Ticarcillin's antibiotic properties arise from its ability to prevent cross-linking of peptidoglycan during cell wall synthesis, when the bacteria tries to divide, causing cell death. Ticarcillin, like penicillin, contains a β-lactam ring that can be cleaved by β-lactamases, resulting in inactivation of the antibiotic. Those bacteria that can express β-lactamases are, therefore, resistant to β-lactam antibiotics. Due, at least in part, to the common β-lactam ring, ticarcillin can cause reactions in patients allergic to penicillin. Ticarcillin is also often paired with a β-lactamase inhibitor such as clavulanic acid.