Dear Editor,Antibiotic resistance has emerged as a major threat to global health;multi-drug resistant bacteria already kill more patients in the United States each year than HIV/AIDS, Parkinsons disease, emphysema and homicide combined (Laxminarayan et al., 2013).Among the most effective bacterial resistance mechanisms are β-lactamases, a family of enzymes that are divided into four distinct classes.Classes A, C and D (serine-β-lactamases, SBLs) use a catalytic site serine residue to initiate inactivation of the antibiotic, while Class B (metallo-β-lactamases, MBLs) relies on a Zn2+-activated hydroxide (Walsh et al., 2005;Bush and Jacoby,2010;Mitic et al., 2014;Lisa et al., 2017).Clinically relevant inhibitors of Class C and D SBLs are available and in use (e.g., clavulanic acid (CA), Drawz et al., 2010), but for MBLs the search for such inhibitors has remained challenging (McGeary et al., 2017).