Methicillin-resistant Staphylococcus aureus

Methicillin-resistant Staphylococcus aureus (MRSA) Bacteria

Colorized scanning electron micrograph of a human neutrophil ingesting MRSA

Methicillin-resistant Staphylococcus aureus (MRSA) is a type of bacteria that causes an infection resistant to common antibiotics, including methicillin, amoxicillin, and penicillin.

Neutrophil MRSA II

Signs and symptoms

Most MRSA infections occur on the skin and are mild, presenting as red, swollen, and painful areas, often resembling pimples or spider bites. However, MRSA infections can also be serious or life-threatening, manifesting as pneumonia, bloodstream infections, or bone and joint infections, and can be difficult to treat.

Risk factors

MRSA infections usually occur in people with weakened immune systems who are in hospitals, nursing homes, or other healthcare centers. They can also occur in healthy people who have skin-to-skin contact with others, such as childcare workers, team athletes, and people who live in crowded conditions. Risk factors include recent hospitalization, invasive procedures, residence in long-term care facilities, and close contact with someone who has MRSA.

Diagnosis

Diagnosis of MRSA infections typically involves taking a sample from the site of infection and performing a culture and antibiotic susceptibility testing to identify the bacteria and determine its resistance to antibiotics.

Prevention

Prevention strategies for MRSA infections include practicing good hand hygiene, maintaining clean environments, using contact precautions when interacting with infected individuals, and the judicious use of antibiotics to prevent the development of resistance. In healthcare settings, proper infection control measures are essential to minimize the spread of MRSA.

Treatment

Treatment of MRSA infections typically involves the use of antibiotics that are still effective against the resistant bacteria, such as vancomycin, daptomycin, or linezolid. In some cases, surgical intervention may be required to drain abscesses or debride infected tissue. The choice of treatment depends on the severity of the infection and the patient's overall health.

Prognosis

The prognosis of MRSA infections varies depending on the severity of the infection and the patient's overall health. Mild skin infections may resolve with appropriate antibiotic treatment, while more severe infections, such as bloodstream infections or pneumonia, may have a higher risk of complications and mortality.

Epidemiology

The prevalence of MRSA infections varies by region and depends on local antibiotic resistance patterns. In some areas, MRSA accounts for a significant proportion of Staphylococcus aureus infections, while in others, the prevalence may be lower. Both hospital-associated MRSA (HA-MRSA) and community-associated MRSA (CA-MRSA) contribute to the overall burden of disease.