Methicillin-resistant Staphylococcus aureus (MRSA)

Definition

Methicillin-resistant Staphylococcus aureus (MRSA) is a type of Staphylococcus bacteria that has developed resistance to methicillin and other beta-lactam antibiotics. It is known for causing difficult-to-treat infections in humans.

5 Must Know Facts For Your Next Test

1. Methicillin resistance in MRSA is primarily due to the mecA gene, which encodes an altered penicillin-binding protein (PBP2a).
2. MRSA can spread through direct contact with an infected wound or by sharing personal items that have touched infected skin.
3. Common infections caused by MRSA include skin and soft tissue infections, but it can also cause more severe conditions like pneumonia and bloodstream infections.
4. Hospitals are common environments for MRSA transmission, leading to healthcare-associated MRSA (HA-MRSA), while community-associated MRSA (CA-MRSA) occurs in otherwise healthy individuals.
5. Vancomycin is often used as a treatment for MRSA infections due to its effectiveness against resistant strains.

Review Questions

• What genetic component allows MRSA to resist methicillin?
• Where are common places for MRSA transmission?
• What type of infections can MRSA cause?

Related terms

Beta-lactam antibiotics: A class of broad-spectrum antibiotics that includes penicillins, cephalosporins, and carbapenems.

Vancomycin: An antibiotic used to treat serious bacterial infections caused by Gram-positive bacteria, including MRSA.

Penicillin-binding proteins (PBPs): Bacterial proteins that bind to beta-lactam antibiotics; alterations in PBPs can lead to antibiotic resistance.