1
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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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2
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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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3
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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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4
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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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5
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Dreisbach A, Wang M, van der Kooi-Pol MM, Reilman E, Koedijk DGAM, Mars RAT, Duipmans J, Jonkman M, Benschop JJ, Bonarius HPJ, Groen H, Hecker M, Otto A, Bäsell K, Bernhardt J, Back JW, Becher D, Buist G, van Dijl JM. Tryptic Shaving of Staphylococcus aureus Unveils Immunodominant Epitopes on the Bacterial Cell Surface. J Proteome Res 2020; 19:2997-3010. [DOI: 10.1021/acs.jproteome.0c00043] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Annette Dreisbach
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P. O. Box 30001, 9700 RB Groningen, the Netherlands
| | - Min Wang
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P. O. Box 30001, 9700 RB Groningen, the Netherlands
| | - Magdalena M. van der Kooi-Pol
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P. O. Box 30001, 9700 RB Groningen, the Netherlands
| | - Ewoud Reilman
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P. O. Box 30001, 9700 RB Groningen, the Netherlands
| | - Dennis G. A. M. Koedijk
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P. O. Box 30001, 9700 RB Groningen, the Netherlands
| | - Ruben A. T. Mars
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P. O. Box 30001, 9700 RB Groningen, the Netherlands
| | - José Duipmans
- Department of Dermatology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9700 RB Groningen, the Netherlands
| | - Marcel Jonkman
- Department of Dermatology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9700 RB Groningen, the Netherlands
| | - Joris J. Benschop
- Pepscan Therapeutics BV, P. O. Box 2098, 8203 AB Lelystad, the Netherlands
| | | | - Herman Groen
- IQ Therapeutics, Rozenburglaan 13a, 9727 DL Groningen, the Netherlands
| | - Michael Hecker
- Institut für Mikrobiologie, Ernst-Moritz-Arndt Universität Greifswald, Friedrich-Ludwig-Jahn-Str. 15, D-17489 Greifswald, Germany
| | - Andreas Otto
- Institut für Mikrobiologie, Ernst-Moritz-Arndt Universität Greifswald, Friedrich-Ludwig-Jahn-Str. 15, D-17489 Greifswald, Germany
| | - Katrin Bäsell
- Institut für Mikrobiologie, Ernst-Moritz-Arndt Universität Greifswald, Friedrich-Ludwig-Jahn-Str. 15, D-17489 Greifswald, Germany
| | - Jörg Bernhardt
- Institut für Mikrobiologie, Ernst-Moritz-Arndt Universität Greifswald, Friedrich-Ludwig-Jahn-Str. 15, D-17489 Greifswald, Germany
| | - Jaap Willem Back
- Pepscan Therapeutics BV, P. O. Box 2098, 8203 AB Lelystad, the Netherlands
| | - Dörte Becher
- Institut für Mikrobiologie, Ernst-Moritz-Arndt Universität Greifswald, Friedrich-Ludwig-Jahn-Str. 15, D-17489 Greifswald, Germany
| | - Girbe Buist
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P. O. Box 30001, 9700 RB Groningen, the Netherlands
| | - Jan Maarten van Dijl
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P. O. Box 30001, 9700 RB Groningen, the Netherlands
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6
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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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7
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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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8
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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: 9] [Impact Index Per Article: 1.8] [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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9
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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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10
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Li J, Li B, Song J, Liu H, Bi W, Dong G, Zhou T. Characteristic and mechanism of immobilization effect of Staphylococcus aureus on human spermatozoa. Microb Pathog 2018; 119:28-34. [PMID: 29601868 DOI: 10.1016/j.micpath.2018.03.049] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2017] [Revised: 03/23/2018] [Accepted: 03/26/2018] [Indexed: 10/17/2022]
Abstract
OBJECTIVE This study was designed to investigate the impacts of Staphylococcus aureus isolated from sperm of male infertility patients, and explore the mechanism of the spermatozoa immobilization attributed to S. aureus. METHODS S. aureus MJ015 and MJ163, the representative strains of immobilization positive and negative group respectively, were obtained from semen of infertile men. Computer-aided sperm analysis (CASA) were performed to measure sperm motility. Transmission electron microscopy (TEM) was utilized to assess morphological alterations of spermatozoa. Two-dimensional gel electrophoresis (2-DE) and liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) were undertaken to analyse the difference between the secretory proteins of MJ015 and MJ163. RESULTS A highly significant decline in motility of spermatozoa after incubating with cultured supernatant of MJ015 by sperm motility measurements, which was not observed when co-cultured with the supernatant of MJ163. TEM illustrated that the culture supernatant of MJ015 contributed to apparently ultrastructural impairment and inhibitory impacts on sperm motility. Various proteins expressed by two samples were identified. Data processing and database search preliminarily establish a link between four differential proteins and spermatozoal immobilization ability. CONCLUSIONS Our data manifested that the clinical isolates of S. aureus have a key role on the motility and morphology of sperm. A better correlation between four identified differentially expressed proteins and the marked decline of the motility of spermatozoa was established.
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Affiliation(s)
- Jiahui Li
- Department of Clinical Laboratory, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325000, China
| | - Bin Li
- Department of Clinical Laboratory, The First Affiliated Hospital of Medical School of Zhejiang University, Hangzhou, 310003, China
| | - Jiangning Song
- Infection and Immunity Program, Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Melbourne, VIC, 3800, Australia; Monash Centre for Data Science, Faculty of Information Technology, Monash University, Melbourne, VIC, 3800, Australia
| | - Haiyang Liu
- Department of Clinical Laboratory, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325000, China
| | - Wenzi Bi
- School of Laboratory Medicine and Life Science, Wenzhou Medical University, Wenzhou, 325035, China
| | - Guofeng Dong
- School of Laboratory Medicine and Life Science, Wenzhou Medical University, Wenzhou, 325035, China
| | - Tieli Zhou
- Department of Clinical Laboratory, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325000, China.
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11
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Distinct virulent network between healthcare- and community-associated Staphylococcus aureus based on proteomic analysis. Clin Proteomics 2018; 15:2. [PMID: 29321722 PMCID: PMC5757299 DOI: 10.1186/s12014-017-9178-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Accepted: 12/22/2017] [Indexed: 12/18/2022] Open
Abstract
Background Staphylococcus aureus (S. aureus or SA) is a leading cause of healthcare-associated (HA-) and community-associated (CA) infection. HA-SA isolates usually cause nosocomial pneumonia, bloodstream infections, catheter-related urinary tract infections, etc. On the other hand, CA-SA isolates usually cause highly fatal diseases, such as SSTIs as well as post influenza necrotic hemorrhagic pneumonia. The differences of the infection types are partially due to the unique characteristics between HA-SA and CA-SA isolates. For example, HA-SA isolates showed strong adherence to host epithelial cells, while CA-SA isolates displayed higher virulence due to the increased activity of the important quorum-sensing system accessory gene regulator (agr). Thus, the aim of this study was to characterize the proteomic difference between HA-SA and CA-SA lineage. Methods In this study, the extracted peptides from those representative strains were analyzed by LC-MS/MS. The protein-protein interaction network was constructed by bioinformatics and their expressions were verified by RT-PCR and Western blot. Results We demonstrated that Agr system (AgrA and AgrC) and its interactive factors (PhoP, SrrB, YycG, SarX, SigB and ClpP) based on the protein–protein interaction network were expressed significantly higher in the epidemic Chinese CA-SA lineage ST398 compared to HA-SA lineage ST239 by LC-MS/MS. We further verified the increased transcription of all these genes in ST398 by RT-PCR, suggesting that the higher expression of these genes/proteins probably play role in the acute infection of CA-SA. Moreover, surface-related proteins (FnbpA, SpA, Atl, ClfA, IsaA, IsaB, LtaS, SsaA and Cna) that are repressed by the Agr system have significantly higher expression in the epidemic Chinese HA-SA clone ST239 in comparison to CA-SA lineage ST398 by LC-MS/MS. Furthermore, we confirmed the significantly increased expression of two important adhesive proteins (Atl and ClfA) in ST239 by Western blot, which may contribute to the durative infection of HA-SA. Conclusion The results suggest that the different proteomic profile, at least partially, contribute to the pathogenic differences between HA-SA and CA-SA. Electronic supplementary material The online version of this article (10.1186/s12014-017-9178-5) contains supplementary material, which is available to authorized users.
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12
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Romero Pastrana F, Thompson JM, Heuker M, Hoekstra H, Dillen CA, Ortines RV, Ashbaugh AG, Pickett JE, Linssen MD, Bernthal NM, Francis KP, Buist G, van Oosten M, van Dam GM, Thorek DLJ, Miller LS, van Dijl JM. Noninvasive optical and nuclear imaging of Staphylococcus-specific infection with a human monoclonal antibody-based probe. Virulence 2017; 9:262-272. [PMID: 29166841 PMCID: PMC5955194 DOI: 10.1080/21505594.2017.1403004] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Staphylococcus aureus infections are a major threat in healthcare, requiring adequate early-stage diagnosis and treatment. This calls for novel diagnostic tools that allow noninvasive in vivo detection of staphylococci. Here we performed a preclinical study to investigate a novel fully-human monoclonal antibody 1D9 that specifically targets the immunodominant staphylococcal antigen A (IsaA). We show that 1D9 binds invariantly to S. aureus cells and may further target other staphylococcal species. Importantly, using a human post-mortem implant model and an in vivo murine skin infection model, preclinical feasibility was demonstrated for 1D9 labeled with the near-infrared fluorophore IRDye800CW to be applied for direct optical imaging of in vivo S. aureus infections. Additionally, 89Zirconium-labeled 1D9 could be used for positron emission tomography imaging of an in vivo S. aureus thigh infection model. Our findings pave the way towards clinical implementation of targeted imaging of staphylococcal infections using the human monoclonal antibody 1D9.
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Affiliation(s)
- Francisco Romero Pastrana
- a Department of Medical Microbiology , University of Groningen, University Medical Center Groningen , Hanzeplein 1, Groningen , RB , The Netherlands
| | - John M Thompson
- b Department of Orthopaedic Surgery , Johns Hopkins University School of Medicine , Baltimore , MD , USA
| | - Marjolein Heuker
- a Department of Medical Microbiology , University of Groningen, University Medical Center Groningen , Hanzeplein 1, Groningen , RB , The Netherlands
| | - Hedzer Hoekstra
- a Department of Medical Microbiology , University of Groningen, University Medical Center Groningen , Hanzeplein 1, Groningen , RB , The Netherlands
| | - Carly A Dillen
- c Department of Dermatology , Johns Hopkins University School of Medicine , Baltimore , MD , USA
| | - Roger V Ortines
- c Department of Dermatology , Johns Hopkins University School of Medicine , Baltimore , MD , USA
| | - Alyssa G Ashbaugh
- c Department of Dermatology , Johns Hopkins University School of Medicine , Baltimore , MD , USA
| | - Julie E Pickett
- d Division of Nuclear Medicine and Molecular Imaging, Department of Radiology and Radiological Science , Johns Hopkins University School of Medicine , Baltimore , MD , USA
| | - Matthijs D Linssen
- e Department of Gastroentrology and Hepatology , University of Groningen, University Medical Center Groningen , Hanzeplein 1, Groningen , RB , The Netherlands.,f Department of clinical Pharmacy and Pharmacology , University of Groningen, University Medical Center Groningen , Hanzeplein 1, Groningen , RB , The Netherlands
| | - Nicholas M Bernthal
- g Department of Orthopaedic Surgery , David Geffen School of Medicine at the University of California, Los Angeles Medical Center , Santa Monica , CA , USA
| | - Kevin P Francis
- g Department of Orthopaedic Surgery , David Geffen School of Medicine at the University of California, Los Angeles Medical Center , Santa Monica , CA , USA.,h PerkinElmer , Alameda , California , CA , USA.,i Department of Surgery , Nuclear Medicine and Molecular Imaging and Intensive Care, University of Groningen, University Medical Center Groningen , Hanzeplein 1, Groningen , RB , The Netherlands
| | - Girbe Buist
- a Department of Medical Microbiology , University of Groningen, University Medical Center Groningen , Hanzeplein 1, Groningen , RB , The Netherlands
| | - Marleen van Oosten
- a Department of Medical Microbiology , University of Groningen, University Medical Center Groningen , Hanzeplein 1, Groningen , RB , The Netherlands
| | - Gooitzen M van Dam
- i Department of Surgery , Nuclear Medicine and Molecular Imaging and Intensive Care, University of Groningen, University Medical Center Groningen , Hanzeplein 1, Groningen , RB , The Netherlands
| | - Daniel L J Thorek
- d Division of Nuclear Medicine and Molecular Imaging, Department of Radiology and Radiological Science , Johns Hopkins University School of Medicine , Baltimore , MD , USA.,j Department of Oncology , Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine , Baltimore , MD , USA
| | - Lloyd S Miller
- b Department of Orthopaedic Surgery , Johns Hopkins University School of Medicine , Baltimore , MD , USA.,c Department of Dermatology , Johns Hopkins University School of Medicine , Baltimore , MD , USA.,k Division of Infectious Disease, Department of Medicine , Johns Hopkins University School of Medicine , Baltimore , MD , USA
| | - Jan Maarten van Dijl
- a Department of Medical Microbiology , University of Groningen, University Medical Center Groningen , Hanzeplein 1, Groningen , RB , The Netherlands
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13
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Koedijk DGAM, Pastrana FR, Hoekstra H, Berg SVD, Back JW, Kerstholt C, Prins RC, Bakker-Woudenberg IAJM, van Dijl JM, Buist G. Differential epitope recognition in the immunodominant staphylococcal antigen A of Staphylococcus aureus by mouse versus human IgG antibodies. Sci Rep 2017; 7:8141. [PMID: 28811514 PMCID: PMC5557936 DOI: 10.1038/s41598-017-08182-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Accepted: 06/29/2017] [Indexed: 11/25/2022] Open
Abstract
The immunodominant staphylococcal antigen A (IsaA) is a potential target for active or passive immunization against the important human pathogen Staphylococcus aureus. Consistent with this view, monoclonal antibodies against IsaA were previously shown to be protective against S. aureus infections in mouse models. Further, patients with the genetic blistering disease epidermolysis bullosa (EB) displayed high IsaA-specific IgG levels that could potentially be protective. Yet, mice actively immunized with IsaA were not protected against S. aureus infection. The present study was aimed at explaining these differences in IsaA-specific immune responses. By epitope mapping, we show that the protective human monoclonal antibody (humAb) 1D9 recognizes a conserved 62-residue N-terminal domain of IsaA. The same region of IsaA is recognized by IgGs in EB patient sera. Further, we show by immunofluorescence microscopy that this N-terminal IsaA domain is exposed on the S. aureus cell surface. In contrast to the humAb 1D9 and IgGs from EB patients, the non-protective IgGs from mice immunized with IsaA were shown to predominantly bind the C-terminal domain of IsaA. Altogether, these observations focus attention on the N-terminal region of IsaA as a potential target for future immunization against S. aureus.
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Affiliation(s)
- Dennis G A M Koedijk
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O. Box 30001, 9700 RB, Groningen, The Netherlands
| | - Francisco Romero Pastrana
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O. Box 30001, 9700 RB, Groningen, The Netherlands
| | - Hedzer Hoekstra
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O. Box 30001, 9700 RB, Groningen, The Netherlands
| | - Sanne van den Berg
- Department of Medical Microbiology and Infectious Diseases, Erasmus University Medical Center, Rotterdam, The Netherlands
| | | | - Carolien Kerstholt
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O. Box 30001, 9700 RB, Groningen, The Netherlands
| | - Rianne C Prins
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O. Box 30001, 9700 RB, Groningen, The Netherlands
| | - Irma A J M Bakker-Woudenberg
- Department of Medical Microbiology and Infectious Diseases, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Jan Maarten van Dijl
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O. Box 30001, 9700 RB, Groningen, The Netherlands.
| | - Girbe Buist
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O. Box 30001, 9700 RB, Groningen, The Netherlands
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Kathirvel M, Buchad H, Nair M. Enhancement of the pathogenicity of Staphylococcus aureus strain Newman by a small noncoding RNA SprX1. Med Microbiol Immunol 2016; 205:563-574. [PMID: 27438010 DOI: 10.1007/s00430-016-0467-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2016] [Accepted: 07/12/2016] [Indexed: 01/22/2023]
Abstract
The pathogenesis of Staphylococcus aureus from local infection to systemic dissemination involves a range of virulence factors including structural and secreted products. Among various control mechanisms, small noncoding RNAs are involved in the regulation of multiple pathogenicity factors in S. aureus. The sRNA SprX which is encoded in the pathogenicity island of methicillin-susceptible S. aureus strain Newman and was shown to influence antibiotic resistance previously, upregulated the expression of virulence genes, especially the cell wall-associated clumping factor B (ClfB) and delta hemolysin (Hld). Bioinformatic analysis revealed several multiple mRNAs associated with pathogenicity as targets for SprX1, one of the three copies of sprX. Both overexpression and chromosomal disruption of sprX1 supported the scheme of upregulation of clfB and hld expression. Altered expression of SprX1 altered the levels of Hld and ClfB mRNAs, hemolysis, clumping of cells, biofilm formation by plate adhesion studies and confocal microscopic analysis as well as infection pathology of modified strains in mice models. ClfB and Hld mRNAs interacted directly with SprX1 in in vitro assays. Increased level of the regulatory RNA, namely RNAIII, that comprises Hld mRNA and also regulates the biofilm formation, indicates that SprX1 may also function through RNAIII for regulating virulence factors. An immunodominant protein, antigen A, was downregulated by SprX1 in two-dimensional electrophoresis. Taken together, these results signify the role of sRNA SprX in the pathogenicity of S. aureus Newman.
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Affiliation(s)
- Manikandan Kathirvel
- Department of Microbiology and Biotechnology Centre, The Maharaja Sayajirao University of Baroda, Vadodara, Gujarat, 390002, India
| | - 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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15
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Abstract
Our studies demonstrate that sodium chloride (NaCl) induces changes in biofilm, mediated by increased production of polysaccharides intercellular adhesion (PIA). We identified 12 proteins that showed higher abundance in increased level of NaCl. This includes one important protein (IsaA) known to be associated with biofilm stability. In addition, we also found higher abundance of a cold shock protein, CspA, at higher NaCl. We have also identified several other proteins that are differentially expressed to the elevated levels of NaCl and mapped them in the regulatory pathways of PIA. The majority of proteins are involved with various aspects bacterial metabolic function. Our results demonstrated that NaCl influences gene regulatory networks controlling exopolysaccharide expression.
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Affiliation(s)
- Nazrul Islam
- Department of Chemical and Biochemical Engineering, University of Maryland Baltimore County (UMBC), 1000 Hilltop Circle, Baltimore, MD 21250, USA
| | - Julia M Ross
- Department of Chemical and Biochemical Engineering, University of Maryland Baltimore County (UMBC), 1000 Hilltop Circle, Baltimore, MD 21250, USA
| | - Mark R Marten
- Department of Chemical and Biochemical Engineering, University of Maryland Baltimore County (UMBC), 1000 Hilltop Circle, Baltimore, MD 21250, USA
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16
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van den Berg S, Bonarius HPJ, van Kessel KPM, Elsinga GS, Kooi N, Westra H, Bosma T, van der Kooi-Pol MM, Koedijk DGAM, Groen H, van Dijl JM, Buist G, Bakker-Woudenberg IAJM. A human monoclonal antibody targeting the conserved staphylococcal antigen IsaA protects mice against Staphylococcus aureus bacteremia. Int J Med Microbiol 2014; 305:55-64. [PMID: 25466204 DOI: 10.1016/j.ijmm.2014.11.002] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Revised: 10/29/2014] [Accepted: 11/04/2014] [Indexed: 10/24/2022] Open
Abstract
Due to substantial therapy failure and the emergence of antibiotic-resistant Staphylococcus aureus strains, alternatives for antibiotic treatment of S. aureus infections are urgently needed. Passive immunization using S. aureus-specific monoclonal antibodies (mAb) could be such an alternative to prevent and treat severe S. aureus infections. The invariantly expressed immunodominant staphylococcal antigen A (IsaA) is a promising target for passive immunization. Here we report the development of the human anti-IsaA IgG1 mAb 1D9, which was shown to bind to all 26 S. aureus isolates tested. These included both methicillin-susceptible and methicillin-resistant S. aureus (MSSA and MRSA, respectively). Immune complexes consisting of IsaA and 1D9 stimulated human as well as murine neutrophils to generate an oxidative burst. In a murine bacteremia model, the prophylactic treatment with a single dose of 5 mg/kg 1D9 improved the survival of mice challenged with S. aureus isolate P (MSSA) significantly, while therapeutic treatment with the same dose did not influence animal survival. Neither prophylactic nor therapeutic treatment with 5 mg/kg 1D9 resulted in improved survival of mice with S. aureus USA300 (MRSA) bacteremia. Importantly, our studies show that healthy S. aureus carriers elicit an immune response which is sufficient to generate protective mAbs against invariant staphylococcal surface antigens. Human mAb 1D9, possibly conjugated to for example another antibody, antibiotics, cytokines or chemokines, may be valuable to fight S. aureus infections in patients.
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Affiliation(s)
- Sanne van den Berg
- Department of Medical Microbiology and Infectious Diseases, Erasmus University Medical Center, Rotterdam, The Netherlands.
| | | | - Kok P M van Kessel
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | | | | | | | | | - Magdalena M van der Kooi-Pol
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Danny G A M Koedijk
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | | | - Jan Maarten van Dijl
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Girbe Buist
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Irma A J M Bakker-Woudenberg
- Department of Medical Microbiology and Infectious Diseases, Erasmus University Medical Center, Rotterdam, The Netherlands
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17
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Pascoe B, Dams L, Wilkinson TS, Harris LG, Bodger O, Mack D, Davies AP. Dormant cells of Staphylococcus aureus are resuscitated by spent culture supernatant. PLoS One 2014; 9:e85998. [PMID: 24523858 PMCID: PMC3921112 DOI: 10.1371/journal.pone.0085998] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Accepted: 12/03/2013] [Indexed: 11/18/2022] Open
Abstract
We describe the first in vitro model of dormancy in Staphylococcus aureus, showing that cells are generated which can be resuscitated by addition of spent medium supernatant taken from cultures of the same organism. Over 30 days, culturable counts in dormant cultures of S. aureus SH1000 fell from 10(6)-10(7) cfu/ml to <10 cfu/ml as measured by the Most Probable Number method in liquid culture, while total counts as determined by microscopy, and supported by data from RT-qPCR, remained around 10(6)-10(7) cells/ml. Supplementing cultures with 25-50% spent medium resulted in a >600-fold increase in bacterial growth. Resuscitation was a specific effect, greatly reduced by boiling or addition of trypsin to the spent supernatant. Supernatant also effected a reduction in lag phase of dormant cultures. SEM demonstrated the presence of small coccoid cells in dormant cultures. The results are similar to those seen with resuscitation promoting factors (Rpfs) in actinobacteria. This is the first time resuscitation has been demonstrated in Staphylococcus aureus, which is an important human pathogen. A better understanding of control and reactivation of dormant cells could lead to major improvements in managing staphylococcal infections; resuscitation could be an important step in restoring susceptibility to antibiotic treatment.
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Affiliation(s)
- Ben Pascoe
- Institute of Life Science, Swansea University College of Medicine, Swansea, United Kingdom
| | - Lucy Dams
- Institute of Life Science, Swansea University College of Medicine, Swansea, United Kingdom
| | - Tom S. Wilkinson
- Institute of Life Science, Swansea University College of Medicine, Swansea, United Kingdom
| | - Llinos G. Harris
- Institute of Life Science, Swansea University College of Medicine, Swansea, United Kingdom
| | - Owen Bodger
- Institute of Life Science, Swansea University College of Medicine, Swansea, United Kingdom
| | - Dietrich Mack
- Institute of Life Science, Swansea University College of Medicine, Swansea, United Kingdom
- Public Health Wales Microbiology Swansea, Swansea, United Kingdom
- Bioscientia Labor Ingelheim, Institut für Medizinische Diagnostik GmbH, Mainz, Germany
| | - Angharad P. Davies
- Institute of Life Science, Swansea University College of Medicine, Swansea, United Kingdom
- Public Health Wales Microbiology Swansea, Swansea, United Kingdom
- * E-mail:
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18
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Abstract
Many Gram-negative and Gram-positive bacteria recycle a significant proportion of the peptidoglycan components of their cell walls during their growth and septation. In many--and quite possibly all--bacteria, the peptidoglycan fragments are recovered and recycled. Although cell-wall recycling is beneficial for the recovery of resources, it also serves as a mechanism to detect cell-wall-targeting antibiotics and to regulate resistance mechanisms. In several Gram-negative pathogens, anhydro-MurNAc-peptide cell-wall fragments regulate AmpC β-lactamase induction. In some Gram-positive organisms, short peptides derived from the cell wall regulate the induction of both β-lactamase and β-lactam-resistant penicillin-binding proteins. The involvement of peptidoglycan recycling with resistance regulation suggests that inhibitors of the enzymes involved in the recycling might synergize with cell-wall-targeted antibiotics. Indeed, such inhibitors improve the potency of β-lactams in vitro against inducible AmpC β-lactamase-producing bacteria. We describe the key steps of cell-wall remodeling and recycling, the regulation of resistance mechanisms by cell-wall recycling, and recent advances toward the discovery of cell-wall-recycling inhibitors.
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Affiliation(s)
- Jarrod W Johnson
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, USA
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19
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Geng J, Chiu CH, Tang P, Chen Y, Shieh HR, Hu S, Chen YYM. Complete genome and transcriptomes of Streptococcus parasanguinis FW213: phylogenic relations and potential virulence mechanisms. PLoS One 2012; 7:e34769. [PMID: 22529932 PMCID: PMC3329508 DOI: 10.1371/journal.pone.0034769] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2011] [Accepted: 03/05/2012] [Indexed: 01/13/2023] Open
Abstract
Streptococcus parasanguinis, a primary colonizer of the tooth surface, is also an opportunistic pathogen for subacute endocarditis. The complete genome of strain FW213 was determined using the traditional shotgun sequencing approach and further refined by the transcriptomes of cells in early exponential and early stationary growth phases in this study. The transcriptomes also discovered 10 transcripts encoding known hypothetical proteins, one pseudogene, five transcripts matched to the Rfam and additional 87 putative small RNAs within the intergenic regions defined by the GLIMMER analysis. The genome contains five acquired genomic islands (GIs) encoding proteins which potentially contribute to the overall pathogenic capacity and fitness of this microbe. The differential expression of the GIs and various open reading frames outside the GIs at the two growth phases suggested that FW213 possess a range of mechanisms to avoid host immune clearance, to colonize host tissues, to survive within oral biofilms and to overcome various environmental insults. Furthermore, the comparative genome analysis of five S. parasanguinis strains indicates that albeit S. parasanguinis strains are highly conserved, variations in the genome content exist. These variations may reflect differences in pathogenic potential between the strains.
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Affiliation(s)
- Jianing Geng
- Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Cheng-Hsun Chiu
- Division of Pediatric Infectious Diseases, Molecular Infectious Disease Research Center, Chang Gung Children's Hospital, Tao-Yuan, Taiwan
- Graduate Institute of Basic Medical Sciences, Chang Gung University, Tao-Yuan, Taiwan
| | - Petrus Tang
- Graduate Institute of Basic Medical Sciences, Chang Gung University, Tao-Yuan, Taiwan
- Bioinformatics Center, Chang Gung University, Tao-Yuan, Taiwan
| | - Yaping Chen
- Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, People's Republic of China
- Graduate University of the Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Hui-Ru Shieh
- Graduate Institute of Basic Medical Sciences, Chang Gung University, Tao-Yuan, Taiwan
- Department of Microbiology and Immunology, Chang Gung University, Tao-Yuan, Taiwan
| | - Songnian Hu
- Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Yi-Ywan M. Chen
- Graduate Institute of Basic Medical Sciences, Chang Gung University, Tao-Yuan, Taiwan
- Department of Microbiology and Immunology, Chang Gung University, Tao-Yuan, Taiwan
- * E-mail:
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20
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Dreisbach A, van Dijl JM, Buist G. The cell surface proteome of Staphylococcus aureus. Proteomics 2011; 11:3154-68. [PMID: 21630461 DOI: 10.1002/pmic.201000823] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2010] [Revised: 02/27/2011] [Accepted: 03/07/2011] [Indexed: 01/15/2023]
Abstract
The Gram-positive bacterium Staphylococcus aureus is a wide spread opportunistic pathogen that can cause a range of life-threatening diseases. To obtain a better understanding of the global mechanisms for pathogenesis and to identify novel targets for therapeutic interventions, the S. aureus proteome has been recently 'dissected' in several studies. Proteins that are exposed on the cell surface - collectively referred to as the 'surfacome' - have received particular attention, because they can directly interact with extracellular molecules, including drugs and antibodies. Accordingly, these proteins represent interesting candidate targets for active or passive immunization against S. aureus. Here, we review the proteomics strategies used, and we compare the results that were so far obtained. Since the surfacome is part of the cell wall proteome, we first present an overview of general properties of the S. aureus cell envelope, cell wall-associated proteins and mechanisms for protein attachment to the cell wall. Then we zoom in on the surfacome, and discuss the pro's and con's of the specific strategies that have been applied for surfacome profiling. The insights thus obtained may serve as leads for future studies on the S. aureus surfacome and possible applications.
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Affiliation(s)
- Annette Dreisbach
- Department of Medical Microbiology, University Medical Centre Groningen and University of Groningen, Groningen, The Netherlands
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21
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Ohniwa RL, Ushijima Y, Saito S, Morikawa K. Proteomic analyses of nucleoid-associated proteins in Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, and Staphylococcus aureus. PLoS One 2011; 6:e19172. [PMID: 21541338 PMCID: PMC3082553 DOI: 10.1371/journal.pone.0019172] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2010] [Accepted: 03/29/2011] [Indexed: 11/18/2022] Open
Abstract
Background The bacterial nucleoid contains several hundred kinds of nucleoid-associated proteins (NAPs), which play critical roles in genome functions such as transcription and replication. Several NAPs, such as Hu and H-NS in Escherichia coli, have so far been identified. Methodology/Principal Findings Log- and stationary-phase cells of E. coli, Pseudomonas aeruginosa, Bacillus subtilis, and Staphylococcus aureus were lysed in spermidine solutions. Nucleoids were collected by sucrose gradient centrifugation, and their protein constituents analyzed by liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS). Over 200 proteins were identified in each species. Envelope and soluble protein fractions were also identified. By using these data sets, we obtained lists of contaminant-subtracted proteins enriched in the nucleoid fractions (csNAP lists). The lists do not cover all of the NAPs, but included Hu regardless of the growth phases and species. In addition, the csNAP lists of each species suggested that the bacterial nucleoid is equipped with the species-specific set of global regulators, oxidation-reduction enzymes, and fatty acid synthases. This implies bacteria individually developed nucleoid associated proteins toward obtaining similar characteristics. Conclusions/Significance Ours is the first study to reveal hundreds of NAPs in the bacterial nucleoid, and the obtained data set enabled us to overview some important features of the nucleoid. Several implications obtained from the present proteomic study may make it a landmark for the future functional and evolutionary study of the bacterial nucleoid.
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Affiliation(s)
- Ryosuke L Ohniwa
- Institute of Basic Medical Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tennodai, Tsukuba, Ibaraki, Japan.
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22
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Dreisbach A, Hempel K, Buist G, Hecker M, Becher D, van Dijl JM. Profiling the surfacome of Staphylococcus aureus. Proteomics 2010; 10:3082-96. [PMID: 20662103 DOI: 10.1002/pmic.201000062] [Citation(s) in RCA: 111] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Staphylococcus aureus is a widespread opportunistic pathogen that can cause a wide variety of life-threatening diseases. Especially for the colonization of human tissues and the development of invasiveness, surface-exposed proteins are of major importance. In the present studies, we optimized a proteolytic shaving approach to identify those surface-exposed protein domains - the surfacome - of S. aureus that are accessible to extracellular bio-macromolecules, for example in the host milieu. Subsequently, this approach was applied to define the surfacomes of four strains with different genetic backgrounds. This resulted in the identification of 96 different proteins. Surprisingly, the overlap between the surfacomes of the four different strains was below 10% and each strain displayed its own characteristic set of surface-exposed proteins. The data were also evaluated at the peptide level and here we observed a similar phenomenon. From 190 unique peptides only five were commonly found in the four strains. Besides well known cell wall proteins, we also identified some essential proteins, several yet uncharacterized exported proteins and predicted intracellular proteins. These results show for the first time that the cell surface of different S. aureus strains is not only highly variable, but also that the displayed proteins are very heterogeneous.
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Affiliation(s)
- Annette Dreisbach
- Department of Medical Microbiology, University Medical Centre Groningen and University of Groningen, Groningen, The Netherlands
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23
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Functional antibodies targeting IsaA of Staphylococcus aureus augment host immune response and open new perspectives for antibacterial therapy. Antimicrob Agents Chemother 2010; 55:165-73. [PMID: 20956605 DOI: 10.1128/aac.01144-10] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Staphylococcus aureus is the most common cause of nosocomial infections. Multiple antibiotic resistance and severe clinical outcomes provide a strong rationale for development of immunoglobulin-based strategies. Traditionally, novel immunological approaches against bacterial pathogens involve antibodies directed against cell surface-exposed virulence-associated epitopes or toxins. In this study, we generated a monoclonal antibody targeting the housekeeping protein IsaA, a suggested soluble lytic transglycosylase of S. aureus, and tested its therapeutic efficacy in two experimental mouse infection models. A murine anti-IsaA antibody of the IgG1 subclass (UK-66P) showed the highest binding affinity in Biacore analysis. This antibody recognized all S. aureus strains tested, including hospital-acquired and community-acquired methicillin-resistant S. aureus strains. Therapeutic efficacy in vivo in mice was analyzed using a central venous catheter-related infection model and a sepsis survival model. In both models, anti-IsaA IgG1 conferred protection against staphylococcal infection. Ex vivo, UK-66P activates professional phagocytes and induces highly microbicidal reactive oxygen metabolites in a dose-dependent manner, resulting in bacterial killing. The study provides proof of concept that monoclonal IgG1 antibodies with high affinity to the ubiquitously expressed, single-epitope-targeting IsaA are effective in the treatment of staphylococcal infection in different mouse models. Anti-IsaA antibodies might be a useful component in an antibody-based therapeutic for prophylaxis or adjunctive treatment of human cases of S. aureus infections.
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24
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Ventura CL, Malachowa N, Hammer CH, Nardone GA, Robinson MA, Kobayashi SD, DeLeo FR. Identification of a novel Staphylococcus aureus two-component leukotoxin using cell surface proteomics. PLoS One 2010; 5:e11634. [PMID: 20661294 PMCID: PMC2905442 DOI: 10.1371/journal.pone.0011634] [Citation(s) in RCA: 166] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2010] [Accepted: 06/23/2010] [Indexed: 01/13/2023] Open
Abstract
Staphylococcus aureus is a prominent human pathogen and leading
cause of bacterial infection in hospitals and the community.
Community-associated methicillin-resistant S. aureus (CA-MRSA)
strains such as USA300 are highly virulent and, unlike hospital strains, often
cause disease in otherwise healthy individuals. The enhanced virulence of
CA-MRSA is based in part on increased ability to produce high levels of secreted
molecules that facilitate evasion of the innate immune response. Although
progress has been made, the factors that contribute to CA-MRSA virulence are
incompletely defined. We analyzed the cell surface proteome (surfome) of USA300
strain LAC to better understand extracellular factors that contribute to the
enhanced virulence phenotype. A total of 113 identified proteins were associated
with the surface of USA300 during the late-exponential phase of growth
in vitro. Protein A was the most abundant surface molecule
of USA300, as indicated by combined Mascot score following analysis of peptides
by tandem mass spectrometry. Unexpectedly, we identified a previously
uncharacterized two-component leukotoxin–herein named LukS-H and
LukF-G (LukGH)-as two of the most abundant surface-associated proteins of
USA300. Rabbit antibody specific for LukG indicated it was also freely secreted
by USA300 into culture media. We used wild-type and isogenic
lukGH deletion strains of USA300 in combination with human
PMN pore formation and lysis assays to identify this molecule as a leukotoxin.
Moreover, LukGH synergized with PVL to enhance lysis of human PMNs in
vitro, and contributed to lysis of PMNs after phagocytosis. We
conclude LukGH is a novel two-component leukotoxin with cytolytic activity
toward neutrophils, and thus potentially contributes to S.
aureus virulence.
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Affiliation(s)
- Christy L. Ventura
- Laboratory of Human Bacterial Pathogenesis, Rocky Mountain Laboratories,
National Institute of Allergy and Infectious Diseases, National Institutes of
Health, Hamilton, Montana, United States of America
| | - Natalia Malachowa
- Laboratory of Human Bacterial Pathogenesis, Rocky Mountain Laboratories,
National Institute of Allergy and Infectious Diseases, National Institutes of
Health, Hamilton, Montana, United States of America
| | - Carl H. Hammer
- Research Technologies Branch, National Institute of Allergy and
Infectious Diseases, National Institutes of Health, Rockville, Maryland, United
States of America
| | - Glenn A. Nardone
- Research Technologies Branch, National Institute of Allergy and
Infectious Diseases, National Institutes of Health, Rockville, Maryland, United
States of America
| | - Mary Ann Robinson
- Research Technologies Branch, National Institute of Allergy and
Infectious Diseases, National Institutes of Health, Rockville, Maryland, United
States of America
| | - Scott D. Kobayashi
- Laboratory of Human Bacterial Pathogenesis, Rocky Mountain Laboratories,
National Institute of Allergy and Infectious Diseases, National Institutes of
Health, Hamilton, Montana, United States of America
| | - Frank R. DeLeo
- Laboratory of Human Bacterial Pathogenesis, Rocky Mountain Laboratories,
National Institute of Allergy and Infectious Diseases, National Institutes of
Health, Hamilton, Montana, United States of America
- * E-mail:
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25
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Shah IM, Dworkin J. Induction and regulation of a secreted peptidoglycan hydrolase by a membrane Ser/Thr kinase that detects muropeptides. Mol Microbiol 2010; 75:1232-43. [PMID: 20070526 DOI: 10.1111/j.1365-2958.2010.07046.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Here, we report that the model Gram-positive organism, Bacillus subtilis, expresses and secretes a muralytic enzyme, YocH, in response to cell wall-derived muropeptides derived from growing cells but not lysed cells. This induction is dependent on PrkC, a membrane Ser/Thr kinase that binds to peptidoglycan and that belongs to a broadly conserved family including the essential PknB kinase of M. tuberculosis. YocH stimulates its own expression in a PrkC-dependent manner demonstrating the presence of an autoregulatory loop during growth. Cells lacking YocH display a survival defect in stationary phase but enzymes secreted by other cells in the culture rescue this defect. The essential translation factor EF-G is an in vivo substrate of PrkC and this phosphorylation occurs in response to muropeptides. Therefore, we hypothesize that YocH is used by the bacterium to digest peptidoglycan released by other bacteria in the milieu and that the presence of these fragments is detected by a membrane kinase that modifies a key regulator of translation as well as to stimulate its own expression.
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Affiliation(s)
- Ishita M Shah
- Department of Microbiology and Immunology, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
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26
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Planchon S, Desvaux M, Chafsey I, Chambon C, Leroy S, Hébraud M, Talon R. Comparative subproteome analyses of planktonic and sessile Staphylococcus xylosus C2a: new insight in cell physiology of a coagulase-negative Staphylococcus in biofilm. J Proteome Res 2009; 8:1797-809. [PMID: 19253936 DOI: 10.1021/pr8004056] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Staphylococcus xylosus is a Gram-positive bacterium found on the skin of mammals and frequently isolated from food plants and fermented cheese or meat. To gain further insight in protein determinants involved in biofilm formation by this coagulase-negative Staphylococcus, a comparative proteomic analysis between planktonic and sessile cells was performed. With the use of a protocol previously developed, protein patterns of the cytoplasmic and cell envelope fractions were compared by 2-DE. Following protein identification by MALDI-TOF mass spectrometry and bioinformatic analyses, this study revealed differences in expression levels of 89 distinct proteins with 55 up-expressed and 34 down-expressed proteins in biofilm compared to planktonic cells. Most proteins differentially expressed were related to nitrogen and carbon metabolisms. Besides amino acid biosynthesis and protein translation, protein determinants related to protein secretion were up-expressed in biofilm, suggesting a more active protein trafficking in sessile cells. While up-expression of several enzymes involved in pentose phosphate and glycolytic pathways was observed in biofilm, connections with unexpected metabolic routes were further unravelled. Indeed, this proteomic analysis allowed identifying novel proteins that could be involved in a previously uncovered exopolysaccharide biosynthetic pathway in S. xylosus as well as several enzymes related to polyketide biosynthesis. This findings are particularly relevant considering exopolysaccharide production in S. xylosus is ica-independent contrary to coagulase-negative model strain Staphylococcus epidermidis RP62A.
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Affiliation(s)
- Stella Planchon
- INRA, UR454 Microbiologie, F-63122 Saint-Genès Champanelle, France
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27
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Relative quantitative comparisons of the extracellular protein profiles of Staphylococcus aureus UAMS-1 and its sarA, agr, and sarA agr regulatory mutants using one-dimensional polyacrylamide gel electrophoresis and nanocapillary liquid chromatography coupled with tandem mass spectrometry. J Bacteriol 2008; 190:5265-78. [PMID: 18539737 DOI: 10.1128/jb.00383-08] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
One-dimensional polyacrylamide gel electrophoresis followed by nanocapillary liquid chromatography coupled with mass spectrometry was used to analyze proteins isolated from Staphylococcus aureus UAMS-1 after 3, 6, 12, and 24 h of in vitro growth. Protein abundance was determined using a quantitative value termed normalized peptide number, and overall, proteins known to be associated with the cell wall were more abundant early on in growth, while proteins known to be secreted into the surrounding milieu were more abundant late in growth. In addition, proteins from spent media and cell lysates of strain UAMS-1 and its isogenic sarA, agr, and sarA agr regulatory mutant strains during exponential growth were identified, and their relative abundances were compared. Extracellular proteins known to be regulated by the global regulators sarA and agr displayed protein levels in accordance with what is known regarding the effects of these regulators. For example, cysteine protease (SspB), endopeptidase (SspA), staphopain (ScpA), and aureolysin (Aur) were higher in abundance in the sarA and sarA agr mutants than in strain UAMS-1. The immunoglobulin G (IgG)-binding protein (Sbi), immunodominant staphylococcal antigen A (IsaA), IgG-binding protein A (Spa), and the heme-iron-binding protein (IsdA) were most abundant in the agr mutant background. Proteins whose abundance was decreased in the sarA mutant included fibrinogen-binding protein (Fib [Efb]), IsaA, lipase 1 and 2, and two proteins identified as putative leukocidin F and S subunits of the two-component leukotoxin family. Collectively, this approach identified 1,263 proteins (matches of two peptides or more) and provided a convenient and reliable way of identifying proteins and comparing their relative abundances.
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28
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Stapleton MR, Horsburgh MJ, Hayhurst EJ, Wright L, Jonsson IM, Tarkowski A, Kokai-Kun JF, Mond JJ, Foster SJ. Characterization of IsaA and SceD, two putative lytic transglycosylases of Staphylococcus aureus. J Bacteriol 2007; 189:7316-25. [PMID: 17675373 PMCID: PMC2168438 DOI: 10.1128/jb.00734-07] [Citation(s) in RCA: 124] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2007] [Accepted: 07/19/2007] [Indexed: 11/20/2022] Open
Abstract
Bacterial cell wall peptidoglycan is a dynamic structure requiring hydrolysis to allow cell wall growth and division. Staphylococcus aureus has many known and putative peptidoglycan hydrolases, including two likely lytic transglycosylases. These two proteins, IsaA and SceD, were both found to have autolytic activity. Regulatory studies showed that the isaA and sceD genes are partially mutually compensatory and that the production of SceD is upregulated in an isaA mutant. The expression of sceD is also greatly upregulated by the presence of NaCl. Several regulators of isaA and sceD expression were identified. Inactivation of sceD resulted in impaired cell separation, as shown by light microscopy, and "clumping" of bacterial cultures. An isaA sceD mutant is attenuated for virulence, while SceD is essential for nasal colonization in cotton rats, thus demonstrating the importance of cell wall dynamics in host-pathogen interactions.
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Affiliation(s)
- Melanie R Stapleton
- Department of Molecular Biology and Biotechnology, University of Sheffield, Western Bank, Sheffield, UK
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29
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Sakata N, Mukai T. Production profile of the soluble lytic transglycosylase homologue inStaphylococcus aureusduring bacterial proliferation. ACTA ACUST UNITED AC 2007; 49:288-95. [PMID: 17328763 DOI: 10.1111/j.1574-695x.2006.00200.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The immunodominant antigen A, IsaA, of Staphylococcus aureus is considered to be a sequence homologue of gram-negative soluble lytic transglycosylase. Recently, it was reported that IsaA production is probably regulated by the essential two-component regulatory system consisting of YycG and YycF. Therefore, we investigated the isaA expression profile by quantifying its gene products at different stages of bacterial growth. In the culture supernatant, IsaA was detectable in the early exponential growth phase and its concentration constantly increased until the early stationary phase. Cell surface IsaA was mainly found on growing bacteria, and disappeared proportionately with a decline in cell proliferation. On the other hand, the isaA transcript rapidly increased at the beginning of the culture, and then stayed at a constant level until the late exponential growth phase. These findings indicated that isaA gene expression was stimulated during the exponential growth phase and repressed in the stationary phase. Thus, IsaA production was associated with active bacterial growth. Our results support the previous report that isaA expression is regulated by YycF, and also suggest that IsaA is probably involved in bacterial proliferation by residing on the cell wall. We also discuss the possibility that isaA transcription may be controlled by SarA.
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Affiliation(s)
- Noriaki Sakata
- Department of Legal Medicine, St Marianna University School of Medicine, Kawasaki, Japan.
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30
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Buist G, Ridder ANJA, Kok J, Kuipers OP. Different subcellular locations of secretome components of Gram-positive bacteria. Microbiology (Reading) 2006; 152:2867-2874. [PMID: 17005968 DOI: 10.1099/mic.0.29113-0] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Gram-positive bacteria contain different types of secretion systems for the transport of proteins into or across the cytoplasmic membrane. Recent studies on subcellular localization of specific components of these secretion systems and their substrates have shown that they can be present at various locations in the cell. The translocons of the general Sec secretion system in the rod-shaped bacteriumBacillus subtilishave been shown to localize in spirals along the cytoplasmic membrane, whereas the translocons in the coccoidStreptococcus pyogenesare located in a microdomain near the septum. In both bacteria the Sec translocons appear to be located near the sites of cell wall synthesis. The Tat secretion system, which is used for the transport of folded proteins, probably localizes in the cytoplasmic membrane and at the cell poles ofB. subtilis. InLactococcus lactisthe ABC transporter dedicated to the transport of a small antimicrobial peptide is distributed throughout the membrane. Possible mechanisms for maintaining the localization of these secretion machineries involve their interaction with proteins of the cytoskeleton or components of the cell wall synthesis machinery, or the presence of lipid subdomains surrounding the transport systems.
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Affiliation(s)
- Girbe Buist
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Kerklaan 30, 9751 NN Haren, The Netherlands
| | - Anja N J A Ridder
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Kerklaan 30, 9751 NN Haren, The Netherlands
| | - Jan Kok
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Kerklaan 30, 9751 NN Haren, The Netherlands
| | - Oscar P Kuipers
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Kerklaan 30, 9751 NN Haren, The Netherlands
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31
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Keep NH, Ward JM, Cohen-Gonsaud M, Henderson B. Wake up! Peptidoglycan lysis and bacterial non-growth states. Trends Microbiol 2006; 14:271-6. [PMID: 16675219 DOI: 10.1016/j.tim.2006.04.003] [Citation(s) in RCA: 112] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2006] [Revised: 03/02/2006] [Accepted: 04/20/2006] [Indexed: 11/27/2022]
Abstract
When stressed, bacteria can enter various non-dividing states, which are medically important. For example, dormancy is used by Mycobacterium tuberculosis to evade host responses. A major breakthrough has been the discovery of resuscitation-promoting factor (Rpf) from Micrococcus luteus, which is an extremely potent anti-dormancy factor. Mycobacteria have multiple proteins that contain this domain. Surprisingly, the highly conserved resuscitation-promoting factor domain has strong structural similarities to lysozyme and soluble lytic transglycosylases, and it has been demonstrated that resuscitation-promoting factors cleave peptidoglycan. This suggests that the activation of dormant cells requires peptidoglycan hydrolysis, which either alters the mechanical properties of the cell wall to facilitate cell division or releases lysis products that function as anti-dormancy signals.
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Affiliation(s)
- Nicholas H Keep
- School of Crystallography and Institute of Structural Molecular Biology, Birkbeck, University of London, Malet Street, London, UK, WC1E 7HX
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