The State of Antimicrobial Resistance of Gram-Negative Bacilli in Canada

In the last two decades, there has been an increase in resistance among Gram-negative bacteria in Canada. From 2007 to 2016, the proportion of ESBL-producing isolates among Escherichia coli and Klebsiella pneumoniae isolates increased from 3.5% to 11.1%. There has also been an increase in carbapenem use over this time period, which may be contributing to the increasing prevalence of carbapenemase-producing Enterobacterales (CPE) in Canada. CPE, which were historically associated with travel, are now mostly acquired domestically. The prevalence of multi-drug resistant (MDR) Pseudomonas aeruginosa has decreased slightly, possibly due to decreasing use of fluoroquinolones and aminoglycosides. Many of the most effective antimicrobials for the treatment of infections with resistant Gram-negative organisms, including many of the novel β-lactam/β-lactamase inhibitors (βL/βLIs), are not marketed in Canada. A coordinated focus on antimicrobial stewardship and infection control is necessary to slow the spread of resistance and to preserve the efficacy of our current antimicrobials for future generations.