Different varieties of the Staphylococcus aureus bacteria that have developed a resistance to antibiotics cause MRSA, according to Mayo Clinic. The bacteria are normally harmless until they enter a person's body through a cut or tear in the skin, which subsequently causes the infection.
Regular Staphylococcus aureus bacteria are found on about one-third of the population, according to Mayo Clinic. Usually, the bacteria are found on a person's skin and nose. Some of these bacteria, after decades of exposure to unnecessary antibiotics, have developed a resistance to antibiotic treatment, which could make the condition very difficult to treat.
MRSA is usually spread via contact, either by touching a person who has it or an object that has been contaminated by the bacteria, states WebMD. The bacteria is especially common on people with weakened immune systems. This makes it much more likely to catch the bacteria in a heath care setting, such as a nursing home, hospital or other care unit. The bacteria can even be spread through surgical wounds or invasive devices, such as feeding tubes or catheters.
While the bacteria are resistant to many antibiotics, there are still some antibiotics that are able to treat the disease, according to Mayo Clinic. In some cases, antibiotics may not be necessary, as a doctor may opt to simply drain MRSA abscesses in order to treat the condition.