Mecillinam（Cat No.:R005595）is a β-lactam antibiotic belonging to the amidinopenicillin class, primarily used against Gram-negative bacteria. It exerts its antibacterial effect by binding specifically to penicillin-binding protein 2 (PBP2), disrupting cell wall synthesis and leading to bacterial lysis. Mecillinam shows strong activity against Enterobacteriaceae, making it useful for treating urinary tract infections and other systemic infections. It is often administered as its prodrug, pivmecillinam, for improved oral bioavailability. With its unique mode of action and narrow spectrum, mecillinam is valuable in combating resistant Gram-negative bacterial infections.