According to 2011 statistics from the Centers for Disease Control and Prevention, MRSA (methicillin-resistant Staphylococcus aureus) causes more than 80,000 invasive infections and 11,000 deaths per year. Some of the most serious complications of the disease, including death, may have a surprising cause.
Scientists at Cedars-Sinai, the Los Angeles based hospital and research institution, published an article today in the journal Cell Host & Microbe that details the implications of managing MRSA, the often difficult to control virulent form of the common staph infection. The research team found that, in mice, treatment of MRSA with antibiotics similar to methicillin, called beta-lactams, caused the MRSA bacteria to build cell walls that are highly inflammatory and damaging to the surrounding tissues. Beta-lactam antibiotics are a broad class that includes penicillin derivatives, cephalosporins, monobactams, and carbapenems, more than half of all available antibiotics are included in this class.
The research essentially shows that prescribing beta-lactam antibiotics to treat infections may worsen the infection, should the source prove to be MRSA, and may even cause death in some cases. The dilemma for doctors, however, is that it can take a day or two to culture MRSA, which makes early diagnosis difficult, and beta-lactam antibiotics are currently one of the most effective defenses against serious non-MRSA infections. The study’s author, Dr. Sabrina Mueller, PhD., does caution that doctors should continue to follow the current national guidelines set by the Infectious Diseases Society of America for antimicrobial treatment of staph infections until the results of the study could be validated in human subjects.
Given the quickly growing number of MRSA infections nationwide, it is unclear at this time whether the guidelines for antibiotic use will change or whether the unfortunate patients whose condition worsens due to the misuse of beta-lactams antibiotics will have any recourse against the doctors that prescribe them. Considering that it is now commonly understood that the overuse of antibiotics caused the rise of resistant bacteria such as MRSA, it will be interesting to see whether, and to what extent, this latest research impacts the use of antibiotics.