Should ceftriaxone-resistant Enterobacterales be tested for ESBLs? A PRO/CON debate

Antimicrobial resistance in Escherichia coli and Pseudomonas aeruginosa before and after the coronavirus disease 2019 (COVID-19) pandemic in the Dominican Republic

Objective

To describe antimicrobial resistance before and after the COVID-19 pandemic in the Dominican Republic.

Design

Retrospective study.

Setting

The study included 49 outpatient laboratory sites located in 13 cities nationwide.

Participants

Patients seeking ambulatory microbiology testing for urine and bodily fluids.

Methods

We reviewed antimicrobial susceptibility reports for Escherichia coli isolates from urine and Pseudomonas aeruginosa (PSAR) from bodily fluids between January 1, 2018, to December 31, 2021, from deidentified susceptibility data extracted from final culture results.

Results

In total, 27,718 urine cultures with E. coli and 2,111 bodily fluid cultures with PSAR were included in the analysis. On average, resistance to ceftriaxone was present in 25.19% of E. coli isolated from urine each year. The carbapenem resistance rates were 0.15% for E. coli and 3.08% for PSAR annually. The average rates of E. coli with phenotypic resistance consistent with possible extended-spectrum β-lactamase (ESBL) in urine were 25.63% and 24.75%, respectively, before and after the COVID-19 pandemic. The carbapenem resistance rates in urine were 0.11% and 0.20%, respectively, a 200% increase. The average rates of PSAR with carbapenem resistance in bodily fluid were 2.33% and 3.84% before and after the COVID-19 pandemic, respectively, a 130% percent increase.

Conclusions

Resistance to carbapenems in PSAR and E. coli after the COVID-19 pandemic is rising. These resistance patterns suggest that ESBL is common in the Dominican Republic. Carbapenem resistance was uncommon but increased after the COVID-19 pandemic.

Extended-spectrum β-lactamases: an update on their characteristics, epidemiology and detection

Extended-spectrum β-lactamase (ESBL)-producing Gram-negative pathogens are a major cause of resistance to expanded-spectrum β-lactam antibiotics. Since their discovery in the early 1980s, they have spread worldwide and an are now endemic in Enterobacterales isolated from both hospital-associated and community-acquired infections. As a result, they are a global public health concern. In the past, TEM- and SHV-type ESBLs were the predominant families of ESBLs. Today CTX-M-type enzymes are the most commonly found ESBL type with the CTX-M-15 variant dominating worldwide, followed in prevalence by CTX-M-14, and CTX-M-27 is emerging in certain parts of the world. The genes encoding ESBLs are often found on plasmids and harboured within transposons or insertion sequences, which has enabled their spread. In addition, the population of ESBL-producing Escherichia coli is dominated globally by a highly virulent and successful clone belonging to ST131. Today, there are many diagnostic tools available to the clinical microbiology laboratory and include both phenotypic and genotypic tests to detect β-lactamases. Unfortunately, when ESBLs are not identified in a timely manner, appropriate antimicrobial therapy is frequently delayed, resulting in poor clinical outcomes. Several analyses of clinical trials have shown mixed results with regards to whether a carbapenem must be used to treat serious infections caused by ESBLs or whether some of the older β-lactam-β-lactamase combinations such as piperacillin/tazobactam are appropriate. Some of the newer combinations such as ceftazidime/avibactam have demonstrated efficacy in patients. ESBL-producing Gram-negative pathogens will continue to be major contributor to antimicrobial resistance worldwide. It is essential that we remain vigilant about identifying them both in patient isolates and through surveillance studies.