group A streptococci. In order to, investigate the most common serotypes of group A streptococci in our country in recent years we studied T-agglutination typing and opacity factor of 120 group A streptococci strains isolated from throat cultures of 930 children.
  
  
  METHODS
  Diffuse, stable suspensions of group A streptococci were tested with polyvalent antisera (T,U,W,X,Y) by slide agglutination. Microplate method was used for opacity factor detection.
  
  
  RESULTS
  T-protein -agglutination patterns U (2,4,6,28) were the most common among typeable strains. The rate of T-protein -agglutination patterns T (1,3,13, B3264) and X (8,14,25,Imp.19) were 20 % and 18 % respectively. Opacity factor production rate of isolated group A streptococci strains was 65%.
  
  
  CONCLUSIONS
  To profit global assessment of rheumatic fever and rheumatic heart disease, more epidemiological and serotyping research is required in our country.
authors.affiliation: Department of Microbiology and Clinical Microbiology, Faculty of Medicine, University of Maltepe, Istanbul, Turkey. ty@ttnet.net.tr
authors.forename: Aynur Eren
authors.initials: AE
authors.lastname: Topkaya
authors.forename: Tekin
authors.initials: T
authors.lastname: Yildirim
authors.forename: Sinan
authors.initials: S
authors.lastname: Arsan
mesh_terms: D000293:Adolescent; D000372:Agglutination Tests; D000907:Antibodies, Bacterial / Q000097:blood*; D000942:Antigens, Bacterial / Q000276:immunology*; D001425:Bacterial Outer Membrane Proteins / Q000276:immunology*; D002352:Carrier Proteins / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D010447:Peptide Hydrolases / Q000032:analysis; D012141:Respiratory Tract Infections / Q000453:epidemiology / Q000382:microbiology*; D012703:Serotyping; D013290:Streptococcal Infections / Q000453:epidemiology / Q000382:microbiology*; D013297:Streptococcus pyogenes / Q000145:classification / Q000302:isolation & purification / Q000472:pathogenicity; D014421:Turkey / Q000453:epidemiology
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D002352:Carrier Proteins; C021908:opacity factor; C014689:streptococcal M protein; D010447:Peptide Hydrolases