Methicillin-resistant Staphylococcus aureus, also known as MRSA, is a dangerous bacterial pathogen. This strain of bacteria, which is resistant to the antibiotic methicillin, may also be resistant to other antibiotics. Antibiotic resistance most commonly occurs when antibiotics are used needlessly or if patients do not take the full course of antibiotics. MRSA infections can be particularly difficult to treat.
Considerations
Although by definition, any strain of Staphylococcus aureus that is resistant to antibiotics is classified as MRSA, MRSA infections are commonly resistant to many antibiotics other than methicillin, MayoClinic.com explains. This is because the same cellular processes that the bacteria use to be resistant to methicillin can also allow them to resist the effects of other antibiotics. These bacteria are most resistant against a class of antibiotics known as beta-lactams, which includes penicillin and methicillin.
Infection Types
There are two different types of MRSA infections. Hospital-acquired MRSA is the result of the prevalence of the bacteria in health care settings as well as the rampant use of antibiotics. The frequent use of antibiotics in health care settings makes them an ideal breeding ground for antibiotic resistant bacteria. The other type of MRSA infection, known as community-acquired MRSA, is contracted outside of health care settings and can be spread by sharing towels and personal items or due to close contact with infected people, the University of Maryland Medical Center explains. Hospital-acquired MRSA can be easier to treat because it is easier to identify the strain of bacteria in a closed setting and determine what treatments are effective.
Analysis
Before a course of treatment can be started, many physicians will send the bacteria off for culture analysis. With this test, the bacteria are grown on special plates and then exposed to different antibiotics. This helps determine which antibiotics the MRSA is still sensitive to and allows doctors to avoid needless use of antibiotics that will be resisted by the bacteria.
Treatment
Sometimes MRSA will only cause a skin abscess to develop, which means that the patient may only need for the abscess to be drained. More serious infection, the New York Times Health Guides explains, can be treated with a variety of antibiotics, including sulfamethoxazole/trimethoprim, vancomycin, linezolid, clindamycin and tetracycline. The choice of antibiotics depends on the results of the bacterial analysis and which antibiotics have been effective in other patients affected by a MRSA outbreak.
Side Effects
Patients who are being treated for MRSA may need high doses of antibiotics, which can result in nausea, vomiting, diarrhea and muscle pains. Vancomycin is particularly potent, but can also cause many side effects, including a skin rash, unusual bruising/bleeding, dizziness and fainting, MedLinePlus explains.
