Staphylococcus aureus

Methicillin-resistant Staphylococcus aureus (MRSA) is a bacterium that is resistant to many antibiotics. Staphylococcus and MRSA cause problems such as skin infections, sepsis, pneumonia, bloodstream infections.

Staphylococcus aureus Staphylococcus aureus is generally found in the skin and nose of healthy people (about one-third of a person). Most people who are infecting the skin and nose with Staphylococcus are not adversely affected and are described as "colonization". Methicillin-resistant Staphylococcus aureus (MRSA) is a special kind of staphylococci that has become unresponsive to many commonly used antibiotics such as penicillin. These bacteria invade the body through the skin due to incision, pain or surgical incision, sometimes infection (such as impetigo, vap, abscess or infected wound). This situation is most likely to happen to people who are already sick but may also occur in healthy people in the area.

Treatment of Staphylococcus aureus infection revolutionized the introduction of antibiotic penicillin in the 1940's. However, most S. aureus strains are currently resistant to penicillin. Staphylococcus aureus decomposes penicillin and produces a substance called beta-lactamase which destroys its antibacterial activity. In the early 1960s, a new class of penicillin antibiotics called methicillin was developed. Methicillin is not degraded by beta-lactamase and is therefore useful for the treatment of infections caused by Staphylococcus aureus strains producing Staphylococcus aureus strains. Subsequently, methicillin is replaced by a better penicillin antibiotic, which is not affected by beta - lactamase like fluxacillin. Unfortunately, some Methicillin-resistant Staphylococcus aureus strains called MRSA (Johnson, 2007), immediately after the introduction of methicillin.

Staphylokinase is an enzyme produced by Staphylococcus aureus. When staphylokinase is released from Staphylococcus aureus to target neutrophils, alpha-alpha-defensin is produced, which is then neutralized by S. aureus. This results in inhibition of the bactericidal action of defensins by activation of plasmin, and staphylokinase increases bacterial infection process. Plasminogen is tightly regulated and is part of the fibrinolytic mechanism that coats fibrin when blood vessels are damaged. Staphylococcus aureus converts plasminogen to fibrin with the aid of fibrin as a cofactor. Staphylokinase is encoded by the Sak gene and regulated by the agr gene. Its structure has a central α helix and a 5β plate stock. . When neutrophils bind to the central alpha link, a conformational change is induced. Therefore, plasminogen is converted to plasmin. Several sites that bind to neutrophils can be found in staphylokinase.