Effects of in vitro combination therapy with polymyxin B on delaying resistance in Klebsiella pneumoniae and insights into the mechanisms of polymyxin-induced resistance

Objective: This study aimed to investigate the effects of polymyxin B (PMB) in combination with other antibiotics on delaying resistance in Klebsiella pneumoniae and to explore the mechanisms underlying PMB-induced resistance. Methods: In vitro continuous induction experiments were performed to obse...

Full description

Saved in:
Bibliographic Details
Main Authors: Huanhuan Zhang, Wei Feng, Fengjun Sun, Te Xu, Yan Qian
Format: Article
Language:English
Published: Elsevier 2025-06-01
Series:Journal of Global Antimicrobial Resistance
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S2213716525000840
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1849473196789596160
author Huanhuan Zhang
Wei Feng
Fengjun Sun
Te Xu
Yan Qian
author_facet Huanhuan Zhang
Wei Feng
Fengjun Sun
Te Xu
Yan Qian
author_sort Huanhuan Zhang
collection DOAJ
description Objective: This study aimed to investigate the effects of polymyxin B (PMB) in combination with other antibiotics on delaying resistance in Klebsiella pneumoniae and to explore the mechanisms underlying PMB-induced resistance. Methods: In vitro continuous induction experiments were performed to observe changes in drug susceptibility with PMB alone vs. in combination. RNA-seq, quantitative reverse transcription PCR, and proteomic analyses were utilized to evaluate differential gene and protein expression between induced-resistant strains and those exhibiting delayed resistance. Then, gene knockout experiments were performed to validate the functional roles of relevant genes. Results: These findings indicated that PMB alone could induce resistance within 1–2 d, whereas the combination with amikacin (AMK) or tigecycline delayed the onset of resistance by 6 d. RNA-seq, quantitative reverse transcription PCR, and proteomic analyses revealed significant upregulation of nlpE, two-component systems, and AcrAB-TolC efflux pump-associated genes in PMB-induced resistant strains, whereas these genes were downregulated in the delayed resistant strains of PMB combined with AMK. Deletion and complementation experiments demonstrated that the expression levels of two-component systems and efflux pump-related genes were downregulated in nlpE knockout strains. Furthermore, PMB induction experiments revealed a significant upregulation of PmrA, PhoP, PhoQ, PagP, and AcrB proteins associated with cationic antimicrobial peptide pathways in the wild-type and nlpE complemented strains, whereas no differential change was observed in the nlpE knockout strain. Conclusions: nlpE contributes to PMB resistance by modulating the AcrAB-TolC efflux pump and the PhoP/Q and PmrA/B two-component systems. The combined use of PMB with AMK effectively delays the development of resistance in K. pneumoniae through the regulation of nlpE and its associated signalling pathways.
format Article
id doaj-art-2869a7d19b7442ab9ea3ee1a25594d64
institution Kabale University
issn 2213-7165
language English
publishDate 2025-06-01
publisher Elsevier
record_format Article
series Journal of Global Antimicrobial Resistance
spelling doaj-art-2869a7d19b7442ab9ea3ee1a25594d642025-08-20T03:24:13ZengElsevierJournal of Global Antimicrobial Resistance2213-71652025-06-014314315410.1016/j.jgar.2025.04.009Effects of in vitro combination therapy with polymyxin B on delaying resistance in Klebsiella pneumoniae and insights into the mechanisms of polymyxin-induced resistanceHuanhuan Zhang0Wei Feng1Fengjun Sun2Te Xu3Yan Qian4Department of Pharmacy, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China; Department of Pharmacy, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, ChinaDepartment of Pharmacy, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, ChinaDepartment of Pharmacy, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, ChinaDepartment of Pharmacy, The First People’s Hospital of Longquanyi District, Chengdu, ChinaDepartment of Pharmacy, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China; Corresponding author. Mailing address: Department of Pharmacy, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, China.Objective: This study aimed to investigate the effects of polymyxin B (PMB) in combination with other antibiotics on delaying resistance in Klebsiella pneumoniae and to explore the mechanisms underlying PMB-induced resistance. Methods: In vitro continuous induction experiments were performed to observe changes in drug susceptibility with PMB alone vs. in combination. RNA-seq, quantitative reverse transcription PCR, and proteomic analyses were utilized to evaluate differential gene and protein expression between induced-resistant strains and those exhibiting delayed resistance. Then, gene knockout experiments were performed to validate the functional roles of relevant genes. Results: These findings indicated that PMB alone could induce resistance within 1–2 d, whereas the combination with amikacin (AMK) or tigecycline delayed the onset of resistance by 6 d. RNA-seq, quantitative reverse transcription PCR, and proteomic analyses revealed significant upregulation of nlpE, two-component systems, and AcrAB-TolC efflux pump-associated genes in PMB-induced resistant strains, whereas these genes were downregulated in the delayed resistant strains of PMB combined with AMK. Deletion and complementation experiments demonstrated that the expression levels of two-component systems and efflux pump-related genes were downregulated in nlpE knockout strains. Furthermore, PMB induction experiments revealed a significant upregulation of PmrA, PhoP, PhoQ, PagP, and AcrB proteins associated with cationic antimicrobial peptide pathways in the wild-type and nlpE complemented strains, whereas no differential change was observed in the nlpE knockout strain. Conclusions: nlpE contributes to PMB resistance by modulating the AcrAB-TolC efflux pump and the PhoP/Q and PmrA/B two-component systems. The combined use of PMB with AMK effectively delays the development of resistance in K. pneumoniae through the regulation of nlpE and its associated signalling pathways.http://www.sciencedirect.com/science/article/pii/S2213716525000840Klebsiella pneumoniaePolymyxin BInduced resistance mechanismCombination therapyDelay resistance
spellingShingle Huanhuan Zhang
Wei Feng
Fengjun Sun
Te Xu
Yan Qian
Effects of in vitro combination therapy with polymyxin B on delaying resistance in Klebsiella pneumoniae and insights into the mechanisms of polymyxin-induced resistance
Journal of Global Antimicrobial Resistance
Klebsiella pneumoniae
Polymyxin B
Induced resistance mechanism
Combination therapy
Delay resistance
title Effects of in vitro combination therapy with polymyxin B on delaying resistance in Klebsiella pneumoniae and insights into the mechanisms of polymyxin-induced resistance
title_full Effects of in vitro combination therapy with polymyxin B on delaying resistance in Klebsiella pneumoniae and insights into the mechanisms of polymyxin-induced resistance
title_fullStr Effects of in vitro combination therapy with polymyxin B on delaying resistance in Klebsiella pneumoniae and insights into the mechanisms of polymyxin-induced resistance
title_full_unstemmed Effects of in vitro combination therapy with polymyxin B on delaying resistance in Klebsiella pneumoniae and insights into the mechanisms of polymyxin-induced resistance
title_short Effects of in vitro combination therapy with polymyxin B on delaying resistance in Klebsiella pneumoniae and insights into the mechanisms of polymyxin-induced resistance
title_sort effects of in vitro combination therapy with polymyxin b on delaying resistance in klebsiella pneumoniae and insights into the mechanisms of polymyxin induced resistance
topic Klebsiella pneumoniae
Polymyxin B
Induced resistance mechanism
Combination therapy
Delay resistance
url http://www.sciencedirect.com/science/article/pii/S2213716525000840
work_keys_str_mv AT huanhuanzhang effectsofinvitrocombinationtherapywithpolymyxinbondelayingresistanceinklebsiellapneumoniaeandinsightsintothemechanismsofpolymyxininducedresistance
AT weifeng effectsofinvitrocombinationtherapywithpolymyxinbondelayingresistanceinklebsiellapneumoniaeandinsightsintothemechanismsofpolymyxininducedresistance
AT fengjunsun effectsofinvitrocombinationtherapywithpolymyxinbondelayingresistanceinklebsiellapneumoniaeandinsightsintothemechanismsofpolymyxininducedresistance
AT texu effectsofinvitrocombinationtherapywithpolymyxinbondelayingresistanceinklebsiellapneumoniaeandinsightsintothemechanismsofpolymyxininducedresistance
AT yanqian effectsofinvitrocombinationtherapywithpolymyxinbondelayingresistanceinklebsiellapneumoniaeandinsightsintothemechanismsofpolymyxininducedresistance