This article on Epainassist.com has been reviewed by a medical professional, as well as checked for facts, to assure the readers the best possible accuracy.

We follow a strict editorial policy and we have a zero-tolerance policy regarding any level of plagiarism. Our articles are resourced from reputable online pages. This article may contains scientific references. The numbers in the parentheses (1, 2, 3) are clickable links to peer-reviewed scientific papers.

The feedback link “Was this Article Helpful” on this page can be used to report content that is not accurate, up-to-date or questionable in any manner.

This article does not provide medical advice.


What Is Methicillin-Susceptible Staphylococcus Aureus (MSSA): Causes, Symptoms, Treatment, Diagnosis, Complications

What Is Methicillin-Susceptible Staphylococcus Aureus (MSSA)?

Methicillin-Susceptible Staphylococcus Aureus (MSSA) is a type of skin infection. It is commonly known as a staph infection and is treated with a course of antibiotics. There are two types of staph infections, and they are classified in the manner in which they respond to the treatment:

  • Methicillin-Susceptible Staphylococcus Aureus (MSSA) infections that are easily treated with antibiotics
  • Methicillin-resistant Staphylococcus aureus (MRSA) infections, though, are resistant to some types of antibiotics (1)

Both types of staph infections are severe conditions and even prove to be life-threatening.

What are the Symptoms of Methicillin-Susceptible Staphylococcus Aureus (MSSA)?

Symptoms of Methicillin-Susceptible Staphylococcus Aureus (MSSA) infection varies depending on where the staph infection is located. This infection can affect your skin (most common), bones, joints, and even blood. Symptoms of Methicillin-Susceptible Staphylococcus Aureus (MSSA) infection range from being mild to life-threatening. (2)

What are the Symptoms of Methicillin-Susceptible Staphylococcus Aureus (MSSA)?

Here are some of the potential signs of a Methicillin-Susceptible Staphylococcus Aureus infection:

Skin Infections: Staph infections such as MSSA most commonly affect the skin. This may cause symptoms such as abscesses, bus bumps, boils, impetigo, and cellulitis.

Aches and Pains: Methicillin-Susceptible Staphylococcus Aureus (MSSA) infections can also cause pain and swelling in the muscles, joints, and even give a headache.

Fever: It is common to get a fever since your body is fighting against infection after all. It is common for a fever to be accompanied by chills, sweating, dehydration, and confusion.

Stomach Issues: The staph bacteria can even cause food poisoning, leading to many types of gastrointestinal symptoms. Some of the common symptoms of food poisoning caused by the staph bacteria are abdominal pain and cramps, nausea, diarrhea, dehydration, and vomiting. (3)

What are the Causes of Methicillin-Susceptible Staphylococcus Aureus Infection (MSSA)?

Staph bacteria can be commonly found on the surface of your skin and inside the nose. According to the Centers for Disease Control and Prevention (CDC), nearly 30 percent of all people have staph bacteria present inside their noses. (4)

Generally, staph bacteria are harmless, and it is also possible to have a staph infection without experiencing any symptoms. In some cases, though, staph bacteria can go on to cause some minor symptoms and easily treatable throat, mouth, nose, and skin infections. Many times staph infections even end up healing on their own.

An infection caused by the staph bacteria can become dangerous if the infection is also present in your blood. This usually happens if you have an advanced form of the infection that has been left untreated. If left untreated, staph infections can also go on to cause many types of life-threatening complications.

In medical settings, the staph bacteria is considered to be highly dangerous because it can easily pass on from one person to the next.

Staph gets transmitted through skin to skin contact, and the most common form of transmission happens from touching something that contains the bacteria and then spreading it to your hands. When you shake hands with someone else, or you touch another surface with your hands, the bacteria automatically gets transferred.

Furthermore, staph bacteria are known to be very resilient. They can remain alive on surfaces such as bedding or doorknobs or table surfaces for a long enough time to allow another person to catch the bacteria and develop an infection.

Who Is A High Risk Of Contracting Methicillin-Susceptible Staphylococcus Aureus (MSSA) Infection?

Methicillin-Susceptible Staphylococcus Aureus (MSSA) infections are known to affect children, adults, and older adults. Here are some factors that increase your risk of contracting Methicillin-Susceptible Staphylococcus Aureus (MSSA) infections:

A Recent Stay At A Healthcare Center/Facility: Staph bacteria are commonly found in places where people with weakened immune systems are likely to come in contact with potentially infected people or surfaces. This may include:

  • Nursing homes
  • Clinics
  • Hospitals
  • Outpatient facilities

Medical Devices: Staph bacteria can also quickly enter your system through infected medical devices that are placed inside the body, including:

  • Intravenous (IV) devices
  • Catheters
  • Tubes used for breathing, feeding, or kidney dialysis

People With A Compromised Immune System Or Having Some Chronic Health Condition: This includes people who have:

  • Cancer
  • Diabetes
  • Lung diseases
  • Kidney diseases
  • Conditions that affect the skin including psoriasis and eczema
  • People who regularly use injection drugs such as insulin are also at a higher risk of infection.

Having an Uncovered Open Wound Or A Draining Wound: Staph bacteria can enter your body through any type of open wound. This is common among people who work or live in close quarters or who play contact sports.

Unhygienic Food Preparation: Staph bacteria can transmit from skin to food if people who are cooking or handling the food do not wash their hands properly.

Sharing Personal Items: Sharing personal items can also increase the risk of contracting staph infection. These items may include:

  • Towels
  • Razors
  • Bedding
  • Uniforms
  • Sports equipment

The chances of this happening are very high in shared housing or locker rooms.

Diagnosing Methicillin-Susceptible Staphylococcus Aureus (MSSA) Infections

If your doctor suspects that you may be suffering from an Methicillin-Susceptible Staphylococcus Aureus (MSSA) infection, then they will proceed to question you about your symptoms and also take down your medical history. They will examine your skin for signs of an infection or any open wound. If you have an open or draining injury, make sure to inform your doctor about it.

Your doctor will also ask you questions to determine whether there is a possibility that you were exposed to the staph bacteria. They are also going to run some tests to confirm a staph infection. These diagnostic tests may include:

Blood test: A blood test is used to identify if there is an increased white blood cell (WBC) count in your blood. A high level of white blood cells in the blood indicates that the body is fighting off an infection. A blood culture may also be used to determine if the infection is in the blood.

Tissue culture: Your doctor will take a tissue sample from the suspected infected area and send it for examination to the lab. The tissue sample will be allowed to grow under controlled conditions in the lab, and then it will be tested. This is helpful in determining whether the infection is MSSA or MRSA, and what type of medications should be used in treating it.

You will receive the results of the culture tests in 2 to 3 days, and the standard blood test report will be given within 24 hours itself. In some cases, the tissue culture test result may take longer.

Once a staph infection is positively diagnosed, your doctor may also run some more tests to check for any complications of the infection.

Treatment of Methicillin-Susceptible Staphylococcus Aureus (MSSA) Infections

Antibiotics are the first step in treating any type of staph infection. Your doctor is going to determine which type of antibiotics are more likely to be effective in your individual case. This is identified by understanding how you got the infection in the first place.

Some of the antibiotics for treating Methicillin-Susceptible Staphylococcus Aureus (MSSA) have to be taken orally, while others have to be administered intravenously. Some of the antibiotics that are prescribed for treating Methicillin-Susceptible Staphylococcus Aureus (MSSA) include: (5, 6)

  • Oxacillin
  • Nafcillin
  • Cephalexin

Antibiotics used for treating Methicillin-Susceptible Staphylococcus Aureus (MSSA) infections include: (7)

  • Linezolid
  • Vancomycin
  • Clindamycin
  • Doxycycline
  • Daptomycin
  • Sulfamethoxazole/trimethoprim

It is essential to take the antibiotics exactly as your doctor has prescribed. It is also critical to finish the entire course of antibiotics, even if you start to feel better.

Otherwise, there is a high risk of the Methicillin-Susceptible Staphylococcus Aureus (MSSA) infection returning.

Your doctor may prescribe additional treatments looking at your symptoms. For example, if you have a skin staph infection, then your doctor may find it necessary to make an incision to drain the fluid from the wound.

If there are any medical devices that are believed to be causing the infection, then your doctor might have the device removed.

Are There Any Complications of an MSSA Infection?

If left untreated, then staph infections can lead to several medical conditions, many of which may even be life-threatening. Here are some of the commonly observed complications of staph infections:

  • The bacteria can infect the bloodstream causing bacteremia.
  • In people with underlying lung conditions, the bacteria can cause pneumonia. (8)

If the bacteria goes on to infect the heart valves, it can cause endocarditis. This, in turn, increases the risk of having a stroke or other heart-related problems. (9, 10)

When the staph bacteria infects the bones, it can cause osteomyelitis. The bacteria are able to reach the bones either through the bloodstream or through drug injections or wounds.

Certain types of staph bacteria can cause toxic shock syndrome, which is a fatal condition that is caused by toxins associated with these specific bacteria.

Septic arthritis is another complication that affects the body’s joints, causing swelling and pain.


Most people will recover from Methicillin-Susceptible Staphylococcus Aureus (MSSA) infections without any problem. However, the healing window does depend on the type of infection you have. If the staph bacteria enter your bloodstream, then these infections can go on to become severe, and even prove to be fatal.

Recovery from staph infections takes a couple of months. The earlier you begin treatment, the better will be the chances of a fast recovery.

If you suspect that you have an Methicillin-Susceptible Staphylococcus Aureus (MSSA) infection, you should consult your doctor right away.


  1. Gordon, R.J. and Lowy, F.D., 2008. Pathogenesis of methicillin-resistant Staphylococcus aureus infection. Clinical infectious diseases, 46(Supplement_5), pp.S350-S359.
  2. Kim, S.H., Kim, K.H., Kim, H.B., Kim, N.J., Kim, E.C., Oh, M.D. and Choe, K.W., 2008. Outcome of vancomycin treatment in patients with methicillin-susceptible
  3. Staphylococcus aureus bacteremia. Antimicrobial agents and chemotherapy, 52(1), pp.192-197.
  4. Le Loir, Y., Baron, F. and Gautier, M., 2003. Staphylococcus aureus and food poisoning. Genet Mol Res, 2(1), pp.63-76.
  5. Cdc.gov. (2020). Staphylococcus aureus in Healthcare Settings | HAI | CDC. [online] Available at: https://www.cdc.gov/hai/organisms/staph.html [Accessed 28 Feb. 2020].
  6. Lee, S., Choe, P.G., Song, K.H., Park, S.W., Kim, H.B., Kim, N.J., Kim, E.C., Park, W.B. and Oh, M.D., 2011. Is cefazolin inferior to nafcillin for treatment of methicillin-susceptible Staphylococcus aureus bacteremia?. Antimicrobial agents and chemotherapy, 55(11), pp.5122-5126.
  7. Bidell, M.R., Patel, N. and O’Donnell, J.N., 2018. Optimal treatment of MSSA bacteraemias: a meta-analysis of cefazolin versus antistaphylococcal penicillins. Journal of Antimicrobial Chemotherapy, 73(10), pp.2643-2651.
  8. French, G.L., 2006. Bactericidal agents in the treatment of MRSA infections—the potential role of daptomycin. Journal of Antimicrobial Chemotherapy, 58(6), pp.1107-1117.
    Kallen, A.J., Brunkard, J., Moore, Z., Budge, P., Arnold, K.E., Fosheim, G., Finelli, L., Beekmann, S.E., Polgreen, P.M., Gorwitz, R. and Hageman, J., 2009. Staphylococcus aureus community-acquired pneumonia during the 2006 to 2007 influenza season. Annals of emergency medicine, 53(3), pp.358-365.
  9. Watanakunakorn, C., Tan, J.S. and Phair, J.P., 1973. Some salient features of Staphylococcus aureus endocarditis. The American journal of medicine, 54(4), pp.473-481.
  10. Watanakunakorn, C. and Baird, I.M., 1977. Staphylococcus aureus bacteremia and endocarditis associated with a removable infected intravenous device. The American journal of medicine, 63(2), pp.253-256.
Team PainAssist
Team PainAssist
Written, Edited or Reviewed By: Team PainAssist, Pain Assist Inc. This article does not provide medical advice. See disclaimer
Last Modified On:March 6, 2020

Recent Posts

Related Posts