MRSA Infection (cont.)
If MRSA is so resistant to many antibiotics, how is it treated or cured?
As stated by the U.S. Centers for Disease Control and Prevention (CDC):
- "First-line treatment for mild abscesses is incision and drainage."
- "If antibiotic treatment is clinically indicated, it should be guided by the susceptibility profile of the organism."
Fortunately, most MRSA still can be treated by certain specific antibiotics (for example, vancomycin
[Vancocin], linezolid [Zyvox], and others, often in combination with vancomycin). Some CA-MRSA strains are susceptible to trimethoprim-sulfamethoxazole (Bactrim), doxycycline, and clindamycin, although reports suggest clindamycin resistance is increasing rapidly. For MRSA carriers, mupirocin antibiotic cream can potentially eliminate MRSA from mucous membrane colonization. Studies suggest mupirocin is much more effective than other topical antibiotics such as bacitracin.
A good medical practice is to determine, by microbiological techniques done in a lab, which antibiotic(s) can kill the MRSA and use it alone or, more often, in combination with additional antibiotics to treat the infected patient. Since resistance can change quickly, antibiotic treatments may need to change also. Many people think they are "cured" after a few antibiotic doses and stop taking the medicine. This is a bad decision because the MRSA may still be viable in or on the person and thus is capable of reinfecting the person. Also, the surviving MRSA may be exposed to low antibiotic doses when the medicine is stopped too soon; this low dose may allow MRSA enough time to become resistant to the medicine. Consequently, MRSA patients (in fact, all patients) treated with appropriate antibiotics should take the entire course of the antibiotic as directed by their doctor. A note of caution is that, in the last few years, there have been reports of a new strain of MRSA that is resistant to vancomycin (VRSA or vancomycin-resistant S. aureus) and other antibiotics. Currently, VRSA is detected more often than a few years ago, but if it becomes widespread, it may be the next "superbug."
Where are other MRSA information sources?
http://www.emedicinehealth.com/slideshow_mrsa_pictures/article_em.htm
http://www.pnas.org/cgi/content/full/99/11/7687
http://www.aafp.org/afp/20061201/tips/18.html
http://www.cdc.gov/ncidod/EID/vol11no06/04-0831.htm
http://www.kaisernetwork.org/daily_reports/rep_index.cfm?DR_ID=45809
http://www.cdc.gov/ncidod/dhqp/ar_MRSA.html
- MRSA means methicillin-resistant Staphylococcus aureus bacteria.
- The majority of MRSA infections are classified as CA-MRSA (community acquired) or HA-MRSA (hospital- or health-care-acquired).
- MRSA infections are transmitted person to person by direct contact with the skin, clothing, or area (for example, sink, bench, bed, utensil) that had recent physical contact with a MRSA-infected person.
- The majority of CA-MRSA starts as skin infections; HA-MRSA can begin an infection of the skin, a wound (often a surgical site), or a location where medical devices are placed (catheters, IV lines or other devices).
- Cellulitis, abscess, or draining pus is often one of the first signs and symptoms of MRSA infections.
- Most MRSA infections are diagnosed by culture and antibiotic sensitivity testing of
Staphylococcus aureus bacteria isolated from an infected site; a PCR test is also available.
- Currently, MRSA bacteria are almost always found to be resistant to multiple antibiotics. All isolated MRSA strains need to have antibiotic susceptibility determined to choose the correct or appropriate antibiotic therapy.
- Treatment of HA-MRSA frequently involves the use of vancomycin, often in combination with other antibiotics given by IV; CA-MRSA can often be treated on an outpatient basis with specific oral or topical antibiotics, but some serious CA-MRSA infections (for example, pneumonia) often require appropriate antibiotics by IV.
- Prevention of MRSA is difficult but possible by excellent hygiene practices, avoiding skin contact with infected people or items they have touched and by wearing disposable gloves, gowns, and masks when treating or visiting hospitalized MRSA patients. Covering skin abrasions and minor lacerations immediately may also help prevent MRSA infections, especially in children and in people involved in group sports activities.
References:
U.S. Centers for Disease Control and Prevention. MRSA Infections, 2009
U.S. Department of Health & Human Services, National Institutes of Health. MRSA, 2008
U.S. Department of Health & Human Services, National Institutes of Health. Genes key to Staph disease severity, 2009
eMedicine.com. Staphylococcus aureus Infections, 2009
Last Editorial Review: 8/21/2009
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