Comparative genomic analysis of the blaOXA-23-carrying plasmids
4 affiliations
- 1The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
- 2The First Clinical Medical College, Guangzhou University of Chinese Medicine, Guangzhou, China
- 3Guangdong Provincial Key Laboratory of Tumor Interventional Diagnosis and Treatment, Zhuhai People’s Hospital (The Affiliated Hospital of Beijing Institute of Technology, Zhuhai Clinical Medical College of Jinan University), Zhuhai, China
- 4Department of Pulmonary and Critical Care Medicine, Zhuhai People’s Hospital (The Affiliated Hospital of Beijing Institute of Technology, Zhuhai Clinical Medical College of Jinan University), Zhuhai, China
Abstract
The global dissemination of the carbapenem resistance gene blaOXA-23 is partly facilitated by plasmids, yet a comprehensive characterization of these vectors is lacking. This study analyzed the blaOXA-23-carrying plasmids selected from the National Center for Biotechnology Information RefSeq database to elucidate their general characteristics and genomic diversity. The blaOXA-23-carrying plasmids were predominantly hosted by Acinetobacter baumannii (94.06%), and their sizes varied widely, from 8.22 to 336.05 kb. Replicon typing revealed that the majority belonged to the RP Rep family, specifically RP-T1 (62 plasmids) and RP-T2 (23 plasmids) types. A key finding of this analysis was the assignment of these two major plasmid groups to distinct plasmid taxonomic units (PTUs): all RP-T1 plasmids were classified as PTU-Pse5, whereas all RP-T2 plasmids were classified as PTU-Pse1. The blaOXA-23 gene of the plasmids was located within four kinds of composite transposons, with Tn2006 (33.67%), Tn2008 (32.67%), and Tn2009 (31.68%) being the predominant genetic contexts. Notably, the 62 plasmids of RP-T1 type (PTU-Pse5) and the 23 plasmids of RP-T2 type (PTU-Pse1), found predominantly in A. baumannii, carried genes encoding relaxases of the MOBF family, T4CPs of t4cp2, and type F T4SS, suggesting they are putatively conjugative. In addition, the 62 plasmids of RP-T1 type (PTU-Pse5) were identified in multiple countries within the data set, while the 23 plasmids of RP-T2 type (PTU-Pse1) were predominantly found in China. These findings provide a genomic view of blaOXA-23 plasmids, suggest their role in disseminating carbapenem resistance across species and regions, and offer a surveillance framework, highlighting key lineages for clinical intervention.
IMPORTANCE: The horizontal transfer of blaOXA-23 to Acinetobacter baumannii and other gram-negative pathogens has conferred high-level carbapenem resistance, posing significant therapeutic challenges in both hospital and community settings. Plasmids carrying conjugative transfer systems serve as key vehicles for the dissemination of blaOXA-23 among clinical isolates. In this study, we identified the plasmid lineages responsible for blaOXA-23 spread and categorized them into a limited number of groups. This finding underscores the considerable risk of horizontal gene transfer in propagating carbapenem resistance and provides a valuable framework for future surveillance efforts to track the transmission of these resistant plasmids. However, this study was based on current knowledge and available data. Given the ever-changing situation of antibiotic resistance, new plasmid variants or transfer mechanisms may emerge, potentially limiting the long‑term applicability and accuracy of our findings.
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BibTeX
@article{weng2026comparative,
title = {{Comparative genomic analysis of the blaOXA-23-carrying plasmids}},
author = {Jiahui Weng and Xiaobin Li and Ziyue Yang and Huiting Huang and Shaofeng Zhan},
journal = {Microbiology Spectrum},
year = {2026},
month = sep,
doi = {10.1128/spectrum.01374-26},
url = {https://doi.org/10.1128/spectrum.01374-26},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Comparative genomic analysis of the blaOXA-23-carrying plasmids
AU - Jiahui Weng
AU - Xiaobin Li
AU - Ziyue Yang
AU - Huiting Huang
AU - Shaofeng Zhan
PY - 2026
DA - 2026/09/29
JO - Microbiology Spectrum
DO - 10.1128/spectrum.01374-26
UR - https://doi.org/10.1128/spectrum.01374-26
AB - The global dissemination of the carbapenem resistance gene blaOXA-23 is partly facilitated by plasmids, yet a comprehensive characterization of these vectors is lacking. This study analyzed the blaOXA-23-carrying plasmids selected from the National Center for Biotechnology Information RefSeq database to elucidate their general characteristics and genomic diversity. The blaOXA-23-carrying plasmids were predominantly hosted by Acinetobacter baumannii (94.06%), and their sizes varied widely, from 8.22 to 336.05 kb. Replicon typing revealed that the majority belonged to the RP Rep family, specifically RP-T1 (62 plasmids) and RP-T2 (23 plasmids) types. A key finding of this analysis was the assignment of these two major plasmid groups to distinct plasmid taxonomic units (PTUs): all RP-T1 plasmids were classified as PTU-Pse5, whereas all RP-T2 plasmids were classified as PTU-Pse1. The blaOXA-23 gene of the plasmids was located within four kinds of composite transposons, with Tn2006 (33.67%), Tn2008 (32.67%), and Tn2009 (31.68%) being the predominant genetic contexts. Notably, the 62 plasmids of RP-T1 type (PTU-Pse5) and the 23 plasmids of RP-T2 type (PTU-Pse1), found predominantly in A. baumannii, carried genes encoding relaxases of the MOBF family, T4CPs of t4cp2, and type F T4SS, suggesting they are putatively conjugative. In addition, the 62 plasmids of RP-T1 type (PTU-Pse5) were identified in multiple countries within the data set, while the 23 plasmids of RP-T2 type (PTU-Pse1) were predominantly found in China. These findings provide a genomic view of blaOXA-23 plasmids, suggest their role in disseminating carbapenem resistance across species and regions, and offer a surveillance framework, highlighting key lineages for clinical intervention. IMPORTANCE: The horizontal transfer of blaOXA-23 to Acinetobacter baumannii and other gram-negative pathogens has conferred high-level carbapenem resistance, posing significant therapeutic challenges in both hospital and community settings. Plasmids carrying conjugative transfer systems serve as key vehicles for the dissemination of blaOXA-23 among clinical isolates. In this study, we identified the plasmid lineages responsible for blaOXA-23 spread and categorized them into a limited number of groups. This finding underscores the considerable risk of horizontal gene transfer in propagating carbapenem resistance and provides a valuable framework for future surveillance efforts to track the transmission of these resistant plasmids. However, this study was based on current knowledge and available data. Given the ever-changing situation of antibiotic resistance, new plasmid variants or transfer mechanisms may emerge, potentially limiting the long‑term applicability and accuracy of our findings.
SN - 2165-0497
ER -