Antibiotic resistance is a worsening global pandemic regarded by the World Health Organization as one of the greatest threats to human health.For bacteria, the most prevalent and important method of resisting antibiotics is through the production of β-lactamase enzymes that inactivate β-lactam antibiotics before they can elicit their bactericidal effects.Because of the growing numbers of inhibitor-resistant β-lactamases, the discovery of new β-lactamase inhibitors represents an urgent, unmet medical need.Finding inhibitors of metallo-β-lactamases (MβL) is particularly challenging because these enzymes do not form covalent, acylated enzyme intermediates required for currently approved and in development inhibitors to inactivate serine-β-lactamases.Characterization of the time-dependent inhibition of metallo-β-lactamases by the title cephalosporin, dubbed S104, is described.Incubation of S104 with NDM-1, VIM-2, and IMP-1 MβLs in 100 mM pH 7.0 Tris buffer containing 100 mM ZnCl2 results in 83%, 81%, and 64% inhibition, resp. and ten minute IC50values in the micromolar range.The kinetic inactivation profile appears biphasic, with initial rapid inactivation followed by slower inactivation.A proposed mechanism will be discussed and supported based upon known ligand-MβL active site structures.