College of Medicine
UNMC_Acronym_Vert_sm_4c
University of Nebraska Medical Center
Home — College of Medicine — Department of Pathology, Microbiology and Immunology — Research — Center for Staphylococcal Research — Education & Training — Fast Facts

Fast Facts

As part of our community outreach and education, we provide information and essential facts about Staphylococcus and methicillin-resistant Staphylococcus aureus, commonly known as MRSA, which is a type of staph that has become resistant to penicillin-based antibiotics.

Magnification shows a strain of S. aureus bacteria. Source: CDC/Matthew J. Arduino, DRPH.

Staph is the common name for a group of bacteria in the genus Staphylococcus, a term that might sound intimidating. By breaking it down, we find that “staph” is Latin for grape-like clusters, and “coccus” is Latin for round, meaning that this is a group of bacteria that appear under the microscope as round, grape-like clusters.

There are more than 30 species of staph, with the most common in humans being Staphylococcus aureus and Staphylococcus epidermidis.

 

Staph Infection Symptoms

Staph infection can occur nearly anywhere in the body, and can range from a minor infection to a life threatening illness.

Skin and soft tissue infections
On the skin, staph infection usually results in a localized area of pus in a boil, abscess, or pimple. The area may appear red, swollen, or warm and may be painful to the touch. Skin infections may also have a blistered or crusted appearance. They may be localized to one small area, or become widespread as is possible with infections like impetigo or cellulitis.
Bacteremia
This type of infection occurs when staph bacteria enter the blood stream, and may travel to many parts of the body. This includes, but is not limited to, an individual’s heart (endocarditis), lungs (pneumonia), bone (osteomyelitis) or to a surgically implanted device like a prosthetic joint or pacemaker. A persistent fever is common with this type of infection, and pain or swelling in the infected area is likely.
Septic arthritis
In this infection, staph bacteria target joints, which may lead to joint swelling, severe pain, fever and chills.
Who's at risk?

Anyone can develop a staph infection, but some groups are at higher risk:

  • Newborns.
  • Women who are breastfeeding.
  • People who frequently are hospitalized.
  • Health care workers.
  • Intravenous drug users.
  • Those with chronic conditions, such as diabetes, cancer, vascular disease and lung disease.
  • Those with weakened immune systems.
  • Those with skin injuries or disorders, an intravenous catheter or surgical incision or implant.

An increasing prevalence of staph is seen in individuals who play contact sports or live in high density population areas such as military camps, dorms or long-term care facilities.

Diagnosis and Treatment

At any time, an estimated 30% of the healthy human population has staph present on skin or in mucous membranes such as the nose or mouth. Most people have been exposed to staph at one time or another. Usually S. aureus lives on the skin without causing any harm or disease. However, damaged skin, injuries and in-dwelling devices such as implants and catheters can allow the bacteria to overcome the natural immune response of the body and lead to a potentially severe infection.

Appearance
Staph infections of the skin are often diagnosed by appearance of the infected area. More serious internal staph infections often require culturing of samples to determine the presence and specific strain of staph.
Antibiotics

Skin infections may be treated with topical antibiotic cream and oral antibiotics, depending on the severity of infection. If abscesses are present, they will likely be drained. Serious or life threatening infections are treated with IV antibiotics.

If the bacteria are cultured for diagnosis, the susceptibility of the particular staph strain to various antibiotics will be tested to determine the most effective treatment.

Device Removal and Replacement

If the infection is associated with an in-dwelling device, such as a catheter or surgical implant, antibiotic treatment alone may not successfully eradicate the bacteria. If this is the case, the in-dwelling device may be removed and replaced.

Prevention

Staph can be transmitted directly, from person-to-person contact, or indirectly by coming into contact with staph on objects such as clothing and sports equipment. Many steps can be taken to reduce one’s risk of contracting a staph infection.

Good Hygiene
Good hygiene such as washing hands properly and frequently, keeping wounds covered, and not sharing personal items such as towels and razors can prevent the spread of infection. In areas used for athletic training, it is important for gear and equipment to be sanitized regularly.
Proper use of antibiotics

Overuse and misuse of antibiotics have resulted in strains of bacteria, such as MRSA, that require lengthy treatment with new antibiotics or combinations of antibiotics. These new drugs or combinations of drugs are often more expensive and more toxic than older antibiotics. Follow best practices for antibiotic use:

  • Use antibiotics for bacterial infections, not viruses such as the common cold.
  • Take antibiotics as directed, and finish the entire course.

In some instances, bacteria have become resistant to all available antibiotics – essentially returning us to the pre-antibiotic era of the 1930s, when people routinely succumbed to routine bacterial infections.

MRSA

MRSA stands for methicillin-resistant Staphylococcus aureus, and is pronounced “mursa.”

Prevalence
MRSA has been especially common in hospital settings (termed Hospital Acquired or HA-MRSA) for many years, and continues to be on the rise. However, over the past few years, a growing number of otherwise healthy individuals who have not been hospitalized are acquiring community associated (termed Community Associated or CA-MRSA) strains of staph. In fact, CA-MRSA infections have been reported worldwide, and are of epidemic proportions in the United States.
Antibiotic resistance
Strains of staph have developed resistance to certain antibiotics and can be more difficult to treat. In the case of MRSA, these strains are resistant to all antibiotics in the beta-lactam (penicillin) class. Therefore, an antibiotic from another class will be chosen. Vancomycin is often used alone or in combination with other antibiotics to treat MRSA. However,  vancomycin-resistant strains also have been observed.
Antibiotics misuse

The overuse of antibiotics over many years has resulted in an ever-growing population of antibiotic resistant bacteria, such as MRSA. Antibiotics are often misused by individuals who take them for viruses, like the common colds. Also, many people who need an antibiotic to overcome a bacterial infection may not take the antibiotics properly, such as not finishing a full course of antibiotics.

Antibiotic-resistant strains of bacteria, such as MRSA,require lengthy treatment with new antibiotics or combinations of antibiotics, which can be more expensive and more toxic than older antibiotics. In some instances, bacteria have become resistant to all available antibiotics