MRSA is a contagious bacterial infection that is frequently featured in the news. Although news sources get most of the basic MRSA facts right, sometimes there are misconceptions that arise about MRSA. This text will discuss the facts about MRSA and dispel a few myths and popular misconceptions about MRSA infections.
MRSA, a virulent drug-resistant strain of a bacterium called Staphylococcus aureus, stands for methicillin-resistant Staphylococcus aureus. Although the bacterium’s resistance to methicillin is described in the name of the strain, methicillin is not commonly used to treat bacterial infections anymore, as methicillin is less effective than other antibiotics in the same class of drugs and has more potential side effects. MRSA is actually resistant to multiple drugs in the beta-lactam family, which is the family of antibiotics that contains penicillin, the first available antibiotic. MRSA produces an enzyme called beta-lactamase that targets a specific part of the drug’s chemical structure and disables the beta-lactam antibiotics. The reason the bacterium is called MRSA is because methicillin is still the drug that is used in the laboratory to test pathogenic bacteria for beta-lactam drug resistance. There are some other antibiotics that are available that MRSA is not resistant to, such as vancomycin and tetracycline.Bacteria become resistant to drugs through random mutation and a subsequent selection process by the administration of the drugs. That is, if a person has a Staph infection and they are taking antibiotics, there is a small chance that some of the bacteria will develop a mutation that allow the bacteria to become resistant to the drug to some degree. If the patient stops taking antibiotics before the infection is cleared, the more resistant surviving bacteria have the chance to multiply and spread. This is why it is extremely important to complete a full course of antibiotics and not just stop taking the medication when symptoms improve.
In the news media, MRSA is sometimes called a “superbug” because of its drug resistance. In reality, many people are already colonized with Staphylococcus aureus bacteria and it does not cause an infection. In those that do contract an infection, the infection is usually minor and clears up with minimal treatment. Even resistant Staph aureus is treatable in the early stages of infection. MRSA is usually contracted in a hospital setting, and those who are ill or who have weakened immune systems are more susceptible to contracting a MRSA infection. MRSA continues to be a public health problem in hospitals and care facilities. Strains of MRSA do exist that are not localized to hospitals and health care facilities. These community-acquired strains are actually more virulent than the hospital strains, and they can infect healthy people and cause outbreaks more easily. In the majority of community-acquired cases, the MRSA infection remains localized to the skin.
According to the Centers for Disease Control and Prevention (CDC), the number of cases of MRSA infections that become invasive are actually decreasing in hospital settings. There has been no evidence of a decrease in community-acquired MRSA transmission.