Gram-Positive Staph Infections

Gram-positive staph infections are bacterial infections that can affect any body system with varying symptoms and degrees of severity. Because of the prevalence of resistant bacteria, treatments vary by the exact bacterial strain. Discuss any concerns or troubling symptoms with your doctor.

Definition

• Staph, short for staphylococcus, infections are caused by Staphylococcus bacteria, which commonly live on human skin or in noses. "Gram positive" refers to the "Gram" method of testing to identify bacteria; gram-positive bacteria are stained by the testing chemical, while gram-negative bacteria are not. While most of the 30 kinds of Staphylococcus bacteria are usually harmless or cause only minor infections, Staphylococcus aureus can cause far more serious infections.

Causes and Symptoms

• A staph infection occurs when the bacterium enters the body. The bacteria can enter through a cut or wound, but they can also spread from person to person through use of a contaminated object or by coughing and sneezing. Because staph infections can affect the heart, lungs, blood or skin, symptoms can vary. Symptoms of skin infections include heat at the infection site, swelling, pain or drainage. Symptoms of non-skin infections, including food poisoning, bacteremia (blood poisoning), septic arthritis (an infection in a joint) and toxic shock syndrome, can include redness, swelling, fever, nausea and vomiting, severe pain, abdominal cramps or diarrhea.

Risks and Complications

• Some people are at greater risk of staph infections or from complications from a staph infection. People with medical devices like a catheter, breathing or feeding tube or dialysis connections are at greater risk because bacteria can travel into the body along these devices. People in full-contact sports could spread staph through sharing equipment, towels or razors or through skin-to-skin contact. People currently or recently in the hospital also are at greater risk for staph infections, which take advantage of weakened immune systems, underlying health problems, surgical sites and burns. If staph enters the bloodstream, it can affect distant organs or lead to sepsis and septic shock.

Treatment

• Staphylococcus aureus infections are treated using antibiotics. While the patient's medical history and the exact strain of staphylococcus helps determine what antibiotic to use, the choice of antibiotic treatment also depends on whether the strain is antibiotic resistant. Staph infections acquired in a hospital are treated with antibiotics effective against MRSA (methicillin-resistant Staphylococcus aureus). Severe infections may require multiple drugs or extended periods of time on the antibiotics.

Staphylococcus aureus and MRSA

• The Merck Manuals Online Medical Library states that staphylococcus aureus is the most dangerous of the common staphylococci. MRSA has received extensive attention as a difficult-to-treat bacteria that is resistant to the most common antibiotics. These infections are becoming more difficult to treat because they are resistant to increasing numbers of antibiotics. Resistance occurs when a bacterium adapt defenses against a particular drug. To help limit resistance, take your full course of antibiotics as prescribed when your doctor decides they are necessary; antibiotics are not effective against viral infections (such as a cold or the flu).