monobactam antibiotic_resistance ARO:0000004 Monobactams are a class of beta-lactam antibiotics with a broad spectrum of antibacterial activity, and have a structure which renders them highly resistant to beta-lactamases. Unlike penams and cephems, monobactams do not have any ring fused to its four-member lactam structure. Monobactam antibiotics are bactericidal, and act by inhibiting the synthesis of the peptidoglycan layer of bacterial cell walls. The peptidoglycan layer is important for cell wall structural integrity, especially in Gram-positive organisms. beta-lactam antibiotic