Streptococcal infections
January 21st, 2010 | 
Author: Streptococcal infections – a group antroponoznyh bacterial infectious diseases with a variety of fur ¬ nism of transmission. Characterized by intoxication, multi ¬ goobraziem clinical manifestations of depending on them ¬ munobiologicheskoy reactivity and localization of the pathogen in the body.
Family streptococci consists of 7 genera, of which in human pathology greatest role belongs to the genus Streptococcus and Enterococcus. Streptococci first found T. Billroth (Th. Billroth) (1874) in the face and wound infection, septicemia and purulent lesions of L. Pasteur (L. Pasteur) (1879). In pure culture isolated Felyayzenom F. (F. Fehleizen) (1883) Rosenbachianum and A. (A. Rosenbach) (1884).
Streptococci are spherical or ovoidnye the cells in smears are placed in pairs or short chains. Streptococci resistant in the environment, are susceptible to disinfectants, high temperatures, can form L-shape. In the presence of specific carbohydrate antigens are subdivided into 17 serogroups, which in turn are divided into groups within serovars. By the ability to cause hemolysis streptococci are 3 options: alpha-hemolytic – causing partial hemolysis with the formation of degradation products ¬ tion of hemoglobin, painted green, beta-hemolytic – cause marked hemolysis and gamma – did not have hemolytic activity. Greatest value in human pathology are group A Streptococcus (S. piogenes), which are pathogens of scarlet fever, pharyngitis, tonsillitis, erysipelas, cellulitis, impetigo, streptococcal toxic shock syndrome, endocarditis, rheumatism ¬ ma, acute glomerulonephritis. Streptococci group A have a large set of pathogenicity factors. К ним относят: липотейхоевую кислоту, которая обеспечивает адгезию стрептококка к эпителию слизистых оболочек; белок М (фимбриальный белок) препятствует фагоцитозу и играет определенную роль в развитии аутоиммунных процессов; капсула — защищает микробную клетку от фагоцитоза; С5а-пептидаза — фермент, инактивирующий С5а-компонент комплемента и препятствующий фагоцитозу; стрептолизины — разрушают эритроциты и другие клетки; эритрогенные токсины проявляют пирогенную активность, стимулируют продукцию макрофагами интерлейкина-1, фактора некроза опухолей, являющихся медиаторами инфекционно-токсического шока. A role to play as kardiogepa Atlantic toxin, pathogen enzymes: hyaluronidase, streptokinase, streptodornaze. Group B streptococci causing meningitis in newborns, pneumonia, endocarditis, obstetric complications in adults.
Streptococcus pneumoniae (S. pneumoniae) – the most frequent pathogen, can cause sinusitis, ear infections, endocarditis, meningitis, septicemia.
Negemoliticheskie streptococci causing endocarditis, dental caries, abscesses. Enterococci may be the cause of the defeat of urinary tract infections, endocarditis, bacteremia, nutritional diseases, dysbacteriosis. In the course of infectious diseases studied scarlet fever, tonsillitis, erysipelas, streptokok tor angina.
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