Staphylococcus aureus is an extremely common bacterium found on the skin of many healthy people. At least two different strains of staph have evolved to be resistant against a large class of antibiotics called beta-lactams. These strains are called methicillin-resistant Staphylococcus aureus, or MRSA, after one of the less-commonly used beta-lactams.
Symptoms of MRSA are the same as symptoms for non-resistant staph infections. The only significant difference is the invulnerability of MRSA to many antibiotics. Staphylococcus can cause infections in many different organ systems, and symptoms vary depending on the type of infection.
Symptoms of MRSA: Skin Infections
Staph, including MRSA, commonly infects the skin, where it can cause any of several types of infection. Cellulitis is a general infection of the connective tissue of the skin; symptoms are redness, pain, and swelling of the skin. Folliculitis is an infection of the hair follicles, causing little whiteheads of pus at the bases of hairs. These small, superficial abscesses are called furuncles; clusters of them are called carbuncles. Boils are larger collections of pus that result from untreated cellulitis or folliculitis. Impetigo (im-puh-TIE-go), also called school sores, is a staph skin infection that causes blisters and sores covered by honey-colored scabs. About 20% of impetigo cases are caused by MRSA (Dhar 2007).
Symptoms of MRSA: Wound Infections and Abscesses
Any time there is a wound or open sore on the skin, whether from surgery, injury, or another cause, bacteria can enter and cause an infection. Staph, including MRSA, are notorious for infecting wounds. The symptoms of a wound infection may include pus, inflammation, and pain from the wound; red streaks on the skin running from the wound toward the heart; fever and swollen lymph nodes; black, dead tissue around the wound; and an unusual or foul odor coming from the wound (WD 2009).
An abscess is a cavity filled with pus that forms as the result of an infection, such as a MRSA infection. In an abscess, the healthy cells surrounding the infection form a wall, which prevents the infection from spreading throughout the body but also limits the ability of the immune system to attack the infection.
Symptoms of MRSA: Organs and Systemic Infections
Staph bacteria, including MRSA, can cause serious, life-threatening infections of internal organs and tissues. These infections often start with more superficial infections, such as the ones described above. Symptoms may include fever and pain at the site of the infection.
Osteomyelitis is an infection of the bone or bone marrow. Pericarditis is an infection of the pericardium, the sac that surrounds the heart. MRSA is one of the possible causes of pneumonia, which causes coughing and difficulty breathing as the result of fluid accumulation in the lungs. Bacteremia is the presence of bacteria such as MRSA in the blood, and can lead to sepsis (blood poisoning), whose more serious symptoms include shock and tachycardia (fast heartrate).
- Dhar, A. Daminan. “Impetigo and Ecthyma.” 2007, Merck Manual of Diagnosis and Therapy. Available online at https://www.merck.com/mmpe/sec10/ch119/ch119i.html
- eMedicineHealth.com. “What Diseases Are Caused by Staphylococcus?” 2009, WebMD, Inc. Available at https://www.emedicinehealth.com/staphylococcus/page2_em.htm#diseases
- WrongDiagnosis.com (WD). “Symptoms of Surgical Wound Infection.” 2009, Health Grades, Inc. Available at https://www.wrongdiagnosis.com/s/surgical_wound_infection/symptoms.htm#symptom_list