methicillinsensitive
Methicillin-sensitive, in microbiology, describes microorganisms that are inhibited by methicillin, a beta-lactam antibiotic. The term is often used in reference to Staphylococcus aureus, where strains are categorized as methicillin-susceptible (MSSA) or methicillin-resistant (MRSA). Methicillin-sensitive organisms are typically susceptible to a range of beta-lactam antibiotics, including isoxazolyl penicillins such as nafcillin and oxacillin.
Methicillin works by binding to penicillin-binding proteins (PBPs) involved in cell wall synthesis. In methicillin-sensitive strains,
Laboratories determine methicillin susceptibility using surrogate tests such as cefoxitin or oxacillin disc diffusion, or molecular
MSSA infections are typically treatable with beta-lactam antibiotics effective against methicillin-susceptible strains, such as nafcillin, oxacillin,