Staphylococcus aureus, or staph, are common bacteria found on the skin and in the nose of many people. While often harmless, they can cause infections if they enter the body through cuts or wounds. A major concern is when staph develops resistance to common antibiotics, known as antibiotic resistance. This resistance makes infections harder to treat, challenging healthcare globally.
Understanding Staphylococcus Aureus
Staphylococcus aureus is a widespread bacteria found on the skin and in the nose of about 30% of individuals. For most people, its presence does not lead to illness. However, when the skin barrier is broken through cuts or wounds, staph can enter the body and cause various infections. These commonly appear as skin issues like boils (painful, pus-filled lumps), impetigo (crusty sores), or cellulitis (spreading redness and swelling). More severe infections can occur if the bacteria spread to the bloodstream, bones, or organs, potentially leading to conditions such as pneumonia or heart valve infections.
Understanding Methicillin-Resistant Staphylococcus Aureus
Methicillin-resistant Staphylococcus aureus, or MRSA, is a specific strain of staph bacteria that has developed resistance to several common antibiotics, including methicillin, oxacillin, penicillin, and amoxicillin. MRSA is not a different type of bacteria altogether, but rather a version of Staphylococcus aureus that has acquired defense mechanisms against these medications.
This antibiotic resistance limits treatment options. MRSA infections are more difficult to treat than those caused by methicillin-susceptible Staphylococcus aureus (MSSA). While many MRSA skin infections are treatable, more serious infections can progress rapidly without effective antibiotics.
How Staph Becomes MRSA
The transformation of regular staph into MRSA is primarily due to genetic changes within the bacteria and the selective pressure from antibiotic use. Bacteria acquire resistance genes, such as the mecA gene, which provides the ability to withstand the effects of certain antibiotics. This gene encodes a modified protein called penicillin-binding protein 2a (PBP2a), which allows bacteria to continue building their cell walls and survive even in the presence of antibiotics like methicillin.
The mecA gene is carried on a mobile genetic element known as the staphylococcal cassette chromosome mec (SCCmec). This mobile element can be transferred between different bacteria, enabling the spread of antibiotic resistance. Widespread and sometimes inappropriate antibiotic use contributes to the rise of resistant strains. When antibiotics are used, susceptible bacteria are killed, but resistant bacteria survive and multiply. This process, known as natural selection, favors resistant strains, increasing their prevalence over time.
Preventing MRSA Infections
Preventing MRSA infections involves several practical hygiene measures. Frequent and thorough handwashing with soap and water for at least 20 seconds is a primary defense against germ spread. Proper care of cuts and scrapes is important; keep them clean and covered with dry bandages until healed.
Avoid sharing personal items like towels, razors, washcloths, and athletic equipment to prevent MRSA transmission. Cleaning frequently touched surfaces is also advised, as MRSA can survive on surfaces. Using antibiotics wisely is another critical preventative measure. Take antibiotics only when necessary and complete the full prescribed course to reduce the development of resistant bacteria.
When to Seek Medical Care
Seek medical attention if you suspect a skin infection, especially if it worsens or does not respond to home care. Signs that warrant a visit to a healthcare professional include red, swollen, or painful skin that is spreading or hot to the touch. The presence of pus or other drainage from a wound, or a fever, are also indicators that medical evaluation is needed.
A doctor can diagnose the infection and determine if it is MRSA or another bacteria type. Prompt diagnosis allows for appropriate treatment, such as draining the infection or prescribing effective antibiotics. Avoid self-treatment for suspected resistant infections to ensure effective management and prevent complications.