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Zou Z, Singh P, Pinkner JS, Obernuefemann CLP, Xu W, Nye TM, Dodson KW, Almqvist F, Hultgren SJ, Caparon MG. Dihydrothiazolo ring-fused 2-pyridone antimicrobial compounds treat Streptococcus pyogenes skin and soft tissue infection. SCIENCE ADVANCES 2024; 10:eadn7979. [PMID: 39093975 PMCID: PMC11296344 DOI: 10.1126/sciadv.adn7979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Accepted: 06/27/2024] [Indexed: 08/04/2024]
Abstract
We have developed GmPcides from a peptidomimetic dihydrothiazolo ring-fused 2-pyridone scaffold that has antimicrobial activities against a broad spectrum of Gram-positive pathogens. Here, we examine the treatment efficacy of GmPcides using skin and soft tissue infection (SSTI) and biofilm formation models by Streptococcus pyogenes. Screening our compound library for minimal inhibitory (MIC) and minimal bactericidal (MBC) concentrations identified GmPcide PS757 as highly active against S. pyogenes. Treatment of S. pyogenes biofilm with PS757 revealed robust efficacy against all phases of biofilm formation by preventing initial biofilm development, ceasing biofilm maturation and eradicating mature biofilm. In a murine model of S. pyogenes SSTI, subcutaneous delivery of PS757 resulted in reduced levels of tissue damage, decreased bacterial burdens, and accelerated rates of wound healing, which were associated with down-regulation of key virulence factors, including M protein and the SpeB cysteine protease. These data demonstrate that GmPcides show considerable promise for treating S. pyogenes infections.
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Affiliation(s)
- Zongsen Zou
- Department of Molecular Microbiology, Center for Women’s Infectious Disease Research, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Pardeep Singh
- Department of Chemistry, Umeå University, SE-90187 Umeå, Sweden
| | - Jerome S. Pinkner
- Department of Molecular Microbiology, Center for Women’s Infectious Disease Research, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Chloe L. P. Obernuefemann
- Department of Molecular Microbiology, Center for Women’s Infectious Disease Research, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Wei Xu
- Department of Molecular Microbiology, Center for Women’s Infectious Disease Research, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Taylor M. Nye
- Department of Molecular Microbiology, Center for Women’s Infectious Disease Research, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Karen W. Dodson
- Department of Molecular Microbiology, Center for Women’s Infectious Disease Research, Washington University School of Medicine, St. Louis, MO 63110, USA
| | | | - Scott J. Hultgren
- Department of Molecular Microbiology, Center for Women’s Infectious Disease Research, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Michael G. Caparon
- Department of Molecular Microbiology, Center for Women’s Infectious Disease Research, Washington University School of Medicine, St. Louis, MO 63110, USA
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2
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Cao R, Su H, Wei Z, He Z, Pan T, Li Y, Sun B. An induced mutation of ABC-transporter component VraF(K84E) contributes to vancomycin resistance and virulence in Staphylococcus aureus strain MW2. Int J Med Microbiol 2024; 315:151624. [PMID: 38838390 DOI: 10.1016/j.ijmm.2024.151624] [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: 02/04/2024] [Revised: 05/22/2024] [Accepted: 05/23/2024] [Indexed: 06/07/2024] Open
Abstract
Staphylococcus aureus is a notorious pathogen responsible for various severe diseases. Due to the emergence of drug-resistant strains, the prevention and treatment of S. aureus infections have become increasingly challenging. Vancomycin is considered to be one of the last-resort drugs for treating most methicillin-resistant S. aureus (MRSA), so it is of great significance to further reveal the mechanism of vancomycin resistance. VraFG is one of the few important ABC (ATP-binding cassette) transporters in S. aureus that can form TCS (two-component systems)/ABC transporter modules. ABC transporters can couple the energy released from ATP hydrolysis to translocate solutes across the cell membrane. In this study, we obtained a strain with decreased vancomycin susceptibility after serial passaging and selection. Subsequently, whole-genome sequencing was performed on this laboratory-derived strain MWA2 and a novel single point mutation was discovered in vraF gene, leading to decreased sensitivity to vancomycin and daptomycin. Furthermore, the mutation reduces autolysis of S. aureus and downregulates the expression of lytM, isaA, and atlA. Additionally, we observed that the mutant has a less net negative surface charge than wild-type strain. We also noted an increase in the expression of the dlt operon and mprF gene, which are associated with cell surface charge and serve to hinder the binding of cationic peptides by promoting electrostatic repulsion. Moreover, this mutation has been shown to enhance hemolytic activity, expand subcutaneous abscesses, reflecting an increased virulence. This study confirms the impact of a point mutation of VraF on S. aureus antibiotic resistance and virulence, contributing to a broader understanding of ABC transporter function and providing new targets for treating S. aureus infections.
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Affiliation(s)
- Ruobing Cao
- Institute of Advanced Technology, University of Science and Technology of China, Hefei, China
| | - Huimin Su
- Department of Oncology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui 230027, China
| | - Zichun Wei
- Institute of Advanced Technology, University of Science and Technology of China, Hefei, China
| | - Zhien He
- Department of Oncology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui 230027, China
| | - Ting Pan
- Department of Oncology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui 230027, China
| | - Yujie Li
- Department of Oncology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui 230027, China.
| | - Baolin Sun
- Institute of Advanced Technology, University of Science and Technology of China, Hefei, China; Department of Oncology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui 230027, China.
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3
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Fait A, Silva SF, Abrahamsson JÅH, Ingmer H. Staphylococcus aureus response and adaptation to vancomycin. Adv Microb Physiol 2024; 85:201-258. [PMID: 39059821 DOI: 10.1016/bs.ampbs.2024.04.006] [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] [Indexed: 07/28/2024]
Abstract
Antibiotic resistance is an increasing challenge for the human pathogen Staphylococcus aureus. Methicillin-resistant S. aureus (MRSA) clones have spread globally, and a growing number display decreased susceptibility to vancomycin, the favoured antibiotic for treatment of MRSA infections. These vancomycin-intermediate S. aureus (VISA) or heterogeneous vancomycin-intermediate S. aureus (hVISA) strains arise from accumulation of a variety of point mutations, leading to cell wall thickening and reduced vancomycin binding to the cell wall building block, Lipid II, at the septum. They display only minor changes in vancomycin susceptibility, with varying tolerance between cells in a population, and therefore, they can be difficult to detect. In this review, we summarize current knowledge of VISA and hVISA. We discuss the role of genetic strain background or epistasis for VISA development and the possibility of strains being 'transient' VISA with gene expression changes mediated by, for example, VraTSR, GraXSR, or WalRK signal transduction systems, leading to temporary vancomycin tolerance. Additionally, we address collateral susceptibility to other antibiotics than vancomycin. Specifically, we estimate how mutations in rpoB, encoding the β-subunit of the RNA polymerase, affect overall protein structure and compare changes with rifampicin resistance. Ultimately, such in-depth analysis of VISA and hVISA strains in terms of genetic and transcriptional changes, as well as changes in protein structures, may pave the way for improved detection and guide antibiotic therapy by revealing strains at risk of VISA development. Such tools will be valuable for keeping vancomycin an asset also in the future.
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Affiliation(s)
- Anaëlle Fait
- Department of Veterinary and Animal Sciences, University of Copenhagen, Frederiksberg, Denmark; Department of Environmental Systems Science, ETH Zürich, Zürich, Switzerland
| | - Stephanie Fulaz Silva
- Department of Veterinary and Animal Sciences, University of Copenhagen, Frederiksberg, Denmark
| | | | - Hanne Ingmer
- Department of Veterinary and Animal Sciences, University of Copenhagen, Frederiksberg, Denmark.
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4
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Costa FG, Mills KB, Crosby HA, Horswill AR. The Staphylococcus aureus regulatory program in a human skin-like environment. mBio 2024; 15:e0045324. [PMID: 38546267 PMCID: PMC11077960 DOI: 10.1128/mbio.00453-24] [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: 02/16/2024] [Accepted: 03/04/2024] [Indexed: 04/09/2024] Open
Abstract
Staphylococcus aureus is a Gram-positive pathogen responsible for the majority of skin and soft tissue infections (SSTIs). S. aureus colonizes the anterior nares of approximately 20%-30% of the population and transiently colonizes the skin, thereby increasing the risk of developing SSTIs and more serious infections. Current laboratory models that mimic the skin surface environment are expensive, require substantial infrastructure, and limit the scope of bacterial physiology studies under human skin conditions. To overcome these limitations, we developed a cost-effective, open-source, chemically defined media recipe termed skin-like medium (SLM) that incorporates key aspects of the human skin surface environment and supports growth of several staphylococcal species. We utilized SLM to investigate the transcriptional response of methicillin-resistant Staphylococcus aureus (MRSA) following growth in SLM compared to a commonly used laboratory media. Through RNA-seq analysis, we observed the upregulation of several virulence factors, including genes encoding functions involved in adhesion, proteolysis, and cytotoxicity. To further explore these findings, we conducted quantitative reverse transcription-PCR (qRT-PCR) experiments to determine the influence of media composition, pH, and temperature on the transcriptional response of key factors involved in adhesion and virulence. We also demonstrated that MRSA primed in SLM adhered better to human corneocytes and demonstrated adhesin-specific phenotypes that previously required genetic manipulation. This improved adherence to corneocytes was dependent on both acidic pH and growth in SLM. These results support the potential utility of SLM as an in vitro model for assessing staphylococcal physiology and metabolism on human skin. IMPORTANCE Staphylococcus aureus is the major cause of skin diseases, and its increased prevalence in skin colonization and infections present a need to understand its physiology in this environment. The work presented here outlines S. aureus upregulation of colonization and virulence factors using a newly developed medium that strives to replicate the human skin surface environment and demonstrates roles for adhesins clumping factor A (ClfA), serine-rich repeat glycoprotein adhesin (SraP), and the fibronectin binding proteins (Fnbps) in human corneocyte adherence.
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Affiliation(s)
- Flavia G. Costa
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Krista B. Mills
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Heidi A. Crosby
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Alexander R. Horswill
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
- Department of Veterans Affairs, Eastern Colorado Healthcare System, Aurora, Colorado, USA
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5
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Wongdontree P, Millan-Oropeza A, Upfold J, Lavergne JP, Halpern D, Lambert C, Page A, Kénanian G, Grangeasse C, Henry C, Fouet A, Gloux K, Anba-Mondoloni J, Gruss A. Oxidative stress is intrinsic to staphylococcal adaptation to fatty acid synthesis antibiotics. iScience 2024; 27:109505. [PMID: 38577105 PMCID: PMC10993138 DOI: 10.1016/j.isci.2024.109505] [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: 07/26/2023] [Revised: 12/08/2023] [Accepted: 03/13/2024] [Indexed: 04/06/2024] Open
Abstract
Antibiotics inhibiting the fatty acid synthesis pathway (FASII) of the major pathogen Staphylococcus aureus reach their enzyme targets, but bacteria continue growth by using environmental fatty acids (eFAs) to produce phospholipids. We assessed the consequences and effectors of FASII-antibiotic (anti-FASII) adaptation. Anti-FASII induced lasting expression changes without genomic rearrangements. Several identified regulators affected the timing of adaptation outgrowth. Adaptation resulted in decreased expression of major virulence factors. Conversely, stress responses were globally increased and adapted bacteria were more resistant to peroxide killing. Importantly, pre-exposure to peroxide led to faster anti-FASII-adaptation by stimulating eFA incorporation. This adaptation differs from reports of peroxide-stimulated antibiotic efflux, which leads to tolerance. In vivo, anti-FASII-adapted S. aureus killed the insect host more slowly but continued multiplying. We conclude that staphylococcal adaptation to FASII antibiotics involves reprogramming, which decreases virulence and increases stress resistance. Peroxide, produced by the host to combat infection, favors anti-FASII adaptation.
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Affiliation(s)
- Paprapach Wongdontree
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350 Jouy-en-Josas, France
| | - Aaron Millan-Oropeza
- PAPPSO Platform, Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
| | - Jennifer Upfold
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350 Jouy-en-Josas, France
| | - Jean-Pierre Lavergne
- Bacterial Pathogens and Protein Phosphorylation, Molecular Microbiology and Structural Biology, UMR 5086 - CNRS / Université de Lyon, Building IBCP, 7 Passage du Vercors, Lyon, France
| | - David Halpern
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350 Jouy-en-Josas, France
| | - Clara Lambert
- Université Paris Cité, Institut Cochin, INSERM, U1016, CNRS, UMR8104, Paris, France
| | - Adeline Page
- Protein Science Facility, SFR BioSciences, CNRS, UMS3444, INSERM US8, Université de Lyon, Lyon, France
| | - Gérald Kénanian
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350 Jouy-en-Josas, France
| | - Christophe Grangeasse
- Bacterial Pathogens and Protein Phosphorylation, Molecular Microbiology and Structural Biology, UMR 5086 - CNRS / Université de Lyon, Building IBCP, 7 Passage du Vercors, Lyon, France
| | - Céline Henry
- PAPPSO Platform, Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
| | - Agnès Fouet
- Université Paris Cité, Institut Cochin, INSERM, U1016, CNRS, UMR8104, Paris, France
| | - Karine Gloux
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350 Jouy-en-Josas, France
| | - Jamila Anba-Mondoloni
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350 Jouy-en-Josas, France
| | - Alexandra Gruss
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350 Jouy-en-Josas, France
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6
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Yang HT, Huang YH, Ho YN. Oceanimonas pelagia sp. nov., a novel biosurfactant-producing and plastic-degrading potential bacterium isolated from marine coastal sediment. Antonie Van Leeuwenhoek 2024; 117:49. [PMID: 38448684 DOI: 10.1007/s10482-024-01948-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: 11/14/2023] [Accepted: 02/08/2024] [Indexed: 03/08/2024]
Abstract
A marine bacterial strain, named NTOU-MSR1T, was isolated from marine sediment of northern coast of Taiwan. This bacterium was Gram-stain-negative, aerobic, and motile, with a single flagellum. Its rod-shaped cells measured approximately 0.5-0.6 µm in width and 1.8-2.0 μm in length. NTOU-MSR1T grew at temperatures ranging from 10 to 45 °C, optimally at 30 °C. The pH range for growth was 7.0-10.0, with optimal growth at pH 7.0-8.0. It tolerated NaCl concentrations up to 12%. The cell membrane predominantly contained fatty acids such C16:1ω7c, C18:1ω7c, and C16:0. The overall genome relatedness indices indicated that strain NTOU-MSR1T had an average nucleotide identity (ANI) of 87.88% and a digital DNA-DNA hybridization (dDDH) value of 35.40% compared to its closest related species, O. marisflavi 102-Na3T. These values fell below the 95% and 70% threshold for species delineation, respectively. These findings suggested that the strain NTOU-MSR1T was a new member of the Oceanimonas genus. Its genomic DNA had a G + C content of 61.0 mol%. Genomic analysis revealed genes associated with the catechol branch of β- ketoadipate pathway for degrading polycyclic aromatic hydrocarbons, resistance to heavy metal, biosynthesis of polyhydroxybutyrate and the production of glycoside hydrolases (GH19, GH23, and GH103) for chitin and glycan digestion. Additionally, NTOU-MSR1T was capable of synthesizing biosurfactants and potentially degrading plastic. The proposed name for this new species is Oceanimonas pelagia, with the type strain designated as NTOU-MSR1T (= BCRC 81403T = JCM 36023T).
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Affiliation(s)
- Hsiao-Tsu Yang
- Institute of Marine Biology, College of Life Science, National Taiwan Ocean University, Keelung, Taiwan
| | - Yi-Hsuan Huang
- Institute of Marine Biology, College of Life Science, National Taiwan Ocean University, Keelung, Taiwan
| | - Ying-Ning Ho
- Institute of Marine Biology, College of Life Science, National Taiwan Ocean University, Keelung, Taiwan.
- Centre of Excellence for the Oceans, National Taiwan Ocean University, Keelung, Taiwan.
- Taiwan Ocean Genome Center, National Taiwan Ocean University, Keelung, Taiwan.
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7
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Kwan JMC, Liang Y, Ng EWL, Sviriaeva E, Li C, Zhao Y, Zhang XL, Liu XW, Wong SH, Qiao Y. In silico MS/MS prediction for peptidoglycan profiling uncovers novel anti-inflammatory peptidoglycan fragments of the gut microbiota. Chem Sci 2024; 15:1846-1859. [PMID: 38303944 PMCID: PMC10829024 DOI: 10.1039/d3sc05819k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 12/19/2023] [Indexed: 02/03/2024] Open
Abstract
Peptidoglycan is an essential exoskeletal polymer across all bacteria. Gut microbiota-derived peptidoglycan fragments (PGNs) are increasingly recognized as key effector molecules that impact host biology. However, the current peptidoglycan analysis workflow relies on laborious manual identification from tandem mass spectrometry (MS/MS) data, impeding the discovery of novel bioactive PGNs in the gut microbiota. In this work, we built a computational tool PGN_MS2 that reliably simulates MS/MS spectra of PGNs and integrated it into the user-defined MS library of in silico PGN search space, facilitating automated PGN identification. Empowered by PGN_MS2, we comprehensively profiled gut bacterial peptidoglycan composition. Strikingly, the probiotic Bifidobacterium spp. manifests an abundant amount of the 1,6-anhydro-MurNAc moiety that is distinct from Gram-positive bacteria. In addition to biochemical characterization of three putative lytic transglycosylases (LTs) that are responsible for anhydro-PGN production in Bifidobacterium, we established that these 1,6-anhydro-PGNs exhibit potent anti-inflammatory activity in vitro, offering novel insights into Bifidobacterium-derived PGNs as molecular signals in gut microbiota-host crosstalk.
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Affiliation(s)
- Jeric Mun Chung Kwan
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University 21 Nanyang Link 637371 Singapore
- Lee Kong Chian School of Medicine, Nanyang Technological University 11 Mandalay Road 308232 Singapore
| | - Yaquan Liang
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University 21 Nanyang Link 637371 Singapore
| | - Evan Wei Long Ng
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University 21 Nanyang Link 637371 Singapore
| | - Ekaterina Sviriaeva
- Lee Kong Chian School of Medicine, Nanyang Technological University 11 Mandalay Road 308232 Singapore
| | - Chenyu Li
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University 21 Nanyang Link 637371 Singapore
| | - Yilin Zhao
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University 21 Nanyang Link 637371 Singapore
| | - Xiao-Lin Zhang
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University 21 Nanyang Link 637371 Singapore
| | - Xue-Wei Liu
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University 21 Nanyang Link 637371 Singapore
| | - Sunny H Wong
- Lee Kong Chian School of Medicine, Nanyang Technological University 11 Mandalay Road 308232 Singapore
| | - Yuan Qiao
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University 21 Nanyang Link 637371 Singapore
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8
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Hauserman MR, Ferraro MJ, Carroll RK, Rice KC. Altered quorum sensing and physiology of Staphylococcus aureus during spaceflight detected by multi-omics data analysis. NPJ Microgravity 2024; 10:2. [PMID: 38191486 PMCID: PMC10774393 DOI: 10.1038/s41526-023-00343-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Accepted: 12/15/2023] [Indexed: 01/10/2024] Open
Abstract
Staphylococcus aureus colonizes the nares of approximately 30% of humans, a risk factor for opportunistic infections. To gain insight into S. aureus virulence potential in the spaceflight environment, we analyzed RNA-Seq, cellular proteomics, and metabolomics data from the "Biological Research in Canisters-23" (BRIC-23) GeneLab spaceflight experiment, a mission designed to measure the response of S. aureus to growth in low earth orbit on the international space station. This experiment used Biological Research in Canisters-Petri Dish Fixation Units (BRIC-PDFUs) to grow asynchronous ground control and spaceflight cultures of S. aureus for 48 h. RNAIII, the effector of the Accessory Gene Regulator (Agr) quorum sensing system, was the most highly upregulated gene transcript in spaceflight relative to ground controls. The agr operon gene transcripts were also highly upregulated during spaceflight, followed by genes encoding phenol-soluble modulins and secreted proteases, which are positively regulated by Agr. Upregulated spaceflight genes/proteins also had functions related to urease activity, type VII-like Ess secretion, and copper transport. We also performed secretome analysis of BRIC-23 culture supernatants, which revealed that spaceflight samples had increased abundance of secreted virulence factors, including Agr-regulated proteases (SspA, SspB), staphylococcal nuclease (Nuc), and EsxA (secreted by the Ess system). These data also indicated that S. aureus metabolism is altered in spaceflight conditions relative to the ground controls. Collectively, these data suggest that S. aureus experiences increased quorum sensing and altered expression of virulence factors in response to the spaceflight environment that may impact its pathogenic potential.
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Affiliation(s)
- Matthew R Hauserman
- Department of Microbiology and Cell Science, IFAS, University of Florida, Gainesville, FL, USA
| | - Mariola J Ferraro
- Department of Microbiology and Cell Science, IFAS, University of Florida, Gainesville, FL, USA
| | - Ronan K Carroll
- Department of Biological Sciences, Ohio University, Athens, OH, USA
| | - Kelly C Rice
- Department of Microbiology and Cell Science, IFAS, University of Florida, Gainesville, FL, USA.
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9
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Hu J, Han X, Ma X, Chen X, Zhou Z, Peng P, Yu Z, Hou Y, Han P, Pang L, Yang Y, Xu J, Wu W. Comparative proteomic analysis of vancomycin-sensitive and vancomycin-intermediate resistant Staphylococcus aureus. Eur J Clin Microbiol Infect Dis 2024; 43:139-153. [PMID: 37985551 DOI: 10.1007/s10096-023-04709-3] [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: 05/17/2023] [Accepted: 11/09/2023] [Indexed: 11/22/2023]
Abstract
PURPOSE The extensive use of vancomycin has led to the development of Staphylococcus aureus strains with varying degrees of resistance to vancomycin. The present study aimed to explore the molecular causes of vancomycin resistance by conducting a proteomics analysis of subcellular fractions isolated from vancomycin-intermediate resistant S. aureus (VISA) and vancomycin-sensitive S. aureus (VSSA) strains. METHODS We conducted proteomics analysis of subcellular fractions isolated from 2 isogenic S. aureus strains: strain 11 (VSSA) and strain 11Y (VISA). We used an integrated quantitative proteomics approach assisted by bioinformatics analysis, and comprehensively investigated the proteome profile. Intensive bioinformatics analysis, including protein annotation, functional classification, functional enrichment, and functional enrichment-based cluster analysis, was used to annotate quantifiable targets. RESULTS We identified 128 upregulated proteins and 21 downregulated proteins in strain 11Y as compared to strain 11. The largest group of differentially expressed proteins was composed of enzymatic proteins associated with metabolic and catalytic activity, which accounted for 32.1% and 50% of the total proteins, respectively. Some proteins were indispensable parts of the regulatory networks of S. aureus that were altered with vancomycin treatment, and these proteins were related to cell wall metabolism, cell adhesion, proteolysis, and pressure response. CONCLUSION Our proteomics study revealed regulatory proteins associated with vancomycin resistance in S. aureus. Some of these proteins were involved in the regulation of cell metabolism and function, which provides potential targets for the development of strategies to manage vancomycin resistance in S. aureus.
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Affiliation(s)
- Jian Hu
- Department of Laboratory Medicine, Yixing Hospital of Traditional Chinese Medicine, Yixing, No. 128 East Yangquan Road, Yicheng Subdistrict, Yixing, 214200, Jiangsu, People's Republic of China
| | - Xinjun Han
- Department of Medical Microbiology and Parasitology, College of Basic Medical Sciences, China Medical University, Shenyang, People's Republic of China
| | - Xiaoxue Ma
- Department of Medical Microbiology and Parasitology, College of Basic Medical Sciences, China Medical University, Shenyang, People's Republic of China
| | - Xutao Chen
- Department of Laboratory Medicine, Yixing Hospital of Traditional Chinese Medicine, Yixing, No. 128 East Yangquan Road, Yicheng Subdistrict, Yixing, 214200, Jiangsu, People's Republic of China
| | - Zhenping Zhou
- Department of Laboratory Medicine, Yixing Hospital of Traditional Chinese Medicine, Yixing, No. 128 East Yangquan Road, Yicheng Subdistrict, Yixing, 214200, Jiangsu, People's Republic of China
| | - Peilan Peng
- Department of Medical Microbiology and Parasitology, College of Basic Medical Sciences, China Medical University, Shenyang, People's Republic of China
| | - Zhao Yu
- Department of Medical Microbiology and Parasitology, College of Basic Medical Sciences, China Medical University, Shenyang, People's Republic of China
| | - Yongzhi Hou
- Department of Medical Microbiology and Parasitology, College of Basic Medical Sciences, China Medical University, Shenyang, People's Republic of China
| | - Peiru Han
- Department of Medical Microbiology and Parasitology, College of Basic Medical Sciences, China Medical University, Shenyang, People's Republic of China
| | - Long Pang
- Department of Medical Microbiology and Parasitology, College of Basic Medical Sciences, China Medical University, Shenyang, People's Republic of China
| | - Yali Yang
- Department of Medical Microbiology and Parasitology, College of Basic Medical Sciences, China Medical University, Shenyang, People's Republic of China
| | - Jia Xu
- Department of Medical Microbiology, Key Laboratory of Environmental Pollution and Microecology of Liaoning Province, Shenyang Medical College, Shenyang, 110034, People's Republic of China.
| | - Wenhui Wu
- Department of Laboratory Medicine, Yixing Hospital of Traditional Chinese Medicine, Yixing, No. 128 East Yangquan Road, Yicheng Subdistrict, Yixing, 214200, Jiangsu, People's Republic of China.
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10
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Plumet L, Morsli M, Ahmad-Mansour N, Clavijo-Coppens F, Berry L, Sotto A, Lavigne JP, Costechareyre D, Molle V. Isolation and Characterization of New Bacteriophages against Staphylococcal Clinical Isolates from Diabetic Foot Ulcers. Viruses 2023; 15:2287. [PMID: 38140529 PMCID: PMC10747802 DOI: 10.3390/v15122287] [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: 10/05/2023] [Revised: 11/09/2023] [Accepted: 11/19/2023] [Indexed: 12/24/2023] Open
Abstract
Staphylococcus sp. is the most common bacterial genus in infections related to diabetic foot ulcers (DFUs). The emergence of multidrug-resistant bacteria places a serious burden on public health systems. Phage therapy is an alternative treatment to antibiotics, overcoming the issue of antibiotic resistance. In this study, six phages (SAVM01 to SAVM06) were isolated from effluents and were used against a panel of staphylococcal clinical samples isolated from DFUs. A genomic analysis revealed that the phages belonged to the Herelleviridae family, with sequences similar to those of the Kayvirus genus. No lysogeny-associated genes, known virulence or drug resistance genes were identified in the phage genomes. The phages displayed a strong lytic and antibiofilm activity against DFU clinical isolates, as well as against opportunistic pathogenic coagulase-negative staphylococci. The results presented here suggest that these phages could be effective biocontrol agents against staphylococcal clinical isolates from DFUs.
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Affiliation(s)
- Lucile Plumet
- VBIC, INSERM U1047, University of Montpellier, 34095 Montpellier, France; (L.P.); (N.A.-M.)
| | - Madjid Morsli
- VBIC, INSERM U1047, Department of Microbiology and Hospital Hygiene, University of Montpellier, CHU Nîmes, 30908 Nîmes, France; (M.M.); (J.-P.L.)
| | - Nour Ahmad-Mansour
- VBIC, INSERM U1047, University of Montpellier, 34095 Montpellier, France; (L.P.); (N.A.-M.)
| | | | - Laurence Berry
- Laboratory of Pathogen and Host Immunity, CNRS UMR5294, University of Montpellier, 34095 Montpellier, France;
| | - Albert Sotto
- VBIC, INSERM U1047, Department of Infectious Diseases, University of de Montpellier, CHU Nîmes, 30908 Nîmes, France;
| | - Jean-Philippe Lavigne
- VBIC, INSERM U1047, Department of Microbiology and Hospital Hygiene, University of Montpellier, CHU Nîmes, 30908 Nîmes, France; (M.M.); (J.-P.L.)
| | | | - Virginie Molle
- VBIC, INSERM U1047, University of Montpellier, 34095 Montpellier, France; (L.P.); (N.A.-M.)
- VBIC, INSERM U1047, Department of Microbiology and Hospital Hygiene, University of Montpellier, CHU Nîmes, 30908 Nîmes, France; (M.M.); (J.-P.L.)
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11
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Gómez-Arrebola C, Hernandez SB, Culp EJ, Wright GD, Solano C, Cava F, Lasa I. Staphylococcus aureus susceptibility to complestatin and corbomycin depends on the VraSR two-component system. Microbiol Spectr 2023; 11:e0037023. [PMID: 37646518 PMCID: PMC10581084 DOI: 10.1128/spectrum.00370-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 06/30/2023] [Indexed: 09/01/2023] Open
Abstract
The overuse of antibiotics in humans and livestock has driven the emergence and spread of antimicrobial resistance and has therefore prompted research on the discovery of novel antibiotics. Complestatin (Cm) and corbomycin (Cb) are glycopeptide antibiotics with an unprecedented mechanism of action that is active even against methicillin-resistant and daptomycin-resistant Staphylococcus aureus. They bind to peptidoglycan and block the activity of peptidoglycan hydrolases required for remodeling the cell wall during growth. Bacterial signaling through two-component transduction systems (TCSs) has been associated with the development of S. aureus antimicrobial resistance. However, the role of TCSs in S. aureus susceptibility to Cm and Cb has not been previously addressed. In this study, we determined that, among all 16 S. aureus TCSs, VraSR is the only one controlling the susceptibility to Cm and Cb. Deletion of vraSR increased bacterial susceptibility to both antibiotics. Epistasis analysis with members of the vraSR regulon revealed that deletion of spdC, which encodes a membrane protein that scaffolds SagB for cleavage of peptidoglycan strands to achieve physiological length, in the vraSR mutant restored Cm and Cb susceptibility to wild-type levels. Moreover, deletion of either spdC or sagB in the wild-type strain increased resistance to both antibiotics. Further analyses revealed a significant rise in the relative amount of peptidoglycan and its total degree of cross-linkage in ΔspdC and ΔsagB mutants compared to the wild-type strain, suggesting that these changes in the cell wall provide resistance to the damaging effect of Cm and Cb. IMPORTANCE Although Staphylococcus aureus is a common colonizer of the skin and digestive tract of humans and many animals, it is also a versatile pathogen responsible for causing a wide variety and number of infections. Treatment of these infections requires the bacteria to be constantly exposed to antibiotic treatment, which facilitates the selection of antibiotic-resistant strains. The development of new antibiotics is, therefore, urgently needed. In this paper, we investigated the role of the sensory system of S. aureus in susceptibility to two new antibiotics: corbomycin and complestatin. The results shed light on the cell-wall synthesis processes that are affected by the presence of the antibiotic and the sensory system responsible for coordinating their activity.
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Affiliation(s)
- Carmen Gómez-Arrebola
- Laboratory of Microbial Pathogenesis, Navarrabiomed, Hospital Universitario de Navarra (HUN), Universidad Pública de Navarra (UPNA), IdiSNA, Pamplona, Spain
| | - Sara B. Hernandez
- Department of Molecular Biology, Laboratory for Molecular Infection Medicine Sweden, Umeå Centre for Microbial Research, Umeå University, Umeå, Sweden
| | - Elizabeth J. Culp
- Department of Biochemistry and Biomedical Sciences, M. G. DeGroote Institute for Infectious Disease Research, David Braley Centre for Antibiotic Discovery, McMaster University, Hamilton, Ontario, Canada
| | - Gerard D. Wright
- Department of Biochemistry and Biomedical Sciences, M. G. DeGroote Institute for Infectious Disease Research, David Braley Centre for Antibiotic Discovery, McMaster University, Hamilton, Ontario, Canada
| | - Cristina Solano
- Laboratory of Microbial Pathogenesis, Navarrabiomed, Hospital Universitario de Navarra (HUN), Universidad Pública de Navarra (UPNA), IdiSNA, Pamplona, Spain
| | - Felipe Cava
- Department of Molecular Biology, Laboratory for Molecular Infection Medicine Sweden, Umeå Centre for Microbial Research, Umeå University, Umeå, Sweden
| | - Iñigo Lasa
- Laboratory of Microbial Pathogenesis, Navarrabiomed, Hospital Universitario de Navarra (HUN), Universidad Pública de Navarra (UPNA), IdiSNA, Pamplona, Spain
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12
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Fan SH, Proctor RA, Ersoy SC, Manna AC, Cheung AL, Götz F, Chambers HF, Bayer AS. Role of the NaHCO 3 Transporter MpsABC in the NaHCO 3-β-Lactam-Responsive Phenotype in Methicillin-Resistant Staphylococcus aureus. Microbiol Spectr 2023; 11:e0014123. [PMID: 37102972 PMCID: PMC10269494 DOI: 10.1128/spectrum.00141-23] [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: 01/09/2023] [Accepted: 04/12/2023] [Indexed: 04/28/2023] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) infections are an increasing concern due to their intrinsic resistance to most standard-of-care β-lactam antibiotics. Recent studies of clinical isolates have documented a novel phenotype, termed NaHCO3 responsiveness, in which a substantial proportion of MRSA strains exhibit enhanced susceptibility to β-lactams such as cefazolin and oxacillin in the presence of NaHCO3. A bicarbonate transporter, MpsAB (membrane potential-generating system), was recently found in S. aureus, where it plays a role in concentrating NaHCO3 for anaplerotic pathways. Here, we investigated the role of MpsAB in mediating the NaHCO3 responsiveness phenotype. Radiolabeled NaH14CO3 uptake profiling revealed significantly higher accumulation in NaHCO3-responsive vs nonresponsive MRSA strains when grown in ambient air. In contrast, under 5% CO2 conditions, NaHCO3-responsive (but not nonresponsive) strains exhibited repressed uptake. Oxacillin MICs were measured in four prototype strains and their mpsABC deletion mutants in the presence of NaHCO3 supplementation under 5% CO2 conditions. NaHCO3-mediated reductions in oxacillin MICs were observed in the responsive parental strains but not in mpsABC deletion mutants. No significant impact on oxacillin MICs was observed in the nonresponsive strains under the same conditions. Transcriptional and translational studies were carried out using both quantitative reverse transcription-PCR (qRT-PCR) and mpsA-green fluorescent protein (GFP) fusion constructs; these investigations showed that mpsA expression and translation were significantly upregulated during mid-exponential-phase growth in oxacillin-NaHCO3-supplemented medium in responsive versus nonresponsive strains. Taken together, these data show that the NaHCO3 transporter MpsABC is a key contributor to the NaHCO3-β-lactam responsiveness phenotype in MRSA. IMPORTANCE MRSA infections are increasingly difficult to treat, due in part to their resistance to most β-lactam antibiotics. A novel and relatively common phenotype, termed NaHCO3 responsiveness, has been identified in which MRSA strains show increased susceptibility in vitro and in vivo to β-lactams in the presence of NaHCO3. A recently described S. aureus NaHCO3 transporter, MpsAB, is involved in intracellular NaHCO3 concentration for anaplerotic pathways. We investigated the role of MpsAB in mediating the NaHCO3 responsiveness phenotype in four prototype MRSA strains (two responsive and two nonresponsive). We demonstrated that MpsABC is an important contributor to the NaHCO3-β-lactam responsiveness phenotype. Our study adds to the growing body of well-defined characteristics of this novel phenotype, which could potentially translate to alternative targets for MRSA treatment using β-lactams.
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Affiliation(s)
- Sook-Ha Fan
- The Lundquist Institute, Torrance, California, USA
| | - Richard A. Proctor
- Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
- Department of Medical Microbiology/Immunology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
| | | | - Adhar C. Manna
- Department of Microbiology & Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Ambrose L. Cheung
- Department of Microbiology & Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Friedrich Götz
- Microbial Genetics, Interfaculty Institute of Microbiology and Infection Medicine Tübingen, University of Tübingen, Germany
| | | | - Arnold S. Bayer
- The Lundquist Institute, Torrance, California, USA
- Geffen School of Medicine at UCLA, Los Angeles, California, USA
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13
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de Oliveira AS, Inácio MM, de Oliveira LS, Elias Moreira AL, Alves Silva GA, Silva LOS, de Oliveira MAP, Giambiagi-deMarval M, Borges CL, Soares CMDA, Parente-Rocha JA. Immunoproteomic and immunoinformatic approaches identify secreted antigens and epitopes from Staphylococcus saprophyticus. Microb Pathog 2023:106171. [PMID: 37244490 DOI: 10.1016/j.micpath.2023.106171] [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: 08/16/2022] [Revised: 05/19/2023] [Accepted: 05/22/2023] [Indexed: 05/29/2023]
Abstract
Urinary tract infections (UTIs) are common human infections that compromise women's health around the world, even though they can affect men and women of all ages. Bacterial species are the primary causative agents of UTIs, while Staphylococcus saprophyticus, a gram-positive bacterium, is especially important for uncomplicated infections in young women. Despite the number of antigenic proteins identified in Staphylococcus aureus and other bacteria of the genus, there is no immunoproteomic study in S. saprophyticus. In this context, since pathogenic microorganisms secrete important proteins that interact with hosts during infection, the present work aims to identify the exoantigens from S. saprophyticus ATCC 15305 by immunoproteomic and immunoinformatic approaches. We identified 32 antigens on the exoproteome of S. saprophyticus ATCC 15305 by immunoinformatic tools. By using 2D-IB immunoproteomic analysis, it was possible to identify 3 antigenic proteins: transglycosylase IsaA, enolase and the secretory antigen Q49ZL8. In addition, 5 antigenic proteins were detected by immunoprecipitation (IP) approach, where the most abundant were bifunctional autolysin and transglycosylase IsaA proteins. The transglycosylase IsaA was the only protein detected by all the tools approaches used in this study. In this work it was possible to describe a total of 36 S. saprophyticus exoantigens. Immunoinformatic analysis allowed the identification of 5 exclusive linear B cell epitopes from S. saprophyticus and 5 epitopes presenting homology with other bacteria that cause UTIs. This work describes, for the first time, the profile of exoantigens secreted by S. saprophyticus and can contribute to the identification of new diagnostic targets of UTIs, as well as to develop vaccines and immunotherapies against bacterial urinary infections.
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Affiliation(s)
- Andrea Santana de Oliveira
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, Brazil.
| | - Moisés Morais Inácio
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, Brazil.
| | - Lucas Silva de Oliveira
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, Brazil.
| | - André Luís Elias Moreira
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, Brazil.
| | - Guilherme Algusto Alves Silva
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, Brazil.
| | - Lana O'Hara Souza Silva
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, Brazil.
| | | | - Marcia Giambiagi-deMarval
- Laboratório de Microbiologia Molecular, Instituto de Microbiologia Prof. Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
| | - Clayton Luiz Borges
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, Brazil.
| | - Célia Maria de Almeida Soares
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, Brazil.
| | - Juliana Alves Parente-Rocha
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, Brazil.
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14
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Jaumaux F, Petit K, Martin A, Rodriguez-Villalobos H, Vermeersch M, Perez-Morga D, Gabant P. Selective Bacteriocins: A Promising Treatment for Staphylococcus aureus Skin Infections Reveals Insights into Resistant Mutants, Vancomycin Resistance, and Cell Wall Alterations. Antibiotics (Basel) 2023; 12:947. [PMID: 37370267 DOI: 10.3390/antibiotics12060947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 05/19/2023] [Accepted: 05/22/2023] [Indexed: 06/29/2023] Open
Abstract
The emergence of antibiotic-resistant S. aureus has become a major public health concern, necessitating the discovery of new antimicrobial compounds. Given that the skin microbiome plays a critical role in the host defence against pathogens, the development of therapies that target the interactions between commensal bacteria and pathogens in the skin microbiome offers a promising approach. Here, we report the discovery of two bacteriocins, cerein 7B and cerein B4080, that selectively inhibit S. aureus without affecting S. epidermidis, a commensal bacterium on the skin. Our study revealed that exposure of S. aureus to these bacteriocins resulted in mutations in the walK/R two-component system, leading to a thickening of the cell wall visible by transmission electron microscopy and subsequent decreased sensitivity to vancomycin. Our findings prompt a nuanced discussion of the potential of those bacteriocins for selective targeting of S. aureus on the skin, given the emergence of resistance and co-resistance with vancomycin. The idea put forward implies that by preserving commensal bacteria, selective compounds could limit the emergence of resistance in pathogenic cells by promoting competition with remaining commensal bacteria, ultimately reducing chronical infections and limiting the spread of antibiotic resistance.
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Affiliation(s)
- Félix Jaumaux
- Structure et Fonction des Membranes Biologiques (SFMB), ULB-Campus Plaine Building BC 3rd Floor Wing C, Blvd Triomphe Access 2, 1050 Brussels, Belgium
- Syngulon, 1402 Seraing, Belgium
| | | | | | | | - Marjorie Vermeersch
- Center for Microscopy and Molecular Imaging (CMMI), Université Libre de Bruxelles, Campus de Charleroi-Gosselies (Biopark)-CP 300, Rue Prof. Jeener & Brachet, 12, 6041 Gosselies, Belgium
| | - David Perez-Morga
- Center for Microscopy and Molecular Imaging (CMMI), Université Libre de Bruxelles, Campus de Charleroi-Gosselies (Biopark)-CP 300, Rue Prof. Jeener & Brachet, 12, 6041 Gosselies, Belgium
- Laboratoire de Parasitologie Moléculaire, Université Libre de Bruxelles, Campus de Charleroi-Gosselies (Biopark)-CP 300, Rue Prof. Jeener & Brachet, 12, 6041 Gosselies, Belgium
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15
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Yan X, Xu Y, Shen C, Chen D. Inactivation of Staphylococcus aureus by Levulinic Acid Plus Sodium Dodecyl Sulfate and their Antibacterial Mechanisms on S. aureus Biofilms by Transcriptomic Analysis. J Food Prot 2023; 86:100050. [PMID: 36916557 DOI: 10.1016/j.jfp.2023.100050] [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: 09/26/2022] [Revised: 01/14/2023] [Accepted: 01/18/2023] [Indexed: 01/27/2023]
Abstract
The combination of levulinic acid (LVA) and sodium dodecyl sulfate (SDS) in recent years has shown a considerable potential to use as an antimicrobial intervention. The objectives of this study were to evaluate the antimicrobial efficacy of the combination against Staphylococcus aureus in both planktonic and biofilm states and to investigate the transcriptional changes in S. aureus biofilms coincubated with sublethal concentrations of LVA and/or SDS. The minimum inhibitory concentrations (MICs) of LVA and SDS determined by the microdilution method were 3.125 and 0.039 mg/mL, respectively. An additive bacteriostatic interaction (fractional inhibitory concentration index = 1) between the two compounds was observed by the checkerboard assay, whereas a synergistic bactericidal activity was displayed by the time-kill assay. The biomass and viable cells in the biofilms were reduced by both antimicrobials either alone or in combination in a dose-dependent manner. Transcriptomics indicated that more differentially expressed (DE) genes were observed in the biofilm treated with SDS (103 up- and 205 downregulated DE genes) and LVA + SDS (187 up and 162 down) than that coincubated with LVA (34 up and 32 down). The SDS and LVA + SDS treatments mainly affected the expression of genes responsible for cell surface proteins, virulence factors, adhesins, and capsular polysaccharides. Both the antibiofilm assay and the transcriptomics indicated that SDS, not LVA, was the major chemical contributing to the antibacterial efficacy of the combination. This study reveals the behavioral responses and protective mechanisms of S. aureus to LVA and SDS applied individually or in combination.
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Affiliation(s)
- Xiaoxue Yan
- College of Food Science, Southwest University, 2 Tiansheng Rd, Beibei, Chongqing 400715, China; Chongqing Key Laboratory of Speciality Food Co-Built by Sichuan and Chongqing, 400715, China
| | - Yiwei Xu
- College of Food Science, Southwest University, 2 Tiansheng Rd, Beibei, Chongqing 400715, China; Chongqing Key Laboratory of Speciality Food Co-Built by Sichuan and Chongqing, 400715, China
| | - Cangliang Shen
- Division of Animal and Nutritional Sciences, West Virginia University, Morgantown, WV 26506, USA
| | - Dong Chen
- College of Food Science, Southwest University, 2 Tiansheng Rd, Beibei, Chongqing 400715, China; Chongqing Key Laboratory of Speciality Food Co-Built by Sichuan and Chongqing, 400715, China.
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16
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Kwan JMC, Qiao Y. Mechanistic Insights into the Activities of Major Families of Enzymes in Bacterial Peptidoglycan Assembly and Breakdown. Chembiochem 2023; 24:e202200693. [PMID: 36715567 DOI: 10.1002/cbic.202200693] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 01/28/2023] [Accepted: 01/30/2023] [Indexed: 01/31/2023]
Abstract
Serving as an exoskeletal scaffold, peptidoglycan is a polymeric macromolecule that is essential and conserved across all bacteria, yet is absent in mammalian cells; this has made bacterial peptidoglycan a well-established excellent antibiotic target. In addition, soluble peptidoglycan fragments derived from bacteria are increasingly recognised as key signalling molecules in mediating diverse intra- and inter-species communication in nature, including in gut microbiota-host crosstalk. Each bacterial species encodes multiple redundant enzymes for key enzymatic activities involved in peptidoglycan assembly and breakdown. In this review, we discuss recent findings on the biochemical activities of major peptidoglycan enzymes, including peptidoglycan glycosyltransferases (PGT) and transpeptidases (TPs) in the final stage of peptidoglycan assembly, as well as peptidoglycan glycosidases, lytic transglycosylase (LTs), amidases, endopeptidases (EPs) and carboxypeptidases (CPs) in peptidoglycan turnover and metabolism. Biochemical characterisation of these enzymes provides valuable insights into their substrate specificity, regulation mechanisms and potential modes of inhibition.
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Affiliation(s)
- Jeric Mun Chung Kwan
- School of Chemistry, Chemical Engineering and Biotechnology (CCEB), 21 Nanyang Link, Singapore, 637371, Singapore.,LKC School of Medicine, Nanyang Technological University (NTU) Singapore, 11 Mandalay Road, Singapore, Singapore, 208232, Singapore
| | - Yuan Qiao
- School of Chemistry, Chemical Engineering and Biotechnology (CCEB), Nanyang Technological University (NTU), Singapore, 21 Nanyang Link, Singapore, 637371, Singapore
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17
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Fait A, Seif Y, Mikkelsen K, Poudel S, Wells JM, Palsson BO, Ingmer H. Adaptive laboratory evolution and independent component analysis disentangle complex vancomycin adaptation trajectories. Proc Natl Acad Sci U S A 2022; 119:e2118262119. [PMID: 35858453 PMCID: PMC9335240 DOI: 10.1073/pnas.2118262119] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Accepted: 05/11/2022] [Indexed: 11/27/2022] Open
Abstract
Human infections with methicillin-resistant Staphylococcus aureus (MRSA) are commonly treated with vancomycin, and strains with decreased susceptibility, designated as vancomycin-intermediate S. aureus (VISA), are associated with treatment failure. Here, we profiled the phenotypic, mutational, and transcriptional landscape of 10 VISA strains adapted by laboratory evolution from one common MRSA ancestor, the USA300 strain JE2. Using functional and independent component analysis, we found that: 1) despite the common genetic background and environmental conditions, the mutational landscape diverged between evolved strains and included mutations previously associated with vancomycin resistance (in vraT, graS, vraFG, walKR, and rpoBCD) as well as novel adaptive mutations (SAUSA300_RS04225, ssaA, pitAR, and sagB); 2) the first wave of mutations affected transcriptional regulators and the second affected genes involved in membrane biosynthesis; 3) expression profiles were predominantly strain-specific except for sceD and lukG, which were the only two genes significantly differentially expressed in all clones; 4) three independent virulence systems (φSa3, SaeR, and T7SS) featured as the most transcriptionally perturbed gene sets across clones; 5) there was a striking variation in oxacillin susceptibility across the evolved lineages (from a 10-fold increase to a 63-fold decrease) that also arose in clinical MRSA isolates exposed to vancomycin and correlated with susceptibility to teichoic acid inhibitors; and 6) constitutive expression of the VraR regulon explained cross-susceptibility, while mutations in walK were associated with cross-resistance. Our results show that adaptation to vancomycin involves a surprising breadth of mutational and transcriptional pathways that affect antibiotic susceptibility and possibly the clinical outcome of infections.
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Affiliation(s)
- Anaëlle Fait
- Department of Veterinary and Animal Sciences, University of Copenhagen, Frederiksberg, 1870 Denmark
| | - Yara Seif
- Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093
- Merck & Co., Inc., South San Francisco, CA 94080
| | - Kasper Mikkelsen
- Department of Veterinary and Animal Sciences, University of Copenhagen, Frederiksberg, 1870 Denmark
| | - Saugat Poudel
- Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093
| | - Jerry M. Wells
- Host-Microbe Interactomics, Animal Sciences Group, Wageningen University, Wageningen, The Netherlands
| | - Bernhard O. Palsson
- Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093
| | - Hanne Ingmer
- Department of Veterinary and Animal Sciences, University of Copenhagen, Frederiksberg, 1870 Denmark
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18
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An Overview of Biofilm Formation-Combating Strategies and Mechanisms of Action of Antibiofilm Agents. LIFE (BASEL, SWITZERLAND) 2022; 12:life12081110. [PMID: 35892912 PMCID: PMC9394423 DOI: 10.3390/life12081110] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/25/2022] [Revised: 07/19/2022] [Accepted: 07/20/2022] [Indexed: 11/19/2022]
Abstract
Biofilm formation on surfaces via microbial colonization causes infections and has become a major health issue globally. The biofilm lifestyle provides resistance to environmental stresses and antimicrobial therapies. Biofilms can cause several chronic conditions, and effective treatment has become a challenge due to increased antimicrobial resistance. Antibiotics available for treating biofilm-associated infections are generally not very effective and require high doses that may cause toxicity in the host. Therefore, it is essential to study and develop efficient anti-biofilm strategies that can significantly reduce the rate of biofilm-associated healthcare problems. In this context, some effective combating strategies with potential anti-biofilm agents, including plant extracts, peptides, enzymes, lantibiotics, chelating agents, biosurfactants, polysaccharides, organic, inorganic, and metal nanoparticles, etc., have been reviewed to overcome biofilm-associated healthcare problems. From their extensive literature survey, it can be concluded that these molecules with considerable structural alterations might be applied to the treatment of biofilm-associated infections, by evaluating their significant delivery to the target site of the host. To design effective anti-biofilm molecules, it must be assured that the minimum inhibitory concentrations of these anti-biofilm compounds can eradicate biofilm-associated infections without causing toxic effects at a significant rate.
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19
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Sionov RV, Banerjee S, Bogomolov S, Smoum R, Mechoulam R, Steinberg D. Targeting the Achilles' Heel of Multidrug-Resistant Staphylococcus aureus by the Endocannabinoid Anandamide. Int J Mol Sci 2022; 23:7798. [PMID: 35887146 PMCID: PMC9319909 DOI: 10.3390/ijms23147798] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 07/10/2022] [Accepted: 07/12/2022] [Indexed: 02/06/2023] Open
Abstract
Antibiotic-resistant Staphylococcus aureus is a major health issue that requires new therapeutic approaches. Accumulating data suggest that it is possible to sensitize these bacteria to antibiotics by combining them with inhibitors targeting efflux pumps, the low-affinity penicillin-binding protein PBP2a, cell wall teichoic acid, or the cell division protein FtsZ. We have previously shown that the endocannabinoid Anandamide (N-arachidonoylethanolamine; AEA) could sensitize drug-resistant S. aureus to a variety of antibiotics, among others, through growth arrest and inhibition of drug efflux. Here, we looked at biochemical alterations caused by AEA. We observed that AEA increased the intracellular drug concentration of a fluorescent penicillin and augmented its binding to membrane proteins with concomitant altered membrane distribution of these proteins. AEA also prevented the secretion of exopolysaccharides (EPS) and reduced the cell wall teichoic acid content, both processes known to require transporter proteins. Notably, AEA was found to inhibit membrane ATPase activity that is necessary for transmembrane transport. AEA did not affect the membrane GTPase activity, and the GTPase cell division protein FtsZ formed the Z-ring of the divisome normally in the presence of AEA. Rather, AEA caused a reduction in murein hydrolase activities involved in daughter cell separation. Altogether, this study shows that AEA affects several biochemical processes that culminate in the sensitization of the drug-resistant bacteria to antibiotics.
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Affiliation(s)
- Ronit Vogt Sionov
- Biofilm Research Laboratory, Institute of Biomedical and Oral Sciences, Faculty of Dentistry, Hadassah Medical School, The Hebrew University of Jerusalem, Jerusalem 9112102, Israel; (S.B.); (S.B.); (D.S.)
| | - Shreya Banerjee
- Biofilm Research Laboratory, Institute of Biomedical and Oral Sciences, Faculty of Dentistry, Hadassah Medical School, The Hebrew University of Jerusalem, Jerusalem 9112102, Israel; (S.B.); (S.B.); (D.S.)
| | - Sergei Bogomolov
- Biofilm Research Laboratory, Institute of Biomedical and Oral Sciences, Faculty of Dentistry, Hadassah Medical School, The Hebrew University of Jerusalem, Jerusalem 9112102, Israel; (S.B.); (S.B.); (D.S.)
| | - Reem Smoum
- Institute for Drug Research, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112102, Israel; (R.S.); (R.M.)
| | - Raphael Mechoulam
- Institute for Drug Research, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112102, Israel; (R.S.); (R.M.)
| | - Doron Steinberg
- Biofilm Research Laboratory, Institute of Biomedical and Oral Sciences, Faculty of Dentistry, Hadassah Medical School, The Hebrew University of Jerusalem, Jerusalem 9112102, Israel; (S.B.); (S.B.); (D.S.)
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20
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Mediati DG, Wong JL, Gao W, McKellar S, Pang CNI, Wu S, Wu W, Sy B, Monk IR, Biazik JM, Wilkins MR, Howden BP, Stinear TP, Granneman S, Tree JJ. RNase III-CLASH of multi-drug resistant Staphylococcus aureus reveals a regulatory mRNA 3'UTR required for intermediate vancomycin resistance. Nat Commun 2022; 13:3558. [PMID: 35732665 PMCID: PMC9217812 DOI: 10.1038/s41467-022-31177-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Accepted: 06/03/2022] [Indexed: 01/13/2023] Open
Abstract
Treatment of methicillin-resistant Staphylococcus aureus infections is dependent on the efficacy of last-line antibiotics including vancomycin. Treatment failure is commonly linked to isolates with intermediate vancomycin resistance (termed VISA). These isolates have accumulated point mutations that collectively reduce vancomycin sensitivity, often by thickening the cell wall. Changes in regulatory small RNA expression have been correlated with antibiotic stress in VISA isolates however the functions of most RNA regulators is unknown. Here we capture RNA-RNA interactions associated with RNase III using CLASH. RNase III-CLASH uncovers hundreds of novel RNA-RNA interactions in vivo allowing functional characterisation of many sRNAs for the first time. Surprisingly, many mRNA-mRNA interactions are recovered and we find that an mRNA encoding a long 3' untranslated region (UTR) (termed vigR 3'UTR) functions as a regulatory 'hub' within the RNA-RNA interaction network. We demonstrate that the vigR 3'UTR promotes expression of folD and the cell wall lytic transglycosylase isaA through direct mRNA-mRNA base-pairing. Deletion of the vigR 3'UTR re-sensitised VISA to glycopeptide treatment and both isaA and vigR 3'UTR deletions impact cell wall thickness. Our results demonstrate the utility of RNase III-CLASH and indicate that S. aureus uses mRNA-mRNA interactions to co-ordinate gene expression more widely than previously appreciated.
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Affiliation(s)
- Daniel G Mediati
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Julia L Wong
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Wei Gao
- Department of Microbiology and Immunology, Peter Doherty Institute, University of Melbourne, Melbourne, VIC, Australia
| | - Stuart McKellar
- Centre for Systems and Synthetic Biology, University of Edinburgh, Edinburgh, UK
| | - Chi Nam Ignatius Pang
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Sylvania Wu
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Winton Wu
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Brandon Sy
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Ian R Monk
- Department of Microbiology and Immunology, Peter Doherty Institute, University of Melbourne, Melbourne, VIC, Australia
| | - Joanna M Biazik
- Electron Microscopy Unit, University of New South Wales, Kensington, NSW, Australia
| | - Marc R Wilkins
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Benjamin P Howden
- Department of Microbiology and Immunology, Peter Doherty Institute, University of Melbourne, Melbourne, VIC, Australia
| | - Timothy P Stinear
- Department of Microbiology and Immunology, Peter Doherty Institute, University of Melbourne, Melbourne, VIC, Australia
| | - Sander Granneman
- Centre for Systems and Synthetic Biology, University of Edinburgh, Edinburgh, UK
| | - Jai J Tree
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia.
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21
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Wang M, Buist G, van Dijl JM. Staphylococcus aureus cell wall maintenance - the multifaceted roles of peptidoglycan hydrolases in bacterial growth, fitness, and virulence. FEMS Microbiol Rev 2022; 46:6604383. [PMID: 35675307 PMCID: PMC9616470 DOI: 10.1093/femsre/fuac025] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 04/22/2022] [Accepted: 05/25/2022] [Indexed: 01/07/2023] Open
Abstract
Staphylococcus aureus is an important human and livestock pathogen that is well-protected against environmental insults by a thick cell wall. Accordingly, the wall is a major target of present-day antimicrobial therapy. Unfortunately, S. aureus has mastered the art of antimicrobial resistance, as underscored by the global spread of methicillin-resistant S. aureus (MRSA). The major cell wall component is peptidoglycan. Importantly, the peptidoglycan network is not only vital for cell wall function, but it also represents a bacterial Achilles' heel. In particular, this network is continuously opened by no less than 18 different peptidoglycan hydrolases (PGHs) encoded by the S. aureus core genome, which facilitate bacterial growth and division. This focuses attention on the specific functions executed by these enzymes, their subcellular localization, their control at the transcriptional and post-transcriptional levels, their contributions to staphylococcal virulence and their overall importance in bacterial homeostasis. As highlighted in the present review, our understanding of the different aspects of PGH function in S. aureus has been substantially increased over recent years. This is important because it opens up new possibilities to exploit PGHs as innovative targets for next-generation antimicrobials, passive or active immunization strategies, or even to engineer them into effective antimicrobial agents.
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Affiliation(s)
- Min Wang
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, PO Box 30001, 9700 RB Groningen, the Netherlands
| | | | - Jan Maarten van Dijl
- Corresponding author: Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O. box 30001, HPC EB80, 9700 RB Groningen, the Netherlands, Tel. +31-50-3615187; Fax. +31-50-3619105; E-mail:
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22
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Ma PY, Chong CW, Than LTL, Sulong AB, Ho KL, Neela VK, Sekawi Z, Liew YK. Impact of IsaA Gene Disruption: Decreasing Staphylococcal Biofilm and Alteration of Transcriptomic and Proteomic Profiles. Microorganisms 2022; 10:microorganisms10061119. [PMID: 35744637 PMCID: PMC9229027 DOI: 10.3390/microorganisms10061119] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 05/26/2022] [Accepted: 05/27/2022] [Indexed: 02/01/2023] Open
Abstract
Staphylococcus aureus expresses diverse proteins at different stages of growth. The immunodominant staphylococcal antigen A (IsaA) is one of the proteins that is constitutively produced by S. aureus during colonisation and infection. SACOL2584 (or isaA) is the gene that encodes this protein. It has been suggested that IsaA can hydrolyse cell walls, and there is still need to study isaA gene disruption to analyse its impact on staphylococcal phenotypes and on alteration to its transcription and protein profiles. In the present study, the growth curve in RPMI medium (which mimics human plasma), autolytic activity, cell wall morphology, fibronectin and fibrinogen adhesion and biofilm formation of S. aureus SH1000 (wildtype) was compared to that of S. aureus MS001 (isaA mutant). RNA sequencing and liquid chromatography–tandem mass spectrometry were carried out on samples of both S. aureus strains taken during the exponential growth phase, followed by bioinformatics analysis. Disruption of isaA had no obvious effect on the growth curve and autolysis ability or thickness of cell walls, but this study revealed significant strength of fibronectin adherence in S. aureus MS001. In particular, the isaA mutant formed less biofilm than S. aureus SH1000. In addition, proteomics and transcriptomics showed that the adhesin/biofilm-related genes and hemolysin genes, such as sasF, sarX and hlgC, were consistently downregulated with isaA gene disruption. The majority of the upregulated genes or proteins in S. aureus MS001 were pur genes. Taken together, this study provides insight into how isaA disruption changes the expression of other genes and has implications regarding biofilm formation and biological processes.
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Affiliation(s)
- Pei Yee Ma
- School of Postgraduate Studies, International Medical University, Kuala Lumpur 57000, Malaysia;
| | - Chun Wie Chong
- School of Pharmacy, Monash University Malaysia, Subang Jaya 47500, Malaysia;
| | - Leslie Thian Lung Than
- Department of Medical Microbiology, Faculty of Medicine and Health Sciences, University Putra Malaysia, Serdang 43400, Malaysia; (L.T.L.T.); (V.K.N.); (Z.S.)
| | - Anita Binti Sulong
- Department of Medical Microbiology and Immunology, Pusat Perubatan UKM, Kuala Lumpur 56000, Malaysia;
| | - Ket Li Ho
- Department of Life Sciences, School of Pharmacy, International Medical University, Kuala Lumpur 57000, Malaysia;
| | - Vasantha Kumari Neela
- Department of Medical Microbiology, Faculty of Medicine and Health Sciences, University Putra Malaysia, Serdang 43400, Malaysia; (L.T.L.T.); (V.K.N.); (Z.S.)
| | - Zamberi Sekawi
- Department of Medical Microbiology, Faculty of Medicine and Health Sciences, University Putra Malaysia, Serdang 43400, Malaysia; (L.T.L.T.); (V.K.N.); (Z.S.)
| | - Yun Khoon Liew
- Department of Life Sciences, School of Pharmacy, International Medical University, Kuala Lumpur 57000, Malaysia;
- Correspondence:
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23
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Chee Wezen X, Chandran A, Eapen RS, Waters E, Bricio-Moreno L, Tosi T, Dolan S, Millership C, Kadioglu A, Gründling A, Itzhaki LS, Welch M, Rahman T. Structure-Based Discovery of Lipoteichoic Acid Synthase Inhibitors. J Chem Inf Model 2022; 62:2586-2599. [PMID: 35533315 PMCID: PMC9131456 DOI: 10.1021/acs.jcim.2c00300] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Indexed: 01/20/2023]
Abstract
Lipoteichoic acid synthase (LtaS) is a key enzyme for the cell wall biosynthesis of Gram-positive bacteria. Gram-positive bacteria that lack lipoteichoic acid (LTA) exhibit impaired cell division and growth defects. Thus, LtaS appears to be an attractive antimicrobial target. The pharmacology around LtaS remains largely unexplored with only two small-molecule LtaS inhibitors reported, namely "compound 1771" and the Congo red dye. Structure-based drug discovery efforts against LtaS remain unattempted due to the lack of an inhibitor-bound structure of LtaS. To address this, we combined the use of a molecular docking technique with molecular dynamics (MD) simulations to model a plausible binding mode of compound 1771 to the extracellular catalytic domain of LtaS (eLtaS). The model was validated using alanine mutagenesis studies combined with isothermal titration calorimetry. Additionally, lead optimization driven by our computational model resulted in an improved version of compound 1771, namely, compound 4 which showed greater affinity for binding to eLtaS than compound 1771 in biophysical assays. Compound 4 reduced LTA production in S. aureus dose-dependently, induced aberrant morphology as seen for LTA-deficient bacteria, and significantly reduced bacteria titers in the lung of mice infected with S. aureus. Analysis of our MD simulation trajectories revealed the possible formation of a transient cryptic pocket in eLtaS. Virtual screening (VS) against the cryptic pocket led to the identification of a new class of inhibitors that could potentiate β-lactams against methicillin-resistant S. aureus. Our overall workflow and data should encourage further drug design campaign against LtaS. Finally, our work reinforces the importance of considering protein conformational flexibility to a successful VS endeavor.
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Affiliation(s)
- Xavier Chee Wezen
- Science
Program, School of Chemical Engineering and Science, Faculty of Engineering,
Computing and Science, Swinburne University
of Technology Sarawak, Kuching 93350, Malaysia
| | - Aneesh Chandran
- Department
of Biotechnology & Microbiology, Kannur
University, Kannur 670 661, Kerala, India
| | | | - Elaine Waters
- Department
of Clinical Infection Microbiology and Immunology, Institute of Infection
and Global Health, University of Liverpool, Liverpool L69 7BE, U.K.
| | - Laura Bricio-Moreno
- Department
of Clinical Infection Microbiology and Immunology, Institute of Infection
and Global Health, University of Liverpool, Liverpool L69 7BE, U.K.
| | - Tommaso Tosi
- Section
of Molecular Microbiology and MRC Centre for Molecular Bacteriology
and Infection, Imperial College London, London SW7 2AZ, U.K.
| | - Stephen Dolan
- Department
of Biochemistry, University of Cambridge, Cambridge CB2 1QW, U.K.
| | - Charlotte Millership
- Section
of Molecular Microbiology and MRC Centre for Molecular Bacteriology
and Infection, Imperial College London, London SW7 2AZ, U.K.
| | - Aras Kadioglu
- Department
of Clinical Infection Microbiology and Immunology, Institute of Infection
and Global Health, University of Liverpool, Liverpool L69 7BE, U.K.
| | - Angelika Gründling
- Section
of Molecular Microbiology and MRC Centre for Molecular Bacteriology
and Infection, Imperial College London, London SW7 2AZ, U.K.
| | - Laura S. Itzhaki
- Department
of PharmacologyUniversity of CambridgeCambridgeCB2 1PDU.K.
| | - Martin Welch
- Department
of Biochemistry, University of Cambridge, Cambridge CB2 1QW, U.K.
| | - Taufiq Rahman
- Department
of PharmacologyUniversity of CambridgeCambridgeCB2 1PDU.K.
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24
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Expression of Staphylococcal Virulence Genes In Situ in Human Skin and Soft Tissue Infections. Antibiotics (Basel) 2022; 11:antibiotics11040527. [PMID: 35453277 PMCID: PMC9032627 DOI: 10.3390/antibiotics11040527] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 04/08/2022] [Accepted: 04/10/2022] [Indexed: 11/16/2022] Open
Abstract
Background: Staphylococcus aureus, the most common pathogen in skin and soft tissue infections (SSTI), harbors many well-characterized virulence genes. However, the expression of many of them in SSTIs is unknown. In this study, S. aureus virulence genes expressed in SSTI were investigated. Methods: Fifty-three subjects presenting to the outpatient’s care and emergency departments with a purulent SSTI at two medical centers in Wisconsin, USA, were enrolled in the study. Total mRNA was extracted from the purulent or swab materials, made into cDNA and sequenced on MiSeq platform. The relative cDNA counts to gmk and identifications of the transcripts were carried out with respect to USA300 reference genome and using SAMTOOLS v.1.3 and BWA, respectively. Result: A significantly higher cDNA count was observed for many of the virulence and regulatory gene transcripts in the pus samples compared to the swab samples relative to the cDNA counts for gmk, a housekeeping gene. They were for lukS-PV (18.6 vs. 14.2), isaA (13.4 vs. 8.5), ssaA (4.8 vs. 3.1), hlgC (1.4 vs. 1.33), atl (17.7 vs. 8.33), clfA (3.9 vs. 0.83), eno (6.04 vs. 3.16), fnbA (5.93 vs. 0.33), saeS (6.3 vs. 1.33), saeR (5.4 vs. 3.33) and agrC (5.6 vs. 1.5). Conclusions: A relative increase in the transcripts of several toxins, adhesion and regulatory genes with respect to a gmk in purulent materials suggests their role in situ during SSTIs, perhaps in an orchestrated manner.
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25
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Aubourg M, Pottier M, Léon A, Bernay B, Dhalluin A, Cacaci M, Torelli R, Ledormand P, Martini C, Sanguinetti M, Auzou M, Gravey F, Giard JC. Inactivation of the Response Regulator AgrA Has a Pleiotropic Effect on Biofilm Formation, Pathogenesis and Stress Response in Staphylococcus lugdunensis. Microbiol Spectr 2022; 10:e0159821. [PMID: 35138170 PMCID: PMC8826819 DOI: 10.1128/spectrum.01598-21] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Accepted: 01/07/2022] [Indexed: 12/24/2022] Open
Abstract
Staphylococcus lugdunensis is a coagulase-negative Staphylococcus that emerges as an important opportunistic pathogen. However, little is known about the regulation underlying the transition from commensal to virulent state. Based on knowledge of S. aureus virulence, we suspected that the agr quorum sensing system may be an important determinant for the pathogenicity of S. lugdunensis. We investigated the functions of the transcriptional regulator AgrA using the agrA deletion mutant. AgrA played a role in cell pigmentation: ΔargA mutant colonies were white while the parental strains were slightly yellow. Compared with the wild-type strain, the ΔargA mutant was affected in its ability to form biofilm and was less able to survive in mice macrophages. Moreover, the growth of ΔagrA was significantly reduced by the addition of 10% NaCl or 0.4 mM H2O2 and its survival after 2 h in the presence of 1 mM H2O2 was more than 10-fold reduced. To explore the mechanisms involved beyond these phenotypes, the ΔagrA proteome and transcriptome were characterized by mass spectrometry and RNA-Seq. We found that AgrA controlled several virulence factors as well as stress-response factors, which are well correlated with the reduced resistance of the ΔagrA mutant to osmotic and oxidative stresses. These results were not the consequence of the deregulation of RNAIII of the agr system, since no phenotype or alteration of the proteomic profile has been observed for the ΔRNAIII mutant. Altogether, our results highlighted that the AgrA regulator of S. lugdunensis played a key role in its ability to become pathogenic. IMPORTANCE Although belonging to the natural human skin flora, Staphylococcus lugdunensis is recognized as a particularly aggressive and destructive pathogen. This study aimed to characterize the role of the response regulator AgrA, which is a component of the quorum-sensing agr system and known to be a major element in the regulation of pathogenicity and biofilm formation in Staphylococcus aureus. In the present study, we showed that, contrary to S. aureus, the agrA deletion mutant produced less biofilm. Inactivation of agrA conferred a white colony phenotype and impacted S. lugdunensis in its ability to survive in mice macrophages and to cope with osmotic and oxidative stresses. By global proteomic and transcriptomic approaches, we identified the AgrA regulon, bringing molecular bases underlying the observed phenotypes. Together, our data showed the importance of AgrA in the opportunistic pathogenic behavior of S. lugdunensis allowing it to be considered as an interesting therapeutic target.
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Affiliation(s)
- Marion Aubourg
- Université de Caen Normandie, Dynamicure, INSERM U1311, CHU de Caen, Caen, France
| | - Marine Pottier
- Université de Caen Normandie, Dynamicure, INSERM U1311, CHU de Caen, Caen, France
- LABÉO Frank Duncombe, Caen, France
| | - Albertine Léon
- Université de Caen Normandie, Dynamicure, INSERM U1311, CHU de Caen, Caen, France
- LABÉO Frank Duncombe, Caen, France
| | - Benoit Bernay
- Plateforme Proteogen SFR ICORE 4206, Université de Caen Normandie, Caen, France
| | - Anne Dhalluin
- Université de Caen Normandie, Dynamicure, INSERM U1311, CHU de Caen, Caen, France
| | - Margherita Cacaci
- Institute of Microbiology, Catholic University of Sacred Heart, L. go F. Vito 1, Rome, Italy
| | - Riccardo Torelli
- Institute of Microbiology, Catholic University of Sacred Heart, L. go F. Vito 1, Rome, Italy
| | | | - Cecilia Martini
- Institute of Microbiology, Catholic University of Sacred Heart, L. go F. Vito 1, Rome, Italy
| | - Maurizio Sanguinetti
- Institute of Microbiology, Catholic University of Sacred Heart, L. go F. Vito 1, Rome, Italy
| | - Michel Auzou
- CHU de Caen, Laboratoire de Microbiologie, Caen, France
| | - François Gravey
- Université de Caen Normandie, Dynamicure, INSERM U1311, CHU de Caen, Caen, France
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26
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Kang X, Ma Q, Wang G, Li N, Mao Y, Wang X, Wang Y, Wang G. Potential Mechanisms of Quercetin Influence the ClfB Protein During Biofilm Formation of Staphylococcus aureus. Front Pharmacol 2022; 13:825489. [PMID: 35153795 PMCID: PMC8831371 DOI: 10.3389/fphar.2022.825489] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Accepted: 01/10/2022] [Indexed: 01/11/2023] Open
Abstract
This study aimed to establish the mode of binding between Quercetin (QEN) and an essential protein called ClfB in forming biofilm in Staphylococcus aureus (S. aureus). In this study, the raw data of GSE163153 were analyzed for quality control, alignment, and gene counts, and the differential analysis detected the key differentially expressed genes (DEGs) assisting in the formation of the S. aureus biofilm. Then, the protein-protein interaction (PPI) and gene function enrichment analyses of the target genes, identified a gene called clfB to be closely related to biofilm formation. ClfB was structurally characterized, molecularly docked, and kinetically simulated to unravel the mode of binding of QEN to ClfB. Meanwhile, the growth curve and transmission electron microscopy methods examined the effect of QEN on the S. aureus growth. Results indicated that the clfB gene was increasingly expressed during biofilm formation and was involved in cell adhesion, pathogenicity, and infection. We identified 5 amino acid sites of ClfB (D272, R331, I379, K391, E490) as potential sites for binding QEN, which would indirectly influence the changes in the functional sites N234, D270, Y273, F328, inhibiting the formation of biofilm. Meanwhile, 128 μg/ml of QEN could significantly inhibit the S. aureus biofilm formation. This manuscript serves as a molecular foundation for QEN as an antibacterial drug providing a new perspective for developing antibacterial drugs.
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Affiliation(s)
- Xinyun Kang
- Veterinary Pharmacology Lab, School of Agriculture, Ningxia University, Yinchuan, China
| | - Qiang Ma
- Veterinary Pharmacology Lab, School of Agriculture, Ningxia University, Yinchuan, China
| | - Guilai Wang
- Yinchuan Hospital of Traditional Chinese Medicine, Yinchuan, China
| | - Na Li
- Veterinary Pharmacology Lab, School of Agriculture, Ningxia University, Yinchuan, China
| | - Yanni Mao
- Veterinary Pharmacology Lab, School of Agriculture, Ningxia University, Yinchuan, China
| | - Xin Wang
- Veterinary Pharmacology Lab, School of Agriculture, Ningxia University, Yinchuan, China
| | - Yuxia Wang
- Veterinary Pharmacology Lab, School of Agriculture, Ningxia University, Yinchuan, China
| | - Guiqin Wang
- Veterinary Pharmacology Lab, School of Agriculture, Ningxia University, Yinchuan, China
- *Correspondence: Guiqin Wang,
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27
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Demonstration of the role of cell wall homeostasis in Staphylococcus aureus growth and the action of bactericidal antibiotics. Proc Natl Acad Sci U S A 2021; 118:2106022118. [PMID: 34716264 PMCID: PMC8612353 DOI: 10.1073/pnas.2106022118] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 09/02/2021] [Indexed: 12/29/2022] Open
Abstract
Bacterial cell wall peptidoglycan is essential, maintaining both cellular integrity and morphology, in the face of internal turgor pressure. Peptidoglycan synthesis is important, as it is targeted by cell wall antibiotics, including methicillin and vancomycin. Here, we have used the major human pathogen Staphylococcus aureus to elucidate both the cell wall dynamic processes essential for growth (life) and the bactericidal effects of cell wall antibiotics (death) based on the principle of coordinated peptidoglycan synthesis and hydrolysis. The death of S. aureus due to depletion of the essential, two-component and positive regulatory system for peptidoglycan hydrolase activity (WalKR) is prevented by addition of otherwise bactericidal cell wall antibiotics, resulting in stasis. In contrast, cell wall antibiotics kill via the activity of peptidoglycan hydrolases in the absence of concomitant synthesis. Both methicillin and vancomycin treatment lead to the appearance of perforating holes throughout the cell wall due to peptidoglycan hydrolases. Methicillin alone also results in plasmolysis and misshapen septa with the involvement of the major peptidoglycan hydrolase Atl, a process that is inhibited by vancomycin. The bactericidal effect of vancomycin involves the peptidoglycan hydrolase SagB. In the presence of cell wall antibiotics, the inhibition of peptidoglycan hydrolase activity using the inhibitor complestatin results in reduced killing, while, conversely, the deregulation of hydrolase activity via loss of wall teichoic acids increases the death rate. For S. aureus, the independent regulation of cell wall synthesis and hydrolysis can lead to cell growth, death, or stasis, with implications for the development of new control regimes for this important pathogen.
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28
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Impact of Bicarbonate-β-Lactam Exposures on Methicillin-Resistant Staphylococcus aureus (MRSA) Gene Expression in Bicarbonate-β-Lactam-Responsive vs. Non-Responsive Strains. Genes (Basel) 2021; 12:genes12111650. [PMID: 34828256 PMCID: PMC8619011 DOI: 10.3390/genes12111650] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 10/06/2021] [Accepted: 10/08/2021] [Indexed: 01/11/2023] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) infections represent a difficult clinical treatment issue. Recently, a novel phenotype was discovered amongst selected MRSA which exhibited enhanced β-lactam susceptibility in vitro in the presence of NaHCO3 (termed ‘NaHCO3-responsiveness’). This increased β-lactam susceptibility phenotype has been verified in both ex vivo and in vivo models. Mechanistic studies to-date have implicated NaHCO3-mediated repression of genes involved in the production, as well as maturation, of the alternative penicillin-binding protein (PBP) 2a, a necessary component of MRSA β-lactam resistance. Herein, we utilized RNA-sequencing (RNA-seq) to identify genes that were differentially expressed in NaHCO3-responsive (MRSA 11/11) vs. non-responsive (COL) strains, in the presence vs. absence of NaHCO3-β-lactam co-exposures. These investigations revealed that NaHCO3 selectively repressed the expression of a cadre of genes in strain 11/11 known to be a part of the sigB-sarA-agr regulon, as well as a number of genes involved in the anchoring of cell wall proteins in MRSA. Moreover, several genes related to autolysis, cell division, and cell wall biosynthesis/remodeling, were also selectively impacted by NaHCO3-OXA exposure in the NaHCO3-responsive strain MRSA 11/11. These outcomes provide an important framework for further studies to mechanistically verify the functional relevance of these genetic perturbations to the NaHCO3-responsiveness phenotype in MRSA.
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29
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Ude Z, Flothkötter N, Sheehan G, Brennan M, Kavanagh K, Marmion CJ. Multi-targeted metallo-ciprofloxacin derivatives rationally designed and developed to overcome antimicrobial resistance. Int J Antimicrob Agents 2021; 58:106449. [PMID: 34644603 DOI: 10.1016/j.ijantimicag.2021.106449] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 09/28/2021] [Accepted: 10/02/2021] [Indexed: 10/20/2022]
Abstract
Antimicrobial resistance is a major global threat to human health due to the rise, spread and persistence of multi-drug-resistant bacteria or 'superbugs'. There is an urgent need to develop novel chemotherapeutics to overcome this overarching challenge. The authors derivatized a clinically used fluoroquinolone antibiotic ciprofloxacin (Cip), and complexed it to a copper phenanthrene framework. This resulted in the development of two novel metallo-antibiotics of general formula [Cu(N,N)(CipHA)]NO3 where N,N represents a phenanthrene ligand and CipHA represents a hydroxamic acid of Cip derivative. Comprehensive studies, including a detailed proteomic study in which Staphylococcus aureus cells were exposed to the complexes, were undertaken to gain an insight into their mode of action. These new complexes possess potent antibacterial activity against S. aureus and methicillin-resistant S. aureus. In addition, they were found to be well tolerated in vivo in Galleria mellonella larvae, which has both functional and structural similarities to the innate immune system of mammals. These findings suggest that proteins involved in virulence, pathogenesis, and the synthesis of nucleotides and DNA repair mechanisms are most affected. In addition, both complexes affected similar cell pathways when compared with clinically used Cip, including cationic antimicrobial peptide resistance. The Cu-DPPZ-CipHA (DPPZ = dipyrido[3,2-a:2',3'-c]phenazine) analogue also induces cell leakage, which leads to an altered proteome indicative of reduced virulence and increased stress.
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Affiliation(s)
- Ziga Ude
- Centre for Synthesis and Chemical Biology, Department of Chemistry, RCSI, University of Medicine and Health Sciences, Dublin, Ireland
| | - Nils Flothkötter
- Centre for Synthesis and Chemical Biology, Department of Chemistry, RCSI, University of Medicine and Health Sciences, Dublin, Ireland
| | - Gerard Sheehan
- SSPC Pharma Research Centre, Department of Biology, Maynooth University, Maynooth, Co. Kildare, Ireland
| | - Marian Brennan
- School of Pharmacy and Biomolecular Sciences, RCSI, University of Medicine and Health Sciences, Dublin, Ireland
| | - Kevin Kavanagh
- SSPC Pharma Research Centre, Department of Biology, Maynooth University, Maynooth, Co. Kildare, Ireland.
| | - Celine J Marmion
- Centre for Synthesis and Chemical Biology, Department of Chemistry, RCSI, University of Medicine and Health Sciences, Dublin, Ireland.
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Apt (Adenine Phosphoribosyltransferase) Mutation in Laboratory-Selected Vancomycin-Intermediate Staphylococcus aureus. Antibiotics (Basel) 2021; 10:antibiotics10050583. [PMID: 34069103 PMCID: PMC8170892 DOI: 10.3390/antibiotics10050583] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 04/19/2021] [Accepted: 04/27/2021] [Indexed: 11/16/2022] Open
Abstract
Comparative genomic sequencing of laboratory-derived vancomycin-intermediate Staphylococcusaureus (VISA) (MM66-3 and MM66-4) revealed unique mutations in both MM66-3 (in apt and ssaA6), and MM66-4 (in apt and walK), compared to hetero-VISA parent strain MM66. Transcriptional profiling revealed that both MM66 VISA shared 79 upregulated genes and eight downregulated genes. Of these, 30.4% of the upregulated genes were associated with the cell envelope, whereas 75% of the downregulated genes were associated with virulence. In concordance with mutations and transcriptome alterations, both VISA strains demonstrated reduced autolysis, reduced growth in the presence of salt and reduced virulence factor activity. In addition to mutations in genes linked to cell wall metabolism (ssaA6 and walK), the same mutation in apt which encodes adenine phosphoribosyltransferase, was confirmed in both MM66 VISA. Apt plays a role in both adenine metabolism and accumulation and both MM66 VISA grew better than MM66 in the presence of adenine or 2-fluoroadenine indicating a reduction in the accumulation of these growth inhibiting compounds in the VISA strains. MM66 apt mutants isolated via 2-fluoroadenine selection also demonstrated reduced susceptibility to the cell wall lytic dye Congo red and vancomycin. Finding that apt mutations contribute to reduced vancomycin susceptibility once again suggests a role for altered purine metabolism in a VISA mechanism.
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Buchad H, Nair M. The small RNA SprX regulates the autolysin regulator WalR in Staphylococcus aureus. Microbiol Res 2021; 250:126785. [PMID: 34000511 DOI: 10.1016/j.micres.2021.126785] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 04/29/2021] [Accepted: 04/30/2021] [Indexed: 10/21/2022]
Abstract
Pathogenesis of Staphylococcus aureus is attributed to its remarkable adaptation to changes in the environment, mediated by the arsenal of virulence factors, which are regulated by intricate mechanisms that include small RNAs (sRNAs) as important regulatory molecules. The sRNA SprX was previously described to be involved in the regulation of S. aureus pathogenicity, by modifying the expression of surface-associated clumping factor B and the secreted delta haemolysin. This study describes the regulation by SprX, of expression of multiple autolysins, which play an essential role in cell wall metabolism and function as important virulence factors that facilitate adhesion, internalization, and immune evasion during S. aureus colonization and pathogenesis. SprX acts by positively regulating the expression of autolysin regulator WalR. Overexpression of SprX resulted in differential regulation of autolysins IsaA, and LytM, while WalR levels were unchanged. SprX knockdown strain exhibited down-regulation of multiple autolytic bands corresponding to the major autolysin AtlA and its process intermediates in cell wall degradation zymography, and 0.2 to 0.1 fold reduction of lytM, atlA, isaA, and walR transcripts in qRT-PCRs. Down-regulation of SprX resulted in altered phenotype with high cell aggregation as analyzed by SEM, decrease in biofilm formation and higher resistance to Triton X-100-induced lysis, all of which indicate that SprX is essential for expression of autolysins. A putative RNA-RNA interaction was indicated in silico between SprX and walR mRNA and further confirmed by in vitro RNA-RNA interaction in electrophoretic mobility shift assays. These findings elucidate a new mechanism in which SprX modulates the S. aureus pathogenicity by regulating the regulator of autolysins in cell wall metabolism and as virulence factors.
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Affiliation(s)
- Hasmatbanu Buchad
- Department of Microbiology and Biotechnology Centre, The Maharaja Sayajirao University of Baroda, Vadodara, Gujarat, 390002, India.
| | - Mrinalini Nair
- Department of Microbiology and Biotechnology Centre, The Maharaja Sayajirao University of Baroda, Vadodara, Gujarat, 390002, India.
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Staphylococcus aureus cell wall structure and dynamics during host-pathogen interaction. PLoS Pathog 2021; 17:e1009468. [PMID: 33788901 PMCID: PMC8041196 DOI: 10.1371/journal.ppat.1009468] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 04/12/2021] [Accepted: 03/12/2021] [Indexed: 01/09/2023] Open
Abstract
Peptidoglycan is the major structural component of the Staphylococcus aureus cell wall, in which it maintains cellular integrity, is the interface with the host, and its synthesis is targeted by some of the most crucial antibiotics developed. Despite this importance, and the wealth of data from in vitro studies, we do not understand the structure and dynamics of peptidoglycan during infection. In this study we have developed methods to harvest bacteria from an active infection in order to purify cell walls for biochemical analysis ex vivo. Isolated ex vivo bacterial cells are smaller than those actively growing in vitro, with thickened cell walls and reduced peptidoglycan crosslinking, similar to that of stationary phase cells. These features suggested a role for specific peptidoglycan homeostatic mechanisms in disease. As S. aureus missing penicillin binding protein 4 (PBP4) has reduced peptidoglycan crosslinking in vitro its role during infection was established. Loss of PBP4 resulted in an increased recovery of S. aureus from the livers of infected mice, which coincided with enhanced fitness within murine and human macrophages. Thicker cell walls correlate with reduced activity of peptidoglycan hydrolases. S. aureus has a family of 4 putative glucosaminidases, that are collectively crucial for growth. Loss of the major enzyme SagB, led to attenuation during murine infection and reduced survival in human macrophages. However, loss of the other three enzymes Atl, SagA and ScaH resulted in clustering dependent attenuation, in a zebrafish embryo, but not a murine, model of infection. A combination of pbp4 and sagB deficiencies resulted in a restoration of parental virulence. Our results, demonstrate the importance of appropriate cell wall structure and dynamics during pathogenesis, providing new insight to the mechanisms of disease. The prevalence of methicillin resistant Staphylococcus aureus (MRSA) in both hospitals and the wider community places a huge weight on healthcare providers. To discover new control regimes, it is therefore important to understand how the pathogen behaves within the relevant environment of the host. This is often hampered by the ability to obtain sufficient ex vivo pathogen samples for study. We have developed a method to isolate S. aureus from the infected host to be able to analyse cellular morphology and structure. S. aureus, isolated from an infected kidney abscess are smaller in size, with thicker cell walls than exponentially growing cells in vitro. Their cell wall peptidoglycan also is less crosslinked. These features suggested the role of components controlling cell wall homeostasis as being important for infections. We tested the role of PBP4, known to increase cell wall crosslinking and found a pbp4 mutant to have increased survival in macrophages and fitness within the murine host. Conversely the peptidoglycan hydrolase SagB, whose loss results in thinner cell walls was attenuated in the murine systemic model of infection, with concomitant loss of fitness within macrophages. Our study reveals an important adaptation to the host environment and the role of those components involved in cell wall homeostasis in vivo.
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Bispo M, Anaya-Sanchez A, Suhani S, Raineri EJM, López-Álvarez M, Heuker M, Szymański W, Romero Pastrana F, Buist G, Horswill AR, Francis KP, van Dam GM, van Oosten M, van Dijl JM. Fighting Staphylococcus aureus infections with light and photoimmunoconjugates. JCI Insight 2020; 5:139512. [PMID: 33048846 PMCID: PMC7710284 DOI: 10.1172/jci.insight.139512] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 10/07/2020] [Indexed: 12/19/2022] Open
Abstract
Infections caused by multidrug-resistant Staphylococcus aureus, especially methicillin-resistant S. aureus (MRSA), are responsible for high mortality and morbidity worldwide. Resistant lineages were previously confined to hospitals but are now also causing infections among healthy individuals in the community. It is therefore imperative to explore therapeutic avenues that are less prone to raise drug resistance compared with today’s antibiotics. An opportunity to achieve this ambitious goal could be provided by targeted antimicrobial photodynamic therapy (aPDT), which relies on the combination of a bacteria-specific targeting agent and light-induced generation of ROS by an appropriate photosensitizer. Here, we conjugated the near-infrared photosensitizer IRDye700DX to a fully human mAb, specific for the invariantly expressed staphylococcal antigen immunodominant staphylococcal antigen A (IsaA). The resulting immunoconjugate 1D9-700DX was characterized biochemically and in preclinical infection models. As demonstrated in vitro, in vivo, and in a human postmortem orthopedic implant infection model, targeted aPDT with 1D9-700DX is highly effective. Importantly, combined with the nontoxic aPDT-enhancing agent potassium iodide, 1D9-700DX overcomes the antioxidant properties of human plasma and fully eradicates high titers of MRSA. We show that the developed immunoconjugate 1D9-700DX targets MRSA and kills it upon illumination with red light, without causing collateral damage to human cells. An immunoconjugate for targeted photodynamic therapy of Staphylococcus aureus infections kills MRSA with high efficacy upon illumination with red light.
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Affiliation(s)
| | | | | | | | | | | | - Wiktor Szymański
- Department of Radiology, Medical Imaging Center, University of Groningen, University Medical Center Groningen, Groningen, Netherlands.,Stratingh Institute for Chemistry, University of Groningen, Groningen, Netherlands
| | | | | | - Alexander R Horswill
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | | | - Gooitzen M van Dam
- Department of Surgery, Division of Surgical Oncology, Nuclear Medicine and Molecular Imaging, Intensive Care, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
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Transcriptomic Analysis of Staphylococcus xylosus in Solid Dairy Matrix Reveals an Aerobic Lifestyle Adapted to Rind. Microorganisms 2020; 8:microorganisms8111807. [PMID: 33212972 PMCID: PMC7698506 DOI: 10.3390/microorganisms8111807] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 11/12/2020] [Accepted: 11/14/2020] [Indexed: 11/17/2022] Open
Abstract
Staphylococcus xylosus is found in the microbiota of traditional cheeses, particularly in the rind of soft smeared cheeses. Despite its frequency, the molecular mechanisms allowing the growth and adaptation of S. xylosus in dairy products are still poorly understood. A transcriptomic approach was used to determine how the gene expression profile is modified during the fermentation step in a solid dairy matrix. S. xylosus developed an aerobic metabolism perfectly suited to the cheese rind. It overexpressed genes involved in the aerobic catabolism of two carbon sources in the dairy matrix, lactose and citrate. Interestingly, S. xylosus must cope with nutritional shortage such as amino acids, peptides, and nucleotides, consequently, an extensive up-regulation of genes involved in their biosynthesis was observed. As expected, the gene sigB was overexpressed in relation with general stress and entry into the stationary phase and several genes under its regulation, such as those involved in transport of anions, cations and in pigmentation were up-regulated. Up-regulation of genes encoding antioxidant enzymes and glycine betaine transport and synthesis systems showed that S. xylosus has to cope with oxidative and osmotic stresses. S. xylosus expressed an original system potentially involved in iron acquisition from lactoferrin.
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Rodríguez-Rojas A, Nath A, El Shazely B, Santi G, Kim JJ, Weise C, Kuropka B, Rolff J. Antimicrobial Peptide Induced-Stress Renders Staphylococcus aureus Susceptible to Toxic Nucleoside Analogs. Front Immunol 2020; 11:1686. [PMID: 33133056 PMCID: PMC7550632 DOI: 10.3389/fimmu.2020.01686] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Accepted: 06/24/2020] [Indexed: 12/12/2022] Open
Abstract
Cationic antimicrobial peptides (AMPs) are active immune effectors of multicellular organisms and are also considered as new antimicrobial drug candidates. One of the problems encountered when developing AMPs as drugs is the difficulty of reaching sufficient killing concentrations under physiological conditions. Here, using pexiganan, a cationic peptide derived from a host defense peptide of the African clawed frog and the first AMP developed into an antibacterial drug, we studied whether sub-lethal effects of AMPs can be harnessed to devise treatment combinations. We studied the pexiganan stress response of Staphylococcus aureus at sub-lethal concentrations using quantitative proteomics. Several proteins involved in nucleotide metabolism were elevated, suggesting a metabolic demand. We then show that Staphylococcus aureus is highly susceptible to antimetabolite nucleoside analogs when exposed to pexiganan, even at sub-inhibitory concentrations. These findings could be used to enhance pexiganan potency while decreasing the risk of resistance emergence, and our findings can likely be extended to other antimicrobial peptides.
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Affiliation(s)
| | - Arpita Nath
- Institut für Biologie, Evolutionary Biology, Freie Universität Berlin, Berlin, Germany
| | - Baydaa El Shazely
- Institut für Biologie, Evolutionary Biology, Freie Universität Berlin, Berlin, Germany
- Zoology Department, Faculty of Science, Alexandria University, Alexandria, Egypt
| | - Greta Santi
- Institut für Biologie, Evolutionary Biology, Freie Universität Berlin, Berlin, Germany
| | - Joshua Jay Kim
- Institut für Biologie, Evolutionary Biology, Freie Universität Berlin, Berlin, Germany
| | - Christoph Weise
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Benno Kuropka
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Jens Rolff
- Institut für Biologie, Evolutionary Biology, Freie Universität Berlin, Berlin, Germany
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Fang K, Park OJ, Hong SH. Controlling biofilms using synthetic biology approaches. Biotechnol Adv 2020; 40:107518. [PMID: 31953206 PMCID: PMC7125041 DOI: 10.1016/j.biotechadv.2020.107518] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 01/09/2020] [Accepted: 01/11/2020] [Indexed: 12/22/2022]
Abstract
Bacterial biofilms are formed by the complex but ordered regulation of intra- or inter-cellular communication, environmentally responsive gene expression, and secretion of extracellular polymeric substances. Given the robust nature of biofilms due to the non-growing nature of biofilm bacteria and the physical barrier provided by the extracellular matrix, eradicating biofilms is a very difficult task to accomplish with conventional antibiotic or disinfectant treatments. Synthetic biology holds substantial promise for controlling biofilms by improving and expanding existing biological tools, introducing novel functions to the system, and re-conceptualizing gene regulation. This review summarizes synthetic biology approaches used to eradicate biofilms via protein engineering of biofilm-related enzymes, utilization of synthetic genetic circuits, and the development of functional living agents. Synthetic biology also enables beneficial applications of biofilms through the production of biomaterials and patterning biofilms with specific temporal and spatial structures. Advances in synthetic biology will add novel biofilm functionalities for future therapeutic, biomanufacturing, and environmental applications.
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Affiliation(s)
- Kuili Fang
- Department of Chemical and Biological Engineering, Illinois Institute of Technology, Chicago, IL 60616, USA
| | - Oh-Jin Park
- Department of Chemical and Biological Engineering, Illinois Institute of Technology, Chicago, IL 60616, USA; Department of Biological and Chemical Engineering, Yanbian University of Science and Technology, Yanji, Jilin, People's Republic of China
| | - Seok Hoon Hong
- Department of Chemical and Biological Engineering, Illinois Institute of Technology, Chicago, IL 60616, USA.
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Valliammai A, Sethupathy S, Ananthi S, Priya A, Selvaraj A, Nivetha V, Aravindraja C, Mahalingam S, Pandian SK. Proteomic profiling unveils citral modulating expression of IsaA, CodY and SaeS to inhibit biofilm and virulence in methicillin-resistant Staphylococcus aureus. Int J Biol Macromol 2020; 158:S0141-8130(20)33095-6. [PMID: 32360467 DOI: 10.1016/j.ijbiomac.2020.04.231] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 04/15/2020] [Accepted: 04/26/2020] [Indexed: 12/17/2022]
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) is one of the dangerous human pathogens and it is categorized as a high priority multi-drug resistant bacterium by WHO. Biofilm forming ability of MRSA is responsible for persistent infections and also difficult to eradicate using antibiotic therapy as biofilm is much more resistant to antibiotics. Thus, targeting biofilm and virulence has become an alternative approach to attenuate the pathogenicity of bacterium without affecting the growth. Hence, the present study was aimed at evaluation of antibiofilm potential of citral against MRSA and to decode the possible mode of action. Citral inhibited biofilm formation by MRSA without affecting growth at 100 μg/mL. Microscopic analyses evidenced that citral greatly hampered the surface adherence of MRSA. Effect of citral on cellular proteome of MRSA was studied using two-dimensional gel electrophoresis (2DGE) and differentially regulated proteins were identified using nano LC-MS/MS and MALDI-TOF/TOF analysis. Gene ontology and STRING analysis revealed that citral differentially regulated the proteins involved in pleotropic transcriptional repression (CodY), cell wall homeostasis (IsaA), regulation of exotoxin secretion (SaeS), cell adhesion, hemolysis, capsular polysaccharide biosynthesis and pathogenesis. Gene expression analysis and in vitro assays further validated the alteration in synthesis of slime, hemolysin, lipase, staphyloxanthin and oxidant susceptibility. Thus, the present study unveiled the multiple protein targeted antibiofilm potential of citral and portrays citral as a promising therapeutic agent to combat biofilm mediated MRSA infections with less possibility of resistance development.
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Affiliation(s)
- Alaguvel Valliammai
- Department of Biotechnology, Alagappa University, Science Campus, Karaikudi 630 003, Tamil Nadu, India
| | - Sivasamy Sethupathy
- Department of Biotechnology, Alagappa University, Science Campus, Karaikudi 630 003, Tamil Nadu, India; Biofuels Institute, School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang, Jiangsu, China
| | - Sivagnanam Ananthi
- Laboratory of Molecular Virology and Cell Biology, Department of Biotechnology, Indian Institute of Technology Madras, Chennai 600 036, Tamil Nadu, India; Department of Preventive Oncology Research, Cancer Institute (WIA), Adyar, Chennai 600 036, Tamil Nadu, India
| | - Arumugam Priya
- Department of Biotechnology, Alagappa University, Science Campus, Karaikudi 630 003, Tamil Nadu, India
| | - Anthonymuthu Selvaraj
- Department of Biotechnology, Alagappa University, Science Campus, Karaikudi 630 003, Tamil Nadu, India
| | - Venkatesan Nivetha
- Department of Biotechnology, Alagappa University, Science Campus, Karaikudi 630 003, Tamil Nadu, India
| | - Chairmandurai Aravindraja
- Department of Biotechnology, Alagappa University, Science Campus, Karaikudi 630 003, Tamil Nadu, India; Department of Periodontology, College of Dentistry, University of Florida, Gainesville, FL, USA
| | - Sundarasamy Mahalingam
- Laboratory of Molecular Virology and Cell Biology, Department of Biotechnology, Indian Institute of Technology Madras, Chennai 600 036, Tamil Nadu, India
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Wolden R, Pain M, Karlsson R, Karlsson A, Aarag Fredheim EG, Cavanagh JP. Identification of surface proteins in a clinical Staphylococcus haemolyticus isolate by bacterial surface shaving. BMC Microbiol 2020; 20:80. [PMID: 32264835 PMCID: PMC7137321 DOI: 10.1186/s12866-020-01778-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 03/31/2020] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND The skin commensal Staphylococcus haemolyticus is an emerging nosocomial pathogen. Despite its clinical relevance, published information about S. haemolyticus virulence factors is scarce. In this study, the adhesive and biofilm forming properties of ten clinical and ten commensal S. haemolyticus strains were examined using standard adhesion and biofilm assays. One of the clinical strains was used to identify expressed surface proteins using bacterial surface shaving. Protein abundance was examined by a comparative analysis between bacterial protein expression after human keratinocyte (HaCaT) colonization and growth in cell culture media supplemented with serum. Relative protein quantification was performed by labeling peptides with tandem mass tags (TMT) prior to Mass Spectrometry analysis. Surface proteins can be used as novel targets for antimicrobial treatment and in diagnostics. RESULTS Adherence to fibronectin, collagen and plastic was low in all tested strains, but with significantly higher adhesion to fibronectin (p = 0.041) and collagen (p = 0.001) in the commensal strains. There was a trend towards higher degree of biofilm formation in the clinical strains (p = 0.059). By using surface shaving, 325 proteins were detected, of which 65 were classified as surface proteins. Analyses showed that the abundance of nineteen (5.8%) proteins were significantly changed following HaCaT colonization. The bacterial Toll/interleukin-1 like (TIRs) domain containing protein (p = 0.04), the transglycosylase SceD (p = 0.01), and the bifunctional autolysin Atl (p = 0.04) showed a 1.4, 1.6- and 1.5-fold increased abundance. The staphylococcal secretory antigen (SsaA) (p = 0.04) was significantly downregulated (- 1.5 fold change) following HaCaT colonization. Among the 65 surface proteins the elastin binding protein (Ebps), LPXAG and LPXSG domain containing proteins and five LPXTG domain containing proteins were identified; three Sdr-like proteins, the extracellular matrix binding protein Embp and a SasH-like protein. CONCLUSIONS This study has provided novel knowledge about expression of S. haemolyticus surface proteins after direct contact with eukaryotic cells and in media supplemented with serum. We have identified surface proteins and immune evasive proteins previously only functionally described in other staphylococcal species. The identification of expressed proteins after host-microbe interaction offers a tool for the discovery and design of novel targets for antimicrobial treatment.
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Affiliation(s)
- Runa Wolden
- Pediatric Research group, Department of Clinical Medicine, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, Norway
| | - Maria Pain
- Pediatric Research group, Department of Clinical Medicine, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, Norway
| | - Roger Karlsson
- Nanoxis Consulting AB, Gothenburg, Sweden
- Department of Infectious Diseases, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Department of Clinical Microbiology, Sahlgrenska University Hospital, SE-413 46, Gothenburg, Region Västra Götaland, Sweden
| | | | - Elizabeth G Aarag Fredheim
- Microbial Pharmacology and Population Biology, Department of Pharmacy, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, Norway
| | - Jorunn Pauline Cavanagh
- Pediatric Research group, Department of Clinical Medicine, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, Norway.
- Department of Pediatrics, The University Hospital of North Norway, Tromsø, Norway.
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Vollaro A, Esposito A, Antonaki E, Iula VD, D’Alonzo D, Guaragna A, De Gregorio E. Steroid Derivatives as Potential Antimicrobial Agents Against Staphylococcus aureus Planktonic Cells. Microorganisms 2020; 8:E468. [PMID: 32218320 PMCID: PMC7232480 DOI: 10.3390/microorganisms8040468] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 03/22/2020] [Accepted: 03/23/2020] [Indexed: 12/28/2022] Open
Abstract
In this work, the antibacterial activity of deflazacort and several of its synthetic precursors was tested against a panel of bacterial pathogens responsible for most drug-resistant infections including Staphylococcus aureus, Enterococcus spp., Acinetobacter baumannii, Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, and Enterobacter spp. The derivative of deflazacort, PYED-1 (pregnadiene-11-hydroxy-16α,17α-epoxy-3,20-dione-1) showed the best antibacterial activity in a dose-dependent way. We focused on the action of PYED-1 against S. aureus cells. PYED-1 exhibited an additive antimicrobial effect with gentamicin and oxacillin against the methicillin-resistant S. aureus isolate 00717. In addition to its antimicrobial effect, PYED-1 was found to repress the expression of several virulence factors of S. aureus, including toxins encoded by the hla (alpha-haemolysin), hlb (beta-haemolysin), lukE-D (leucotoxins E-D), and sea (staphylococcal enterotoxin A) genes, and cell surface factors (fnbB (fibronectin-binding protein B) and capC (capsule biosynthesis protein C)). The expression levels of autolysin isaA (immunodominant staphylococcal antigen) were also increased.
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Affiliation(s)
- Adriana Vollaro
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Via S. Pansini 5, 80131 Naples, Italy; (A.V.); (E.A.)
| | - Anna Esposito
- Department of Chemical Sciences, University of Naples Federico II, Via Cintia, 80126 Naples, Italy; (A.E.); (D.D.)
| | - Eleni Antonaki
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Via S. Pansini 5, 80131 Naples, Italy; (A.V.); (E.A.)
| | - Vita Dora Iula
- Complex Operative Unit of Clinical Pathology, “Ospedale del Mare-ASL NA1 Centro”, 80147 Naples, Italy;
| | - Daniele D’Alonzo
- Department of Chemical Sciences, University of Naples Federico II, Via Cintia, 80126 Naples, Italy; (A.E.); (D.D.)
| | - Annalisa Guaragna
- Department of Chemical Sciences, University of Naples Federico II, Via Cintia, 80126 Naples, Italy; (A.E.); (D.D.)
| | - Eliana De Gregorio
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Via S. Pansini 5, 80131 Naples, Italy; (A.V.); (E.A.)
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40
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A Staphylococcus pro-apoptotic peptide induces acute exacerbation of pulmonary fibrosis. Nat Commun 2020; 11:1539. [PMID: 32210242 PMCID: PMC7093394 DOI: 10.1038/s41467-020-15344-3] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Accepted: 03/03/2020] [Indexed: 11/08/2022] Open
Abstract
Idiopathic pulmonary fibrosis (IPF) is a chronic and fatal disease of unknown etiology; however, apoptosis of lung alveolar epithelial cells plays a role in disease progression. This intractable disease is associated with increased abundance of Staphylococcus and Streptococcus in the lungs, yet their roles in disease pathogenesis remain elusive. Here, we report that Staphylococcus nepalensis releases corisin, a peptide conserved in diverse staphylococci, to induce apoptosis of lung epithelial cells. The disease in mice exhibits acute exacerbation after intrapulmonary instillation of corisin or after lung infection with corisin-harboring S. nepalensis compared to untreated mice or mice infected with bacteria lacking corisin. Correspondingly, the lung corisin levels are significantly increased in human IPF patients with acute exacerbation compared to patients without disease exacerbation. Our results suggest that bacteria shedding corisin are involved in acute exacerbation of IPF, yielding insights to the molecular basis for the elevation of staphylococci in pulmonary fibrosis.
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41
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A Kayvirus Distant Homolog of Staphylococcal Virulence Determinants and VISA Biomarker Is a Phage Lytic Enzyme. Viruses 2020; 12:v12030292. [PMID: 32156046 PMCID: PMC7150955 DOI: 10.3390/v12030292] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2019] [Revised: 03/02/2020] [Accepted: 03/04/2020] [Indexed: 01/07/2023] Open
Abstract
Staphylococcal bacteriophages of the Kayvirus genus are candidates for therapeutic applications. One of their proteins, Tgl, is slightly similar to two staphylococcal virulence factors, secreted autolysins of lytic transglycosylase motifs IsaA and SceD. We show that Tgl is a lytic enzyme secreted by the bacterial transport system and localizes to cell peripheries like IsaA and SceD. It causes lysis of E. coli cells expressing the cloned tgl gene, but could be overproduced when depleted of signal peptide. S. aureus cells producing Tgl lysed in the presence of nisin, which mimics the action of phage holin. In vitro, Tgl protein was able to destroy S. aureus cell walls. The production of Tgl decreased S. aureus tolerance to vancomycin, unlike the production of SceD, which is associated with decreased sensitivity to vancomycin. In the genomes of kayviruses, the tgl gene is located a few genes away from the lysK gene, encoding the major endolysin. While lysK is a late phage gene, tgl can be transcribed by a host RNA polymerase, like phage early genes. Taken together, our data indicate that tgl belongs to the kayvirus lytic module and encodes an additional endolysin that can act in concert with LysK in cell lysis.
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Schuster CF, Wiedemann DM, Kirsebom FCM, Santiago M, Walker S, Gründling A. High-throughput transposon sequencing highlights the cell wall as an important barrier for osmotic stress in methicillin resistant Staphylococcus aureus and underlines a tailored response to different osmotic stressors. Mol Microbiol 2019; 113:699-717. [PMID: 31770461 PMCID: PMC7176532 DOI: 10.1111/mmi.14433] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 11/24/2019] [Indexed: 12/28/2022]
Abstract
Staphylococcus aureus is an opportunistic pathogen that can cause soft tissue infections but is also a frequent cause of foodborne illnesses. One contributing factor for this food association is its high salt tolerance allowing this organism to survive commonly used food preservation methods. How this resistance is mediated is poorly understood, particularly during long-term exposure. In this study, we used transposon sequencing (TN-seq) to understand how the responses to osmotic stressors differ. Our results revealed distinctly different long-term responses to NaCl, KCl and sucrose stresses. In addition, we identified the DUF2538 domain containing gene SAUSA300_0957 (gene 957) as essential under salt stress. Interestingly, a 957 mutant was less susceptible to oxacillin and showed increased peptidoglycan crosslinking. The salt sensitivity phenotype could be suppressed by amino acid substitutions in the transglycosylase domain of the penicillin-binding protein Pbp2, and these changes restored the peptidoglycan crosslinking to WT levels. These results indicate that increased crosslinking of the peptidoglycan polymer can be detrimental and highlight a critical role of the bacterial cell wall for osmotic stress resistance. This study will serve as a starting point for future research on osmotic stress response and help develop better strategies to tackle foodborne staphylococcal infections.
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Affiliation(s)
- Christopher F Schuster
- Section of Molecular Microbiology and MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, UK
| | - David M Wiedemann
- Section of Molecular Microbiology and MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, UK
| | - Freja C M Kirsebom
- Section of Molecular Microbiology and MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, UK
| | - Marina Santiago
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA, USA
| | - Suzanne Walker
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA, USA
| | - Angelika Gründling
- Section of Molecular Microbiology and MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, UK
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43
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Structural and Functional Dynamics of Staphylococcus aureus Biofilms and Biofilm Matrix Proteins on Different Clinical Materials. Microorganisms 2019; 7:microorganisms7120584. [PMID: 31756969 PMCID: PMC6955704 DOI: 10.3390/microorganisms7120584] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 11/14/2019] [Accepted: 11/18/2019] [Indexed: 12/27/2022] Open
Abstract
Medical device-associated staphylococcal infections are a common and challenging problem. However, detailed knowledge of staphylococcal biofilm dynamics on clinically relevant surfaces is still limited. In the present study, biofilm formation of the Staphylococcus aureus ATCC 25923 strain was studied on clinically relevant materials-borosilicate glass, plexiglass, hydroxyapatite, titanium and polystyrene-at 18, 42 and 66 h. Materials with the highest surface roughness and porosity (hydroxyapatite and plexiglass) did not promote biofilm formation as efficiently as some other selected materials. Matrix-associated poly-N-acetyl-β-(1-6)-glucosamine (PNAG) was considered important in young (18 h) biofilms, whereas proteins appeared to play a more important role at later stages of biofilm development. A total of 460 proteins were identified from biofilm matrices formed on the indicated materials and time points-from which, 66 proteins were proposed to form the core surfaceome. At 18 h, the appearance of several r-proteins and glycolytic adhesive moonlighters, possibly via an autolysin (AtlA)-mediated release, was demonstrated in all materials, whereas classical surface adhesins, resistance- and virulence-associated proteins displayed greater variation in their abundances depending on the used material. Hydroxyapatite-associated biofilms were more susceptible to antibiotics than biofilms formed on titanium, but no clear correlation between the tolerance and biofilm age was observed. Thus, other factors, possibly the adhesive moonlighters, could have contributed to the observed chemotolerant phenotype. In addition, a protein-dependent matrix network was observed to be already well-established at the 18 h time point. To the best of our knowledge, this is among the first studies shedding light into matrix-associated surfaceomes of S. aureus biofilms grown on different clinically relevant materials and at different time points.
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Staphylococcus aureus ClpX localizes at the division septum and impacts transcription of genes involved in cell division, T7-secretion, and SaPI5-excision. Sci Rep 2019; 9:16456. [PMID: 31712583 PMCID: PMC6848492 DOI: 10.1038/s41598-019-52823-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Accepted: 10/12/2019] [Indexed: 11/25/2022] Open
Abstract
In all living cells, molecular chaperones are essential for facilitating folding and unfolding of proteins. ClpX is a highly conserved ATP-dependent chaperone that besides functioning as a classical chaperone can associate with ClpP to form the ClpXP protease. To investigate the relative impact of the ClpXP protease and the ClpX chaperone in cell physiology of the important pathogenic bacterium Staphylococcus aureus, we assessed the transcriptional changes induced by inactivating only ClpXP, or by completely deleting ClpX. This analysis revealed that ClpX has a profound impact on S. aureus cell physiology that is mediated primarily via ClpXP-dependent pathways. As an example, ClpX impacts expression of virulence genes entirely via ClpXP-dependent mechanisms. Furthermore, ClpX controls a high number of genes and sRNAs via pathways involving both ClpXP protease and ClpX chaperone activities; an interesting example being genes promoting excision and replication of the pathogenicity island SaPI5. Independently of ClpP, ClpX, impacts transcription of only a restricted number of genes involved in peptidoglycan synthesis, cell division, and type seven secretion. Finally, we demonstrate that ClpX localizes in single foci in close proximity to the division septum lending support to the idea that ClpX plays a role in S. aureus cell division.
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Efthimiou G, Tsiamis G, Typas MA, Pappas KM. Transcriptomic Adjustments of Staphylococcus aureus COL (MRSA) Forming Biofilms Under Acidic and Alkaline Conditions. Front Microbiol 2019; 10:2393. [PMID: 31681245 PMCID: PMC6813237 DOI: 10.3389/fmicb.2019.02393] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Accepted: 10/02/2019] [Indexed: 01/13/2023] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) strains are important human pathogens and a significant health hazard for hospitals and the food industry. They are resistant to β-lactam antibiotics including methicillin and extremely difficult to treat. In this study, we show that the Staphylococcus aureus COL (MRSA) strain, with a known complete genome, can easily survive and grow under acidic and alkaline conditions (pH5 and pH9, respectively), both planktonically and as a biofilm. A microarray-based analysis of both planktonic and biofilm cells was performed under acidic and alkaline conditions showing that several genes are up- or down-regulated under different environmental conditions and growth modes. These genes were coding for transcription regulators, ion transporters, cell wall biosynthetic enzymes, autolytic enzymes, adhesion proteins and antibiotic resistance factors, most of which are associated with biofilm formation. These results will facilitate a better understanding of the physiological adjustments occurring in biofilm-associated S. aureus COL cells growing in acidic or alkaline environments, which will enable the development of new efficient treatment or disinfection strategies.
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Affiliation(s)
- Georgios Efthimiou
- Department of Genetics and Biotechnology, Faculty of Biology, National and Kapodistrian University of Athens, Athens, Greece
| | - George Tsiamis
- Department of Environmental Engineering, University of Patras, Agrinio, Greece
| | - Milton A Typas
- Department of Genetics and Biotechnology, Faculty of Biology, National and Kapodistrian University of Athens, Athens, Greece
| | - Katherine M Pappas
- Department of Genetics and Biotechnology, Faculty of Biology, National and Kapodistrian University of Athens, Athens, Greece
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46
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Roles of lytic transglycosylases in biofilm formation and β-lactam resistance in methicillin-resistant Staphylococcus aureus. Antimicrob Agents Chemother 2019:AAC.01277-19. [PMID: 31570396 DOI: 10.1128/aac.01277-19] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Staphylococcus aureus is responsible for numerous community outbreaks and is one of the most frequent causes of nosocomial infections with significant morbidity and mortality. While the function of lytic transglycosylases (LTs) in relation to cell division, biofilm formation, and antibiotic resistance has been determined for several bacteria, their role in S. aureus remains largely unknown. The only known LTs in S. aureus are immunodominant staphylococcal antigen A (IsaA) and Staphylococcus epidermidis D protein (SceD). Our study demonstrates that, in a strain of methicillin-resistant S. aureus (MRSA), IsaA and SceD contribute differently to biofilm formation and β-lactam resistance. Deletion of isaA, but not sceD, led to decreased biofilm formation. Additionally, in isaA-deleted strains, β-lactam resistance was significantly decreased compared to that of wild-type strains. Plasmid-based expression of mecA, a major determinant of β-lactam resistance in MRSA, in an isaA-deleted strain did not restore β-lactam resistance, demonstrating that the β-lactam susceptibility phenotype is exhibited by isaA mutant regardless of the production level of PBP2a. Overall, our results suggest that IsaA is a potential therapeutic target for MRSA infections.
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47
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Wang J, Wang J, Wang Y, Sun P, Zou X, Ren L, Zhang C, Liu E. Protein expression profiles in methicillin-resistant Staphylococcus aureus (MRSA) under effects of subminimal inhibitory concentrations of imipenem. FEMS Microbiol Lett 2019; 366:5570583. [PMID: 31529016 DOI: 10.1093/femsle/fnz195] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 09/12/2019] [Indexed: 12/25/2022] Open
Abstract
Imipenem is a beta-lactam antibiotic mainly active against gram-negative bacterial pathogens and also could cause cell wall impairment in methicillin-resistant Staphylococcus aureus(MRSA). However, related antibacterial mechanisms of imipenem on MRSA and mixed infections of MRSA and gram-negative bacteria are relatively poorly revealed. This study was to identify proteins in the MRSA response to subminimal inhibitory concentrations (sub-MICs) of imipenem treatment. Our results showed that 240 and 58 different expression proteins (DEPs) in sub-MICs imipenem-treated S3 (a standard MRSA strain) and S23 (a clinical MRSA strain) strains were identified through the isobaric tag for relative and absolute quantitation method when compared with untreated S3 and S23 strains, respectively, which was further confirmed by multiple reactions monitoring. Our result also demonstrated that expressions of multiple DEPs involved in cellular proliferation, metabolism and virulence were significantly changed in S3 and S23 strains, which was proved by gene ontology annotations and qPCR analysis. Further, transmission electron microscopy and scanning electron microscopy analysis showed cell wall deficiency, cell lysis and abnormal nuclear mitosis on S23 strain. Our study provides important information for understanding the antibacterial mechanisms of imipenem on MRSA and for better usage of imipenem on patients co-infected with MRSA and other multidrug-resistant gram-negative bacteria.
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Affiliation(s)
- Jichun Wang
- Department of Respiratory Medicine, Children's Hospital of Chongqing Medical University, No. 136, Zhongshan 2nd Road, Yuzhong District, Chongqing 400014, China.,Department of Pediatrics, Affiliated Hospital of Inner Mongolia Medical University, No. 1, Tongdao North Street, Huimin District, Hohhot, Inner Mongolia 010050, China
| | - Junrui Wang
- Clinical Laboratory, Affiliated Hospital of Inner Mongolia Medical University, No. 1, Tongdao North Street, Huimin District, Hohhot, Inner Mongolia 010050, China
| | - Yanyan Wang
- Clinical Laboratory, Affiliated Hospital of Inner Mongolia Medical University, No. 1, Tongdao North Street, Huimin District, Hohhot, Inner Mongolia 010050, China
| | - Peng Sun
- Pathogen and Immunity Research Center, College of Basic Medicine, Inner Mongolia Medical University, Jinshan Avenue, Hohhot, Inner Mongolia 010110, China
| | - Xiaohui Zou
- Chinese National Influenza Center, National Institute for Viral Disease Control and Prevention; China CDC, Key Laboratory for Medical Virology, Ministry of Health, Beijing 102206, China
| | - Luo Ren
- Pediatrics Institute, Children's Hospital Chongqing Medical University, No. 136, Zhong Shan 2nd Road, Yuzhong District, Chongqing 400014, China
| | - Chunxia Zhang
- Department of Pediatrics, Affiliated Hospital of Inner Mongolia Medical University, No. 1, Tongdao North Street, Huimin District, Hohhot, Inner Mongolia 010050, China
| | - Enmei Liu
- Pediatrics Institute, Children's Hospital Chongqing Medical University, No. 136, Zhong Shan 2nd Road, Yuzhong District, Chongqing 400014, China
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48
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Jenkins CH, Wallis R, Allcock N, Barnes KB, Richards MI, Auty JM, Galyov EE, Harding SV, Mukamolova GV. The lytic transglycosylase, LtgG, controls cell morphology and virulence in Burkholderia pseudomallei. Sci Rep 2019; 9:11060. [PMID: 31363151 PMCID: PMC6667503 DOI: 10.1038/s41598-019-47483-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Accepted: 07/15/2019] [Indexed: 02/07/2023] Open
Abstract
Burkholderia pseudomallei is the causative agent of the tropical disease melioidosis. Its genome encodes an arsenal of virulence factors that allow it, when required, to switch from a soil dwelling bacterium to a deadly intracellular pathogen. With a high intrinsic resistance to antibiotics and the ability to overcome challenges from the host immune system, there is an increasing requirement for new antibiotics and a greater understanding into the molecular mechanisms of B. pseudomallei virulence and dormancy. The peptidoglycan remodeling enzymes, lytic transglycosylases (Ltgs) are potential targets for such new antibiotics. Ltgs cleave the glycosidic bonds within bacterial peptidoglycan allowing for the insertion of peptidoglycan precursors during cell growth and division, and cell membrane spanning structures such as flagella and secretion systems. Using bioinformatic analysis we have identified 8 putative Ltgs in B. pseudomallei K96243. We aimed to investigate one of these Ltgs, LtgG (BPSL3046) through the generation of deletion mutants and biochemical analysis. We have shown that LtgG is a key contributor to cellular morphology, division, motility and virulence in BALB/c mice. We have determined the crystal structure of LtgG and have identified various amino acids likely to be important in peptidoglycan binding and catalytic activity. Recombinant protein assays and complementation studies using LtgG containing a site directed mutation in aspartate 343, confirmed the essentiality of this amino acid in the function of LtgG.
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Affiliation(s)
- Christopher H Jenkins
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, UK.
- Defence Science and Technology Laboratory, Chemical, Biological and Radiological Division, Porton Down, Salisbury, Wiltshire, UK.
| | - Russell Wallis
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, UK
- The Leicester Institute of Structural and Chemical Biology, Henry Wellcome Building, University of Leicester, Leicester, UK
| | - Natalie Allcock
- Electron Microscopy Facility, Core Biotechnology Services, University of Leicester, Leicester, UK
| | - Kay B Barnes
- Defence Science and Technology Laboratory, Chemical, Biological and Radiological Division, Porton Down, Salisbury, Wiltshire, UK
| | - Mark I Richards
- Defence Science and Technology Laboratory, Chemical, Biological and Radiological Division, Porton Down, Salisbury, Wiltshire, UK
| | - Joss M Auty
- Department of Respiratory Sciences, University of Leicester, Leicester, UK
| | - Edouard E Galyov
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, UK
- Department of Genetics and Genome Biology, University of Leicester, Leicester, UK
| | - Sarah V Harding
- Defence Science and Technology Laboratory, Chemical, Biological and Radiological Division, Porton Down, Salisbury, Wiltshire, UK
- Department of Respiratory Sciences, University of Leicester, Leicester, UK
| | - Galina V Mukamolova
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, UK.
- Department of Respiratory Sciences, University of Leicester, Leicester, UK.
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49
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Wu X, Song Q, Han A. Interacting proteins of the essential two-component system YycFG in Bacillus subtilis. J Basic Microbiol 2019; 59:950-959. [PMID: 31339578 DOI: 10.1002/jobm.201800701] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 06/14/2019] [Accepted: 06/24/2019] [Indexed: 11/06/2022]
Abstract
Two-component signal transduction systems (TCSs) play a major role in adaption and survival of microorganisms in a dynamic and sometimes dangerous environment. YycFG is an essential TCS for many Gram-positive bacteria, such as Bacillus subtilis, which regulates many important biological processes. However, its functional essentiality remains largely unknown. Here, we report several YycFG interacting proteins through coimmunoprecipitation (Co-IP) and mass spectrometry (MS) analyses. We engineered the B. subtilis genome by a knock-in approach to express YycG with a C-terminal Flag and YycF with an N-terminal HA tag. Immunoprecipitated fractions using anti-Flag or anti-HA agarose were subjected to MS analyses. A total of 41 YycG interacting proteins and four YycF interacting proteins were identified, most of which are involved in cellular metabolic processes, including cell wall synthesis and modification. The interactions of YycG with AsnB and FabL, as examples, were further validated in vitro. This study provided a clue that YycFG may be directly involved in regulation of bacterial central metabolic pathways.
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Affiliation(s)
- Xuanang Wu
- State Key Laboratory for Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiang'an, Xiamen, China
| | - Qi Song
- State Key Laboratory for Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiang'an, Xiamen, China
| | - Aidong Han
- State Key Laboratory for Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiang'an, Xiamen, China
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50
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Misal SA, Li S, Tang H, Radivojac P, Reilly JP. Identification of N-terminal protein processing sites by chemical labeling mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2019; 33:1015-1023. [PMID: 30884002 PMCID: PMC6522274 DOI: 10.1002/rcm.8435] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 03/01/2019] [Accepted: 03/09/2019] [Indexed: 06/09/2023]
Abstract
RATIONALE Proteins undergo post-translational modifications and proteolytic processing that can affect their biological function. Processing often involves the loss of single residues. Cleavage of signal peptides from the N-terminus is commonly associated with translocation. Recent reports have suggested that other processing sites also exist. METHODS The secreted proteins from S. aureus N315 were precipitated with trichloroacetic acid (TCA) and amidinated with S-methyl thioacetimidate (SMTA). Amidinated proteins were digested with trypsin and analyzed with a high-resolution orbitrap mass spectrometer. RESULTS Sixteen examples of Staphylococcus aureus secretory proteins that lose an N-terminal signal peptide during their export were identified using this amidination approach. The N-termini of proteins with and without methionine were identified. Unanticipated protein cleavages due to sortase and an unknown protease were also uncovered. CONCLUSIONS A simple N-terminal amidination based mass spectrometry approach is described that facilitates identification of the N-terminus of a mature protein and the discovery of unexpected processing sites.
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Affiliation(s)
- Santosh A Misal
- Department of Chemistry, Indiana University, Bloomington, Indiana, USA
| | - Sujun Li
- School of Informatics, Computing, and Engineering, Indiana University, Bloomington, Indiana, USA
| | - Haixu Tang
- School of Informatics, Computing, and Engineering, Indiana University, Bloomington, Indiana, USA
| | - Predrag Radivojac
- School of Informatics, Computing, and Engineering, Indiana University, Bloomington, Indiana, USA
| | - James P Reilly
- Department of Chemistry, Indiana University, Bloomington, Indiana, USA
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