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Tajer L, Paillart JC, Dib H, Sabatier JM, Fajloun Z, Abi Khattar Z. Molecular Mechanisms of Bacterial Resistance to Antimicrobial Peptides in the Modern Era: An Updated Review. Microorganisms 2024; 12:1259. [PMID: 39065030 PMCID: PMC11279074 DOI: 10.3390/microorganisms12071259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2024] [Revised: 06/10/2024] [Accepted: 06/18/2024] [Indexed: 07/28/2024] Open
Abstract
Antimicrobial resistance (AMR) poses a serious global health concern, resulting in a significant number of deaths annually due to infections that are resistant to treatment. Amidst this crisis, antimicrobial peptides (AMPs) have emerged as promising alternatives to conventional antibiotics (ATBs). These cationic peptides, naturally produced by all kingdoms of life, play a crucial role in the innate immune system of multicellular organisms and in bacterial interspecies competition by exhibiting broad-spectrum activity against bacteria, fungi, viruses, and parasites. AMPs target bacterial pathogens through multiple mechanisms, most importantly by disrupting their membranes, leading to cell lysis. However, bacterial resistance to host AMPs has emerged due to a slow co-evolutionary process between microorganisms and their hosts. Alarmingly, the development of resistance to last-resort AMPs in the treatment of MDR infections, such as colistin, is attributed to the misuse of this peptide and the high rate of horizontal genetic transfer of the corresponding resistance genes. AMP-resistant bacteria employ diverse mechanisms, including but not limited to proteolytic degradation, extracellular trapping and inactivation, active efflux, as well as complex modifications in bacterial cell wall and membrane structures. This review comprehensively examines all constitutive and inducible molecular resistance mechanisms to AMPs supported by experimental evidence described to date in bacterial pathogens. We also explore the specificity of these mechanisms toward structurally diverse AMPs to broaden and enhance their potential in developing and applying them as therapeutics for MDR bacteria. Additionally, we provide insights into the significance of AMP resistance within the context of host-pathogen interactions.
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Affiliation(s)
- Layla Tajer
- Laboratory of Applied Biotechnology (LBA3B), Azm Center for Research in Biotechnology and Its Applications, Department of Cell Culture, EDST, Lebanese University, Tripoli 1300, Lebanon; (L.T.); (Z.F.)
| | - Jean-Christophe Paillart
- CNRS, Architecture et Réactivité de l’ARN, UPR 9002, Université de Strasbourg, 2 Allée Konrad Roentgen, F-67000 Strasbourg, France;
| | - Hanna Dib
- College of Engineering and Technology, American University of the Middle East, Egaila 54200, Kuwait;
| | - Jean-Marc Sabatier
- CNRS, INP, Inst Neurophysiopathol, Aix-Marseille Université, 13385 Marseille, France
| | - Ziad Fajloun
- Laboratory of Applied Biotechnology (LBA3B), Azm Center for Research in Biotechnology and Its Applications, Department of Cell Culture, EDST, Lebanese University, Tripoli 1300, Lebanon; (L.T.); (Z.F.)
- Department of Biology, Faculty of Sciences 3, Lebanese University, Campus Michel Slayman Ras Maska, Tripoli 1352, Lebanon
| | - Ziad Abi Khattar
- Faculty of Medicine and Medical Sciences, University of Balamand, Kalhat, P.O. Box 100, Tripoli, Lebanon
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2
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Yao M, Wang K, Song G, Hu Y, Chen J, Li T, Liang L, Wu J, Xu H, Wang L, Zheng Y, Zhang X, Yin Y, Yao S, Wu K. Transcriptional regulation of TacL-mediated lipoteichoic acids biosynthesis by ComE during competence impacts pneumococcal transformation. Front Cell Infect Microbiol 2024; 14:1375312. [PMID: 38779562 PMCID: PMC11109429 DOI: 10.3389/fcimb.2024.1375312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Accepted: 04/08/2024] [Indexed: 05/25/2024] Open
Abstract
Competence development is essential for bacterial transformation since it enables bacteria to take up free DNA from the surrounding environment. The regulation of teichoic acid biosynthesis is tightly controlled during pneumococcal competence; however, the mechanism governing this regulation and its impact on transformation remains poorly understood. We demonstrated that a defect in lipoteichoic acid ligase (TacL)-mediated lipoteichoic acids (LTAs) biosynthesis was associated with impaired pneumococcal transformation. Using a fragment of tacL regulatory probe as bait in a DNA pulldown assay, we successfully identified several regulatory proteins, including ComE. Electrophoretic mobility shift assays revealed that phosphomimetic ComE, but not wild-type ComE, exhibited specific binding to the probe. DNase I footprinting assays revealed the specific binding sequences encompassing around 30 base pairs located 31 base pairs upstream from the start codon of tacL. Expression of tacL was found to be upregulated in the ΔcomE strain, and the addition of exogenous competence-stimulating peptide repressed the tacL transcription in the wild-type strain but not the ΔcomE mutant, indicating that ComE exerted a negative regulatory effect on the transcription of tacL. Mutation in the JH2 region of tacL upstream regulatory sequence led to increased LTAs abundance and displayed higher transformation efficiency. Collectively, our work identified the regulatory mechanisms that control LTAs biosynthesis during competence and thereby unveiled a repression mechanism underlying pneumococcal transformation.
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Affiliation(s)
- Miao Yao
- Department of Laboratory Medicine, The First People’s Hospital of Zunyi (The Third Affiliated Hospital of Zunyi Medical University), Zunyi, Guizhou, China
- Scientific Research Center, The First People’s Hospital of Zunyi (The Third Affiliated Hospital of Zunyi Medical University), Zunyi, Guizhou, China
| | - Kun Wang
- Department of Laboratory Medicine, The First People’s Hospital of Zunyi (The Third Affiliated Hospital of Zunyi Medical University), Zunyi, Guizhou, China
- Scientific Research Center, The First People’s Hospital of Zunyi (The Third Affiliated Hospital of Zunyi Medical University), Zunyi, Guizhou, China
| | - Guangming Song
- Department of Laboratory Medicine, The First People’s Hospital of Zunyi (The Third Affiliated Hospital of Zunyi Medical University), Zunyi, Guizhou, China
- Scientific Research Center, The First People’s Hospital of Zunyi (The Third Affiliated Hospital of Zunyi Medical University), Zunyi, Guizhou, China
| | - Yumeng Hu
- Department of Laboratory Medicine, The First People’s Hospital of Zunyi (The Third Affiliated Hospital of Zunyi Medical University), Zunyi, Guizhou, China
- Scientific Research Center, The First People’s Hospital of Zunyi (The Third Affiliated Hospital of Zunyi Medical University), Zunyi, Guizhou, China
| | - Jiali Chen
- Department of Laboratory Medicine, The First People’s Hospital of Zunyi (The Third Affiliated Hospital of Zunyi Medical University), Zunyi, Guizhou, China
- Scientific Research Center, The First People’s Hospital of Zunyi (The Third Affiliated Hospital of Zunyi Medical University), Zunyi, Guizhou, China
| | - Tingting Li
- Department of Laboratory Medicine, The First People’s Hospital of Zunyi (The Third Affiliated Hospital of Zunyi Medical University), Zunyi, Guizhou, China
- Scientific Research Center, The First People’s Hospital of Zunyi (The Third Affiliated Hospital of Zunyi Medical University), Zunyi, Guizhou, China
| | - Longying Liang
- Department of Laboratory Medicine, The First People’s Hospital of Zunyi (The Third Affiliated Hospital of Zunyi Medical University), Zunyi, Guizhou, China
- Scientific Research Center, The First People’s Hospital of Zunyi (The Third Affiliated Hospital of Zunyi Medical University), Zunyi, Guizhou, China
| | - Jie Wu
- Scientific Research Center, The First People’s Hospital of Zunyi (The Third Affiliated Hospital of Zunyi Medical University), Zunyi, Guizhou, China
| | - Hongmei Xu
- Key Laboratory of Laboratory Medical Diagnostics Designated by the Ministry of Education, School of Laboratory Medicine, Chongqing Medical University, Chongqing, China
| | - Libin Wang
- Key Laboratory of Laboratory Medical Diagnostics Designated by the Ministry of Education, School of Laboratory Medicine, Chongqing Medical University, Chongqing, China
| | - Yuqiang Zheng
- Key Laboratory of Laboratory Medical Diagnostics Designated by the Ministry of Education, School of Laboratory Medicine, Chongqing Medical University, Chongqing, China
| | - Xuemei Zhang
- Key Laboratory of Laboratory Medical Diagnostics Designated by the Ministry of Education, School of Laboratory Medicine, Chongqing Medical University, Chongqing, China
| | - Yibing Yin
- Key Laboratory of Laboratory Medical Diagnostics Designated by the Ministry of Education, School of Laboratory Medicine, Chongqing Medical University, Chongqing, China
| | - Shifei Yao
- Department of Laboratory Medicine, The First People’s Hospital of Zunyi (The Third Affiliated Hospital of Zunyi Medical University), Zunyi, Guizhou, China
- Scientific Research Center, The First People’s Hospital of Zunyi (The Third Affiliated Hospital of Zunyi Medical University), Zunyi, Guizhou, China
| | - Kaifeng Wu
- Department of Laboratory Medicine, The First People’s Hospital of Zunyi (The Third Affiliated Hospital of Zunyi Medical University), Zunyi, Guizhou, China
- Scientific Research Center, The First People’s Hospital of Zunyi (The Third Affiliated Hospital of Zunyi Medical University), Zunyi, Guizhou, China
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3
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Sari RF, Fadilah F, Maladan Y, Sarassari R, Safari D. A narrative review of genomic characteristics, serotype, immunogenicity, and vaccine development of Streptococcus pneumoniae capsular polysaccharide. Clin Exp Vaccine Res 2024; 13:91-104. [PMID: 38752009 PMCID: PMC11091432 DOI: 10.7774/cevr.2024.13.2.91] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 03/31/2024] [Accepted: 04/05/2024] [Indexed: 05/18/2024] Open
Abstract
This narrative review describes genomic characteristic, serotyping, immunogenicity, and vaccine development of Streptococcus pneumoniae capsular polysaccharide (CPS). CPS is a primary virulence factor of S. pneumoniae. The genomic characteristics of S. pneumoniae CPS, including the role of biosynthetic gene and genetic variation within cps (capsule polysaccharide) locus which may lead to serotype replacement are still being investigated. One hundred unique serotypes of S. pneumoniae have been identified through various methods of serotyping using phenotypic and genotypic approach. The advantages and limitations of each method are various, emphasizing the need for accurate and comprehensive serotyping for effective disease surveillance and vaccine targeting. In addition, we elaborate the critical role of CPS in vaccine development by providing an overview of immunogenicity, ongoing research of pneumococcal vaccines, and the impact on disease burden.
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Affiliation(s)
- Ratna Fathma Sari
- Master’s Programme in Biomedical Sciences, Faculty of Medicine, University of Indonesia, Jakarta, Indonesia
- Eijkman Research Center for Molecular Biology, National Research and Innovation Agency, Cibinong, Indonesia
| | - Fadilah Fadilah
- Medical Chemistry Department, Faculty of Medicine, University of Indonesia, Jakarta, Indonesia
| | - Yustinus Maladan
- Eijkman Research Center for Molecular Biology, National Research and Innovation Agency, Cibinong, Indonesia
| | - Rosantia Sarassari
- Eijkman Research Center for Molecular Biology, National Research and Innovation Agency, Cibinong, Indonesia
| | - Dodi Safari
- Eijkman Research Center for Molecular Biology, National Research and Innovation Agency, Cibinong, Indonesia
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4
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Mattos-Graner RO, Klein MI, Alves LA. The complement system as a key modulator of the oral microbiome in health and disease. Crit Rev Microbiol 2024; 50:138-167. [PMID: 36622855 DOI: 10.1080/1040841x.2022.2163614] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 12/22/2022] [Accepted: 12/23/2022] [Indexed: 01/10/2023]
Abstract
In this review, we address the interplay between the complement system and host microbiomes in health and disease, focussing on oral bacteria known to contribute to homeostasis or to promote dysbiosis associated with dental caries and periodontal diseases. Host proteins modulating complement activities in the oral environment and expression profiles of complement proteins in oral tissues were described. In addition, we highlight a sub-set of bacterial proteins involved in complement evasion and/or dysregulation previously characterized in pathogenic species (or strains), but further conserved among prototypical commensal species of the oral microbiome. Potential roles of these proteins in host-microbiome homeostasis and in the emergence of commensal strain lineages with increased virulence were also addressed. Finally, we provide examples of how commensal bacteria might exploit the complement system in competitive or cooperative interactions within the complex microbial communities of oral biofilms. These issues highlight the need for studies investigating the effects of the complement system on bacterial behaviour and competitiveness during their complex interactions within oral and extra-oral host sites.
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Affiliation(s)
- Renata O Mattos-Graner
- Department of Oral Diagnosis, Piracicaba Dental School, State University of Campinas (UNICAMP), Sao Paulo, Brazil
| | - Marlise I Klein
- Department of Oral Diagnosis, Piracicaba Dental School, State University of Campinas (UNICAMP), Sao Paulo, Brazil
| | - Lívia Araújo Alves
- Department of Oral Diagnosis, Piracicaba Dental School, State University of Campinas (UNICAMP), Sao Paulo, Brazil
- School of Dentistry, Cruzeiro do Sul University (UNICSUL), Sao Paulo, Brazil
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5
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Wang L, Liu M, Qi Y, Wang J, Shi Q, Xie X, Zhou C, Ma L. hsdSA regulated extracellular vesicle-associated PLY to protect Streptococcus pneumoniae from macrophage killing via LAPosomes. Microbiol Spectr 2024; 12:e0099523. [PMID: 38018988 PMCID: PMC10783081 DOI: 10.1128/spectrum.00995-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 08/01/2023] [Indexed: 11/30/2023] Open
Abstract
IMPORTANCE S. pneumoniae is a major human pathogen that undergoes a spontaneous and reversible phase variation that allows it to survive in different host environments. Interestingly, we found hsdSA , a gene that manipulated the phase variation, promoted the survival and replication of S. pneumoniae in macrophages by regulating EV production and EV-associated PLY. More importantly, here we provided the first evidence that higher EV-associated PLY (produced by D39) could form LAPosomes that were single membrane compartments containing S. pneumoniae, which are induced by integrin β1/NOX2/ROS pathway. At the same time, EV-associated PLY increased the permeability of lysosome membrane and induced an insufficient acidification to escape the host killing, and ultimately prolonged the survival of S. pneumoniae in macrophages. In contrast, lower EV-associated PLY (produced by D39ΔhsdSA ) activated ULK1 recruitment to form double-layered autophagosomes to eliminate bacteria.
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Affiliation(s)
- Liping Wang
- College of Life Science and Technology, China Pharmaceutical University, Nanjing, Jiangsu, China
| | - Mengyuan Liu
- College of Life Science and Technology, China Pharmaceutical University, Nanjing, Jiangsu, China
| | - Yixin Qi
- College of Life Science and Technology, China Pharmaceutical University, Nanjing, Jiangsu, China
| | - Jian Wang
- College of Life Science and Technology, China Pharmaceutical University, Nanjing, Jiangsu, China
| | - Qixue Shi
- College of Life Science and Technology, China Pharmaceutical University, Nanjing, Jiangsu, China
| | - Xiaolin Xie
- College of Life Science and Technology, China Pharmaceutical University, Nanjing, Jiangsu, China
| | - Changlin Zhou
- College of Life Science and Technology, China Pharmaceutical University, Nanjing, Jiangsu, China
| | - Lingman Ma
- College of Life Science and Technology, China Pharmaceutical University, Nanjing, Jiangsu, China
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6
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Sun J, Wen S, Wang Z, Liu W, Lin Y, Gu J, Mao W, Xu X, He Q, Cai X. Glaesserella parasuis QseBC two-component system senses epinephrine and regulates capD expression. Microbiol Spectr 2023; 11:e0150823. [PMID: 37882555 PMCID: PMC10714720 DOI: 10.1128/spectrum.01508-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Accepted: 09/16/2023] [Indexed: 10/27/2023] Open
Abstract
IMPORTANCE The key bacterial pathogen Glaesserella parasuis, which can cause Glässer's disease, has caused significant financial losses to the swine industry worldwide. Capsular polysaccharide (CPS) is an important virulence factor for bacteria, providing the ability to avoid recognition and killing by the host immune system. Exploring the alteration of CPS synthesis in G. parasuis in response to epinephrine stimulation can lay the groundwork for revealing the pathogenic mechanism of G. parasuis as well as providing ideas for Glässer's disease control.
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Affiliation(s)
- Ju Sun
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Siting Wen
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Zhichao Wang
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Wei Liu
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Yan Lin
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Jiayun Gu
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Weiting Mao
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Xiaojuan Xu
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Qigai He
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Xuwang Cai
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, Hubei, China
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7
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Rueff AS, van Raaphorst R, Aggarwal SD, Santos-Moreno J, Laloux G, Schaerli Y, Weiser JN, Veening JW. Synthetic genetic oscillators demonstrate the functional importance of phenotypic variation in pneumococcal-host interactions. Nat Commun 2023; 14:7454. [PMID: 37978173 PMCID: PMC10656556 DOI: 10.1038/s41467-023-43241-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 11/03/2023] [Indexed: 11/19/2023] Open
Abstract
Phenotypic variation is the phenomenon in which clonal cells display different traits even under identical environmental conditions. This plasticity is thought to be important for processes including bacterial virulence, but direct evidence for its relevance is often lacking. For instance, variation in capsule production in the human pathogen Streptococcus pneumoniae has been linked to different clinical outcomes, but the exact relationship between variation and pathogenesis is not well understood due to complex natural regulation. In this study, we use synthetic oscillatory gene regulatory networks (GRNs) based on CRISPR interference (CRISPRi) together with live cell imaging and cell tracking within microfluidics devices to mimic and test the biological function of bacterial phenotypic variation. We provide a universally applicable approach for engineering intricate GRNs using only two components: dCas9 and extended sgRNAs (ext-sgRNAs). Our findings demonstrate that variation in capsule production is beneficial for pneumococcal fitness in traits associated with pathogenesis providing conclusive evidence for this longstanding question.
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Affiliation(s)
- Anne-Stéphanie Rueff
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Biophore Building, CH-1015, Lausanne, Switzerland
| | - Renske van Raaphorst
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Biophore Building, CH-1015, Lausanne, Switzerland
- de Duve Institute, UCLouvain, 75 Avenue Hippocrate, 1200, Brussels, Belgium
| | - Surya D Aggarwal
- Department of Microbiology, New York University School of Medicine, New York, NY, USA
| | - Javier Santos-Moreno
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Biophore Building, CH-1015, Lausanne, Switzerland
- Pompeu Fabra University, Barcelona, Spain
| | - Géraldine Laloux
- de Duve Institute, UCLouvain, 75 Avenue Hippocrate, 1200, Brussels, Belgium
| | - Yolanda Schaerli
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Biophore Building, CH-1015, Lausanne, Switzerland
| | - Jeffrey N Weiser
- Department of Microbiology, New York University School of Medicine, New York, NY, USA
| | - Jan-Willem Veening
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Biophore Building, CH-1015, Lausanne, Switzerland.
- Department of Pediatrics, University of California San Diego, La Jolla, CA, USA.
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA, USA.
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8
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Xiao J, Zhang Y, Zhang J, Liu B, Wang H, Yang R, Yin Y, Zhang X. Identification of cis-acting elements upstream of regR gene in streptococcus pneumoniae. Microb Pathog 2023; 182:106263. [PMID: 37481005 DOI: 10.1016/j.micpath.2023.106263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 07/04/2023] [Accepted: 07/18/2023] [Indexed: 07/24/2023]
Abstract
The identification and characterization of functional cis-acting elements is of fundamental importance for comprehending the regulatory mechanisms of gene transcription and bacterial pathogenesis. The transcription factor RegR has been demonstrated to control both competence and virulence in Streptococcus pneumoniae. Despite the clear contribution of RegR to these pathways, the mechanisms underlying its transcriptional regulation remain poorly understood. In this study, we conducted mutational analysis, gene dissection and luciferase activity assays to characterize the cis-elements situated upstream of the regR gene. Our findings revealed that a 311 bp 3'-terminal DNA sequence of the spd0300 gene represents a central region of the upstream cis-acting element of regR. Further investigations identified two structurally similar enhancer-like sequences within this region which feature prominently in the regulation of regR transcription. Furthermore, employing DNA pull-down assays allowed us to enrich the trans-acting factors with the potential to interact with these cis-acting elements. Notably, we found that the competence regulator ComE was implicated in the regulation of regR transcription, a finding which was corroborated by electrophoretic mobility shift assays (EMSA) and quantitative real-time PCR analyses (qRT-PCR). Taken together, our data thus provide fresh insight into the transcriptional regulation of regR.
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Affiliation(s)
- Jiangming Xiao
- Department of Laboratory Medicine, Key Laboratory of Diagnostic Medicine (Ministry of Education), Chongqing Medical University, Chongqing, 400016, China
| | - Yapeng Zhang
- Department of Laboratory Medicine, Key Laboratory of Diagnostic Medicine (Ministry of Education), Chongqing Medical University, Chongqing, 400016, China
| | | | - Bichen Liu
- Department of Laboratory Medicine, Key Laboratory of Diagnostic Medicine (Ministry of Education), Chongqing Medical University, Chongqing, 400016, China
| | - Hanyi Wang
- Department of Laboratory Medicine, Key Laboratory of Diagnostic Medicine (Ministry of Education), Chongqing Medical University, Chongqing, 400016, China
| | - Rui Yang
- Department of Laboratory Medicine, Key Laboratory of Diagnostic Medicine (Ministry of Education), Chongqing Medical University, Chongqing, 400016, China
| | - Yibing Yin
- Department of Laboratory Medicine, Key Laboratory of Diagnostic Medicine (Ministry of Education), Chongqing Medical University, Chongqing, 400016, China
| | - Xuemei Zhang
- Department of Laboratory Medicine, Key Laboratory of Diagnostic Medicine (Ministry of Education), Chongqing Medical University, Chongqing, 400016, China.
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9
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Rueff AS, van Raaphorst R, Aggarwal S, Santos-Moreno J, Laloux G, Schaerli Y, Weiser JN, Veening JW. Rewiring capsule production by CRISPRi-based genetic oscillators demonstrates a functional role of phenotypic variation in pneumococcal-host interactions. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.03.543575. [PMID: 37398107 PMCID: PMC10312626 DOI: 10.1101/2023.06.03.543575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Phenotypic variation is the phenomenon in which clonal cells display different traits even under identical environmental conditions. This plasticity is thought to be important for processes including bacterial virulence1-8, but direct evidence for its relevance is often lacking. For instance, variation in capsule production in the human pathogen Streptococcus pneumoniae has been linked to different clinical outcomes9-14, but the exact relationship between variation and pathogenesis is not well understood due to complex natural regulation15-20. In this study, we used synthetic oscillatory gene regulatory networks (GRNs) based on CRISPR interference together with live cell microscopy and cell tracking within microfluidics devices to mimic and test the biological function of bacterial phenotypic variation. We provide a universally applicable approach for engineering intricate GRNs using only two components: dCas9 and extended sgRNAs (ext-sgRNAs). Our findings demonstrate that variation in capsule production is beneficial for pneumococcal fitness in traits associated with pathogenesis providing conclusive evidence for this longstanding question.
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Affiliation(s)
- Anne-Stéphanie Rueff
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Biophore Building, CH-1015 Lausanne, Switzerland
| | - Renske van Raaphorst
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Biophore Building, CH-1015 Lausanne, Switzerland
- de Duve Institute, UCLouvain, 75 Avenue Hippocrate, 1200 Brussels, Belgium
| | - Surya Aggarwal
- Department of Microbiology, New York University School of Medicine, New York, NY, USA
| | - Javier Santos-Moreno
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Biophore Building, CH-1015 Lausanne, Switzerland
- Present address: Pompeu Fabra University, Barcelona, Spain
| | - Géraldine Laloux
- de Duve Institute, UCLouvain, 75 Avenue Hippocrate, 1200 Brussels, Belgium
| | - Yolanda Schaerli
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Biophore Building, CH-1015 Lausanne, Switzerland
| | - Jeffrey N. Weiser
- Department of Microbiology, New York University School of Medicine, New York, NY, USA
| | - Jan-Willem Veening
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Biophore Building, CH-1015 Lausanne, Switzerland
- Department of Pediatrics, University of California San Diego, La Jolla, California, USA
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California, USA
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10
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Yu WL, Pan JG, Qin RX, Lu ZH, Bai XH, Sun Y. TCS01 Two-Component System Influenced the Virulence of Streptococcus pneumoniae by Regulating PcpA. Infect Immun 2023; 91:e0010023. [PMID: 37052497 PMCID: PMC10187121 DOI: 10.1128/iai.00100-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2023] [Accepted: 03/26/2023] [Indexed: 04/14/2023] Open
Abstract
Streptococcus pneumoniae relies on two-component systems (TCSs) to regulate the processes of pathogenicity, osmotic pressure, chemotaxis, and energy metabolism. The TCS01 system of S. pneumoniae is composed of HK01 (histidine kinase) and RR01 (response regulator). Previous studies have reported that an rr01 mutant reduced the pneumococcal virulence in rat pneumonia, bacteremia, a nasopharyngeal model, and infective endocarditis. However, the mechanism of TCS01 (HK/RR01) regulating pneumococcal virulence remains unclear. Here, pneumococcal mutant strains Δrr01, Δhk01, and Δrr01&hk01 were constructed, and bacterial adhesion and invasion to A549 cells were compared. RNA sequencing was performed in D39 wild-type and Δrr01 strains, and transcript profile changes were analyzed. Differentially expressed virulence genes in the Δrr01 strain were screened out and identified by quantitative real-time PCR (qRT-PCR). Our results showed that pneumococcal mutant strains exhibited attenuated adhesion and invasion to A549 cells and differential transcript profiles. Results of qRT-PCR identification showed that the differential virulence genes screened out were downregulated. Among those changed virulence genes in the Δrr01 strain, the downregulated expression level of choline binding protein pcpA was the most obvious. Complementation of rr01 and overexpression of pcpA in the Δrr01 strain partially restored both pneumococcal adhesion and invasion, and rr01 complementation made the expression of pcpA upregulated. These findings revealed that rr01 influenced pneumococcal virulence by regulating pcpA.
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Affiliation(s)
- Wei-Li Yu
- The First Department of Intensive Care Unit, The Second Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China
| | - Jin-Ge Pan
- The First Department of Intensive Care Unit, The Second Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China
| | - Ru-Xue Qin
- The First Department of Intensive Care Unit, The Second Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China
| | - Zhong-Hua Lu
- The First Department of Intensive Care Unit, The Second Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China
| | - Xiao-Hui Bai
- College of Life and Environment Sciences, Huangshan University, Huangshan, Anhui, China
| | - Yun Sun
- The First Department of Intensive Care Unit, The Second Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China
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11
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Echlin H, Iverson A, Sardo U, Rosch JW. Airway proteolytic control of pneumococcal competence. PLoS Pathog 2023; 19:e1011421. [PMID: 37256908 PMCID: PMC10259803 DOI: 10.1371/journal.ppat.1011421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 06/12/2023] [Accepted: 05/11/2023] [Indexed: 06/02/2023] Open
Abstract
Streptococcus pneumoniae is an opportunistic pathogen that colonizes the upper respiratory tract asymptomatically and, upon invasion, can lead to severe diseases including otitis media, sinusitis, meningitis, bacteremia, and pneumonia. One of the first lines of defense against pneumococcal invasive disease is inflammation, including the recruitment of neutrophils to the site of infection. The invasive pneumococcus can be cleared through the action of serine proteases generated by neutrophils. It is less clear how serine proteases impact non-invasive pneumococcal colonization, which is the key first step to invasion and transmission. One significant aspect of pneumococcal biology and adaptation in the respiratory tract is its natural competence, which is triggered by a small peptide CSP. In this study, we investigate if serine proteases are capable of degrading CSP and the impact this has on pneumococcal competence. We found that CSP has several potential sites for trypsin-like serine protease degradation and that there were preferential cleavage sites recognized by the proteases. Digestion of CSP with two different trypsin-like serine proteases dramatically reduced competence in a dose-dependent manner. Incubation of CSP with mouse lung homogenate also reduced recombination frequency of the pneumococcus. These ex vivo experiments suggested that serine proteases in the lower respiratory tract reduce pneumococcal competence. This was subsequently confirmed measuring in vivo recombination frequencies after induction of protease production via poly (I:C) stimulation and via co-infection with influenza A virus, which dramatically lowered recombination events. These data shed light on a new mechanism by which the host can modulate pneumococcal behavior and genetic exchange via direct degradation of the competence signaling peptide.
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Affiliation(s)
- Haley Echlin
- Department of Infectious Diseases, St Jude Children’s Research Hospital, Memphis, Tennessee, United States of America
| | - Amy Iverson
- Department of Infectious Diseases, St Jude Children’s Research Hospital, Memphis, Tennessee, United States of America
| | - Ugo Sardo
- Department of Infectious Diseases, St Jude Children’s Research Hospital, Memphis, Tennessee, United States of America
| | - Jason W. Rosch
- Department of Infectious Diseases, St Jude Children’s Research Hospital, Memphis, Tennessee, United States of America
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12
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Kant S, Sun Y, Pancholi V. StkP- and PhpP-Mediated Posttranslational Modifications Modulate the S. pneumoniae Metabolism, Polysaccharide Capsule, and Virulence. Infect Immun 2023; 91:e0029622. [PMID: 36877045 PMCID: PMC10112228 DOI: 10.1128/iai.00296-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 02/09/2023] [Indexed: 03/07/2023] Open
Abstract
Pneumococcal Ser/Thr kinase (StkP) and its cognate phosphatase (PhpP) play a crucial role in bacterial cytokinesis. However, their individual and reciprocal metabolic and virulence regulation-related functions have yet to be adequately investigated in encapsulated pneumococci. Here, we demonstrate that the encapsulated pneumococcal strain D39-derived D39ΔPhpP and D39ΔStkP mutants displayed differential cell division defects and growth patterns when grown in chemically defined media supplemented with glucose or nonglucose sugars as the sole carbon source. Microscopic and biochemical analyses supported by RNA-seq-based global transcriptomic analyses of these mutants revealed significantly down- and upregulated polysaccharide capsule formation and cps2 genes in D39ΔPhpP and D39ΔStkP mutants, respectively. While StkP and PhpP individually regulated several unique genes, they also participated in sharing the regulation of the same set of differentially regulated genes. Cps2 genes were reciprocally regulated in part by the StkP/PhpP-mediated reversible phosphorylation but independent of the MapZ-regulated cell division process. StkP-mediated dose-dependent phosphorylation of CcpA proportionately inhibited CcpA-binding to Pcps2A, supporting increased cps2 gene expression and capsule formation in D39ΔStkP. While the attenuation of the D39ΔPhpP mutant in two mouse infection models corroborated with several downregulated capsules-, virulence-, and phosphotransferase systems (PTS)-related genes, the D39ΔStkP mutant with increased amounts of polysaccharide capsules displayed significantly decreased virulence in mice compared to the D39 wild-type, but more virulence compared to D39ΔPhpP. NanoString technology-based inflammation-related gene expression and Meso Scale Discovery-based multiplex chemokine analysis of human lung cells cocultured with these mutants confirmed their distinct virulence phenotypes. StkP and PhpP may, therefore, serve as critical therapeutic targets.
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Affiliation(s)
- Sashi Kant
- Department of Pathology, Ohio State University College of Medicine, Columbus, Ohio, USA
| | - Youcheng Sun
- Department of Pathology, Ohio State University College of Medicine, Columbus, Ohio, USA
| | - Vijay Pancholi
- Department of Pathology, Ohio State University College of Medicine, Columbus, Ohio, USA
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13
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Glanville DG, Gazioglu O, Marra M, Tokars VL, Kushnir T, Habtom M, Croucher NJ, Nebenzahl YM, Mondragón A, Yesilkaya H, Ulijasz AT. Pneumococcal capsule expression is controlled through a conserved, distal cis-regulatory element during infection. PLoS Pathog 2023; 19:e1011035. [PMID: 36719895 PMCID: PMC9888711 DOI: 10.1371/journal.ppat.1011035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Accepted: 11/29/2022] [Indexed: 02/01/2023] Open
Abstract
Streptococcus pneumoniae (the pneumococcus) is the major cause of bacterial pneumonia in the US and worldwide. Studies have shown that the differing chemical make-up between serotypes of its most important virulence factor, the capsule, can dictate disease severity. Here we demonstrate that control of capsule synthesis is also critical for infection and facilitated by two broadly conserved transcription factors, SpxR and CpsR, through a distal cis-regulatory element we name the 37-CE. Strikingly, changing only three nucleotides within this sequence is sufficient to render pneumococcus avirulent. Using in vivo and in vitro approaches, we present a model where SpxR interacts as a unique trimeric quaternary structure with the 37-CE to enable capsule repression in the airways. Considering its dramatic effect on infection, variation of the 37-CE between serotypes suggests this molecular switch could be a critical contributing factor to this pathogen's serotype-specific disease outcomes.
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Affiliation(s)
- David G. Glanville
- Department of Microbiology and Immunology, Loyola University Chicago, Maywood, Illinois, United States of America
| | - Ozcan Gazioglu
- Department of Respiratory Sciences, University of Leicester, University Road, Leicester, United Kingdom
| | - Michela Marra
- Department of Microbiology and Immunology, Loyola University Chicago, Maywood, Illinois, United States of America
| | - Valerie L. Tokars
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Tatyana Kushnir
- The Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of The Negev, Beer-Sheva, Israel
| | - Medhanie Habtom
- Department of Respiratory Sciences, University of Leicester, University Road, Leicester, United Kingdom
| | - Nicholas J. Croucher
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Sir Michael Uren Hub, Imperial College London, London, United Kingdom
| | - Yaffa Mizrachi Nebenzahl
- The Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of The Negev, Beer-Sheva, Israel
| | - Alfonso Mondragón
- Department of Molecular Biosciences, Northwestern University, Evanston, Illinois, United States of America
| | - Hasan Yesilkaya
- Department of Respiratory Sciences, University of Leicester, University Road, Leicester, United Kingdom
| | - Andrew T. Ulijasz
- Department of Microbiology and Immunology, Loyola University Chicago, Maywood, Illinois, United States of America
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14
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Zautner AE, Tersteegen A, Schiffner CJ, Ðilas M, Marquardt P, Riediger M, Delker AM, Mäde D, Kaasch AJ. Human Erysipelothrix rhusiopathiae infection via bath water – case report and genome announcement. Front Cell Infect Microbiol 2022; 12:981477. [PMID: 36353709 PMCID: PMC9637936 DOI: 10.3389/fcimb.2022.981477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 10/03/2022] [Indexed: 11/24/2022] Open
Abstract
Erysipelothrix rhusiopathiae is a facultative anaerobic, environmentally stable, Gram-positive rod that causes swine and avian erysipelas as a zoonotic pathogen. In humans, the main manifestations described are circumscribed erysipeloid, generalized erysipeloid, and endocarditis. Here, we report a 46-year-old female patient who presented to the physician because of redness and marked functio laesa of the hand, in terms of a pain-related restricted range of motion, and was treated surgically. E. rhusopathiae was detected in tissue biopsy. The source of infection was considered to be a pond in which both swine and, later, her dog bathed. The genome of the isolate was completely sequenced and especially the presumptive virulence associated factors as well as the presumptive antimicrobial resistance genes, in particular a predicted homologue to the multiple sugar metabolism regulator (MsmR), several predicted two-component signal transduction systems, three predicted hemolysins, two predicted neuraminidases, three predicted hyaluronate lyases, the surface protective antigen SpaA, a subset of predicted enzymes that potentially confer resistance to reactive oxygen species (ROS), several predicted phospholipases that could play a role in the escape from phagolysosomes into host cell cytoplasm as well as a predicted vancomycin resistance locus (vex23-vncRS) and three predicted MATE efflux transporters were investigated in more detail.
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Affiliation(s)
- Andreas E. Zautner
- Institut für Medizinische Mikrobiologie und Krankenhaushygiene, Medizinische Fakultät der Otto-von-Guericke Universität Magdeburg, Magdeburg, Germany
- *Correspondence: Andreas E. Zautner,
| | - Aljoscha Tersteegen
- Institut für Medizinische Mikrobiologie und Krankenhaushygiene, Medizinische Fakultät der Otto-von-Guericke Universität Magdeburg, Magdeburg, Germany
| | - Conrad-Jakob Schiffner
- Institut für Medizinische Mikrobiologie und Krankenhaushygiene, Medizinische Fakultät der Otto-von-Guericke Universität Magdeburg, Magdeburg, Germany
| | - Milica Ðilas
- Institut für Medizinische Mikrobiologie und Krankenhaushygiene, Medizinische Fakultät der Otto-von-Guericke Universität Magdeburg, Magdeburg, Germany
| | - Pauline Marquardt
- Institut für Medizinische Mikrobiologie und Krankenhaushygiene, Medizinische Fakultät der Otto-von-Guericke Universität Magdeburg, Magdeburg, Germany
| | - Matthias Riediger
- Institut für Medizinische Mikrobiologie und Krankenhaushygiene, Medizinische Fakultät der Otto-von-Guericke Universität Magdeburg, Magdeburg, Germany
| | - Anna Maria Delker
- Universitätsklinik für Plastische, Ästhetische und Handchirurgie Medizinische Fakultät der Otto-von-Guericke Universität Magdeburg, Magdeburg, Germany
| | - Dietrich Mäde
- Landesamt für Verbraucherschutz Sachsen-Anhalt, Halle (Saale), Germany
| | - Achim J. Kaasch
- Institut für Medizinische Mikrobiologie und Krankenhaushygiene, Medizinische Fakultät der Otto-von-Guericke Universität Magdeburg, Magdeburg, Germany
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15
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Xiao S, Suo W, Zhang J, Zhang X, Yin Y, Guo X, Zheng Y. Mga Spn is a negative regulator of capsule and phosphorylcholine biosynthesis and influences the virulence of Streptococcus pneumoniae D39. Virulence 2021; 12:2366-2381. [PMID: 34506260 PMCID: PMC8437459 DOI: 10.1080/21505594.2021.1972539] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Global transcriptional regulators are prevalent in gram-positive pathogens. The transcriptional regulators of the Mga/AtxA family regulate target gene expression by directly binding to the promoter regions, that results in the coordinated expression of virulence factors. The spd_1587 gene of Streptococcus pneumoniae strain D39 encodes MgaSpn, which shares sequence similarity with global transcriptional regulators of the Mga/AtxA family. In this study, we demonstrated that MgaSpn regulates the biosynthesis of the capsule and phosphorylcholine, which play key roles in disease severity in S. pneumoniae infections. MgaSpn directly binds to the cps and lic1 promoters and affects the biosynthesis of the capsule and phosphorylcholine. MgaSpn binds to two specific sites on the promoter of cps, one of which contains the −35 box of the promoter, with high affinity. Consistently, low-molecular-weight capsule components were observed in the mgaSpn-null mutant strain. Moreover, we found that phosphorylcholine content was notably increased in the unencapsulated mgaSpn mutant strain. The mgaSpn null mutant caused more severe systemic disease than the parental strain D39. These findings indicate that the pneumococcal MgaSpn protein can inhibit capsule and phosphorylcholine production, thereby affecting the virulence of S. pneumoniae.
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Affiliation(s)
- Shengnan Xiao
- Department of Medicine Laboratory, Children's Hospital of Chongqing Medical University; National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders; and Chongqing Key Laboratory of Pediatrics, Chongqing, People's Republic of China
| | - Weicai Suo
- Department of Medicine Laboratory, Children's Hospital of Chongqing Medical University; National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders; and Chongqing Key Laboratory of Pediatrics, Chongqing, People's Republic of China
| | - Jinghui Zhang
- Key Laboratory of Diagnostic Medicine Designated by the Ministry of Education, Chongqing Medical University, Chongqing, People's Republic of China
| | - Xuemei Zhang
- Key Laboratory of Diagnostic Medicine Designated by the Ministry of Education, Chongqing Medical University, Chongqing, People's Republic of China
| | - Yibing Yin
- Key Laboratory of Diagnostic Medicine Designated by the Ministry of Education, Chongqing Medical University, Chongqing, People's Republic of China
| | - Xinlin Guo
- Department of Medicine Laboratory, Children's Hospital of Chongqing Medical University; National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders; and Chongqing Key Laboratory of Pediatrics, Chongqing, People's Republic of China
| | - Yuqiang Zheng
- Department of Medicine Laboratory, Children's Hospital of Chongqing Medical University; National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders; and Chongqing Key Laboratory of Pediatrics, Chongqing, People's Republic of China
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16
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Inactivation of Transcriptional Regulator FabT Influences Colony Phase Variation of Streptococcus pneumoniae. mBio 2021; 12:e0130421. [PMID: 34399624 PMCID: PMC8406281 DOI: 10.1128/mbio.01304-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Streptococcus pneumoniae is an opportunistic pathogen that can alter its cell surface phenotype in response to the host environment. We demonstrated that the transcriptional regulator FabT is an indirect regulator of capsular polysaccharide, an important virulence factor of Streptococcus pneumoniae. Transcriptome analysis between the wild-type D39s and D39ΔfabT mutant strains unexpectedly identified a differentially expressed gene encoding a site-specific recombinase, PsrA. PsrA catalyzes the inversion of 3 homologous hsdS genes in a type I restriction-modification (RM) system SpnD39III locus and is responsible for the reversible switch of phase variation. Our study demonstrated that upregulation of PsrA in a D39ΔfabT mutant correlated with an increased ratio of transparent (T) phase variants. Inactivation of the invertase PsrA led to uniform opaque (O) variants. Direct quantification of allelic variants of hsdS derivatives and inversions of inverted repeats indicated that the recombinase PsrA fully catalyzes the inversion mediated by IR1 and IR3, and FabT mediated the recombination of the hsdS alleles in PsrA-dependent and PsrA-independent manners. In addition, compared to D39s, the ΔfabT mutant exhibited reduced nasopharyngeal colonization and was more resistant to phagocytosis and less adhesive to epithelial cells. These results indicated that phase variation in the ΔfabT mutant also affects other cell surface components involved in host interactions.
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17
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Ayoola MB, Nakamya MF, Shack LA, Park S, Lim J, Lee JH, Ross MK, Eoh H, Nanduri B. SP_0916 Is an Arginine Decarboxylase That Catalyzes the Synthesis of Agmatine, Which Is Critical for Capsule Biosynthesis in Streptococcus pneumoniae. Front Microbiol 2020; 11:578533. [PMID: 33072045 PMCID: PMC7531197 DOI: 10.3389/fmicb.2020.578533] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 08/24/2020] [Indexed: 12/26/2022] Open
Abstract
The global burden of invasive pneumococcal diseases, including pneumonia and sepsis, caused by Streptococcus pneumoniae, a Gram-positive bacterial pathogen, remains a major global health risk. The success of pneumococcus as a pathogen can be attributed to its ability to regulate the synthesis of capsular polysaccharide (CPS) during invasive disease. We previously reported that deletion of a putative lysine decarboxylase (LDC; ΔSP_0916) in pneumococcal serotype 4 (TIGR4) results in reduced CPS. SP_0916 locus is annotated as either an arginine or a LDC in pneumococcal genomes. In this study, by biochemical characterization of the recombinant SP_0916, we determined the substrate specificity of SP_0916 and show that it is an arginine decarboxylase (speA/ADC). We also show that deletion of the polyamine transporter (potABCD) predicted to import putrescine and spermidine results in reduced CPS, while deletion of spermidine synthase (speE) for the conversion of putrescine to spermidine had no impact on the capsule. Targeted metabolomics identified a correlation between reduced levels of agmatine and loss of capsule in ΔspeA and ΔpotABCD, while agmatine levels were comparable between the encapsulated TIGR4 and ΔspeE. Exogenous supplementation of agmatine restored CPS in both ΔpotABCD and ΔspeA. These results demonstrate that agmatine is critical for regulating the CPS, a predominant virulence factor in pneumococci.
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Affiliation(s)
- Moses B Ayoola
- Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Starkville, MS, United States
| | - Mary F Nakamya
- Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Starkville, MS, United States
| | - Leslie A Shack
- Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Starkville, MS, United States
| | - Seongbin Park
- Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Starkville, MS, United States
| | - Juhyeon Lim
- Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, CA, United States
| | - Jung Hwa Lee
- Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Starkville, MS, United States
| | - Matthew K Ross
- Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Starkville, MS, United States
| | - Hyungjin Eoh
- Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, CA, United States
| | - Bindu Nanduri
- Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Starkville, MS, United States.,Institute for Genomics, Biocomputing and Biotechnology, Mississippi State University, Starkville, MS, United States
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18
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Abstract
Capsular polysaccharide is a key factor underlying the virulence of Streptococcus pneumoniae in human diseases. Thus, a deep understanding of capsular polysaccharide synthesis is essential for uncovering the pathogenesis of S. pneumoniae infection. In this study, we show that protein SPD_1495 interacts with phosphorylated ComE to negatively regulate the formation of capsular polysaccharide. Deletion of spd1495 increased capsular polysaccharide synthesis and thereby enhanced bacterial virulence. These findings further reveal the synthesis mechanism of capsular polysaccharide and provide new insight into the biology of this clinically important bacterium. Streptococcus pneumoniae, a Gram-positive human pathogen, causes a series of serious diseases in humans. SPD_1495 from S. pneumoniae is annotated as a hypothetical ABC sugar-binding protein in the NCBI database, but there are few reports on detailed biological functions of SPD_1495. To fully study the influence of SPD_1495 on bacterial virulence in S. pneumoniae, we constructed a deletion mutant (D39Δspd1495) and an overexpressing strain (D39spd1495+). Comparative analysis of iTRAQ-based quantitative proteomic data of the wild-type D39 strain (D39-WT) and D39Δspd1495 showed that several differentially expressed proteins that participate in capsular polysaccharide synthesis, such as Cps2M, Cps2C, Cps2L, Cps2T, Cps2E, and Cps2D, were markedly upregulated in D39Δspd1495. Subsequent transmission electron microscopy and uronic acid detection assay confirmed that capsular polysaccharide synthesis was enhanced in D39Δspd1495 compared to that in D39-WT. Moreover, knockout of spd1495 resulted in increased capsular polysaccharide synthesis, as well as increased bacterial virulence, as confirmed by the animal study. Through a coimmunoprecipitation assay, surface plasmon resonance, and electrophoretic mobility shift assay, we found that SPD_1495 negatively regulated cps promoter expression by interacting with phosphorylated ComE, a negative transcriptional regulator for capsular polysaccharide formation. Overall, this study suggested that SPD_1495 negatively regulates capsular polysaccharide formation and thereby enhances bacterial virulence in the host. These findings also provide valuable insights into understanding the biology of this clinically important bacterium. IMPORTANCE Capsular polysaccharide is a key factor underlying the virulence of Streptococcus pneumoniae in human diseases. Thus, a deep understanding of capsular polysaccharide synthesis is essential for uncovering the pathogenesis of S. pneumoniae infection. In this study, we show that protein SPD_1495 interacts with phosphorylated ComE to negatively regulate the formation of capsular polysaccharide. Deletion of spd1495 increased capsular polysaccharide synthesis and thereby enhanced bacterial virulence. These findings further reveal the synthesis mechanism of capsular polysaccharide and provide new insight into the biology of this clinically important bacterium.
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19
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Ghosh P, Shah M, Ravichandran S, Park SS, Iqbal H, Choi S, Kim KK, Rhee DK. Pneumococcal VncR Strain-Specifically Regulates Capsule Polysaccharide Synthesis. Front Microbiol 2019; 10:2279. [PMID: 31632380 PMCID: PMC6781885 DOI: 10.3389/fmicb.2019.02279] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Accepted: 09/18/2019] [Indexed: 11/19/2022] Open
Abstract
Capsular polysaccharides (CPS), a major virulence factor in Streptococcus pneumoniae, become thicker during blood invasion while not during asymptomatic nasopharyngeal colonization. However, the underlying mechanism controlling this differential pneumococcal CPS regulation remain unclear. Here, we show how VncR, the response regulator of the vancomycin resistance locus (vncRS operon), regulates CPS expression in vncR mutants in three serotype (type 2, 3, and 6B) backgrounds upon exposure to serum lactoferrin (LF). Comparative analysis of CPS levels in the wild type (WT) of three strains and their isogenic vncR mutants after LF exposure revealed a strain-specific alteration in CPS production. Consistently, VncR-mediated strain-specific CPS production is correlated with pneumococcal virulence, in vivo. Electrophoretic mobility-shift assay and co-immunoprecipitation revealed an interaction between VncR and the cps promoter (cpsp) in the presence of serum. In addition, in silico analysis uncovered this protein-DNA interaction, suggesting that VncR binds with the cpsp, and recognizes the strain-specific significance of the tandem repeats in cpsp. Taken together, the interaction of VncR and cpsp after serum exposure plays an essential role in regulating differential strain-specific CPS production, which subsequently determines strain-specific systemic virulence. This study highlights how host protein LF contributes to pneumococcal VncR-mediated CPS production. As CPS plays a significant role in immune evasion, these findings suggest that drugs designed to interrupt the VncR-mediated CPS production could help to combat pneumococcal infections.
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Affiliation(s)
| | - Masaud Shah
- Department of Molecular Science and Technology, Ajou University, Suwon, South Korea
| | - Subramaniyam Ravichandran
- Department of Molecular Cell Biology, School of Medicine, Sungkyunkwan University, Suwon, South Korea
| | - Sang-Sang Park
- School of Pharmacy, Sungkyunkwan University, Suwon, South Korea
| | - Hamid Iqbal
- School of Pharmacy, Sungkyunkwan University, Suwon, South Korea
| | - Sangdun Choi
- Department of Molecular Science and Technology, Ajou University, Suwon, South Korea
| | - Kyeong Kyu Kim
- Department of Molecular Cell Biology, School of Medicine, Sungkyunkwan University, Suwon, South Korea
| | - Dong Kwon Rhee
- School of Pharmacy, Sungkyunkwan University, Suwon, South Korea
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20
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Ayoola MB, Shack LA, Nakamya MF, Thornton JA, Swiatlo E, Nanduri B. Polyamine Synthesis Effects Capsule Expression by Reduction of Precursors in Streptococcus pneumoniae. Front Microbiol 2019; 10:1996. [PMID: 31555234 PMCID: PMC6727871 DOI: 10.3389/fmicb.2019.01996] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2019] [Accepted: 08/15/2019] [Indexed: 12/20/2022] Open
Abstract
Streptococcus pneumoniae (pneumococcus, Spn) colonizes the human nasopharynx asymptomatically but can cause infections such as otitis media, and invasive pneumococcal disease such as community-acquired pneumonia, meningitis, and sepsis. Although the success of Spn as a pathogen can be attributed to its ability to synthesize and regulate capsular polysaccharide (CPS) for survival in the host, the mechanisms of CPS regulation are not well-described. Recent studies from our lab demonstrate that deletion of a putative polyamine biosynthesis gene (ΔcadA) in Spn TIGR4 results in the loss of the capsule. In this study, we characterized the transcriptome and metabolome of ΔcadA and identified specific mechanisms that could explain the regulatory role of polyamines in pneumococcal CPS biosynthesis. Our data indicate that impaired polyamine synthesis impacts galactose to glucose interconversion via the Leloir pathway which limits the availability of UDP-galactose, a precursor of serotype 4 CPS, and UDP-N-acetylglucosamine (UDP-GlcNAc), a nucleotide sugar precursor that is at the intersection of CPS and peptidoglycan repeat unit biosynthesis. Reduced carbon flux through glycolysis, coupled with altered fate of glycolytic intermediates further supports impaired synthesis of UDP-GlcNAc. A significant increase in the expression of transketolases indicates a potential shift in carbon flow toward the pentose phosphate pathway (PPP). Higher PPP activity could constitute oxidative stress responses in ΔcadA which warrants further investigation. The results from this study clearly demonstrate the potential of polyamine synthesis, targeted for cancer therapy in human medicine, for the development of novel prophylactic and therapeutic strategies for treating bacterial infections.
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Affiliation(s)
- Moses B Ayoola
- Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Starkville, MS, United States
| | - Leslie A Shack
- Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Starkville, MS, United States
| | - Mary F Nakamya
- Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Starkville, MS, United States
| | - Justin A Thornton
- Department of Biological Sciences, Mississippi State University, Starkville, MS, United States
| | - Edwin Swiatlo
- Section of Infectious Diseases, Southeast Louisiana Veterans Health Care System, New Orleans, LA, United States
| | - Bindu Nanduri
- Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Starkville, MS, United States.,Institute for Genomics, Biocomputing and Biotechnology, Mississippi State University, Starkville, MS, United States
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21
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Rowe HM, Karlsson E, Echlin H, Chang TC, Wang L, van Opijnen T, Pounds SB, Schultz-Cherry S, Rosch JW. Bacterial Factors Required for Transmission of Streptococcus pneumoniae in Mammalian Hosts. Cell Host Microbe 2019; 25:884-891.e6. [PMID: 31126758 DOI: 10.1016/j.chom.2019.04.012] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 02/18/2019] [Accepted: 04/02/2019] [Indexed: 02/06/2023]
Abstract
The capacity of Streptococcus pneumoniae to successfully transmit and colonize new human hosts is a critical aspect of pneumococcal population biology and a prerequisite for invasive disease. However, the bacterial mechanisms underlying this process remain largely unknown. To identify bacterial factors required for transmission, we conducted a high-throughput genetic screen with a transposon sequencing (Tn-seq) library of a pneumococcal strain in a ferret transmission model. Key players in both metabolism and transcriptional regulation were identified as required for efficient bacterial transmission. Targeted deletion of the putative C3-degrading protease CppA, iron transporter PiaA, or competence regulatory histidine kinase ComD significantly decreased transmissibility in a mouse model, further validating the screen. Maternal vaccination with recombinant surface-exposed PiaA and CppA alone or in combination blocked transmission in offspring and were more effective than capsule-based vaccines. These data underscore the possibility of targeting pneumococcal transmission as a means of eliminating invasive disease in the population.
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Affiliation(s)
- Hannah M Rowe
- Department of Infectious Diseases, St Jude Children's Research Hospital, Memphis, TN, USA
| | - Erik Karlsson
- Department of Infectious Diseases, St Jude Children's Research Hospital, Memphis, TN, USA
| | - Haley Echlin
- Department of Infectious Diseases, St Jude Children's Research Hospital, Memphis, TN, USA
| | - Ti-Cheng Chang
- Department of Computational Biology, St Jude Children's Research Hospital, Memphis, TN, USA
| | - Lei Wang
- Department of Biostatistics, St Jude Children's Research Hospital, Memphis, TN, USA
| | | | - Stanley B Pounds
- Department of Biostatistics, St Jude Children's Research Hospital, Memphis, TN, USA
| | - Stacey Schultz-Cherry
- Department of Infectious Diseases, St Jude Children's Research Hospital, Memphis, TN, USA
| | - Jason W Rosch
- Department of Infectious Diseases, St Jude Children's Research Hospital, Memphis, TN, USA.
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22
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Abstract
The polysaccharide capsule of Streptococcus pneumoniae is the dominant surface structure of the organism and plays a critical role in virulence, principally by interfering with host opsonophagocytic clearance mechanisms. The capsule is the target of current pneumococcal vaccines, but there are 98 currently recognised polysaccharide serotypes and protection is strictly serotype-specific. Widespread use of these vaccines is driving changes in serotype prevalence in both carriage and disease. This chapter summarises current knowledge on the role of the capsule and its regulation in pathogenesis, the mechanisms of capsule synthesis, the genetic basis for serotype differences, and provides insights into how so many structurally distinct capsular serotypes have evolved. Such knowledge will inform ongoing refinement of pneumococcal vaccination strategies.
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23
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Ye W, Zhang J, Shu Z, Yin Y, Zhang X, Wu K. Pneumococcal LytR Protein Is Required for the Surface Attachment of Both Capsular Polysaccharide and Teichoic Acids: Essential for Pneumococcal Virulence. Front Microbiol 2018; 9:1199. [PMID: 29951042 PMCID: PMC6008509 DOI: 10.3389/fmicb.2018.01199] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 05/16/2018] [Indexed: 11/13/2022] Open
Abstract
The LytR-Cps-Psr family proteins are commonly present in Gram-positive bacteria, which have been shown to implicate in anchoring cell wall-related glycopolymers to the peptidoglycan. Here, we report the cellular function of SPD_1741 (LytR) in Streptococcus pneumoniae and its role in virulence of pneumococci. Pneumococcal ΔlytR mutants have been successfully constructed by replacing the lytR gene with erm cassette. The role of LytR in pneumococcal growth was determined by growth experiments, and surface accessibility of the LytR protein was analyzed using flow cytometry. Transmission electron microscopy (TEM) and immunoblotting were used to reveal the changes in capsular polysaccharide (CPS). Dot blot and ELISA were used to quantify the amount of teichoic acids (TAs). The contribution of LytR on bacterial virulence was assessed using in vitro phagocytosis assays and infection experiments. Compared to the wild-type strain, the ΔlytR mutant showed a defect in growth which merely grew to a maximal OD620 of 0.2 in the liquid medium. The growth of the ΔlytR mutant could be restored by addition of recombinant ΔTM-LytR protein in culture medium in a dose-dependent manner. TEM results showed that the D39ΔlytR mutant was impaired in the surface attachment of CPS. Deletion of lytR gene also impaired the retention of TAs on the surface of pneumococci. The reduction of CPS and TAs on the pneumocccal cells were confirmed using Dot blot and ELISA assays. Compared to wild-type D39, the ΔlytR mutant was more susceptible to the phagocytosis. Animal studies showed that the ability to colonize the nasophaynx and virulence of pneumococci were affected by impairment of the lytR gene. Collectively, these results suggest that pneumococcal LytR is involved in anchoring both the CPS and TAs to cell wall, which is important for virulence of pneumococci.
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Affiliation(s)
- Weijie Ye
- Key Laboratory of Diagnostic Medicine Designated by the Ministry of Education, Department of Laboratory Medicine, Chongqing Medical University, Chongqing, China
| | - Jinghui Zhang
- Key Laboratory of Diagnostic Medicine Designated by the Ministry of Education, Department of Laboratory Medicine, Chongqing Medical University, Chongqing, China
| | - Zhaoche Shu
- Key Laboratory of Diagnostic Medicine Designated by the Ministry of Education, Department of Laboratory Medicine, Chongqing Medical University, Chongqing, China
| | - Yibing Yin
- Key Laboratory of Diagnostic Medicine Designated by the Ministry of Education, Department of Laboratory Medicine, Chongqing Medical University, Chongqing, China
| | - Xuemei Zhang
- Key Laboratory of Diagnostic Medicine Designated by the Ministry of Education, Department of Laboratory Medicine, Chongqing Medical University, Chongqing, China
| | - Kaifeng Wu
- Key Laboratory of Diagnostic Medicine Designated by the Ministry of Education, Department of Laboratory Medicine, Chongqing Medical University, Chongqing, China.,Department of Laboratory Medicine, The Third Affiliated Hospital of Zunyi Medical University, Zunyi, China
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