What are the virulence factors of Streptococcus?

What are the virulence factors of Streptococcus?

Virulence factors of group A streptococci include (1) M protein and lipoteichoic acid for attachment; (2) a hyaluronic acid capsule that inhibits phagocytosis; (3) other extracellular products, such as pyrogenic (erythrogenic) toxin, which causes the rash of scarlet fever; and (4) streptokinase, streptodornase (DNase B …

What are the main virulence factors of Streptococcus pyogenes?

GAS strains express many virulence factors including surface protein M, streptolysins, streptokinase, hyaluronidase, peptidoglycan, and teichoic acid. Protein M is considered as the main virulence factor, limiting phagocytosis, disturbing the function of complement, and being responsible for adhesion [4].

What are the virulence factors of viruses?

Viral virulence is influenced by viral genes in four categories: (1) those that affect the ability of the virus to replicate, (2) those that affect host defense mechanisms, (3) those that affect tropism, spread throughout the body and transmissibility, and (4) those that encode or produce products that are directly …

What is the major virulence factor of Streptococcus pneumoniae?

1. Polysaccharide capsule: S. pneumoniae’s extracellular polysaccharide capsule, the most important virulence factor (55), helps to initiate infection by allowing the bacterium to adhere to host cells and cause inflammation, while also providing protection from the host’s immune system (54, 55).

Which of the following is a virulence factor of Streptococcus pneumoniae?

The polysaccharide capsule is probably the most important virulence factor of the pneumococcus. The role of the capsule in virulence stems from its antiphagocytic activity [1]. Antibody to cell wall constituents of the pneumococcus becomes attached to the surface of the organism, and in turn binds complement.

What causes streptococcus?

Strep infection may lead to inflammatory illnesses, including: Scarlet fever, a streptococcal infection characterized by a prominent rash. Inflammation of the kidney (poststreptococcal glomerulonephritis) Rheumatic fever, a serious inflammatory condition that can affect the heart, joints, nervous system and skin.

What is virulent virus?

Definition. A virus that lyses its host immediately upon infection and often cause disease. Supplement.

What is the most important virulence factor?

Virulence factors of the organisms causing cystitis and pyelonephritis have been extensively studied. With the most common etiological agent, Escherichia coli, it has been demonstrated that an important virulence factor is the ability of the bacterial cells to adhere to epithelial cells in the urinary tract mucosa.

What are the virulence factors of Clostridium tetani?

tetani also possesses potential virulence factors. ORFs for tetanolysin O, hemolysin, and fibronectin-binding proteins, as well as genes for surface-layer (S-layer) proteins have been identified (Brüggemann 2003). Tetanolysin, discussed below, is one of the two exotoxins produced by C. tetani, in addition to TeTx.