What are some common diseases caused by Streptococcus pyogenes?
What are some common diseases caused by Streptococcus pyogenes?
Life-threatening infections caused by Streptococcus pyogenes (group A streptococcus) include scarlet fever, bacteremia, pneumonia, necrotizing fasciitis, myonecrosis and Streptococcal Toxic Shock Syndrome (StrepTSS).
Which diseases are manifestation of superantigens?
Superantigens cause symptoms via release of immune cytokines. These proteins should be considered potential causes of illnesses such as rheumatic fever, arthritis, Kawasaki syndrome, atopic dermatitis, and guttate psoriasis because of their potent immune system-altering capacity.
Does pyogenes produce superantigens?
Superantigens produced by Streptococcus pyogenes have been implicated with streptococcal toxic shock syndrome (STSS). We analyzed 19 acute-phase serum samples for mitogenic activity from patients with severe streptococcal disease.
What are superantigens give any two examples?
Examples of superantigens include toxic shock syndrome toxin-1 (TSST-1), Streptococcal pyrogenic exotoxins (SPE), Staphylococcal enterotoxins (SE), and enterotoxogenic E. coli (ETEC) enterotoxin.
Where is Streptococcus pyogenes commonly found?
pyogenes are the dental plaque, hypopharynx, and the upper respiratory tract. Clinical samples can be isolated from skin lesions, inflammatory secretions, or blood. S. pyogenes can also be found in loose connective tissue inflammation in the maxillofacial region, pulpitis, or infection after exelcymosis.
How do you get infected with Streptococcus pyogenes?
Infections caused by S. pyogenes are highly contagious. Transmission can occur through airborne droplets, hand contact with nasal discharge or with objects or surfaces contaminated with bacteria, skin contact with contaminated lesions, or contaminated food sources.
What is the role of superantigens?
Superantigens (SAgs) are a class of antigens that result in excessive activation of the immune system. Specifically it causes non-specific activation of T-cells resulting in polyclonal T cell activation and massive cytokine release.
What are superantigens why they elicit strong immune response?
Superantigens are bacterial proteins that generate a powerful immune response by binding to Major Histocompatibility Complex class II molecules on antigen-presenting cells and T cell receptors on T cells.
Where are superantigens produced?
intracellularly
Structure. SAgs are produced intracellularly by bacteria and are released upon infection as extracellular mature toxins.
Can superantigens cause sepsis?
Systemic reactions to superantigens may also contribute to the severity of S. aureus sepsis [11].
How do superantigens cause toxic effects?
Superantigens interact with antigen-presenting cells (APCs) and T cells to induce T cell proliferation and massive cytokine production, which leads to fever, rash, capillary leak, and subsequent hypotension, the major symptoms of toxic shock syndrome. Both S.