Staphylococcus aureus

Staphylococcus aureus : An Emerging Super Bug

Staphylococcus aureus, a catalase-positive, gram-positive cocci-shapted bacteria, has been implicated in hospital acquired infections since the 1950s when the organisms developed a resistant to penicillin. Even during the golden age of antibiotics, about 50% ofS. aureus strains were found to be resistant to penicillin and later penicillian derivative drugs. The organism quickly became resistnat to newer and more powerful antibiotics, such as tertracycline and the aminoglycosides. S. aureus is a member of the family Micrococcaceae which comprises four genera: Micrococcus, Staphylococcus, Planococcus, and Stomatococcus. Staphyolococcus are natural habitants of skin and mucouse membranes of humans. The bacterial can be found throughout the environment from dust to door knobes. It is common even in the most cleanest healthcare facilities. Most species of Staphycococcus are oppertunistic pathogens, S. aureus , however, has been considered a serious bacterial pathogen since the organism developed a resistance to penicillin in the 1950s.

1. A, B, C, C2, D, E and F

1. TSST-1: toxic shock syndrome toxin

Protein A: binds to antibody molecules which makes the organism resistant to
phagocyctosis and fixation of complement

Capsular polysaccharide: enables the organism to resist phagocytosis

Peptidoglycan: cell wall consituent which allows the organism to attach to host's cell membranes and resist unfavorable environmental conditions

Teichoic acid:

What Is Toxic Shock Syndrome?

TSS is a systemic illness, which means that it affects the whole body. It can be caused by one of two different types of bacteria, Staphylococcus aureus and Streptococcus pyogenes — although toxic shock that is caused by the Streptococcus bacteria is rarer. These bacteria can produce toxins. In some people whose bodies can't fight these toxins, the immune system reacts. This reaction causes the symptoms associated with TSS.

When people think of TSS, they often think of tampon use. That's because the earliest cases of the illness, back in the late 1970s, were related to superabsorbent tampons. Research led to better tampons and better habits for using them — such as changing tampons more often. The number of TSS cases dropped dramatically. Today about half of all TSS cases are linked to menstruation.

Aside from tampon use, TSS has been linked to skin infections that are typically minor and can be associated with the chickenpox rash. TSS has also been reported following surgical procedures, giving birth, and prolonged use of nasal packing for nosebleeds — although all of these are rare.

What Are the Signs and Symptoms?

Symptoms of TSS occur suddenly. Because it's an illness that is caused by a toxin, many of the body's organ systems are affected. The signs and symptoms of TSS include:

high fever (greater than 102° Fahrenheit [38.8° Celsius])
rapid drop in blood pressure (with lightheadedness or fainting)
sunburn-like rash on the entire body
vomiting and diarrhea
severe muscle aches or weakness
bright red coloring of the eyes, throat, and vagina
headache, confusion, disorientation, or seizures
kidney and other organ failure
The average time before symptoms appear for TSS is 2 to 3 days after an infection with Staphylococcus or Streptococcus, although this can vary depending on the cause of the infection

The risk of getting TSS is already low. But you can reduce it still further by simply following some common-sense precautions:

Clean and bandage any skin wounds.
Change bandages regularly, rather than keeping them on for several days.
Check wounds for signs of infection. If a wound gets red, swollen, painful, or tender, or if you develop a fever, call your doctor right away.

If you're a girl whose period has started, the best way to avoid TSS is to use sanitary napkins instead of tampons.
For girls who prefer to use tampons, select the ones with the lowest absorbency that can handle your menstrual flow and change them frequently. You can also alternate the use of tampons with sanitary napkins.
If you've already had an episode of TSS or have been infected with S. aureus, don't use tampons or contraceptive devices that have been associated with TSS (such as diaphragms and contraceptive sponges).

What Do Doctors Do?

TSS is a medical emergency. If you think you or someone you know may have TSS, call a doctor right away. Depending on the symptoms, a doctor may see you in the office or refer you to a hospital emergency department for immediate evaluation and testing.

If doctors suspect TSS, they will probably start intravenous (IV) fluids and antibiotics as soon as possible. They may take a sample from the suspected site of the infection, such as the skin, nose, or vagina, to check it for TSS. They may also take a blood sample. Other blood tests can help monitor how various organs like the kidneys are working and check for other diseases that may be causing the symptoms.

Medical staff will remove tampons, contraceptive devices, or wound packing; clean any wounds; and, if there is a pocket of infection (called an abscess), a doctor may need to drain pus from the infected area.

People with TSS typically need to stay in the hospital, often in the intensive care unit, for several days to closely monitor blood pressure, respiratory status, and to look for signs of other problems, such as organ damage.

TSS is a very rare illness that's usually not fatal if recognized and treated promptly