ORIGINAL RESEARCH article
Front. Microbiol.
Sec. Microbial Physiology and Metabolism
The Poly (A) Polymerase pcnB Modulates Virulence and Resistance in Klebsiella pneumoniae by Differentially Regulating Chromosomal mRNA Stability and Plasmid Copy Number
Provisionally accepted
- 1Anhui Agricultural University, Hefei, China
- 2Anhui Academy of Medical Sciences, Hefei, China
Select one of your emails
You have multiple emails registered with Frontiers:
Notify me on publication
Please enter your email address:
If you already have an account, please login
You don't have a Frontiers account ? You can register here
Klebsiella pneumoniae is a leading cause of healthcare-associated infections, with emerging strains exhibiting both multidrug resistance and hypervirulence, largely mediated by plasmid-encoded genes. Poly (A) polymerase I, encoded by pcnB, plays a key role in RNA degradation and plasmid copy number control, yet its global regulatory impact in K. pneumoniae remains unclear. Here, we constructed a pcnB deletion mutant in K. pneumoniae ATCC 13883 using CRISPR-Cas9 and examined its effects on chromosomal virulence factors and plasmid-borne resistance. Deletion of pcnB impaired bacterial growth and metabolic activity, reduced biofilm formation, but unexpectedly enhanced siderophore and exopolysaccharide production via upregulation of chromosomal virulence genes. In contrast, pcnB deletion drastically reduced the copy number and stability of a ColE1-type plasmid carrying a spectinomycin resistance gene (aadA), leading to decreased aadA expression and a twofold reduction in antibiotic resistance. These findings reveal the dual role of pcnB as a repressor of chromosomal virulence genes and an activator of plasmid maintenance, highlighting its potential as a novel target for anti-virulence and anti-resistance strategies.
Keywords: Klebsiella pneumoniae1, pcnB2, Siderophore3, EPS4, Antibiotic resistance5, biofilm6
Received: 19 Sep 2025; Accepted: 21 Nov 2025.
Copyright: © 2025 ZHANG, ZHANG, WANG, ZHANG, Xu and ZHANG. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence:
Yong Xu, xuyong1013@163.com
Chen ZHANG, swzzc001@163.com
Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.