Clonal Distribution and Its Association With the Carbapenem Resistance Mechanisms of Carbapenem-Non-Susceptible Pseudomonas aeruginosa Isolates From Korean Hospitals

Nayeong Kim; Seo Yeon Ko; Seong Yong Park; Seong Yeob Kim; Da Eun Lee; Ki Tae Kwon; Yu Kyung Kim; Je Chul Lee

doi:10.3343/alm.2023.0369

Clonal Distribution and Its Association With the Carbapenem Resistance Mechanisms of Carbapenem-Non-Susceptible Pseudomonas aeruginosa Isolates From Korean Hospitals

Ann Lab Med. 2024 Mar 4. doi: 10.3343/alm.2023.0369. Online ahead of print.

Authors

Nayeong Kim¹, Seo Yeon Ko¹, Seong Yong Park¹, Seong Yeob Kim¹, Da Eun Lee², Ki Tae Kwon^{2

3}, Yu Kyung Kim^{2

4}, Je Chul Lee^{1

2}

Affiliations

¹ Department of Microbiology, School of Medicine, Kyungpook National University, Daegu, Korea.
² Kyungpook National University Hospital National Culture Collection for Pathogens (KNUH-NCCP), Kyungpook National University Hospital, Daegu, Korea.
³ Department of Internal Medicine, School of Medicine, Kyungpook National University, Daegu, Korea.
⁴ Department of Laboratory Medicine, School of Medicine, Kyungpook National University, Daegu, Korea.

PMID: 38433574
DOI: 10.3343/alm.2023.0369

Abstract

Background: Carbapenem resistance in Pseudomonas aeruginosa is a serious global health problem. We investigated the clonal distribution and its association with the carbapenem resistance mechanisms of carbapenem-non-susceptible P. aeruginosa isolates from three Korean hospitals.

Methods: A total of 155 carbapenem-non-susceptible P. aeruginosa isolates collected between 2011 and 2019 were analyzed for sequence types (STs), antimicrobial susceptibility, and carbapenem resistance mechanisms, including carbapenemase production, the presence of resistance genes, OprD mutations, and the hyperproduction of AmpC β-lactamase.

Results: Sixty STs were identified in carbapenem-non-susceptible P. aeruginosa isolates. Two high-risk clones, ST235 (N=41) and ST111 (N=20), were predominant; however, sporadic STs were more prevalent than high-risk clones. The resistance rate to amikacin was the lowest (49.7%), whereas that to piperacillin was the highest (92.3%). Of the 155 carbapenem-non-susceptible isolates, 43 (27.7%) produced carbapenemases. Three metallo-β-lactamase (MBL) genes, bla_IMP-6 (N=38), bla_VIM-2 (N=3), and bla_NDM-1 (N=2), were detected. bla_IMP-6 was detected in clonal complex 235 isolates. Two ST773 isolates carried bla_NDM-1 and rmtB. Frameshift mutations in oprD were identified in all isolates tested, regardless of the presence of MBL genes. Hyperproduction of AmpC was detected in MBL gene-negative isolates.

Conclusions: Frameshift mutations in oprD combined with MBL production or hyperproduction of AmpC are responsible for carbapenem resistance in P. aeruginosa. Further attention is required to curb the emergence and spread of new carbapenem-resistant P. aeruginosa clones.

Keywords: AmpC; Carbapenem resistance; Metallo-β-lactamase; OprD; Pseudomonas aeruginosa; Sequence type.