What does the M protein of Streptococcus pyogenes do?

M protein is strongly anti-phagocytic and is the major virulence factor for group A streptococci (Streptococcus pyogenes). It binds to serum factor H, destroying C3-convertase and preventing opsonization by C3b. Bacteria like S. pyogenes, which possess M protein are classified in group A of the Lancefield system.

Does Streptococcus pyogenes produce M proteins?

pyogenes to persist in infected tissues can be primarily attributed to the cell surface M protein, a molecule that gives the streptococcus the ability to resist phagocytosis by polymorphonuclear leukocytes in the absence of type-specific antibodies.

What are the effects of Streptococcus pyogenes?

Streptococcus pyogenes is a Gram-positive bacterium (Figure 1) that causes several diseases in humans, including pharyngitis, skin infections, acute rheumatic fever, scarlet fever, poststreptococcal glomerulonephritis, a toxic shock–like syndrome, and necrotizing fasciitis.

What does the M protein help with?

The M protein coats group A streptococci (GAS) and acts as the primary antigen and determinant of type-specific immunity. M is essential for GAS virulence, providing antiphagocytic functions critical to survival in human tissues and fluids.

What is the M protein in your blood?

M-protein is an antibody—or part of an antibody—that can show up in tests of your blood and/or urine, and its presence can mean different things. In blood cancers such as myeloma, the ‘M’ in ‘M protein’ stands for monoclonal. A monoclonal protein is produced by the abnormal, cancerous or precancerous cells.

What is protein M?

What does Streptococcus pyogenes interact with?

Streptococcus pyogenes is a major human pathogen that causes a variety of diseases ranging from mild skin and throat infections to fatal septicemia. In severe invasive infections, S. pyogenes encounters and interacts with components of the extracellular matrix (ECM), including small leucine rich-proteoglycans (SLRPs).

How does Streptococcus pyogenes cause strep?

Strep throat is caused by infection with a bacterium known as Streptococcus pyogenes, also called group A streptococcus. Streptococcal bacteria are contagious. They can spread through droplets when someone with the infection coughs or sneezes, or through shared food or drinks.

Is Streptococcus pyogenes helpful or harmful?

Streptococcus pyogenes is an important global human pathogen that causes a wide variety of acute infections, such as soft tissue infections and pharyngitis; severe life-threatening infections, such as streptococcal toxic shock syndrome; and devastating postinfectious sequelae, such as rheumatic fever and …

How does Streptococcus pyogenes enter the body?

These bacteria are spread by direct contact with discharges from the nose and throat of infected people or by contact with infected wounds or sores on the skin. The risk of spreading the infection is highest when a person is ill, such as when people have “strep throat” or an infected wound.

What are the two roles M protein plays in its infectious process?

M Protein-Mediated Invasion M protein is an important virulence factor expressed on the surface of S. pyogenes and plays multiple roles in streptococcal infection, including resistance to phagocytosis, adherence to epidermal keratinocytes, microcolony formation and invasion of epithelial cells [192].

What is the function of the M protein in strep?

The M protein coats group A streptococci (GAS) and acts as the primary antigen and determinant of type-specific immunity. M is essential for GAS virulence, providing antiphagocytic functions critical to survival in human tissues and fluids.

Why is the global incidence of Streptococcus pyogenes so high?

While the incidence of many diseases has declined in developed countries, regions of the world with low income and poor infrastructure continue to suffer a high burden of Streptococcus pyogenes (group A streptococci) diseases with millions of deaths yearly ( Carapetis, Steer, Mulholland, & Weber, 2005 ).

Is Group A Streptococcus pyogenes a notifiable disease?

Many countries with established infectious disease surveillance programs undertake relatively little surveillance of diseases caused by S. pyogenes and other pyogenic streptococci. However, this has improved over the years with many countries establishing the presence of invasive group A streptococcal infections as a statutory notifiable disease.

What is the role of M protein in gas?

M is essential for GAS virulence, providing antiphagocytic functions critical to survival in human tissues and fluids. Specific regions of M protein also serve as shared antigens, and cross-reactivity between these epitopes and human proteins may be the source of autoimmune sequelae such as rheumatic heart disease.