AUTHOR=Ko Weihsin , Tseng Songlu , Chou Chiahsin , Li Tianmeng , Li Rose , Zhang Yaqiao , Li Yun , Lv Yuan 

TITLE=Molecular epidemiology and comparative genomics of carbapenemase-producing Escherichia coli isolates from 19 tertiary hospitals in China from 2019 to 2020

JOURNAL=Frontiers in Microbiology

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2023.1056399

DOI=10.3389/fmicb.2023.1056399

ISSN=1664-302X

ABSTRACT=<sec><title>Background</title><p>The clinical use of carbapenems is facing challenges due to increased carbapenemase-producing <italic>Escherichia coli</italic> (CP-EC) infections over the past decade. Meanwhile, whole-genome sequencing (WGS) is an important method for bacterial epidemiological research. We aim to provide more gene-based surveys to explore the genomics and occurrence of CP-EC in China.</p></sec><sec><title>Methods</title><p>A total of 780 <italic>Escherichia coli</italic> isolates were collected by the China Antimicrobial Resistance Surveillance Trial (CARST) from 2019 to 2020. An antibacterial susceptibility test was performed by using the agar dilution method. CP-EC were detected by the modified carbapenem inactivation method (mCIM), EDTA-modified carbapenem inactivation method (eCIM), and polymerase chain reaction (PCR). Homology analysis was performed by multilocus sequence typing (MLST). A conjugation experiment was performed to verify the transferability of plasmids carrying carbapenemase genes. WGS was conducted to explore the gene-environment of the carbapenemase gene.</p></sec><sec><title>Result</title><p>Of the 780 <italic>Escherichia coli</italic> isolates, 31 isolates were insensitive to carbapenem with a rate of 4%. Among them, 13 CP-EC isolates had transferability of the <italic>bla</italic><sub><italic>NDM</italic></sub> gene. These isolates belonged to nine distinct sequence types (STs), with some correlation. We found that two (2/13, 15.4%) of the CP-EC isolates that were collected from blood specimens were highly pathogenic and also showed high transferability of the <italic>bla</italic><sub><italic>NDM</italic></sub> gene. In addition, eight (8/13, 61.5%) of the CP-EC isolates were found to be multidrug-resistant.</p></sec><sec><title>Conclusion</title><p>With the increasing use of carbapenem, CP-EC isolates accounted for nearly half of the total carbapenem-insensitive <italic>Escherichia coli</italic> isolates. Our findings highlight the urgent need to pay attention to CP-EC isolates in bloodstream infections and ESBL-producing CP-EC isolates. Based on the One Health concept, we suggest various measures, including the development of bacterial vaccines, antibiotic management, and establishment of better medical environments, to avoid the outbreak of CP-EC.</p></sec>