Effect of Porins and bla Expression on Activity of Imipenem with Relebactam in Klebsiella pneumoniae: Can Antibiotic Combinations Overcome Resistance?

Imipenem with relebactam is a novel β-lactam-β-lactamase inhibitor that has activity against most KPC-producing Enterobacteriaceae. Using 10 isolates of KPC-possessing Klebsiella pneumoniae, we assessed the relationship between imipenem-relebactam minimum inhibitory concentrations (MICs) and mechanisms known to contribute to antimicrobial resistance. The effect of adding a second agent was assessed by time-kill experiments.

Activity of Ceftazidime-Avibactam Against Clinical Isolates of Klebsiella pneumoniae, Including KPC-Carrying Isolates, Endemic to New York City.

In this report, we examined the (1) activity of ceftazidime-avibactam against clinical isolates Klebsiella pneumoniae, including those harboring bla, (2) potential mechanisms leading to reduced susceptibility, and (3) activity of ceftazidime-avibactam when combined with other agents. Of 802 carbapenem-resistant isolates of K. pneumoniae gathered from New York City from 1999 to 2014, all were susceptible to ceftazidime-avibactam.