Development
MRSA stands for methicillin-resistant Staphylococcus aureus, which is a kind of bacteria. Because methicillin is a type of antibiotic that is commonly used to treat this kind of bacteria, these MRSA bacteria are resistant to antibiotic treatment. According to the National Institute of Allergy and Infectious Diseases, antibiotic-resistant bacteria are the result of bacteria evolving to survive the drugs that we use to treat them. Antibiotics, such as methicillin, work to disrupt the processes within the bacteria that allow them to stay alive. However, all bacteria are not genetically identical. Some bacteria have naturally developed genetic changes that allow them to be resistant to the action of antibiotics. As a result, when these bacteria are treated with an antibiotic, they can survive while the other bacteria around them are killed. This allows the resistant bacteria to reproduce and pass on the genes that grant them resistance to their offspring. As a result, the more that antibiotics are used, the greater the risk that antibiotic-resistant bacteria (such as MRSA) will develop.
MRSA in Hospitals
According to the Centers for Disease Control and Prevention, MRSA infections were first noticed in hospitals and other health care settings, where antibiotics are used to treat patients with infections and help patients with weakened immune systems avoid potentially life-threatening infections. Unfortunately, this rampant use of antibiotics also accelerates the evolution of strains of bacteria that are antibiotic-resistant. MRSA strains can spread easily throughout hospitals by contamination of health care workers' hands, which can infect patients with weakened immune systems or with IVs or catheters in place.
Community MRSA
MRSA can also evolve outside of the hospital. According to the Mayo Clinic, this can happen because antibiotics are often needlessly used, such as for the treatment of viral infections. Antibiotics can also be found in the food of livestock to make them grow larger. Rain can cause these antibiotics to run off and contaminate the water supply, further speeding the evolution of these bacteria. MRSA can be spread throughout the community by skin-on-skin contact, so it tends to spread throughout athletes who play contact sports. It can also be spread by sharing clothing, towels or razors. In addition, MRSA can spread quickly among kids because they tend to play closely together.
