How does bacteria become MRSA?

Bacteria become Methicillin-resistant Staphylococcus aureus (MRSA) through the acquisition of specific genes that confer resistance to methicillin and other beta-lactam antibiotics. This typically occurs via horizontal gene transfer, where genetic material is exchanged between bacteria, often through plasmids or transposons. The most common gene responsible for this resistance is mecA, which alters the penicillin-binding proteins in the bacteria, preventing antibiotics from effectively targeting them. Overuse and misuse of antibiotics in healthcare and agriculture further promote the development and spread of MRSA.