β-Lactam antibiotics

The family of antibiotics built around the β-lactam ring, including penicillins, cephalosporins, carbapenems, and monobactams, which kill bacteria by blocking cell-wall synthesis. They are the most widely used antibiotics in both human and veterinary medicine, and their residues in milk and meat are strictly regulated: dairy farmers must observe withdrawal periods after treatment, and milk is routinely screened for β-lactam residues because even traces can trigger allergic reactions in sensitive consumers and disrupt cheese and yoghurt starter cultures. Their dominance has driven the spread of β-lactamase-mediated resistance among foodborne pathogens, making prudent use in livestock a food-safety priority and residue testing a daily routine of the dairy industry.