Difference Between MRSA and Staph Infection

Staphylococcus aureus (staph) is one of the most common bacterial organisms that reside on the skin. Usually, it does not cause problems, but it can lead to several types of infections when it gets under the skin, in the blood, or to other body organs.

Methicillin-resistant Staphylococcus aureus (MRSA) is the same bacteria, but a strain that is resistant to certain commonly used antibiotics (drugs that prevent the growth of or kill bacteria).

This article discusses the differences between MRSA and the typical staph infection, known as methicillin-sensitive Staphylococcus aureus (MSSA), as well as how to treat and prevent them.

mrsa bacteria

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MRSA and Staph

MRSA is a type of staph, so people can develop the same types of infections with either organism.

The difference between the two is that MRSA is more difficult to treat since it is resistant to certain antibiotics. Because the only difference is the antibiotic sensitivity, a typical staph infection is referred to as methicillin-sensitive Staphylococcus aureus.

What Is MRSA?

MRSA is a strain of Staphylococcus aureus that is resistant to certain antibiotics, specifically methicillin, which is similar to penicillin.

Symptoms

The symptoms associated with MRSA infections are the same as those of an MSSA infection and depend on the part of the body that is infected.

Skin infections cause:

  • Redness
  • Swelling
  • Warmth
  • Pain

Deeper skin infections can form abscesses that drain pus. Severe skin infections can also be associated with fever

Some skin infections spread to other organs in the body, such as the lungs, heart, and bones, and causes the following:

  • MRSA pneumonia (in the lungs) causes fever, cough, and shortness of breath.
  • MRSA infections of the heart are called endocarditis, and lead to fever, palpitations, weight loss, and a heart murmur.
  • An infection of the bones called osteomyelitis causes deep pain.

Like MSSA, MRSA can also lead to bacterial blood poisoning, called sepsis. Patients with sepsis have fever, lethargy, a fast heart rate, and low blood pressure.

Appearance

There is no way to tell the difference between MSSA and MRSA based on how the infection looks on the skin or other appearance-related symptoms.

Causes

Antibiotic-resistant organisms were previously only common in healthcare settings such as hospitals and nursing homes. However, MRSA has spread outside healthcare settings and is widely prevalent in the general community.

MRSA usually spreads by contact with someone who has an infection, or by touching dry surfaces that carry the bacterium. The organism can be transmitted through shared towels, clothing, and razors. Bacteria can live on high-use surfaces like door handles, athletic equipment, and TV remotes for months.

MRSA is also transmitted by sharing needles used to inject drugs or medications. People who inject drugs are 16 times more likely to develop a severe staph infection than the general public.

Treatment

Since MRSA is resistant to some commonly used antibiotics, healthcare providers must use other treatments to cure the infection.

Simple skin infections are treated with oral clindamycin, trimethoprim-sulfamethoxazole, doxycycline, or linezolid. Complex or severe infections require intravenous (IV) therapy with vancomycin or daptomycin. 

The Infectious Diseases Society of America recommends that healthcare providers use typical antibiotic therapy to treat skin infections, even though MRSA is common outside of the hospital setting. Antibiotics that treat MRSA should be considered if the infection does not respond to initial therapy.

How to Know If You Have MRSA

If you have a staph skin infection that is not getting better while taking antibiotics, you might have MRSA.

When to See a Healthcare Provider

There is no way to know whether a person has MRSA or MSSA based on the look of the infection or symptoms. If you suspect a staph infection, a healthcare provider should evaluate it and determine whether treatment is necessary.

What to Do If You Do Have MRSA

Like MSSA, MRSA is contagious. Staph can also be ingested and lead to gastrointestinal illnesses associated with vomiting and diarrhea.

To prevent the spread to other people, you should cover your infection and avoid handling or preparing food for other people.

Prevention

You can reduce your risk of MRSA infections by doing the following:

  • Maintain good hand and body hygiene. This means washing your hands often and bathing regularly, particularly after exercise and group activities.
  • Avoid sharing personal items such as towels, linens, clothing, and razors, especially with someone who has an infection.
  • Clean athletic equipment before and after each use.
  • Speak to a healthcare provider early if you think you have an infection to prevent severe disease.

Summary

MRSA is a strain of Staphylococcus aureus resistant to commonly used antibiotics. The infection is otherwise the same as any other staph infection. MRSA treatment requires certain antibiotics that the organism is not resistant to. You can prevent the spread of MRSA by maintaining good hygiene, avoiding shared use of linens and razors, cleaning exercise equipment, and covering your wounds.

A Word From Verywell

Everyone is at risk for MRSA infections, and there is no way to tell the difference between a resistant organism and a sensitive organism. However, MRSA is treatable with several different antibiotics. If you suspect a skin infection or something deeper, speak with your healthcare provider about what to do next.

Frequently Asked Questions

  • What does MRSA look like?

    MRSA looks the same as any other staph infection. Skin infections present with redness, swelling, warmth, and pain. Sometimes there is a yellow crust around pimples. MRSA abscesses will be significantly swollen and soft in the middle with pus inside.

  • How long does MRSA take to heal?

    Healing time depends on the type of MRSA infection. A skin infection will improve one to two days after starting antibiotic therapy, and the typical duration of treatment is seven days. However, a deeper heart or blood condition requires several weeks of treatment.

  • How long does MRSA live on surfaces?

    Staph bacteria can survive on linens for days to weeks. One study showed that staph could survive on dry surfaces like doorknobs for months.

  • Does MRSA itch when healing?

    When a wound begins to heal, the inflammation and immune response in the area stimulates sensory nerves that send signals to the brain interpreted as an itch. Therefore, all wounds—including those caused by MRSA—itch when they are healing.

  • How long is MRSA contagious for after starting antibiotics?

    MRSA is contagious as long as the bacterium is still causing an infection. Therefore, a person is potentially contagious until the wound heals. It's essential to keep wounds covered to avoid spreading bacteria to other people.

6 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Centers for Disease Control and Prevention. MRSA: general information.

  2. MedlinePlus. Staphylococcal infections.

  3. Hassoun A, Linden PK, Friedman B. Incidence, prevalence, and management of MRSA bacteremia across patient populations—a review of recent developments in MRSA management and treatmentCrit Care. 2017;21(1):211. doi:10.1186/s13054-017-1801-3

  4. Kramer A, Schwebke I, Kampf G. How long do nosocomial pathogens persist on inanimate surfaces? A systematic review. BMC Infect Dis. 2006;6:130. doi:10.1186/1471-2334-6-130

  5. Tong SY, Davis JS, Eichenberger E, Holland TL, Fowler VG Jr. Staphylococcus aureus infections: epidemiology, pathophysiology, clinical manifestations, and management. Clin Microbiol Rev. 2015;28(3):603-61. doi:10.1128/CMR.00134-14

  6. Liu C, Bayer A, Cosgrove SE, et al. Clinical practice guidelines by the infectious diseases society of america for the treatment of methicillin-resistant staphylococcus aureus infections in adults and childrenClinical Infectious Diseases. 2011;52(3):e18-e55. doi:10.1093/cid/ciq146

By Christine Zink, MD
Dr. Christine Zink, MD, is a board-certified emergency medicine with expertise in the wilderness and global medicine. She completed her medical training at Weill Cornell Medical College and residency in emergency medicine at New York-Presbyterian Hospital. She utilizes 15-years of clinical experience in her medical writing.