Staphyllococci

Staphyllococci

Assis.prof D.Nebras .Al-dabagh

S. aureus has long been recognized as one of the most important bacteria that cause disease in humans. It is the leading cause of skin and soft tissue infections such as abscesses (boils), furuncles, and cellulitis. Although most staph infections are not serious, S. aureus can cause serious infections such as bloodstream infections, pneumonia, or bone and joint infections.
Signs and symptoms of infection
• Most infections caused by S. aureus are skin and soft tissue infections such as abscesses or cellulitis.
Abscess
• Pocket of infection that forms at the site of injury, Usually filled with pus.Area surrounding the abscess is usually red, painful and swollen and the skin .
Cellulitis
• An infection of the underlying layers of the skin.
• Usually results from a scrape or cut in the skin which allows bacteria to enter, although no injury may be apparent.
• Cellulitis can occur anywhere in the body, but most often occurs on the legs or arms.
• Symptoms include redness, swelling, and pain at the site of infection.
• S. aureus can also cause serious infections such as pneumonia (infection of the lungs) or bacteremia (bloodstream infection).
o Symptoms of these infections include: difficulty breathing, malaise, fever, or chills.


Types of staph infections
Staphylococcus aureus infections range from mild to life threatening.
The most common staphylococcal infections are
• Skin infections, often causing abscesses
• Bloodstream infections: When a catheter that is inserted in a vein has remained in place for a long time .However, the bacteria can travel through the bloodstream (called bacteremia) and infect almost any site in the body, particularly heart valves (endocarditis) and bones (osteomyelitis).
• The bacteria also tend to accumulate on medical devices in the body, such as artificial heart valves or joints, heart pacemakers, and catheters inserted through the skin into blood vessels.
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• Osteomyelitis: When Staphylococcus aureus spreads to the bone from infection in the bloodstream or from infection in adjacent soft tissue, as may occur in people with diabetes .
• Lung infection (pneumonia): When people have had influenza (particularly) or a bloodstream infection, when people are taking corticosteroids or drugs that suppress the immune system (immunosuppressants), or when they are hospitalized because they need tracheal intubation and mechanical ventilation (called hospital-acquired pneumonia)
Staph toxins
There are many strains of Staphylococcus aureus. Some strains produce toxins that can cause staphylococcal food poisoning, toxic shock syndrome, or scalded skin syndrome.
Toxic shock syndrome is also caused by toxins produced by some streptococci. This syndrome causes rapidly progressive and severe symptoms that include fever, rash, dangerously low blood pressure, and failure of several organs. Most cases of Toxic Shock Syndrome occur in menstruating females in association with the use of tampons. Other cases may occur in association with postoperative wound infections, nasal packing, or other factors.
Toxic Shock Syndrome (TSS) is a rare acute multisystemic disease caused by toxins (such as “toxic shock syndrome toxin-1” [TSST-1], enterotoxin B, enterotoxin C) produced by certain strains (particularly phage group I) of the bacterium Staphylococcus aureus (S. aureus). TSS is most common in menstruating women who use highly absorbent tampons. Evidence suggests that the prolonged use of tampons in the presence (i.e., colonization) of toxin-secreting S. aureus strains may promote increased production of the toxin, which may enter the bloodstream through the uterus or tiny cuts within the vaginal lining.


Transmission

• S. aureus is most often spread to others by contaminated hands.

• The skin and mucous membranes are usually an effective barrier against infection. However, if these barriers are breached (e.g., skin damage due to trauma or mucosal damage due to viral infection) S. aureus may gain access to underlying tissues or the bloodstream and cause infection.

• In recent years physicians and other health care providers have observed an increasing number of people with MRSA infections .

MRSA is different from other staph bacteria because it has built up a resistance to most of the antibiotics doctors usually use to treat staph infections. (Methicillin is a type of antibiotic, which is why the strain is called "methicillin-resistant.")
MRSA, (methicillin-resistant staphylococcus aureus), is a form of contagious bacterial infection that is resistant to numerous antibiotics including methicillin, amoxicillin, penicillin, and oxacillin.
MRSA stands for methicillin-resistant Staphylococcus aureus. It causes a staph infection (pronounced "staff infection") that is resistant to several common antibiotics. There are two types of infection. Hospital-associated MRSA happens to people in health care settings. Community-associated MRSA happens to people who have close skin-to-skin contact with others, such as athletes involved in football and wrestling.

Prevention
• Wash your hands often using plain soap and water for at least 20 seconds each time. You might also want to carry alcohol-based instant hand sanitizers or wipes in your bag for times when you can t wash your hands.
• If you have a cut or broken skin, keep it clean and covered with a bandage.
• Don t share razors, towels, uniforms, or other items that come into contact with bare skin.
• Cover shared sports equipment with a barrier (clothing or a towel) to prevent skin from touching it. The equipment also should be cleaned before each use with a disinfectant that works against MRSA.

Types of staph infections

Staphylococcus aureus infections range from mild to life threatening.
The most common staphylococcal infections are
Skin infections, often causing abscesses
bacteremia :bacteria can travel through the bloodstream and infect almost any site in the body, particularly heart valves (endocarditis) and bones (osteomyelitis).
The bacteria also tend to accumulate on medical devices in the body, such as artificial heart valves or joints, heart pacemakers, and catheters inserted through the skin into blood vessels.