What Is Methicillin-Resistant Staphylococcus Aureus (MRSA)?
MRSA stands for methicillin-resistant Staphylococcus aureus (S. aureus) bacteria. This organism is known for causing skin infections in addition to many other types of infections. There are other designations in the scientific literature for these bacteria according to where the bacteria are acquired by patients, such as community-acquired MRSA (CA-MRSA or CMRSA), hospital-acquired or health-care-acquired MRSA (HA-MRSA or HMRSA), or epidemic MRSA (EMRSA).
Statistical data suggest that as many as 19,000 people per year die from MRSA in the U.S.; current data suggest this number has declined by about 25%-35% in recent years, in part, because of prevention practices at hospitals and home care.
Although S. aureus has been causing infections (Staph infections) probably as long as the human race has existed, MRSA has a relatively short history.
MRSA was first noted in 1961, about two years after the antibiotic methicillin was initially used to treat S. aureus and other infectious bacteria. The resistance to methicillin was due to a penicillin-binding protein coded for by a mobile genetic element termed the methicillin-resistant gene (mecA).
In recent years, the gene has continued to evolve so that many MRSA strains are currently resistant to several different antibiotics such as penicillin, oxacillin, and amoxicillin (Amoxil, Dispermox, Trimox). HA-MRSA are often also resistant to tetracycline (Sumycin), erythromycin (E-Mycin, Eryc, Ery-Tab, PCE, Pediazole, Ilosone), and clindamycin (Cleocin).