Transcriptional evaluation of functional genes of resistance, biofilm and quorum sensing in CTX-M15 ESBL-producing Klebsiella pneumoniae after meropenem concentration based on serum level

IF 3.4 4区生物学 Q3 MICROBIOLOGY

Research in microbiology Pub Date : 2025-09-01 DOI:10.1016/j.resmic.2025.104304

Suzana Carstensen , Paula Hansen Suss , Gabriel Burato Ortis , Rita Estrela , Edlaine Rijo Costa , Fernanda L. Moreira , Thalissa Colodiano Martins , Joao Paulo Telles , Felipe Francisco Tuon

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引用次数: 0

Abstract

Background

Klebsiella pneumoniae is a leading cause of multidrug-resistant hospital-acquired infections. Resistance to carbapenems, particularly meropenem, is increasingly reported and often linked to β-lactamase production, porin alterations, and efflux pump overexpression. However, the immediate transcriptional response of clinical isolates to meropenem remains poorly characterized.

Aim

To investigate the transcriptomic response of a CTX-M-15-producing K. pneumoniae clinical isolate to clinically relevant meropenem exposure and identify potential non-enzymatic resistance and survival mechanisms.

Methods

A meropenem-susceptible K. pneumoniae isolate was recovered from a bacteremic patient and confirmed to carry CTX-M-15, SHV-182, and OXA-1 β-lactamase genes. Time-kill assays were performed using serum-level meropenem concentrations. RNA was extracted at multiple time points (0, 10, 30, and 60 min) post-exposure, followed by RNA-sequencing. Differential gene expression was analyzed using DESeq2. Resistance genes were identified via genome sequencing and annotated using CARD and VFDB databases.

Results

Meropenem exhibited a concentration-dependent bactericidal effect, with full inhibition sustained only at serum-level concentrations. Transcriptomic analysis revealed significant upregulation of genes linked to biofilm formation (e.g., osmB, lipoproteins), efflux pumps (mepA, acrB), and cell wall remodeling (murJ, lpoB). No differential expression was observed for blaCTX-M-15, blaOXA-1, or blaSHV-182. The transcriptional regulator ompR was induced, suggesting membrane permeability adjustments.

Conclusion

K. pneumoniae rapidly activates adaptive stress responses under meropenem exposure, primarily through biofilm-related genes, efflux pumps, and membrane remodeling rather than increased β-lactamase expression. These findings underscore the complexity of antimicrobial tolerance mechanisms and may inform novel therapeutic strategies targeting transcriptional plasticity in multidrug-resistant pathogens.

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基于血清水平美罗培南对CTX-M15产esbl肺炎克雷伯菌耐药、生物膜和群体感应功能基因的转录评价

背景：肺炎克雷伯菌是多药耐药医院获得性感染的主要原因。对碳青霉烯类，特别是美罗培南的耐药性越来越多地被报道，并且通常与β-内酰胺酶产生、孔蛋白改变和外排泵过表达有关。然而，临床分离株对美罗培南的直接转录反应仍然缺乏特征。目的：研究产ctx - m -15肺炎克雷伯菌临床分离株对临床相关美罗培南暴露的转录组反应，并确定潜在的非酶耐药和生存机制。方法：从1例菌血症患者中分离出1株美罗培尼敏感肺炎克雷伯菌，证实其携带CTX-M-15、SHV-182和OXA-1 β-内酰胺酶基因。使用血清水平美罗培南浓度进行时间杀伤测定。在暴露后的多个时间点（0、10、30和60分钟）提取RNA，然后进行RNA测序。采用DESeq2分析差异基因表达。抗性基因通过基因组测序鉴定，并使用CARD和VFDB数据库进行注释。结果：美罗培南表现出浓度依赖的杀菌效果，只有在血清水平浓度下才能持续完全抑制。转录组学分析显示，与生物膜形成（如osmB、脂蛋白）、外排泵（mepA、acrB）和细胞壁重塑（murJ、lpoB）相关的基因显著上调。blaCTX-M-15、blaOXA-1或blaSHV-182未见差异表达。诱导转录调节因子ompR，提示膜通透性调节。结论：肺炎克雷伯菌在美罗培南暴露下快速激活适应性应激反应，主要通过生物膜相关基因、外排泵和膜重塑，而不是增加β-内酰胺酶的表达。这些发现强调了抗菌素耐受性机制的复杂性，并可能为针对多药耐药病原体的转录可塑性提供新的治疗策略。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Research in microbiology 生物-微生物学

CiteScore

4.10

自引率

3.80%

发文量

审稿时长

16 days

期刊介绍： Research in Microbiology is the direct descendant of the original Pasteur periodical entitled Annales de l''Institut Pasteur, created in 1887 by Emile Duclaux under the patronage of Louis Pasteur. The Editorial Committee included Chamberland, Grancher, Nocard, Roux and Straus, and the first issue began with Louis Pasteur''s "Lettre sur la Rage" which clearly defines the spirit of the journal:"You have informed me, my dear Duclaux, that you intend to start a monthly collection of articles entitled "Annales de l''Institut Pasteur". You will be rendering a service that will be appreciated by the ever increasing number of young scientists who are attracted to microbiological studies. In your Annales, our laboratory research will of course occupy a central position, but the work from outside groups that you intend to publish will be a source of competitive stimulation for all of us."That first volume included 53 articles as well as critical reviews and book reviews. From that time on, the Annales appeared regularly every month, without interruption, even during the two world wars. Although the journal has undergone many changes over the past 100 years (in the title, the format, the language) reflecting the evolution in scientific publishing, it has consistently maintained the Pasteur tradition by publishing original reports on all aspects of microbiology.