What Is Microbiology - Streptococcus Pyogenes Infection

​Streptococcus pyogenes infection 

Streptococcal pharyngitis is caused by streptococcus pyogenes. Streptococcal pyogenes is associated with pharyngitis in children.

Pharyngitis is best detected via rapid strep test. 

Streptococcus pyogenes may be transmitted via direct contact or respiratory droplets. Streptococcus pyogenes is a gram positive coccus which is sensitive to bacitracin. Streptococcus pyogenes is lancefield group A with beta hemolytic properties. 

The virulence factors of streptococcus pyogenes may include structural component such as M protein,( M protein autoantibodies may lead to rheumatic fever due to it cross react with the heart muscle) M - like protein, F protein and hyaluronic acid capsule, enzymes such as hyaluronidase, DNase, C5a peptidase, streptokinase, streptolysin O and streptolysin S as well as erythrogenic superantigen toxins such as Spe A, Spe B and Spe C. 

Anti streptolysin O antibodies ( ASO) is useful in detecting any streptococcus pyogenes infection in cases of patient with rheumatic fever.

Besides pharyngitis, streptococcus pyogenes may also present with Scarlet fever. Scarlet fever is characterized by diffuse rash, strawberry tongue and fever. Other infections may include skin infections due to breaks and cut of the skin. These include, erysipelas, impetigo, necrotizing fasciitis. Other conditions may include streptococcal shock syndrome, sepsis, acute glomerulonephritis and rheumatic fever. 

The treatment may include surgical debridement in cases of skin lesions or penicillin as well as erythromycin.