Polymyxin B combined with amikacin delays the resistance of Klebsiella pneumoniae to polymyxin B by modulating the expression of NlpE
IF 2.6
4区 医学
Q3 INFECTIOUS DISEASES
引用次数: 0
Abstract
Objectives
This study investigated the mechanisms underlying polymyxin B (PMB)-induced resistance and examined the role of PMB in combination with amikacin (AMK) in delaying the development of resistance.
Methods
In vitro continuous induction of three Klebsiella pneumoniae strains was performed using PMB alone or in combination with AMK, and variations in the minimum inhibitory concentration (MIC) were determined via the microdilution method. The Kp81 strain, which presented the most significant delay in resistance development, was selected for analysis of the expression of relevant genes via qRT–PCR. Homologous recombination techniques were employed to construct nlpE and cpxR gene knockout and complemented Kp81 strains, and the expression levels of these genes, as well as changes in the MIC following continuous induction, were assessed. Additionally, the biofilm-forming abilities of the strains were analyzed via crystal violet staining and confocal laser scanning microscopy.
Results
The results indicate that the combination of PMB and AMK can delay the development of resistance to PMB in K. pneumoniae. qRT–PCR analysis demonstrated a significant increase in the expression of phoP, nlpE, cpxR, and acrA in the resistant strain Kp81·R, whereas these genes were significantly downregulated in the resistant delay strain Kp81·DR. Notably, after 20 h of PMB treatment, the expression of nlpE was markedly elevated in the nlpE knockout strain. cpxR exhibited synchronized dynamic changes with nlpE in both the nlpE knockout and complemented strains, whereas acrA showed a similar expression pattern in the cpxR knockout and complemented strains. Additionally, the absence of nlpE or cpxR was found to delay PMB resistance. Furthermore, biofilm formation was significantly increased in both the resistant strains and those treated with PMB, while the combination of PMB with AMK inhibited biofilm formation.
Conclusions
The combination of PMB and AMK can delay the development of resistance in K. pneumoniae to PMB. The nlpE gene, as a key regulatory factor, can influence PMB resistance by modulating the CpxA/R two-component system and biofilm formation.
多粘菌素B联合阿米卡星通过调节NlpE的表达延缓肺炎克雷伯菌对多粘菌素B的耐药性。
目的：探讨多粘菌素B （PMB）诱导耐药的机制，并探讨PMB联合阿米卡星（AMK）延缓耐药发生的作用。方法：采用PMB单独或联合AMK对3株肺炎克雷伯菌进行体外连续诱导，并通过微量稀释法测定最小抑制浓度（MIC）的变化。选择耐药延迟最明显的菌株Kp81，通过qRT-PCR分析相关基因的表达情况。采用同源重组技术构建nlpE和cpxR基因敲除并补充Kp81菌株，评估这两个基因的表达水平以及连续诱导后的MIC变化。此外，通过结晶紫染色和激光共聚焦扫描显微镜分析了菌株的生物膜形成能力。结果：PMB联合AMK可延缓肺炎克雷伯菌对PMB的耐药发展。qRT-PCR分析显示，抗性菌株Kp81·R中phoP、nlpE、cpxR和acrA的表达量显著增加，而抗性延迟菌株Kp81·DR中这些基因的表达量显著下调。值得注意的是，PMB处理20 h后，nlpE敲除菌株的nlpE表达显著升高。cpxR在nlpE敲除株和补体株中均表现出与nlpE同步的动态变化，而acrA在cpxR敲除株和补体株中表现出相似的表达模式。此外，nlpE或cpxR的缺失被发现延迟PMB的耐药。此外，耐药菌株和经PMB处理的菌株的生物膜形成均显著增加，而PMB与AMK联用抑制了生物膜的形成。结论：PMB联合AMK可延缓肺炎克雷伯菌对PMB的耐药发展。nlpE基因作为关键调控因子，通过调控CpxA/R双组分体系和生物膜的形成，影响PMB耐药性。
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
Infection Genetics and Evolution
医学-传染病学
CiteScore
8.40
自引率
0.00%
发文量
215
审稿时长
82 days
期刊介绍：
(aka Journal of Molecular Epidemiology and Evolutionary Genetics of Infectious Diseases -- MEEGID)
Infectious diseases constitute one of the main challenges to medical science in the coming century. The impressive development of molecular megatechnologies and of bioinformatics have greatly increased our knowledge of the evolution, transmission and pathogenicity of infectious diseases. Research has shown that host susceptibility to many infectious diseases has a genetic basis. Furthermore, much is now known on the molecular epidemiology, evolution and virulence of pathogenic agents, as well as their resistance to drugs, vaccines, and antibiotics. Equally, research on the genetics of disease vectors has greatly improved our understanding of their systematics, has increased our capacity to identify target populations for control or intervention, and has provided detailed information on the mechanisms of insecticide resistance.
However, the genetics and evolutionary biology of hosts, pathogens and vectors have tended to develop as three separate fields of research. This artificial compartmentalisation is of concern due to our growing appreciation of the strong co-evolutionary interactions among hosts, pathogens and vectors.
Infection, Genetics and Evolution and its companion congress [MEEGID](http://www.meegidconference.com/) (for Molecular Epidemiology and Evolutionary Genetics of Infectious Diseases) are the main forum acting for the cross-fertilization between evolutionary science and biomedical research on infectious diseases.
Infection, Genetics and Evolution is the only journal that welcomes articles dealing with the genetics and evolutionary biology of hosts, pathogens and vectors, and coevolution processes among them in relation to infection and disease manifestation. All infectious models enter the scope of the journal, including pathogens of humans, animals and plants, either parasites, fungi, bacteria, viruses or prions. The journal welcomes articles dealing with genetics, population genetics, genomics, postgenomics, gene expression, evolutionary biology, population dynamics, mathematical modeling and bioinformatics. We also provide many author benefits, such as free PDFs, a liberal copyright policy, special discounts on Elsevier publications and much more. Please click here for more information on our author services .
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