Emerging epidemic of metallo-β-lactamase-mediated resistances

A structured objective within the SENTRY Antimicrobial Surveillance Program has detected the widespread occurrence of metallo-β-lactamases (MβL) capable of rendering numerous bacteria (Pseudomonas aeruginosa, Acinetobacter spp., Serratia marcescens, etc.) resistant to β-lactam agents such as penicillins, cephalosporins, and carbapenems. The rates of occurrence and the number of enzyme types clearly have escalated since 2000, severely limiting treatment options in Asia, Europe, and Latin America. Organisms harboring metallo-β-lactamases have recently been reported in western Canada and in Texas (blaVIM-7), signaling the urgent need for accurate diagnostic tests by clinical laboratories and the requirement for more potent antimicrobial agents. Unfortunately, the number of new drugs with activity against these Gram-negative pathogens is essentially nil, because of limited interest in antimicrobial research by large pharmaceutical companies. We find ourselves at a critical time in the history of medicine, where the genetic mutations and acquisitions from environmental sources by bacteria (metallo-β-lactamase) may leave us with no lifesaving therapeutic options. Action by government, industry, and academics working as one seems to be the required path to regain our previous advantage over infesting microbes.