Mei-Juan Yang, Meng-Jie Li, Li-Dan Huang, Xin-Wei Zhang, Yan-Ying Huang, Xiao-Yu Gou, Sui-Ning Chen, Jie Yan, Peng Du, Ai-Hua Sun
{"title":"响应调节蛋白 CiaR 调节肺炎链球菌的 ccn-microRNAs 转录和β-内酰胺类抗生素耐药性转换。","authors":"Mei-Juan Yang, Meng-Jie Li, Li-Dan Huang, Xin-Wei Zhang, Yan-Ying Huang, Xiao-Yu Gou, Sui-Ning Chen, Jie Yan, Peng Du, Ai-Hua Sun","doi":"10.1016/j.ijantimicag.2024.107387","DOIUrl":null,"url":null,"abstract":"<p><strong>Introduction: </strong>Streptococcus pneumoniae does not produce β-lactamases and its reduced susceptibility to β-lactam antibiotics is predominantly caused by mutations of penicillin-binding proteins (PBPs), but mechanisms of PBP mutation-unrelated β-lactam antibiotic resistance in pneumococcal strains remain poorly characterized.</p><p><strong>Methods: </strong>Susceptibility of S. pneumoniae ATCC49619 and its ciaR gene-knockout, -complemented, or -over-expression mutant (ΔciaR, CΔciaR, or ciaR<sup>OE</sup>) to penicillin, cefotaxime, and imipenem was detected using E-test. Levels of pneumococcal ciaR-mRNA, five ccn-microRNAs, and six pbps-mRNAs were determined by qRT-PCR. Recombinant CiaR (rCiaR) binding to the promoters of ccn-microRNA genes was confirmed using electrophoresis mobility shift and chromatin immunoprecipitation assays. Sequence matching between the ccn-microRNAs and pbps-mRNAs were analyzed using IntaRNA software.</p><p><strong>Results: </strong>S. pneumoniae ATCC49619 was sensitive to the three β-lactam antibiotics, but over-expression of CiaR, a response regulator protein in two-component system, caused the increase of MICs against these antibiotics. The ciaR<sup>OE</sup> mutant exhibited the significantly increased transcription of ccn-microRNAs but notably decreased transcription of pbps-mRNAs, conversely the ΔciaR mutant displayed decreased levels of ccn-microRNAs and increasesed transcription of pbps-mRNAs. rCiaR could bind to the promoters of all ccn-microRNA genes in vitro and within cells. The three antibiotics at 1/8 minimal inhibitory concentrations caused a significant increase in the ciaR-mRNA and ccn-microRNAs. The mRNA-binding seed sequences in the five ccn-microRNAs matched all the promoter-containing sequences of pbps-mRNAs.</p><p><strong>Conclusions: </strong>β-lactam antibiotics at low-concentrations induce PBP mutation-unrelated antibiotic resistance conversion of S. pneumoniae by decrease of PBPs through pathway of CiaR-mediated transcriptional increase of ccn-microRNAs and ccn-microRNA-dependent degradation of pbp-mRNAs.</p>","PeriodicalId":13818,"journal":{"name":"International Journal of Antimicrobial Agents","volume":" ","pages":"107387"},"PeriodicalIF":4.9000,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Response regulator protein CiaR regulates the transcription of ccn-microRNAs and β-lactam antibiotic resistance conversion of Streptococcus pneumoniae.\",\"authors\":\"Mei-Juan Yang, Meng-Jie Li, Li-Dan Huang, Xin-Wei Zhang, Yan-Ying Huang, Xiao-Yu Gou, Sui-Ning Chen, Jie Yan, Peng Du, Ai-Hua Sun\",\"doi\":\"10.1016/j.ijantimicag.2024.107387\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><strong>Introduction: </strong>Streptococcus pneumoniae does not produce β-lactamases and its reduced susceptibility to β-lactam antibiotics is predominantly caused by mutations of penicillin-binding proteins (PBPs), but mechanisms of PBP mutation-unrelated β-lactam antibiotic resistance in pneumococcal strains remain poorly characterized.</p><p><strong>Methods: </strong>Susceptibility of S. pneumoniae ATCC49619 and its ciaR gene-knockout, -complemented, or -over-expression mutant (ΔciaR, CΔciaR, or ciaR<sup>OE</sup>) to penicillin, cefotaxime, and imipenem was detected using E-test. Levels of pneumococcal ciaR-mRNA, five ccn-microRNAs, and six pbps-mRNAs were determined by qRT-PCR. Recombinant CiaR (rCiaR) binding to the promoters of ccn-microRNA genes was confirmed using electrophoresis mobility shift and chromatin immunoprecipitation assays. Sequence matching between the ccn-microRNAs and pbps-mRNAs were analyzed using IntaRNA software.</p><p><strong>Results: </strong>S. pneumoniae ATCC49619 was sensitive to the three β-lactam antibiotics, but over-expression of CiaR, a response regulator protein in two-component system, caused the increase of MICs against these antibiotics. The ciaR<sup>OE</sup> mutant exhibited the significantly increased transcription of ccn-microRNAs but notably decreased transcription of pbps-mRNAs, conversely the ΔciaR mutant displayed decreased levels of ccn-microRNAs and increasesed transcription of pbps-mRNAs. rCiaR could bind to the promoters of all ccn-microRNA genes in vitro and within cells. The three antibiotics at 1/8 minimal inhibitory concentrations caused a significant increase in the ciaR-mRNA and ccn-microRNAs. The mRNA-binding seed sequences in the five ccn-microRNAs matched all the promoter-containing sequences of pbps-mRNAs.</p><p><strong>Conclusions: </strong>β-lactam antibiotics at low-concentrations induce PBP mutation-unrelated antibiotic resistance conversion of S. pneumoniae by decrease of PBPs through pathway of CiaR-mediated transcriptional increase of ccn-microRNAs and ccn-microRNA-dependent degradation of pbp-mRNAs.</p>\",\"PeriodicalId\":13818,\"journal\":{\"name\":\"International Journal of Antimicrobial Agents\",\"volume\":\" \",\"pages\":\"107387\"},\"PeriodicalIF\":4.9000,\"publicationDate\":\"2024-11-18\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"International Journal of Antimicrobial Agents\",\"FirstCategoryId\":\"3\",\"ListUrlMain\":\"https://doi.org/10.1016/j.ijantimicag.2024.107387\",\"RegionNum\":2,\"RegionCategory\":\"医学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"INFECTIOUS DISEASES\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"International Journal of Antimicrobial Agents","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1016/j.ijantimicag.2024.107387","RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"INFECTIOUS DISEASES","Score":null,"Total":0}
Response regulator protein CiaR regulates the transcription of ccn-microRNAs and β-lactam antibiotic resistance conversion of Streptococcus pneumoniae.
Introduction: Streptococcus pneumoniae does not produce β-lactamases and its reduced susceptibility to β-lactam antibiotics is predominantly caused by mutations of penicillin-binding proteins (PBPs), but mechanisms of PBP mutation-unrelated β-lactam antibiotic resistance in pneumococcal strains remain poorly characterized.
Methods: Susceptibility of S. pneumoniae ATCC49619 and its ciaR gene-knockout, -complemented, or -over-expression mutant (ΔciaR, CΔciaR, or ciaROE) to penicillin, cefotaxime, and imipenem was detected using E-test. Levels of pneumococcal ciaR-mRNA, five ccn-microRNAs, and six pbps-mRNAs were determined by qRT-PCR. Recombinant CiaR (rCiaR) binding to the promoters of ccn-microRNA genes was confirmed using electrophoresis mobility shift and chromatin immunoprecipitation assays. Sequence matching between the ccn-microRNAs and pbps-mRNAs were analyzed using IntaRNA software.
Results: S. pneumoniae ATCC49619 was sensitive to the three β-lactam antibiotics, but over-expression of CiaR, a response regulator protein in two-component system, caused the increase of MICs against these antibiotics. The ciaROE mutant exhibited the significantly increased transcription of ccn-microRNAs but notably decreased transcription of pbps-mRNAs, conversely the ΔciaR mutant displayed decreased levels of ccn-microRNAs and increasesed transcription of pbps-mRNAs. rCiaR could bind to the promoters of all ccn-microRNA genes in vitro and within cells. The three antibiotics at 1/8 minimal inhibitory concentrations caused a significant increase in the ciaR-mRNA and ccn-microRNAs. The mRNA-binding seed sequences in the five ccn-microRNAs matched all the promoter-containing sequences of pbps-mRNAs.
Conclusions: β-lactam antibiotics at low-concentrations induce PBP mutation-unrelated antibiotic resistance conversion of S. pneumoniae by decrease of PBPs through pathway of CiaR-mediated transcriptional increase of ccn-microRNAs and ccn-microRNA-dependent degradation of pbp-mRNAs.
期刊介绍：
The International Journal of Antimicrobial Agents is a peer-reviewed publication offering comprehensive and current reference information on the physical, pharmacological, in vitro, and clinical properties of individual antimicrobial agents, covering antiviral, antiparasitic, antibacterial, and antifungal agents. The journal not only communicates new trends and developments through authoritative review articles but also addresses the critical issue of antimicrobial resistance, both in hospital and community settings. Published content includes solicited reviews by leading experts and high-quality original research papers in the specified fields.
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