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Jian Y, Chen T, Yang Z, Xiang G, Xu K, Wang Y, Zhao N, He L, Liu Q, Li M. Small regulatory RNA RSaX28 promotes virulence by reinforcing the stability of RNAIII in community-associated ST398 clonotype Staphylococcus aureus. Emerg Microbes Infect 2024; 13:2341972. [PMID: 38597192 PMCID: PMC11034457 DOI: 10.1080/22221751.2024.2341972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Accepted: 04/06/2024] [Indexed: 04/11/2024]
Abstract
Staphylococcus aureus (S. aureus) is a notorious pathogen that cause metastatic or complicated infections. Hypervirulent ST398 clonotype strains, remarkably increased in recent years, dominated Community-associated S. aureus (CA-SA) infections in the past decade in China. Small RNAs like RNAIII have been demonstrated to play important roles in regulating the virulence of S. aureus, however, the regulatory roles played by many of these sRNAs in the ST398 clonotype strains are still unclear. Through transcriptome screening and combined with knockout phenotype analysis, we have identified a highly transcribed sRNA, RSaX28, in the ST398 clonotype strains. Sequence analysis revealed that RSaX28 is highly conserved in the most epidemic clonotypes of S. aureus, but its high transcription level is particularly prominent in the ST398 clonotype strains. Characterization of RSaX28 through RACE and Northern blot revealed its length to be 533nt. RSaX28 is capable of promoting the hemolytic ability, reducing biofilm formation capacity, and enhancing virulence of S. aureus in the in vivo murine infection model. Through IntaRNA prediction and EMSA validation, we found that RSaX28 can specifically interact with RNAIII, promoting its stability and positively regulating the translation of downstream alpha-toxin while inhibiting the translation of Sbi, thereby regulating the virulence and biofilm formation capacity of the ST398 clonotype strains. RSaX28 is an important virulence regulatory factor in the ST398 clonotype S. aureus and represents a potential important target for future treatment and immune intervention against S. aureus infections.
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Affiliation(s)
- Ying Jian
- Department of Laboratory Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, People’s Republic of China
| | - Tianchi Chen
- Department of Laboratory Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, People’s Republic of China
| | - Ziyu Yang
- Department of Laboratory Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, People’s Republic of China
| | - Guoxiu Xiang
- Department of Laboratory Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, People’s Republic of China
| | - Kai Xu
- Department of Laboratory Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, People’s Republic of China
| | - Yanan Wang
- Department of Laboratory Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, People’s Republic of China
| | - Na Zhao
- Department of Laboratory Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, People’s Republic of China
| | - Lei He
- Department of Laboratory Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, People’s Republic of China
| | - Qian Liu
- Department of Laboratory Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, People’s Republic of China
| | - Min Li
- Department of Laboratory Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, People’s Republic of China
- Faculty of Medical Laboratory Science, College of Health Science and Technology, School of Medicine, Shanghai Jiao Tong University, Shanghai, People’s Republic of China
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2
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Hallier M, Bronsard J, Dréano S, Sassi M, Cattoir V, Felden B, Augagneur Y. RNAIII is linked with the pentose phosphate pathway through the activation of RpiRc in Staphylococcus aureus. mSphere 2024:e0034823. [PMID: 38591898 DOI: 10.1128/msphere.00348-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 03/18/2024] [Indexed: 04/10/2024] Open
Abstract
Staphylococcus aureus RNAIII is a dual-function regulatory RNA that controls the expression of multiple virulence genes and especially the transition from adhesion to the production of exotoxins. However, its contribution to S. aureus central metabolism remains unclear. Using MS2-affinity purification coupled with RNA sequencing, we uncovered more than 50 novel RNAIII-mRNA interactions. Among them, we demonstrate that RNAIII is a major activator of the rpiRc gene, encoding a regulator of the pentose phosphate pathway (PPP). RNAIII binds the 5' UTR of rpiRc mRNA to favor ribosome loading, leading to an increased expression of RpiRc and, subsequently, of two PPP enzymes. Finally, we show that RNAIII and RpiRc are involved in S. aureus fitness in media supplemented with various carbohydrate sources related to PPP and glycolysis. Collectively, our data depict an unprecedented phenotype associated with the RNAIII regulon, especially the direct implication of RNAIII in central metabolic activity modulation. These findings show that the contribution of RNAIII in Staphylococcus aureus adaptation goes far beyond what was initially reported. IMPORTANCE Staphylococcus aureus is a major human pathogen involved in acute and chronic infections. Highly recalcitrant to antibiotic treatment, persistent infections are mostly associated with the loss of RNAIII expression, a master RNA regulator responsible for the switch from colonization to infection. Here, we used the MS2 affinity purification coupled with RNA sequencing approach to identify novel mRNA targets of RNAIII and uncover novel functions. We demonstrate that RNAIII is an activator of the expression of genes involved in the pentose phosphate pathway and is implicated in the adjustment of bacterial fitness as a function of carbohydrate sources. Taken together, our results demonstrate an unprecedented role of RNAIII that goes beyond the knowledge gained so far and contributes to a better understanding of the role of RNAIII in bacterial adaptation expression and the coordination of a complex regulatory network.
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Affiliation(s)
- Marc Hallier
- QCPS (Quality Control in Protein Synthesis), IGDR UMR CNRS 6290, Université de Rennes 1, Rennes, France
- BRM (Bacterial Regulatory RNAs and Medicine), UMR_S 1230, Université de Rennes 1, Rennes, France
| | - Julie Bronsard
- BRM (Bacterial Regulatory RNAs and Medicine), UMR_S 1230, Université de Rennes 1, Rennes, France
| | - Stéphane Dréano
- Molecular Bases of Tumorigenesis: VHL Disease Team, CNRS UMR 6290 IGDR, BIOSIT, Université de Rennes 1, Rennes, France
| | - Mohamed Sassi
- BRM (Bacterial Regulatory RNAs and Medicine), UMR_S 1230, Université de Rennes 1, Rennes, France
| | - Vincent Cattoir
- BRM (Bacterial Regulatory RNAs and Medicine), UMR_S 1230, Université de Rennes 1, Rennes, France
| | - Brice Felden
- BRM (Bacterial Regulatory RNAs and Medicine), UMR_S 1230, Université de Rennes 1, Rennes, France
| | - Yoann Augagneur
- BRM (Bacterial Regulatory RNAs and Medicine), UMR_S 1230, Université de Rennes 1, Rennes, France
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Kim S, Lee JH, Kim YG, Tan Y, Lee J. Hydroquinones Inhibit Biofilm Formation and Virulence Factor Production in Staphylococcus aureus. Int J Mol Sci 2022; 23:ijms231810683. [PMID: 36142597 PMCID: PMC9506180 DOI: 10.3390/ijms231810683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 09/05/2022] [Accepted: 09/09/2022] [Indexed: 11/16/2022] Open
Abstract
Staphylococcus aureus is one of the major pathogens responsible for antimicrobial resistance-associated death. S. aureus can secrete various exotoxins, and staphylococcal biofilms play critical roles in antibiotic tolerance and the persistence of chronic infections. Here, we investigated the inhibitory effects of 18 hydroquinones on biofilm formation and virulence factor production by S. aureus. It was found that 2,5-bis(1,1,3,3-tetramethylbutyl) hydroquinone (TBHQ) at 1 µg/mL efficiently inhibits biofilm formation by two methicillin-sensitive and two methicillin-resistant S. aureus strains with MICs of 5 µg/mL, whereas the backbone compound hydroquinone did not (MIC > 400 µg/mL). In addition, 2,3-dimethylhydroquinone and tert-butylhydroquinone at 50 µg/mL also exhibited antibiofilm activity. TBHQ at 1 µg/mL significantly decreased the hemolytic effect and lipase production by S. aureus, and at 5−50 µg/mL was non-toxic to the nematode Caenorhabditis elegans and did not adversely affect Brassica rapa seed germination or growth. Transcriptional analyses showed that TBHQ suppressed the expression of RNAIII (effector of quorum sensing). These results suggest that hydroquinones, particularly TBHQ, are potentially useful for inhibiting S. aureus biofilm formation and virulence.
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Affiliation(s)
- Sanghun Kim
- School of Chemical Engineering, Yeungnam University, Gyeongsan 38541, Korea
| | - Jin-Hyung Lee
- School of Chemical Engineering, Yeungnam University, Gyeongsan 38541, Korea
| | - Yong-Guy Kim
- School of Chemical Engineering, Yeungnam University, Gyeongsan 38541, Korea
| | - Yulong Tan
- Special Food Research Institute, Qingdao Agricultural University, Qingdao 266109, China
| | - Jintae Lee
- School of Chemical Engineering, Yeungnam University, Gyeongsan 38541, Korea
- Correspondence: ; Tel.: +82-53-810-2533
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Kinney KJ, Stach JM, Kulhankova K, Brown M, Salgado-Pabón W. Vegetation Formation in Staphylococcus Aureus Endocarditis Inversely Correlates With RNAIII and sarA Expression in Invasive Clonal Complex 5 Isolates. Front Cell Infect Microbiol 2022; 12:925914. [PMID: 35860377 PMCID: PMC9289551 DOI: 10.3389/fcimb.2022.925914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 06/14/2022] [Indexed: 01/29/2023] Open
Abstract
Infective endocarditis (IE) is one of the most feared and lethal diseases caused by Staphylococcus aureus. Once established, the infection is fast-progressing and tissue destructive. S. aureus of the clonal complex 5 (CC5) commonly cause IE yet are severely understudied. IE results from bacterial colonization and formation of tissue biofilms (known as vegetations) on injured or inflamed cardiac endothelium. S. aureus IE is promoted by adhesins, coagulases, and superantigens, with the exotoxins and exoenzymes likely contributing to tissue destruction and dissemination. Expression of the large repertoire of virulence factors required for IE and sequelae is controlled by complex regulatory networks. We investigated the temporal expression of the global regulators agr (RNAIII), rot, sarS, sarA, sigB, and mgrA in 8 invasive CC5 isolates and established intrinsic expression patterns associated with IE outcomes. We show that vegetation formation, as tested in the rabbit model of IE, inversely correlates with RNAIII and sarA expression during growth in Todd-Hewitt broth (TH). Large vegetations with severe sequelae arise from strains with high-level expression of colonization factors but slower transition towards expression of the exotoxins. Overall, strains proficient in vegetation formation, a hallmark of IE, exhibit lower expression of RNAIII and sarA. Simultaneous high expression of RNAIII, sarA, sigB, and mgrA is the one phenotype assessed in this study that fails to promote IE. Thus, RNAIII and sarA expression that provides for rheostat control of colonization and virulence genes, rather than an on and off switch, promote both vegetation formation and lethal sepsis.
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Affiliation(s)
- Kyle J. Kinney
- Department of Microbiology and Immunology, University of Iowa Carver College of Medicine, Iowa City, IA, United States
| | - Jessica M. Stach
- Department of Microbiology and Immunology, University of Iowa Carver College of Medicine, Iowa City, IA, United States
| | - Katarina Kulhankova
- Department of Microbiology and Immunology, University of Iowa Carver College of Medicine, Iowa City, IA, United States
| | - Matthew Brown
- Department of Microbiology and Immunology, University of Iowa Carver College of Medicine, Iowa City, IA, United States
| | - Wilmara Salgado-Pabón
- Department of Microbiology and Immunology, University of Iowa Carver College of Medicine, Iowa City, IA, United States,Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, WI, United States,*Correspondence: Wilmara Salgado-Pabón,
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5
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Luz BSRD, Nicolas A, Chabelskaya S, Rodovalho VDR, Le Loir Y, Azevedo VADC, Felden B, Guédon E. Environmental Plasticity of the RNA Content of Staphylococcus aureus Extracellular Vesicles. Front Microbiol 2021; 12:634226. [PMID: 33776967 PMCID: PMC7990786 DOI: 10.3389/fmicb.2021.634226] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 02/18/2021] [Indexed: 12/13/2022] Open
Abstract
The roles of bacterial extracellular vesicles (EVs) in cell-to-cell signaling are progressively being unraveled. These membranous spheres released by many living cells carry various macromolecules, some of which influence host-pathogen interactions. Bacterial EVs contain RNA, which may serve in communicating with their infected hosts. Staphylococcus aureus, an opportunistic human and animal pathogen, produces EVs whose RNA content is still poorly characterized. Here, we investigated in depth the RNA content of S. aureus EVs. A high-throughput RNA sequencing approach identified RNAs in EVs produced by the clinical S. aureus strain HG003 under different environmental conditions: early- and late-stationary growth phases, and presence or absence of a sublethal vancomycin concentration. On average, sequences corresponding to 78.0% of the annotated transcripts in HG003 genome were identified in HG003 EVs. However, only ~5% of them were highly covered by reads (≥90% coverage) indicating that a large fraction of EV RNAs, notably mRNAs and sRNAs, were fragmented in EVs. According to growth conditions, from 86 to 273 highly covered RNAs were identified into the EVs. They corresponded to 286 unique RNAs, including 220 mRNAs. They coded for numerous virulence-associated factors (hld encoded by the multifunctional sRNA RNAIII, agrBCD, psmβ1, sbi, spa, and isaB), ribosomal proteins, transcriptional regulators, and metabolic enzymes. Twenty-eight sRNAs were also detected, including bona fide RsaC. The presence of 22 RNAs within HG003 EVs was confirmed by reverse transcription quantitative PCR (RT-qPCR) experiments. Several of these 286 RNAs were shown to belong to the same transcriptional units in S. aureus. Both nature and abundance of the EV RNAs were dramatically affected depending on the growth phase and the presence of vancomycin, whereas much less variations were found in the pool of cellular RNAs of the parent cells. Moreover, the RNA abundance pattern differed between EVs and EV-producing cells according to the growth conditions. Altogether, our findings show that the environment shapes the RNA cargo of the S. aureus EVs. Although the composition of EVs is impacted by the physiological state of the producing cells, our findings suggest a selective packaging of RNAs into EVs, as proposed for EV protein cargo. Our study shedds light to the possible roles of potentially functional RNAs in S. aureus EVs, notably in host-pathogen interactions.
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Affiliation(s)
- Brenda Silva Rosa Da Luz
- INRAE, Institut Agro, STLO, Rennes, France.,Laboratory of Cellular and Molecular Genetics, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | | | - Svetlana Chabelskaya
- BRM [Bacterial Regulatory RNAs and Medicine] UMR_S 1230, University of Rennes, Inserm, Rennes, France
| | - Vinícius de Rezende Rodovalho
- INRAE, Institut Agro, STLO, Rennes, France.,Laboratory of Cellular and Molecular Genetics, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | | | - Vasco Ariston de Carvalho Azevedo
- Laboratory of Cellular and Molecular Genetics, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Brice Felden
- BRM [Bacterial Regulatory RNAs and Medicine] UMR_S 1230, University of Rennes, Inserm, Rennes, France
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6
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Yang H, Xu S, Huang K, Xu X, Hu F, He C, Shu W, Wang Z, Gong F, Zhang C, Liu Q. Anti-staphylococcus Antibiotics Interfere With the Transcription of Leucocidin ED Gene in Staphylococcus aureus Strain Newman. Front Microbiol 2020; 11:265. [PMID: 32194524 PMCID: PMC7066085 DOI: 10.3389/fmicb.2020.00265] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2019] [Accepted: 02/05/2020] [Indexed: 11/13/2022] Open
Abstract
Antibiotics have been described to modulate bacterial virulence gene expression. This study aimed to assess the changes caused by anti-Staphylococcus agents in the transcription of leucocidin ED (lukED) gene of Staphylococcus aureus strain Newman in vitro and in vivo and to determine whether the altered expression is agr dependent. The bacteria were exposed to subinhibitory concentrations [1/2, 1/4, or 1/8 minimal inhibitory concentration (MIC)] of 11 antibiotics, and the expression of lukE and agr-effector RNAIII was determined using qRT-PCR. In vivo experiments were performed to evaluate the impact exerted by six representative antibiotics on the transcription of both genes. Molecular analysis showed that in vitro lukE transcription was dramatically promoted in the Newman strain exposed to sub-MICs of vancomycin, trimethoprim-sulfamethoxazole, clindamycin, gentamicin, daptomycin, and ciprofloxacin and considerably reduced when stimulated by cefazolin, erythromycin, rifampicin, tigecycline, and linezolid. In the murine abscess model, tigecycline significantly decreased the transcription of lukE and the bacterial numbers, whereas vancomycin increased them; although cefazolin increased the lukE expression (contrary to the in vitro effect), it had a remarkable role in reducing bacterial load. The correspondence analysis shows that RNAIII expression varied under seven of 11 antibiotics in vitro, and six drugs in vivo were consistent with lukE transcripts. In conclusion, our data show that anti-Staphylococcus antibiotics exert modulatory effects on lukE expression in vitro and/or in vivo, and the changed expression caused by some drugs may be involved with agr activity, thus providing a guide to choose appropriate agents to avoid promoting bacterial virulence in lukED-positive S. aureus infections.
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Affiliation(s)
- Han Yang
- Department of Clinical Laboratory, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Su Xu
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, China
| | - Kaifeng Huang
- Department of Clinical Laboratory, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xiaogang Xu
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, China
| | - Fupin Hu
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, China
| | - Chunyan He
- Department of Clinical Laboratory, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Wen Shu
- Department of Clinical Laboratory, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Zhiyan Wang
- Department of Cardiology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Fang Gong
- Department of Clinical Laboratory, The Third Hospital Affiliated to Nantong University, Wuxi, China
| | - Chuanling Zhang
- Department of Clinical Laboratory, Xiaoshan Hospital, Hangzhou, China
| | - Qingzhong Liu
- Department of Clinical Laboratory, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
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Susilo YB, Sihto HM, Rådström P, Stephan R, Johler S, Schelin J. Reduced Enterotoxin D Formation on Boiled Ham in Staphylococcus Aureus Δagr Mutant. Toxins (Basel) 2017; 9:E263. [PMID: 28841182 PMCID: PMC5618196 DOI: 10.3390/toxins9090263] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Revised: 08/21/2017] [Accepted: 08/24/2017] [Indexed: 11/16/2022] Open
Abstract
Staphylococcal food poisoning (SFP) is a common cause of foodborne illness worldwide, and enterotoxin D (SED) is one of the most frequent Staphylococcus aureus enterotoxins associated with it. It has been reported that the expression and formation of SED in S. aureus is regulated by the quorum sensing Agr system. In this study, the effect of agr deletion on sed expression in S. aureus grown on boiled ham was investigated. Growth, sed mRNA and SED protein levels in an S. aureus wild type strain and its isogenic Δagr mutant were monitored for 14 days at 22 °C. The results showed that although deletion of the agr gene did not affect the growth rate or maximum cell density of S. aureus on boiled ham, it had a pronounced effect on SED formation during the first 5 days of incubation. The SED concentration was not reflected in the amount of preceding sed transcripts, suggesting that sed transcription levels may not always reflect SED formation. The expression of RNAIII transcript, the regulatory signal of the Agr system, was also monitored. Similar transcription patterns were observed for RNAIII and sed. Surprisingly, in the Δagr mutant, sed expression was comparable to that in the wild type strain, and was thus unaffected by deletion of the Agr system. These results demonstrate that the Agr system appears to only partially affect SED formation, even in a real food environment.
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Affiliation(s)
- Yusak Budi Susilo
- Applied Microbiology, Department of Chemistry, Lund University, SE-221 00 Lund, Sweden.
| | - Henna-Maria Sihto
- Institute for Food Safety and Hygiene, University of Zurich, CH-8057 Zurich, Switzerland.
| | - Peter Rådström
- Applied Microbiology, Department of Chemistry, Lund University, SE-221 00 Lund, Sweden.
| | - Roger Stephan
- Institute for Food Safety and Hygiene, University of Zurich, CH-8057 Zurich, Switzerland.
| | - Sophia Johler
- Institute for Food Safety and Hygiene, University of Zurich, CH-8057 Zurich, Switzerland.
| | - Jenny Schelin
- Applied Microbiology, Department of Chemistry, Lund University, SE-221 00 Lund, Sweden.
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Abstract
Compounds that inhibit virulence gene expression in bacterial pathogens have received increasing interest as possible alternatives to the traditional antibiotic treatment of infections. For the human pathogen Staphylococcus aureus, we have developed two simple assays based on reporter gene fusions to central virulence genes that are easily applicable for screening various sources of natural and synthetic peptides for anti-virulence effects. The plate assay is qualitative but simultaneously assesses the effect of gradient concentrations of the investigated compound, whereas the liquid assay is quantitative and can be employed to address whether a compound is acting on the central quorum sensing regulatory system, agr, that controls a large number of virulence genes in S. aureus.
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Affiliation(s)
- Martin Saxtorph Bojer
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Stigbøjlen 4, FrederiksbergC, 1870, Denmark
| | - Mara Baldry
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Stigbøjlen 4, FrederiksbergC, 1870, Denmark
| | - Hanne Ingmer
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Stigbøjlen 4, FrederiksbergC, 1870, Denmark.
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Bordeau V, Cady A, Revest M, Rostan O, Sassi M, Tattevin P, Donnio PY, Felden B. Staphylococcus aureus Regulatory RNAs as Potential Biomarkers for Bloodstream Infections. Emerg Infect Dis 2016; 22:1570-8. [PMID: 27224202 PMCID: PMC4994353 DOI: 10.3201/eid2209.151801] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
These RNAs predict disease severity and provide targets for therapeutic approaches. Staphylococcus aureus is a commensal bacterium and pathogen. Identifying biomarkers for the transition from colonization to disease caused by this organism would be useful. Several S. aureus small RNAs (sRNAs) regulate virulence. We investigated presence and expression of 8 sRNAs in 83 S. aureus strains from 42 patients with sepsis or septic shock and 41 asymptomatic colonized carriers. Small pathogenicity island sRNAs sprB and sprC were clade specific. Six sRNAs had variable expression not correlated with clinical status. Expression of RNAIII was lower in strains from septic shock patients than in strains from colonized patients. When RNAIII was associated with expression of sprD, colonizing strains could be discriminated from strains in patients with bloodstream infections, including patients with sepsis and septic shock. Isolates associated with colonization might have sRNAs with target expression different from those of disease isolates. Monitoring expression of RNAIII and sprD could help determine severity of bloodstream infections.
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Lioliou E, Fechter P, Caldelari I, Jester BC, Dubrac S, Helfer AC, Boisset S, Vandenesch F, Romby P, Geissmann T. Various checkpoints prevent the synthesis of Staphylococcus aureus peptidoglycan hydrolase LytM in the stationary growth phase. RNA Biol 2016; 13:427-40. [PMID: 26901414 DOI: 10.1080/15476286.2016.1153209] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
In Staphylococcus aureus, peptidoglycan metabolism plays a role in the host inflammatory response and pathogenesis. Transcription of the peptidoglycan hydrolases is activated by the essential 2-component system WalKR at low cell density. During stationary growth phase, WalKR is not active and transcription of the peptidoglycan hydrolase genes is repressed. In this work, we studied regulation of expression of the glycylglycine endopeptidase LytM. We show that, in addition to the transcriptional regulation mediated by WalKR, the synthesis of LytM is negatively controlled by a unique mechanism at the stationary growth phase. We have identified 2 different mRNAs encoding lytM, which vary in the length of their 5' untranslated (5'UTR) regions. LytM is predominantly produced from the WalKR-regulated mRNA transcript carrying a short 5'UTR. The lytM mRNA is also transcribed as part of a polycistronic operon with the upstream SA0264 gene and is constitutively expressed. Although SA0264 protein can be synthesized from the longer operon transcript, lytM cannot be translated because its ribosome-binding site is sequestered into a translationally inactive secondary structure. In addition, the effector of the agr system, RNAIII, can inhibit translation of lytM present on the operon without altering the transcript level but does not have an effect on the translation of the upstream gene. We propose that this dual regulation of lytM expression, at the transcriptional and post-transcriptional levels, contributes to prevent cell wall damage during the stationary phase of growth.
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Affiliation(s)
- Efthimia Lioliou
- a Architecture et Réactivité de l'ARN, Université de Strasbourg, CNRS, IBMC , 15 rue René Descartes, Strasbourg , France
| | - Pierre Fechter
- a Architecture et Réactivité de l'ARN, Université de Strasbourg, CNRS, IBMC , 15 rue René Descartes, Strasbourg , France
| | - Isabelle Caldelari
- a Architecture et Réactivité de l'ARN, Université de Strasbourg, CNRS, IBMC , 15 rue René Descartes, Strasbourg , France
| | - Brian C Jester
- b Institute of Systems and Synthetic Biology, University of Evry-Val-d'Essonne, CNRS FRE3561 , Evry , France
| | - Sarah Dubrac
- c Unité de Biologie des Bactéries pathogènes à Gram-positif, Institut Pasteur , 28 rue du Dr Roux, Paris , France
| | - Anne-Catherine Helfer
- a Architecture et Réactivité de l'ARN, Université de Strasbourg, CNRS, IBMC , 15 rue René Descartes, Strasbourg , France
| | - Sandrine Boisset
- d CIRI, Center International de Recherche en Infectiologie - Inserm U1111 - Université Lyon 1 - Ecole Normale Supérieure de Lyon - CNRS UMR5308 , 21 Avenue Tony Garnier, LYON cedex 07 , France
| | - François Vandenesch
- d CIRI, Center International de Recherche en Infectiologie - Inserm U1111 - Université Lyon 1 - Ecole Normale Supérieure de Lyon - CNRS UMR5308 , 21 Avenue Tony Garnier, LYON cedex 07 , France
| | - Pascale Romby
- a Architecture et Réactivité de l'ARN, Université de Strasbourg, CNRS, IBMC , 15 rue René Descartes, Strasbourg , France
| | - Thomas Geissmann
- d CIRI, Center International de Recherche en Infectiologie - Inserm U1111 - Université Lyon 1 - Ecole Normale Supérieure de Lyon - CNRS UMR5308 , 21 Avenue Tony Garnier, LYON cedex 07 , France
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11
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Gupta RK, Luong TT, Lee CY. RNAIII of the Staphylococcus aureus agr system activates global regulator MgrA by stabilizing mRNA. Proc Natl Acad Sci U S A 2015; 112:14036-41. [PMID: 26504242 DOI: 10.1073/pnas.1509251112] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
RNAIII, the effector of the agr quorum-sensing system, plays a key role in virulence gene regulation in Staphylococcus aureus, but how RNAIII transcriptionally regulates its downstream genes is not completely understood. Here, we show that RNAIII stabilizes mgrA mRNA, thereby increasing the production of MgrA, a global transcriptional regulator that affects the expression of many genes. The mgrA gene is transcribed from two promoters, P1 and P2, to produce two mRNA transcripts with long 5' UTR. Two adjacent regions of the mgrA mRNA UTR transcribed from the upstream P2 promoter, but not the P1 promoter, form a stable complex with two regions of RNAIII near the 5' and 3' ends. We further demonstrate that the interaction has several biological effects. We propose that MgrA can serve as an intermediary regulator through which agr exerts its regulatory function.
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