by D. Vogt

Created on: July 27, 2010

MRSA, or Methicillin-Resistant Staphylococcus Aureus, is, as the name suggests, increasingly difficult to treat because of its evolved resistance to common antibiotics. So-called "superbugs," or bacteria against which antibiotics are now ineffective, are gradually increasing both in quantity and severity. Particularly in hospital settings, one of the most concerning of the new superbugs is MRSA.

MRSA simply refers to a number of strains of common S. aureus, which can infect the nose, the urinary tract, the respiratory tract, and open cuts and wounds. When a MRSA infection spreads into the body, it typically takes the form of pimple-like spots on the skin, which grow in size as the bacteria inside them multiplies. If the pathogen begins to infect internal organs, it can become life-threatening, causing pneumonia, sepsis, and toxic shock. Hospitals, prisons, food production sites, and gyms are known to be hotbeds of Staph aureus and particularly of MRSA.

Diagnosis of MRSA is a relatively simple procedure, but because of its increased resistance, treatment is substantially more difficult. Traditionally, Staph aureus was treated with standard front-line antibiotics, including penicillin. However, MRSA has evolved resistance to these common antibiotics through years of use, overuse, and misuse (in particular, increased resistance is known to occur when people fail to complete the entire prescribed course of antibiotics on schedule, and also when antibiotics are overprescribed and used when they do not need to be).

However, after penicillin, MRSA then went on to develop resistance to the next set of drugs commonly used against it. Some strains can still be effectively attacked using clandomycin, sulfa drugs, or tetracyclines, but others are resistant to these as well. This led doctors to switch to what was previously the last-ditch antibiotic of last resort, vancomycin. Vancomycin is taken by IV and, although less effective against unresistant bacteria than some other antibiotics, could be used in cases where those antibiotics were no longer effective.

Unfortunately, some strains of MRSA are now becoming vancomycin-resistant as well. Newer and more exotic antibiotics, like linezolid, are therefore becoming the new last lines of defence against MRSA. However, at present, bacterial resistance is probably accumulating at a rate significantly faster than new antibiotics are being invented, tested, and approved. There is a real risk, therefore, that within the foreseeable future we may have no antibiotics guaranteed to be effective against MRSA. This fear is leading to extreme caution in treatment of new MRSA cases, especially in controlled settings like hospitals. If antibiotics become entirely ineffective, it may require new investment in the previous approach to anti-bacterial medicine (and used throughout the Cold War in the Soviet Union), phage therapy.

- Sources and More Information -

Mayo Clinic. "MRSA Infection."

National Institutes of Health. "MRSA: MedlinePlus Medical Encyclopedia."

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