Publication: Isolation ratio and T- serotyping of group A streptococci from pediatric upper respiratory tract infections in Turkey
Abstract
Amaç: Akut romatizmal ateş, A grubu streptokokların neden olduğu tonsillofarenjitlerden sonra gelişen non-süpüratif bir sekeldir. A grubu streptokokların M1, M3, M5, M6, M14, M18, M19, M24 gibi belirli M serotipleri bu tür sekellere yol açmaktadır. M proteinlere karşı oluşan antikorlar streptokoklara karşı bağışıklığı sağlarken, romatizmal ateşe de neden olurlar. Anti-M serumları ticari olarak elde edilemediğinden, birçok laboratuvarda A grupları, T agglütinasyon paterni ve opasite faktörü ile serotiplenmektedir. Ülkemizde, son zamanlarda yaygın olan serotipleri belirlemek amacıyla, 930 çocuktan alınan boğaz sürüntülerinden izole edilen 120 streptokok kökeninin, T protein tipi ve opasite faktörü araştırılmıştır. Yöntemler: T protein tipini belirlemek üzere, A grubu streptokok kökenlerinin homojen süspansiyonları, polivalan antiserumlarla (T, U, W, X, Y) lam agglütinasyon yöntemi ile karşılaştırılmıştır. Opasite faktörünü belirlemek için mikroplak yöntemi kullanılmıştır. Bulgular: Serotiplenebilen kökenler arasında en sık saptanan, T-protein agglütinasyon paterni U (2, 4, 6, 28) olmuştur (%30). Bunu T-protein agglütinasyon paterni olarak %20 ile T (1, 3, 13, B3264) ve % 18 ile X (8, 14, 25, Imp.19) izlemiştir. Sonuç: Romatizmal ateş ve romatizmal kalp hastalıklarını genel olarak değerlendirebilmek için, ülkemizde daha fazla epidemiyolojik ve serotip çalışmalarına ihtiyaç vardır.
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 %. Conclusion: To profit global assessment of rheumatic fever and rheumatic heart disease, more epidemiologic and serotyping research is required in our country.
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 %. Conclusion: To profit global assessment of rheumatic fever and rheumatic heart disease, more epidemiologic and serotyping research is required in our country.