Imipenem-Relebactam Susceptibility and Genotypic Characteristics of Carbapenem-Resistant Enterobacterales (CRE) Identified during Population-Based Surveillance

Epidemiology of carbapenem-resistant organisms in Alameda County, California, 2019-2021

Objective

Carbapenem-resistant organisms (CROs) are an urgent health threat. Since 2017, Alameda County Health Public Health Department (ACPHD) mandates reporting of carbapenem-resistant Enterobacterales (CRE) and encourages voluntary reporting of non-CRE CROs including carbapenem-resistant Acinetobacter baumannii (CRAB) and carbapenem-resistant Pseudomonas aeruginosa (CRPA). Surveillance data from ACPHD were analyzed to describe the epidemiology of CROs and target public health interventions.

Methods

Healthcare facilities in Alameda County reported CRO cases and submitted isolates to ACPHD to characterize carbapenemase genes; deaths were identified via the California Electronic Death Registration System. CRO cases with isolates resistant to one or more carbapenems were analyzed from surveillance data from July 2019 to June 2021.

Results

Four hundred and forty-two cases of CROs were reported to Alameda County from 408 patients. The county case rate for CROs was 29 cases per 100,000 population, and cases significantly increased over the 2-year period. CRPA was most commonly reported (157 cases, 36%), and cases of CRAB increased 1.83-fold. One-hundred eighty-six (42%) cases were identified among residents of long-term care facilities; 152 (37%) patients had died by January 2022. One hundred and seven (24%) cases produced carbapenemases.

Conclusions

The high burden of CROs in Alameda County highlights the need for continued partnership on reporting, testing, and infection prevention to limit the spread of resistant organisms. A large proportion of cases were identified in vulnerable long-term care residents, and CRAB was an emerging CRO among this population. Screening for CROs and surveillance at the local level are important to understand epidemiology and implement public health interventions.

Global Resistance of Imipenem/Relebactam against Gram-Negative Bacilli: Systematic Review and Meta-Analysis

Background

Relebactam, previously known as MK-7655, is currently being tested in combination with imipenem as a class A and class C β-lactamase inhibitor, including KPC from Klebsiella pneumoniae.

Objective

The objective of the current study was to evaluate the activity of imipenem/relebactam against gram-negative bacilli.

Methods

After applying exclusion and inclusion criteria, 72 articles with full texts that describe the prevalence of imipenem/relebactam resistance were chosen for the meta-analysis and systematic review. Articles published between January 2015 and February 2023 were surveyed. The systematic literature search was conducted in PubMed, Web of Science, Google Scholar, and Scopus.

Results

The pooled estimation of 282,621 sample isolates revealed that the prevalence rate of imipenem/relebactam resistance is roughly 14.6% (95% CI, 0.116%-0.182%).

Conclusions

The findings of this analysis show that imipenem/relebactam resistance is rare in the majority of developed countries. Given that relebactam has proven to restore the activity of imipenem against current clinical isolates, further research into imipenem/relebactam is necessary.

Infectious Diseases Society of America 2022 Guidance on the Treatment of Extended-Spectrum β-lactamase Producing Enterobacterales (ESBL-E), Carbapenem-Resistant Enterobacterales (CRE), and Pseudomonas aeruginosa with Difficult-to-Treat Resistance (DTR-P. aeruginosa)

BACKGROUND

The Infectious Diseases Society of America (IDSA) is committed to providing up-to-date guidance on the treatment of antimicrobial-resistant infections. The initial guidance document on infections caused by extended-spectrum β-lactamase producing Enterobacterales (ESBL-E), carbapenem-resistant Enterobacterales (CRE), and Pseudomonas aeruginosa with difficult-to-treat resistance (DTR-P. aeruginosa) was published on 17 September 2020. Over the past year, there have been a number of important publications furthering our understanding of the management of ESBL-E, CRE, and DTR-P. aeruginosa infections, prompting a rereview of the literature and this updated guidance document.

METHODS

A panel of 6 infectious diseases specialists with expertise in managing antimicrobial-resistant infections reviewed, updated, and expanded previously developed questions and recommendations about the treatment of ESBL-E, CRE, and DTR-P. aeruginosa infections. Because of differences in the epidemiology of resistance and availability of specific anti-infectives internationally, this document focuses on the treatment of infections in the United States.

RESULTS

Preferred and alternative treatment recommendations are provided with accompanying rationales, assuming the causative organism has been identified and antibiotic susceptibility results are known. Approaches to empiric treatment, duration of therapy, and other management considerations are also discussed briefly. Recommendations apply for both adult and pediatric populations.

CONCLUSIONS

The field of antimicrobial resistance is highly dynamic. Consultation with an infectious diseases specialist is recommended for the treatment of antimicrobial-resistant infections. This document is current as of 24 October 2021. The most current versions of IDSA documents, including dates of publication, are available at www.idsociety.org/practice-guideline/amr-guidance/.