S . p y o g e n e s i s a c a t a l a s e - n e g a t i v e a e r o b i c G r a m - p o s i t i v e c o c c u s h a v e c h a i n l i k e a r r a n g e m e n t . S . p y o g e n e s , i s o n e o f t h e m o s t v i r u l e n t s p e c i e s c a u s i n g h u m a n i n f e c t i o n s . S . p y o g e n e s i s a p r o t o t y p e b a c t e r i u m t h a t c a u s e s e x o t o x i n - m e d i a t e d i n f e c t i o n s . T h e s i z e o f s e q u e n c e d S . p y o g e n e s g e n o m e s i s a b o u t 1 . 8 8 M b p ( r a n g e : 1 . 8 2 1 . 9 4 M b p ) , O n e i m p o r t a n t f e a t u r e o f t h e S . p y o g e n e s g e n o m e i s t h a t i t s g e n e t i c v a r i a t i o n i s l a r g e l y d e t e r m i n e d b y t h e p r e s e n c e o f p r o p h a g e s o r p r o p h a g e - l i k e e l e m e n t s . T h e s e p r o p h a g e - l i k e e l e m e n t s f r e q u e n t l y c a r r y v i r u l e n c e m e c h a n i s m s s u c h a s e x o t o x i n , e n d o t o x i n a d h e s i n , a n d s u p e r a n t i g e n g e n e s T h e r e a r e a t l e a s t 5 1 7 , 0 0 0 d e a t h s g l o b a l l y e a c h y e a r d u e t o s e v e r e S . p y o g e n e s i n f e c t i o n s a n d r h e u m a t i c f e v e r d i s e a s e a l o n e c a u s e s 2 3 3 , 0 0 0 d e a t h s .
Organism Details:
Shape and Size
< 2 µm , Round or Ovoid shaped.
Genome Information
Streptococcus Pyogenes is a Gram-Positive,facultatively anaerobic. Streptococcus Pyogenes strain MGAS9429 chromosome ( GI:94987631) has a circular DNA chromosome of 1836467 bp .The genome structure of Streptococcus Pyogenes consists of 1,962 genes and and 1,877 coding proteins, Pseudo Genes: 2, rRNAs: 18 ( 5S, 16S, 23S ), tRNAs: 67 . The GC content of Streptococcus Pyogenes is about 38.5% .
A c h a r a c t e r i s t i c o f S p y o g e n e s i s t h e o r g a n i s m s a b i l i t y t o i n v a d e e p i t h e l i a l c e l l s . S t r e p t o c o c c u s p y o g e n e s p r o d u c e s t h r e e t y p e s o f e x o t o x i n s . T h e s e t o x i n s a r e r e s p o n s i b l e f o r c a u s i n g f e v e r a n d s c a r l e t f e v e r r a s h e s ; t h e y a l s o i n c r e a s e t h e r i s k o f e n d o t o x i c s h o c k a n d d e p r e s s a n t i b o d y s y n t h e s i s . S t r e p t o c o c c u s p y o g e n e s a l s o p r o d u c e s s t r e p t o k i n a s e , a t o x i n t h a t d i g e s t s b l o o d c l o t s t o a s s i s t i n t h e i n v a s i o n o f w o u n d s . P y r o g e n i c e x o t o x i n s T h e s e t o x i n s a r e r e s p o n s i b l e f o r t h e r a s h o f s c a r l e t f e v e r . O t h e r p a t h o g e n i c e f f e c t s c a u s e d b y t h e s e s u b s t a n c e s i n c l u d e p y r o g e n i c i t y , c y t o t o x i c i t y , a n d e n h a n c e m e n t o f s u s c e p t i b i l i t y t o e n d o t o x i n . S P E B i s a p r e c u r s o r o f a c y s t e i n e p r o t e a s e , a n o t h e r d e t e r m i n a n t o f v i r u l e n c e .
Disease
Streptococcal infection most common site are the
upper respiratory tract and the skin and soft tissues. Streptococcal pharyngitis and tonsillitis can be followed by local and distant suppurative complications (such as peritonsillar and retropharyngeal abscesses) or non-suppurative sequelae (acute rheumatic fever being commoner than post-streptococcal glomerulonephritis after respiratory tract infections).Also responsible to cause wide array of infection
Tonsils, cellulitis,Sensitive Cervical Lymph Nodes Malaise ,cellulitis,endocarditis, erysipelas, impetigo, meningitis, necrotizing fasciitis, pneumonia, ,shock syndrome scarlet fever, strep throat, Scarlet fever (pink-red rash and fever), Glomerulonephritis (inflammation, hematuriia, fever, edema, hypertension, urinary sediment abnormalties and severe kidney pain)