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Zeden MS, Schuster CF, Gründling A. Allelic Exchange: Construction of an Unmarked In-Frame Deletion in Staphylococcus aureus. Cold Spring Harb Protoc 2023; 2023:107945. [PMID: 37117029 DOI: 10.1101/pdb.top107945] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/30/2023]
Abstract
Here we describe an allelic-exchange procedure for the construction of an unmarked gene deletion in the bacterium Staphylococcus aureus As a practical example, we outline the construction of a tagO gene deletion in S. aureus using the allelic-exchange plasmid pIMAY*. We first present the general principles of the allelic-exchange method, along with information on counterselectable markers. Furthermore, we summarize relevant cloning procedures, such as the splicing by overhang extension (SOE) polymerase chain reaction (PCR) and Gibson assembly methods, and we conclude by giving some general consideration to performing genetic modifications in S. aureus.
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Affiliation(s)
- Merve S Zeden
- Microbiology, School of Biological and Chemical Sciences, University of Galway, Galway H91 TK33, Ireland
| | - Christopher F Schuster
- Center for Pandemic Vaccines and Therapeutics (ZEPAI), Paul-Ehrlich-Institute, 63225 Langen, Germany
| | - Angelika Gründling
- Section of Molecular Microbiology and Medical Research Council Centre for Molecular Bacteriology and Infection, Imperial College London, London, SW7 2AZ, United Kingdom
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2
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Clayton K, Holbrook DJ, Vallejo A, Porter G, Sirvent S, Davies J, Pople J, Lim FL, Christodoulides M, Polak ME, Ardern-Jones MR. Skin programming of inflammatory responses to Staphylococcus aureus is compartmentalized according to epidermal keratinocyte differentiation status. Br J Dermatol 2023; 188:396-406. [PMID: 36637891 DOI: 10.1093/bjd/ljac088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 10/20/2022] [Accepted: 11/05/2022] [Indexed: 01/14/2023]
Abstract
BACKGROUND Acute cutaneous inflammation causes microbiome alterations as well as ultrastructural changes in epidermis stratification. However, the interactions between keratinocyte proliferation and differentiation status and the skin microbiome have not been fully explored. OBJECTIVES Hypothesizing that the skin microbiome contributes to regulation of keratinocyte differentiation and can modify antimicrobial responses, we examined the effect of exposure to commensal (Staphylococcus epidermidis, SE) or pathogenic (Staphylococcus aureus, SA) challenge on epidermal models. METHODS Explant biopsies were taken to investigate species-specific antimicrobial effects of host factors. Further investigations were performed in reconstituted epidermal models by bulk transcriptomic analysis alongside secreted protein profiling. Single-cell RNA sequencing analysis was performed to explore the keratinocyte populations responsible for SA inflammation. A dataset of 6391 keratinocytes from control (2044 cells), SE challenge (2028 cells) and SA challenge (2319 cells) was generated from reconstituted epidermal models. RESULTS Bacterial lawns of SA, not SE, were inhibited by human skin explant samples, and microarray analysis of three-dimensional epidermis models showed that host antimicrobial peptide expression was induced by SE but not SA. Protein analysis of bacterial cocultured models showed that SA exposure induced inflammatory mediator expression, indicating keratinocyte activation of other epidermal immune populations. Single-cell DropSeq analysis of unchallenged naive, SE-challenged and SA-challenged epidermis models was undertaken to distinguish cells from basal, spinous and granular layers, and to interrogate them in relation to model exposure. In contrast to SE, SA specifically induced a subpopulation of spinous cells that highly expressed transcripts related to epidermal inflammation and antimicrobial response. Furthermore, SA, but not SE, specifically induced a basal population that highly expressed interleukin-1 alarmins. CONCLUSIONS These findings suggest that SA-associated remodelling of the epidermis is compartmentalized to different keratinocyte populations. Elucidating the mechanisms regulating bacterial sensing-triggered inflammatory responses within tissues will enable further understanding of microbiome dysbiosis and inflammatory skin diseases, such as atopic eczema.
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Affiliation(s)
- Kalum Clayton
- Clinical and Experimental Sciences, Sir Henry Wellcome Laboratories, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Daniel J Holbrook
- Clinical and Experimental Sciences, Sir Henry Wellcome Laboratories, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Andres Vallejo
- Clinical and Experimental Sciences, Sir Henry Wellcome Laboratories, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Gemma Porter
- Clinical and Experimental Sciences, Sir Henry Wellcome Laboratories, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Sofia Sirvent
- Clinical and Experimental Sciences, Sir Henry Wellcome Laboratories, Faculty of Medicine, University of Southampton, Southampton, UK
| | - James Davies
- Clinical and Experimental Sciences, Sir Henry Wellcome Laboratories, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Jenny Pople
- Unilever, Colworth Science Park, Sharnbrook, Bedford, UK
| | - Fei Ling Lim
- Unilever, Colworth Science Park, Sharnbrook, Bedford, UK
| | - Myron Christodoulides
- Clinical and Experimental Sciences, Sir Henry Wellcome Laboratories, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Marta E Polak
- Clinical and Experimental Sciences, Sir Henry Wellcome Laboratories, Faculty of Medicine, University of Southampton, Southampton, UK.,Institute for Life Sciences, University of Southampton, Southampton, UK
| | - Michael R Ardern-Jones
- Clinical and Experimental Sciences, Sir Henry Wellcome Laboratories, Faculty of Medicine, University of Southampton, Southampton, UK.,Department of Dermatology, University Hospitals Southampton NHS Foundation Trust, Southampton, UK
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3
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Panthee S, Hamamoto H, Paudel A, Kaito C, Suzuki Y, Sekimizu K. Hybrid assembly using long reads resolves repeats and completes the genome sequence of a laboratory strain of Staphylococcus aureus subsp. Aureus RN4220. Heliyon 2022; 8:e11376. [PMID: 36387480 PMCID: PMC9660545 DOI: 10.1016/j.heliyon.2022.e11376] [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: 01/16/2022] [Revised: 06/30/2022] [Accepted: 10/27/2022] [Indexed: 11/07/2022] Open
Abstract
Staphylococcus aureus RN4220 has been extensively used by staphylococcal researchers as an intermediate strain for genetic manipulation due to its ability to accept foreign DNA. Despite its wide use in laboratories, its complete genome is not available. In this study, we used a hybrid genome assembly approach using minION long reads and Illumina short reads to sequence the complete genome of S. aureus RN4220. The comparative analysis of the annotated complete genome showed the presence of 39 genes fragmented in the previous assembly, many of which were located near the repeat regions. Using RNA-Seq reads, we showed that a higher number of reads could be mapped to the complete genome than the draft genome and the gene expression profile obtained using the complete genome also differs from that obtained from the draft genome. Furthermore, by comparative transcriptomic analysis, we showed the correlation between expression levels of staphyloxanthin biosynthetic genes and the production of yellow pigment. This study highlighted the importance of long reads in completing microbial genomes, especially those possessing repetitive elements. S. aureus RN4220 is used as an intermediate strain for genetic manipulation. We completed its genome and found 39 fragmented genes in previous genome assembly. RNA-Seq analysis improved mapping of the reads with the use of complete genome. Expression of staphyloxanthin biosynthetic genes was correlated with its production.
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4
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Kouijzer JJP, Noordermeer DJ, van Leeuwen WJ, Verkaik NJ, Lattwein KR. Native valve, prosthetic valve, and cardiac device-related infective endocarditis: A review and update on current innovative diagnostic and therapeutic strategies. Front Cell Dev Biol 2022; 10:995508. [PMID: 36263017 PMCID: PMC9574252 DOI: 10.3389/fcell.2022.995508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2022] [Accepted: 09/06/2022] [Indexed: 11/13/2022] Open
Abstract
Infective endocarditis (IE) is a life-threatening microbial infection of native and prosthetic heart valves, endocardial surface, and/or indwelling cardiac device. Prevalence of IE is increasing and mortality has not significantly improved despite technological advances. This review provides an updated overview using recent literature on the clinical presentation, diagnosis, imaging, causative pathogens, treatment, and outcomes in native valve, prosthetic valve, and cardiac device-related IE. In addition, the experimental approaches used in IE research to improve the understanding of disease mechanisms and the current diagnostic pipelines are discussed, as well as potential innovative diagnostic and therapeutic strategies. This will ultimately help towards deriving better diagnostic tools and treatments to improve IE patient outcomes.
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Affiliation(s)
- Joop J. P. Kouijzer
- Thoraxcenter, Department of Biomedical Engineering, Erasmus MC University Medical Center, Rotterdam, Netherlands
- *Correspondence: Joop J. P. Kouijzer,
| | - Daniëlle J. Noordermeer
- Thoraxcenter, Department of Biomedical Engineering, Erasmus MC University Medical Center, Rotterdam, Netherlands
| | - Wouter J. van Leeuwen
- Department of Cardiothoracic Surgery, Erasmus MC University Medical Center, Rotterdam, Netherlands
| | - Nelianne J. Verkaik
- Department of Medical Microbiology and Infectious Diseases, Erasmus MC University Medical Center, Rotterdam, Netherlands
| | - Kirby R. Lattwein
- Thoraxcenter, Department of Biomedical Engineering, Erasmus MC University Medical Center, Rotterdam, Netherlands
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5
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Garrett SR, Mariano G, Dicks J, Palmer T. Homologous recombination between tandem paralogues drives evolution of a subset of type VII secretion system immunity genes in firmicute bacteria. Microb Genom 2022; 8. [PMID: 35960642 PMCID: PMC9484751 DOI: 10.1099/mgen.0.000868] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The type VII secretion system (T7SS) is found in many Gram-positive firmicutes and secretes protein toxins that mediate bacterial antagonism. Two T7SS toxins have been identified in Staphylococcus aureus, EsaD a nuclease toxin that is counteracted by the EsaG immunity protein, and TspA, which has membrane depolarising activity and is neutralised by TsaI. Both toxins are polymorphic, and strings of non-identical esaG and tsaI immunity genes are encoded in all S. aureus strains. To investigate the evolution of esaG repertoires, we analysed the sequences of the tandem esaG genes and their encoded proteins. We identified three blocks of high sequence similarity shared by all esaG genes and identified evidence of extensive recombination events between esaG paralogues facilitated through these conserved sequence blocks. Recombination between these blocks accounts for loss and expansion of esaG genes in S. aureus genomes and we identified evidence of such events during evolution of strains in clonal complex 8. TipC, an immunity protein for the TelC lipid II phosphatase toxin secreted by the streptococcal T7SS, is also encoded by multiple gene paralogues. Two blocks of high sequence similarity locate to the 5′ and 3′ end of tipC genes, and we found strong evidence for recombination between tipC paralogues encoded by Streptococcus mitis BCC08. By contrast, we found only a single homology block across tsaI genes, and little evidence for intergenic recombination within this gene family. We conclude that homologous recombination is one of the drivers for the evolution of T7SS immunity gene clusters.
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Affiliation(s)
- Stephen R Garrett
- Microbes in Health and Disease Theme, Newcastle University Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Giuseppina Mariano
- Microbes in Health and Disease Theme, Newcastle University Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Jo Dicks
- Culture Collections, UK Health Security Agency, 61 Colindale Ave, London, NW9 5EQ, UK
| | - Tracy Palmer
- Microbes in Health and Disease Theme, Newcastle University Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
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6
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Antibiotic Exposure Leads to Reduced Phage Susceptibility in Vancomycin Intermediate Staphylococcus aureus (VISA). Antimicrob Agents Chemother 2022; 66:e0224721. [PMID: 35708333 PMCID: PMC9295574 DOI: 10.1128/aac.02247-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
Abstract
In the time of antimicrobial resistance, phage therapy is frequently suggested as a possible solution for such difficult-to-treat infections. Vancomycin-intermediate Staphylococcus aureus (VISA) remains a relatively rare yet increasing occurrence in the clinic for which phage therapy may be an option. However, the data presented herein suggest a potential cross-resistance mechanism to phage following vancomycin exposure in VISA strains. When comparing genetically similar strains differing in their susceptibility to vancomycin, those with intermediate levels of vancomycin resistance displayed decreased sensitivity to phage in solid and liquid assays. Serial passaging with vancomycin induced both reduced vancomycin susceptibility and phage sensitivity. As a consequence, the process of phage infection was shown to be interrupted after DNA ejection from adsorbed phage but prior to phage DNA replication, as demonstrated through adsorption assays, lysostaphin sensitivity assays, electron microscopy, and quantitative PCR (qPCR). At a time when phage products are being used for experimental treatments and tested in clinical trials, it is important to understand possible interference between mechanisms underlying antibiotic and phage resistance in order to design effective therapeutic regimens.
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7
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Polaske TJ, Gahan CG, Nyffeler KE, Lynn DM, Blackwell HE. Identification of small molecules that strongly inhibit bacterial quorum sensing using a high-throughput lipid vesicle lysis assay. Cell Chem Biol 2021; 29:605-614.e4. [PMID: 34932995 PMCID: PMC9035047 DOI: 10.1016/j.chembiol.2021.12.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 09/27/2021] [Accepted: 11/29/2021] [Indexed: 01/15/2023]
Abstract
Strategies to both monitor and block bacterial quorum sensing (QS), and thus associated infections, are of significant interest. We developed a straightforward assay to monitor biosurfactants and lytic agents produced by bacteria under the control of QS. The method is based on the lysis of synthetic lipid vesicles containing the environmentally sensitive fluorescent dye calcein. This assay allows for the in situ screening of compounds capable of altering biosurfactant production by bacteria, and thereby the identification of molecules that could potentially modulate QS pathways, and avoids the constraints of many of the cell-based assays in use today. Application of this assay in a high-throughput format revealed five molecules capable of blocking vesicle lysis by S. aureus. Two of these compounds were found to almost completely inhibit agr-based QS in S. aureus and represent the most potent small-molecule-derived QS inhibitors reported in this formidable pathogen.
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Affiliation(s)
- Thomas J Polaske
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, WI 53706, USA
| | - Curran G Gahan
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, 1415 Engineering Dr., Madison, WI 53706, USA
| | - Kayleigh E Nyffeler
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, WI 53706, USA; Microbiology Doctoral Training Program, University of Wisconsin-Madison, 1550 Linden Dr., Madison, WI 53706, USA
| | - David M Lynn
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, WI 53706, USA; Department of Chemical and Biological Engineering, University of Wisconsin-Madison, 1415 Engineering Dr., Madison, WI 53706, USA.
| | - Helen E Blackwell
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, WI 53706, USA.
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8
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Bossé JT, Li Y, Cohen LM, Stegger M, Angen Ø, Lacouture S, Gottschalk M, Lei L, Koene M, Kuhnert P, Bandara AB, Inzana TJ, Holden MTG, Harris D, Oshota O, Maskell DJ, Tucker AW, Wren BW, Rycroft AN, Langford PR, On Behalf Of The BRaDP T Consortium. Complete genome for Actinobacillus pleuropneumoniae serovar 8 reference strain 405: comparative analysis with draft genomes for different laboratory stock cultures indicates little genetic variation. Microb Genom 2021; 7. [PMID: 34818145 PMCID: PMC8743550 DOI: 10.1099/mgen.0.000687] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We report here the complete genome sequence of the widely studied Actinobacillus pleuropneumoniae serovar 8 reference strain 405, generated using the Pacific Biosciences (PacBio) RS II platform. Furthermore, we compared draft sequences generated by Illumina sequencing of six stocks of this strain, including the same original stock used to generate the PacBio sequence, held in different countries and found little genetic variation, with only three SNPs identified, all within the degS gene. However, sequences of two small plasmids, pARD3079 and p405tetH, detected by Illumina sequencing of the draft genomes were not identified in the PacBio sequence of the reference strain.
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Affiliation(s)
- Janine T Bossé
- Section of Paediatric Infectious Diseases, Department of Infectious Diseases, Imperial College London, London, UK
| | - Yanwen Li
- Section of Paediatric Infectious Diseases, Department of Infectious Diseases, Imperial College London, London, UK
| | - Liza Miriam Cohen
- Department of Production Animal Clinical Sciences Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Ås, Norway
| | - Marc Stegger
- Department of Bacteria, Parasites and Fungi, Statens Serum Institut, Copenhagen, Denmark
| | - Øystein Angen
- Department of Bacteria, Parasites and Fungi, Statens Serum Institut, Copenhagen, Denmark
| | - Sonia Lacouture
- Groupe de Recherche sur les Maladies Infectieuses du Porc, Faculté de Médecine Vétérinaire, Université de Montréal, Québec, Canada
| | - Marcelo Gottschalk
- Groupe de Recherche sur les Maladies Infectieuses du Porc, Faculté de Médecine Vétérinaire, Université de Montréal, Québec, Canada
| | - Liancheng Lei
- College of Veterinary Medicine, Jilin University, Changchun, P.R China
| | - Miriam Koene
- Wageningen Bioveterinary Research, Lelystad, The Netherlands
| | - Peter Kuhnert
- Institute of Veterinary Bacteriology, Vetsuisse Faculty, Universität Bern, Bern, Switzerland
| | - Aloka B Bandara
- Virginia-Maryland Regional College of Veterinary Medicine, Blacksburg, USA
| | - Thomas J Inzana
- Present address: College of Veterinary Medicine, Long Island University, Brookville, USA.,Virginia-Maryland Regional College of Veterinary Medicine, Blacksburg, USA
| | - Matthew T G Holden
- Present address: School of Medicine, University of St Andrews, St Andrews, UK.,The Wellcome Trust Sanger Institute, Cambridge, UK
| | - David Harris
- The Wellcome Trust Sanger Institute, Cambridge, UK
| | - Olusegun Oshota
- Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
| | - Duncan J Maskell
- Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
| | - Alexander W Tucker
- Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
| | - Brendan W Wren
- Faculty of Infectious & Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Andrew N Rycroft
- Department of Pathology and Pathogen Biology, The Royal Veterinary College, Hatfield, UK
| | - Paul R Langford
- Section of Paediatric Infectious Diseases, Department of Infectious Diseases, Imperial College London, London, UK
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9
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Abstract
The type VII protein secretion system (T7SS) of Staphylococcus aureus is encoded at the ess locus. T7 substrate recognition and protein transport are mediated by EssC, a membrane-bound multidomain ATPase. Four EssC sequence variants have been identified across S. aureus strains, each accompanied by a specific suite of substrate proteins. The ess genes are upregulated during persistent infection, and the secretion system contributes to virulence in disease models. It also plays a key role in intraspecies competition, secreting nuclease and membrane-depolarizing toxins that inhibit the growth of strains lacking neutralizing immunity proteins. A genomic survey indicates that the T7SS is widely conserved across staphylococci and is encoded in clusters that contain diverse arrays of toxin and immunity genes. The presence of genomic islands encoding multiple immunity proteins in species such as Staphylococcus warneri that lack the T7SS points to a major role for the secretion system in bacterial antagonism. Expected final online publication date for the Annual Review of Microbiology, Volume 75 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Lisa Bowman
- Microbes in Health and Disease Theme, Newcastle University Biosciences Institute, Newcastle University, Newcastle upon Tyne NE2 4HH, United Kingdom; ,
| | - Tracy Palmer
- Microbes in Health and Disease Theme, Newcastle University Biosciences Institute, Newcastle University, Newcastle upon Tyne NE2 4HH, United Kingdom; ,
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10
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Staphylococcus aureus adapts to the host nutritional landscape to overcome tissue-specific branched-chain fatty acid requirement. Proc Natl Acad Sci U S A 2021; 118:2022720118. [PMID: 33753501 DOI: 10.1073/pnas.2022720118] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
During infection, pathogenic microbes adapt to the nutritional milieu of the host through metabolic reprogramming and nutrient scavenging. For the bacterial pathogen Staphylococcus aureus, virulence in diverse infection sites is driven by the ability to scavenge myriad host nutrients, including lipoic acid, a cofactor required for the function of several critical metabolic enzyme complexes. S. aureus shuttles lipoic acid between these enzyme complexes via the amidotransferase, LipL. Here, we find that acquisition of lipoic acid, or its attachment via LipL to enzyme complexes required for the generation of acetyl-CoA and branched-chain fatty acids, is essential for bacteremia, yet dispensable for skin infection in mice. A lipL mutant is auxotrophic for carboxylic acid precursors required for synthesis of branched-chain fatty acids, an essential component of staphylococcal membrane lipids and the agent of membrane fluidity. However, the skin is devoid of branched-chain fatty acids. We showed that S. aureus instead scavenges host-derived unsaturated fatty acids from the skin using the secreted lipase, Geh, and the unsaturated fatty acid-binding protein, FakB2. Moreover, murine infections demonstrated the relevance of host lipid assimilation to staphylococcal survival. Altogether, these studies provide insight into an adaptive trait that bypasses de novo lipid synthesis to facilitate S. aureus persistence during superficial infection. The findings also reinforce the inherent challenges associated with targeting bacterial lipogenesis as an antibacterial strategy and support simultaneous inhibition of host fatty acid salvage during treatment.
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11
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Krebs CF, Reimers D, Zhao Y, Paust HJ, Bartsch P, Nuñez S, Rosemblatt MV, Hellmig M, Kilian C, Borchers A, Enk LUB, Zinke M, Becker M, Schmid J, Klinge S, Wong MN, Puelles VG, Schmidt C, Bertram T, Stumpf N, Hoxha E, Meyer-Schwesinger C, Lindenmeyer MT, Cohen CD, Rink M, Kurts C, Franzenburg S, Koch-Nolte F, Turner JE, Riedel JH, Huber S, Gagliani N, Huber TB, Wiech T, Rohde H, Bono MR, Bonn S, Panzer U, Mittrücker HW. Pathogen-induced tissue-resident memory T H17 (T RM17) cells amplify autoimmune kidney disease. Sci Immunol 2020; 5:5/50/eaba4163. [PMID: 32769171 DOI: 10.1126/sciimmunol.aba4163] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Revised: 05/11/2020] [Accepted: 07/16/2020] [Indexed: 12/14/2022]
Abstract
Although it is well established that microbial infections predispose to autoimmune diseases, the underlying mechanisms remain poorly understood. After infection, tissue-resident memory T (TRM) cells persist in peripheral organs and provide immune protection against reinfection. However, whether TRM cells participate in responses unrelated to the primary infection, such as autoimmune inflammation, is unknown. By using high-dimensional single-cell analysis, we identified CD4+ TRM cells with a TH17 signature (termed TRM17 cells) in kidneys of patients with ANCA-associated glomerulonephritis. Experimental models demonstrated that renal TRM17 cells were induced by pathogens infecting the kidney, such as Staphylococcus aureus, Candida albicans, and uropathogenic Escherichia coli, and persisted after the clearance of infections. Upon induction of experimental glomerulonephritis, these kidney TRM17 cells rapidly responded to local proinflammatory cytokines by producing IL-17A and thereby exacerbate renal pathology. Thus, our data show that pathogen-induced TRM17 cells have a previously unrecognized function in aggravating autoimmune disease.
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Affiliation(s)
- Christian F Krebs
- III. Department of Medicine, Division of Translational Immunology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany. .,Hamburg Center for Translational Immunology (HCTI), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Daniel Reimers
- Institute for Immunology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Yu Zhao
- Institute of Medical Systems Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Hans-Joachim Paust
- III. Department of Medicine, Division of Translational Immunology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Patricia Bartsch
- III. Department of Medicine, Division of Translational Immunology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | | | | | - Malte Hellmig
- III. Department of Medicine, Division of Translational Immunology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Christoph Kilian
- III. Department of Medicine, Division of Translational Immunology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Alina Borchers
- III. Department of Medicine, Division of Translational Immunology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Leon U B Enk
- III. Department of Medicine, Division of Translational Immunology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Michael Zinke
- III. Department of Medicine, Division of Translational Immunology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Martina Becker
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Joanna Schmid
- Institute for Immunology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Stefanie Klinge
- Institute for Immunology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Milagros N Wong
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Victor G Puelles
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Department of Nephrology, Monash Health, and Center for Inflammatory Diseases, Monash University, Melbourne, VIC, Australia
| | - Constantin Schmidt
- Institute for Immunology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Tabea Bertram
- Institute for Immunology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Natascha Stumpf
- Institutes of Molecular Medicine and Experimental Immunology (IMMEI), Rheinische Friedrich-Wilhelms-Universität, Bonn, Germany
| | - Elion Hoxha
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Catherine Meyer-Schwesinger
- Institute for Cellular and Integrative Physiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Maja T Lindenmeyer
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Clemens D Cohen
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Nephrological Center, Medical Clinic and Policlinic IV, University of Munich, Munich, Germany
| | - Michael Rink
- Department of Urology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Christian Kurts
- Institutes of Molecular Medicine and Experimental Immunology (IMMEI), Rheinische Friedrich-Wilhelms-Universität, Bonn, Germany
| | - Sören Franzenburg
- Institute of Clinical Molecular Biology, Kiel University, Kiel, Germany
| | - Friedrich Koch-Nolte
- Hamburg Center for Translational Immunology (HCTI), University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Institute for Immunology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Jan-Eric Turner
- Hamburg Center for Translational Immunology (HCTI), University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Jan-Hendrik Riedel
- III. Department of Medicine, Division of Translational Immunology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Samuel Huber
- Hamburg Center for Translational Immunology (HCTI), University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,I. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Nicola Gagliani
- Hamburg Center for Translational Immunology (HCTI), University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,I. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Immunology and Allergy Unit, Department of Medicine, Solna, Karolinska Institute and University Hospital, 17176 Stockholm, Sweden
| | - Tobias B Huber
- Hamburg Center for Translational Immunology (HCTI), University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Thorsten Wiech
- Faculty of Medicine and Science, Universidad San Sebastian, Santiago, Chile
| | - Holger Rohde
- Institute for Medical Microbiology, Virology and Hygiene, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Maria Rosa Bono
- Department of Biology, Faculty of Sciences, Universidad de Chile, Santiago, Chile
| | - Stefan Bonn
- Hamburg Center for Translational Immunology (HCTI), University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Institute of Medical Systems Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,German Center for Neurodegenerative Diseases, Tübingen, Germany.,Center for Biomedical AI, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Ulf Panzer
- III. Department of Medicine, Division of Translational Immunology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Hamburg Center for Translational Immunology (HCTI), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Hans-Willi Mittrücker
- Hamburg Center for Translational Immunology (HCTI), University Medical Center Hamburg-Eppendorf, Hamburg, Germany. .,Institute for Immunology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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12
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Häffner N, Bär J, Dengler Haunreiter V, Mairpady Shambat S, Seidl K, Crosby HA, Horswill AR, Zinkernagel AS. Intracellular Environment and agr System Affect Colony Size Heterogeneity of Staphylococcus aureus. Front Microbiol 2020; 11:1415. [PMID: 32695082 PMCID: PMC7339952 DOI: 10.3389/fmicb.2020.01415] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2020] [Accepted: 06/02/2020] [Indexed: 12/21/2022] Open
Abstract
Staphylococcus aureus causes chronic and relapsing infections, which may be difficult to treat. So-called small colony variants (SCVs) have been associated with chronic infections and their occurrence has been shown to increase under antibiotic pressure, low pH and intracellular localization. In clinics, S. aureus isolated from invasive infections often show a dysfunction in the accessory gene regulator (agr), a major virulence regulatory system in S. aureus. To assess whether intracellular environment and agr function influence SCV formation, an infection model was established using lung epithelial cells and skin fibroblasts. This allowed analyzing intracellular survival and localization of a panel of S. aureus wild type strains and their isogenic agr knock out mutants as well as a natural dysfunctional agr strain by confocal laser scanning microscopy (CLSM). Furthermore, bacterial colonies were quantified after 1, 3, and 5 days of intracellular survival by time-lapse analysis to determine kinetics of colony appearance and SCV formation. Here, we show that S. aureus strains with an agr knock out predominantly resided in a neutral environment, whereas wild type strains and an agr complemented strain resided in an acidic environment. S. aureus agr mutants derived from an intracellular environment showed a higher percentage of SCVs as compared to their corresponding wild type strains. Neutralizing acidic phagolysosomes with chloroquine resulted in a significant reduction of SCVs in S. aureus wild type strain 6850, but not in its agr mutant indicating a pH dependent formation of SCVs in the wild type strain. The in-depth understanding of the interplay between intracellular persistence, agr function and pH should help to identify new therapeutic options facilitating the treatment of chronic S. aureus infections in the future.
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Affiliation(s)
- Nicola Häffner
- Department of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Julian Bär
- Department of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Vanina Dengler Haunreiter
- Department of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Srikanth Mairpady Shambat
- Department of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Kati Seidl
- Department of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Heidi A Crosby
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO, United States
| | - Alexander R Horswill
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO, United States.,Department of Veterans Affairs Eastern Colorado Health Care System, Denver, CO, United States
| | - Annelies S Zinkernagel
- Department of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
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13
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Kossakowska-Zwierucho M, Szewczyk G, Sarna T, Nakonieczna J. Farnesol potentiates photodynamic inactivation of Staphylococcus aureus with the use of red light-activated porphyrin TMPyP. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2020; 206:111863. [PMID: 32224392 DOI: 10.1016/j.jphotobiol.2020.111863] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 02/11/2020] [Accepted: 03/19/2020] [Indexed: 02/06/2023]
Abstract
Photodynamic inactivation (PDI) or antibacterial photodynamic therapy (aPDT) is a method based on the use of a photosensitizer, light of a proper wavelength and oxygen, which combined together leads to an oxidative stress and killing of target cells. PDI can be applied towards various pathogenic bacteria independently on their antibiotic resistance profile. Optimization of photodynamic treatment to eradicate the widest range of human pathogens remains challenging despite the availability of numerous photosensitizing compounds. Therefore, a search for molecules that could act as adjuvants potentiating antibacterial photoinactivation is of high scientific and clinical importance. Here we propose farnesol (FRN), a well described sesquiterpene, as a potent adjuvant of PDI, which specifically sensitizes Staphylococcus aureus to 5,10,15,20-tetrakis(1-methylpyridinium-4-yl)porphyrin tetratosylate (TMPyP) upon red light irradiation. Interestingly, the observed potentiation strongly depends on the presence of light. Analysis of this combined action of FRN and TMPyP, however, showed no influence of farnesol on TMPyP photochemical properties, i.e. the amount of reactive oxygen species that were produced by TMPyP in the presence of FRN. The accumulation rate of TMPyP in Staphylococcus aureus cells did not change, as well as the influence of staphyloxanthin inhibition. The precise mechanism of observed sensitization is unclear and probably involves specific molecular targets.
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Affiliation(s)
- Monika Kossakowska-Zwierucho
- Laboratory of Molecular Diagnostics, Intercollegiate Faculty of Biotechnology University of Gdansk and Medical University of Gdansk, Gdansk, Poland
| | - Grzegorz Szewczyk
- Department of Biophysics, Faculty of Biotechnology, Jagiellonian University, Krakow, Poland
| | - Tadeusz Sarna
- Department of Biophysics, Faculty of Biotechnology, Jagiellonian University, Krakow, Poland
| | - Joanna Nakonieczna
- Laboratory of Molecular Diagnostics, Intercollegiate Faculty of Biotechnology University of Gdansk and Medical University of Gdansk, Gdansk, Poland.
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14
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Lattwein KR, Shekhar H, Kouijzer JJP, van Wamel WJB, Holland CK, Kooiman K. Sonobactericide: An Emerging Treatment Strategy for Bacterial Infections. ULTRASOUND IN MEDICINE & BIOLOGY 2020; 46:193-215. [PMID: 31699550 PMCID: PMC9278652 DOI: 10.1016/j.ultrasmedbio.2019.09.011] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 09/03/2019] [Accepted: 09/16/2019] [Indexed: 05/04/2023]
Abstract
Ultrasound has been developed as both a diagnostic tool and a potent promoter of beneficial bio-effects for the treatment of chronic bacterial infections. Bacterial infections, especially those involving biofilm on implants, indwelling catheters and heart valves, affect millions of people each year, and many deaths occur as a consequence. Exposure of microbubbles or droplets to ultrasound can directly affect bacteria and enhance the efficacy of antibiotics or other therapeutics, which we have termed sonobactericide. This review summarizes investigations that have provided evidence for ultrasound-activated microbubble or droplet treatment of bacteria and biofilm. In particular, we review the types of bacteria and therapeutics used for treatment and the in vitro and pre-clinical experimental setups employed in sonobactericide research. Mechanisms for ultrasound enhancement of sonobactericide, with a special emphasis on acoustic cavitation and radiation force, are reviewed, and the potential for clinical translation is discussed.
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Affiliation(s)
- Kirby R Lattwein
- Department of Biomedical Engineering, Thoraxcenter, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands.
| | - Himanshu Shekhar
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, University of Cincinnati, Cincinnati, Ohio, USA
| | - Joop J P Kouijzer
- Department of Biomedical Engineering, Thoraxcenter, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Willem J B van Wamel
- Department of Medical Microbiology and Infectious Diseases, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Christy K Holland
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, University of Cincinnati, Cincinnati, Ohio, USA
| | - Klazina Kooiman
- Department of Biomedical Engineering, Thoraxcenter, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
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15
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Roch M, Lelong E, Panasenko OO, Sierra R, Renzoni A, Kelley WL. Thermosensitive PBP2a requires extracellular folding factors PrsA and HtrA1 for Staphylococcus aureus MRSA β-lactam resistance. Commun Biol 2019; 2:417. [PMID: 31754647 PMCID: PMC6858329 DOI: 10.1038/s42003-019-0667-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 10/25/2019] [Indexed: 12/21/2022] Open
Abstract
Staphylococcus aureus is a major human pathogen and represents a clinical challenge because of widespread antibiotic resistance. Methicillin resistant Staphylococcus aureus (MRSA) is particularly problematic and originates by the horizontal acquisition of mecA encoding PBP2a, an extracellular membrane anchored transpeptidase, which confers resistance to β-lactam antibiotics by allosteric gating of its active site channel. Herein, we show that dual disruption of PrsA, a lipoprotein chaperone displaying anti-aggregation activity, together with HtrA1, a membrane anchored chaperone/serine protease, resulted in severe and synergistic attenuation of PBP2a folding that restores sensitivity to β-lactams such as oxacillin. Purified PBP2a has a pronounced unfolding transition initiating at physiological temperatures that leads to irreversible precipitation and complete loss of activity. The concordance of genetic and biochemical data highlights the necessity for extracellular protein folding factors governing MRSA β-lactam resistance. Targeting the PBP2a folding pathway represents a particularly attractive adjuvant strategy to combat antibiotic resistance.
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Affiliation(s)
- Mélanie Roch
- Department of Microbiology and Molecular Medicine, University Hospital and Medical School of Geneva, 1 rue Michel-Servet, Geneva, CH-1211 Switzerland
| | - Emmanuelle Lelong
- Service of Infectious Diseases and Department of Medical Specialties, University Hospital and Medical School of Geneva, 4 rue Gabrielle-Perret-Gentil, Geneva, CH-1206 Switzerland
| | - Olesya O. Panasenko
- Department of Microbiology and Molecular Medicine, University Hospital and Medical School of Geneva, 1 rue Michel-Servet, Geneva, CH-1211 Switzerland
- Service of Infectious Diseases and Department of Medical Specialties, University Hospital and Medical School of Geneva, 4 rue Gabrielle-Perret-Gentil, Geneva, CH-1206 Switzerland
| | - Roberto Sierra
- Department of Microbiology and Molecular Medicine, University Hospital and Medical School of Geneva, 1 rue Michel-Servet, Geneva, CH-1211 Switzerland
| | - Adriana Renzoni
- Service of Infectious Diseases and Department of Medical Specialties, University Hospital and Medical School of Geneva, 4 rue Gabrielle-Perret-Gentil, Geneva, CH-1206 Switzerland
| | - William L. Kelley
- Department of Microbiology and Molecular Medicine, University Hospital and Medical School of Geneva, 1 rue Michel-Servet, Geneva, CH-1211 Switzerland
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16
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Limoli DH, Warren EA, Yarrington KD, Donegan NP, Cheung AL, O'Toole GA. Interspecies interactions induce exploratory motility in Pseudomonas aeruginosa. eLife 2019; 8:47365. [PMID: 31713513 PMCID: PMC6910820 DOI: 10.7554/elife.47365] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Accepted: 10/30/2019] [Indexed: 11/13/2022] Open
Abstract
Microbes often live in multispecies communities where interactions among community members impact both the individual constituents and the surrounding environment. Here, we developed a system to visualize interspecies behaviors at initial encounters. By imaging two prevalent pathogens known to be coisolated from chronic illnesses, Pseudomonas aeruginosa and Staphylococcus aureus, we observed P. aeruginosa can modify surface motility in response to secreted factors from S. aureus. Upon sensing S. aureus, P. aeruginosa transitioned from collective to single-cell motility with an associated increase in speed and directedness – a behavior we refer to as ‘exploratory motility’. Explorer cells moved preferentially towards S. aureus and invaded S. aureus colonies through the action of the type IV pili. These studies reveal previously undescribed motility behaviors and lend insight into how P. aeruginosa senses and responds to other species. Identifying strategies to harness these interactions may open avenues for new antimicrobial strategies.
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Affiliation(s)
- Dominique H Limoli
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, United States.,Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, United States
| | - Elizabeth A Warren
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, United States
| | - Kaitlin D Yarrington
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, United States
| | - Niles P Donegan
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, United States
| | - Ambrose L Cheung
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, United States
| | - George A O'Toole
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, United States
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17
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Staphylococcus aureus small colony variants impair host immunity by activating host cell glycolysis and inducing necroptosis. Nat Microbiol 2019; 5:141-153. [PMID: 31686028 PMCID: PMC10184863 DOI: 10.1038/s41564-019-0597-0] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 09/19/2019] [Indexed: 01/29/2023]
Abstract
Staphylococcus aureus small colony variants (SCVs) are frequently associated with chronic infection, yet they lack expression of many virulence determinants associated with the pathogenicity of wild-type strains. We found that both wild-type S. aureus and a ΔhemB SCV prototype potently activate glycolysis in host cells. Glycolysis and the generation of mitochondrial reactive oxygen species were sufficient to induce necroptosis, a caspase-independent mechanism of host cell death that failed to eradicate S. aureus and instead promoted ΔhemB SCV pathogenicity. To support ongoing glycolytic activity, the ΔhemB SCV induced over a 100-fold increase in the expression of fumC, which encodes an enzyme that catalyses the degradatin of fumarate, an inhibitor of glycolysis. Consistent with fumC-dependent depletion of local fumarate, the ΔhemB SCV failed to elicit trained immunity and protection from a secondary infectious challenge in the skin. The reliance of the S. aureus SCV population on glycolysis accounts for much of its role in the pathogenesis of S. aureus skin infection.
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18
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Astley R, Miller FC, Mursalin MH, Coburn PS, Callegan MC. An Eye on Staphylococcus aureus Toxins: Roles in Ocular Damage and Inflammation. Toxins (Basel) 2019; 11:E356. [PMID: 31248125 PMCID: PMC6628431 DOI: 10.3390/toxins11060356] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 06/13/2019] [Accepted: 06/15/2019] [Indexed: 12/12/2022] Open
Abstract
Staphylococcus aureus (S. aureus) is a common pathogen of the eye, capable of infecting external tissues such as the tear duct, conjunctiva, and the cornea, as well the inner and more delicate anterior and posterior chambers. S. aureus produces numerous toxins and enzymes capable of causing profound damage to tissues and organs, as well as modulating the immune response to these infections. Unfortunately, in the context of ocular infections, this can mean blindness for the patient. The role of α-toxin in corneal infection (keratitis) and infection of the interior of the eye (endophthalmitis) has been well established by comparing virulence in animal models and α-toxin-deficient isogenic mutants with their wild-type parental strains. The importance of other toxins, such as β-toxin, γ-toxin, and Panton-Valentine leukocidin (PVL), have been analyzed to a lesser degree and their roles in eye infections are less clear. Other toxins such as the phenol-soluble modulins have yet to be examined in any animal models for their contributions to virulence in eye infections. This review discusses the state of current knowledge of the roles of S. aureus toxins in eye infections and the controversies existing as a result of the use of different infection models. The strengths and limitations of these ocular infection models are discussed, as well as the need for physiological relevance in the study of staphylococcal toxins in these models.
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Affiliation(s)
- Roger Astley
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
| | - Frederick C Miller
- Department of Cell Biology and Department of Family and Preventive Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
| | - Md Huzzatul Mursalin
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
| | - Phillip S Coburn
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
| | - Michelle C Callegan
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
- Dean McGee Eye Institute, 608 Stanton L. Young Blvd., DMEI PA-418, Oklahoma City, OK 73104, USA.
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19
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Lerche CJ, Christophersen LJ, Goetze JP, Nielsen PR, Thomsen K, Enevold C, Høiby N, Jensen PØ, Bundgaard H, Moser C. Adjunctive dabigatran therapy improves outcome of experimental left-sided Staphylococcus aureus endocarditis. PLoS One 2019; 14:e0215333. [PMID: 31002679 PMCID: PMC6474597 DOI: 10.1371/journal.pone.0215333] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 03/29/2019] [Indexed: 12/13/2022] Open
Abstract
Background Staphylococcus aureus is the most frequent and fatal cause of left-sided infective endocarditis (IE). New treatment strategies are needed to improve the outcome. S. aureus coagulase promotes clot and fibrin formation. We hypothesized that dabigatran, could reduce valve vegetations and inflammation in S. aureus IE. Methods We used a rat model of severe aortic valve S. aureus IE. All infected animals were randomized to receive adjunctive dabigatran (10 mg/kg b.i.d., n = 12) or saline (controls, n = 11) in combination with gentamicin. Valve vegetation size, bacterial load, cytokine, cell integrins expression and peripheral platelets and neutrophils were assessed 3 days post-infection. Results Adjunctive dabigatran treatment significantly reduced valve vegetation size compared to controls (p< 0.0001). A significant reduction of the bacterial load in aortic valves was seen in dabigatran group compared to controls (p = 0.02), as well as expression of key pro-inflammatory markers keratinocyte-derived chemokine, IL-6, ICAM-1, TIMP-1, L-selectin (p< 0.04). Moreover, the dabigatran group had a 2.5-fold increase of circulating platelets compared to controls and a higher expression of functional and activated platelets (CD62p+) unbound to neutrophils. Conclusion Adjunctive dabigatran reduced the vegetation size, bacterial load, and inflammation in experimental S. aureus IE.
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Affiliation(s)
- Christian J. Lerche
- Department of Clinical Microbiology, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
- Institute of Immunology and Microbiology, University of Copenhagen, Denmark
- * E-mail:
| | - Lars J. Christophersen
- Department of Clinical Microbiology, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Jens Peter Goetze
- Department of Clinical Biochemistry, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Pia R. Nielsen
- Department of Pathology, Zealand University Hospital, Roskilde, Denmark
| | - Kim Thomsen
- Department of Clinical Microbiology, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Christian Enevold
- Institute for Inflammation Research, Department of Rheumatology and Spine Disease, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Niels Høiby
- Department of Clinical Microbiology, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
- Institute of Immunology and Microbiology, University of Copenhagen, Denmark
| | - Peter Ø. Jensen
- Department of Clinical Microbiology, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
- Institute of Immunology and Microbiology, University of Copenhagen, Denmark
- Institute for Inflammation Research, Department of Rheumatology and Spine Disease, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Henning Bundgaard
- Department of Cardiology, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Claus Moser
- Department of Clinical Microbiology, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
- Institute of Immunology and Microbiology, University of Copenhagen, Denmark
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20
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Andreoni F, Toyofuku M, Menzi C, Kalawong R, Mairpady Shambat S, François P, Zinkernagel AS, Eberl L. Antibiotics Stimulate Formation of Vesicles in Staphylococcus aureus in both Phage-Dependent and -Independent Fashions and via Different Routes. Antimicrob Agents Chemother 2019; 63:e01439-18. [PMID: 30509943 PMCID: PMC6355553 DOI: 10.1128/aac.01439-18] [Citation(s) in RCA: 79] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 11/18/2018] [Indexed: 12/29/2022] Open
Abstract
Bacterial membrane vesicle research has so far focused mainly on Gram-negative bacteria. Only recently have Gram-positive bacteria been demonstrated to produce and release extracellular membrane vesicles (MVs) that contribute to bacterial virulence. Although treatment of bacteria with antibiotics is a well-established trigger of bacterial MV formation, the underlying mechanisms are poorly understood. In this study, we show that antibiotics can induce MVs through different routes in the important human pathogen Staphylococcus aureus DNA-damaging agents and antibiotics inducing the SOS response triggered vesicle formation in lysogenic strains of S. aureus but not in their phage-devoid counterparts. The β-lactam antibiotics flucloxacillin and ceftaroline increased vesicle formation in a prophage-independent manner by weakening the peptidoglycan layer. We present evidence that the amount of DNA associated with MVs formed by phage lysis is greater than that for MVs formed by β-lactam antibiotic-induced blebbing. The purified MVs derived from S. aureus protected the bacteria from challenge with daptomycin, a membrane-targeting antibiotic, both in vitro and ex vivo in whole blood. In addition, the MVs protected S. aureus from killing in whole blood, indicating that antibiotic-induced MVs function as a decoy and thereby contribute to the survival of the bacterium.
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Affiliation(s)
- Federica Andreoni
- Division of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Masanori Toyofuku
- Department of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Carmen Menzi
- Division of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Ratchara Kalawong
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Srikanth Mairpady Shambat
- Division of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Patrice François
- Laboratoire de Recherche Génomique, Service des Maladies Infectieuses, Centre Médical Universitaire, Geneva, Switzerland
| | - Annelies S Zinkernagel
- Division of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Leo Eberl
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
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21
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Thermal and Nutritional Regulation of Ribosome Hibernation in Staphylococcus aureus. J Bacteriol 2018; 200:JB.00426-18. [PMID: 30297357 PMCID: PMC6256015 DOI: 10.1128/jb.00426-18] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2018] [Accepted: 09/25/2018] [Indexed: 12/13/2022] Open
Abstract
The dimerization of 70S ribosomes (100S complex) plays an important role in translational regulation and infectivity of the major human pathogen Staphylococcus aureus. Although the dimerizing factor HPF has been characterized biochemically, the pathways that regulate 100S ribosome abundance remain elusive. We identified a metabolite- and nutrient-sensing transcription factor, CodY, that serves both as an activator and a repressor of hpf expression in nutrient- and temperature-dependent manners. Furthermore, CodY-mediated activation of hpf masks a secondary hpf transcript derived from a general stress response SigB promoter. CodY and SigB regulate a repertoire of virulence genes. The unexpected link between ribosome homeostasis and the two master virulence regulators provides new opportunities for alternative druggable sites. The translationally silent 100S ribosome is a poorly understood form of the dimeric 70S complex that is ubiquitously found in all bacterial phyla. The elimination of the hibernating 100S ribosome leads to translational derepression, ribosome instability, antibiotic sensitivity, and biofilm defects in some bacteria. In Firmicutes, such as the opportunistic pathogen Staphylococcus aureus, a 190-amino acid protein called hibernating-promoting factor (HPF) dimerizes and conjoins two 70S ribosomes through a direct interaction between the HPF homodimer, with each HPF monomer tethered on an individual 70S complex. While the formation of the 100S ribosome in gammaproteobacteria and cyanobacteria is exclusively induced during postexponential growth phase and darkness, respectively, the 100S ribosomes in Firmicutes are constitutively produced from the lag-logarithmic phase through the post-stationary phase. Very little is known about the regulatory pathways that control hpf expression and 100S ribosome abundance. Here, we show that a general stress response (GSR) sigma factor (SigB) and a GTP-sensing transcription factor (CodY) integrate nutrient and thermal signals to regulate hpf synthesis in S. aureus, resulting in an enhanced virulence of the pathogen in a mouse model of septicemic infection. CodY-dependent regulation of hpf is strain specific. An epistasis analysis further demonstrated that CodY functions upstream of the GSR pathway in a condition-dependent manner. The results reveal an important link between S. aureus stress physiology, ribosome metabolism, and infection biology. IMPORTANCE The dimerization of 70S ribosomes (100S complex) plays an important role in translational regulation and infectivity of the major human pathogen Staphylococcus aureus. Although the dimerizing factor HPF has been characterized biochemically, the pathways that regulate 100S ribosome abundance remain elusive. We identified a metabolite- and nutrient-sensing transcription factor, CodY, that serves both as an activator and a repressor of hpf expression in nutrient- and temperature-dependent manners. Furthermore, CodY-mediated activation of hpf masks a secondary hpf transcript derived from a general stress response SigB promoter. CodY and SigB regulate a repertoire of virulence genes. The unexpected link between ribosome homeostasis and the two master virulence regulators provides new opportunities for alternative druggable sites.
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22
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Wenzel M, Vischer NOE, Strahl H, Hamoen LW. Assessing Membrane Fluidity and Visualizing Fluid Membrane Domains in Bacteria Using Fluorescent Membrane Dyes. Bio Protoc 2018; 8:e3063. [PMID: 34532528 DOI: 10.21769/bioprotoc.3063] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Revised: 10/06/2018] [Accepted: 10/29/2018] [Indexed: 11/02/2022] Open
Abstract
Membrane fluidity is a key parameter of bacterial membranes that undergoes quick adaptation in response to environmental challenges and has recently emerged as an important factor in the antibacterial mechanism of membrane-targeting antibiotics. The specific level of membrane fluidity is not uniform across the bacterial cell membrane. Rather, specialized microdomains associated with different cellular functions can exhibit fluidity values that significantly deviate from the average. Assessing changes in the overall membrane fluidity and formation of membrane microdomains is therefore pivotal to understand both the functional organization of the bacterial cell membrane as well as antibiotic mechanisms. Here we describe how two fluorescent membrane dyes, laurdan and DiIC12, can be employed to assess membrane fluidity in living bacteria. We focus on Bacillus subtilis, since this organism has been relatively well-studied with respect to membrane domains. However, we also describe how these assays can be adapted for other bacteria such as Staphylococcus aureus and Streptococcus pneumoniae.
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Affiliation(s)
- Michaela Wenzel
- Bacterial Cell Biology, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands.,Department of Medical Microbiology and Infection Control, Amsterdam University Medical Centers, Location VUMC, Amsterdam, The Netherlands
| | - Norbert O E Vischer
- Bacterial Cell Biology, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands
| | - Henrik Strahl
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Leendert W Hamoen
- Bacterial Cell Biology, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands
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Genomics of experimental adaptation of Staphylococcus aureus to a natural combination of insect antimicrobial peptides. Sci Rep 2018; 8:15359. [PMID: 30337550 PMCID: PMC6193990 DOI: 10.1038/s41598-018-33593-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 08/29/2018] [Indexed: 12/25/2022] Open
Abstract
Antimicrobial peptides (AMP) are highly conserved immune effectors across the tree of life and are employed as combinations. In the beetle Tenebrio molitor, a defensin and a coleoptericin are highly expressed in vivo after inoculation with S. aureus. The defensin displays strong in vitro activity but no survival benefit in vivo. The coleoptericin provides a survival benefit in vivo, but no activity in vitro. This suggests a potentiating effect in vivo, and here we wanted to investigate the effects of this combination on resistance evolution using a bottom-approach in vitro starting with a combination of two abundant AMPs only. We experimentally evolved S. aureus in the presence of the defensin and a combination of the defensin and coleoptericin. Genome re-sequencing showed that resistance was associated with mutations in either the pmt or nsa operons. Strains with these mutations show longer lag phases, slower Vmax, and nsa mutants reach lower final population sizes. Mutations in the rpo operon showed a further increase in the lag phase in nsa mutants but not in pmt mutants. In contrast, final MICs (minimum inhibitory concentrations) do not differ according to mutation. All resistant lines display AMP but not antibiotic cross-resistance. Costly resistance against AMPs readily evolves for an individual AMP as well as a naturally occurring combination in vitro and provides broad protection against AMPs. Such non-specific resistance could result in strong selection on host immune systems that rely on cocktails of AMPs.
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Stoll H, Ost M, Singh A, Mehling R, Neri D, Schäfer I, Velic A, Macek B, Kretschmer D, Weidenmaier C, Hector A, Handgretinger R, Götz F, Peschel A, Hartl D, Rieber N. Staphylococcal Enterotoxins Dose-Dependently Modulate the Generation of Myeloid-Derived Suppressor Cells. Front Cell Infect Microbiol 2018; 8:321. [PMID: 30271756 PMCID: PMC6146041 DOI: 10.3389/fcimb.2018.00321] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Accepted: 08/22/2018] [Indexed: 11/13/2022] Open
Abstract
Staphylococcus aureus is one of the major human bacterial pathogens causing a broad spectrum of serious infections. Myeloid-derived suppressor cells (MDSC) represent an innate immune cell subset capable of regulating host-pathogen interactions, yet their role in the pathogenesis of S. aureus infections remains incompletely defined. The aim of this study was to determine the influence of different S. aureus strains and associated virulence factors on human MDSC generation. Using an in vitro MDSC generation assay we demonstrate that low concentrations of supernatants of different S. aureus strains led to an induction of functional MDSC, whereas increased concentrations, conversely, reduced MDSC numbers. The concentration-dependent reduction of MDSC correlated with T cell proliferation and cytotoxicity. Several findings supported a role for staphylococcal enterotoxins in modulating MDSC generation. Staphylococcal enterotoxins recapitulated concentration-dependent MDSC induction and inhibition, T cell proliferation and cytotoxicity, while an enterotoxin-deficient S. aureus strain largely failed to alter MDSC. Taken together, we identified staphylococcal enterotoxins as main modulators of MDSC generation. The inhibition of MDSC generation by staphylococcal enterotoxins might represent a novel therapeutic target in S. aureus infections and beyond in non-infectious conditions, such as cancer.
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Affiliation(s)
- Hartmut Stoll
- Department of Pediatrics I, University of Tuebingen, Tuebingen, Germany
| | - Michael Ost
- Department of Pediatrics I, University of Tuebingen, Tuebingen, Germany
| | - Anurag Singh
- Department of Pediatrics I, University of Tuebingen, Tuebingen, Germany
| | - Roman Mehling
- Department of Pediatrics I, University of Tuebingen, Tuebingen, Germany
| | - Davide Neri
- Department of Pediatrics I, University of Tuebingen, Tuebingen, Germany
| | - Iris Schäfer
- Department of Pediatrics I, University of Tuebingen, Tuebingen, Germany
| | - Ana Velic
- Proteome Center Tuebingen, Interfaculty Institute for Cell Biology, University of Tuebingen, Tuebingen, Germany
| | - Boris Macek
- Proteome Center Tuebingen, Interfaculty Institute for Cell Biology, University of Tuebingen, Tuebingen, Germany
| | - Dorothee Kretschmer
- Interfaculty Institute of Microbiology and Infection Medicine, University of Tuebingen, Tuebingen, Germany
| | - Christopher Weidenmaier
- Interfaculty Institute of Microbiology and Infection Medicine, University of Tuebingen, Tuebingen, Germany
| | - Andreas Hector
- Department of Pediatrics I, University of Tuebingen, Tuebingen, Germany
| | | | - Friedrich Götz
- Interfaculty Institute of Microbiology and Infection Medicine, University of Tuebingen, Tuebingen, Germany
| | - Andreas Peschel
- Interfaculty Institute of Microbiology and Infection Medicine, University of Tuebingen, Tuebingen, Germany.,German Centre for Infection Research (DZIF), Partner Site Tuebingen, Tuebingen, Germany
| | - Dominik Hartl
- Department of Pediatrics I, University of Tuebingen, Tuebingen, Germany.,German Centre for Infection Research (DZIF), Partner Site Tuebingen, Tuebingen, Germany
| | - Nikolaus Rieber
- Department of Pediatrics I, University of Tuebingen, Tuebingen, Germany.,German Centre for Infection Research (DZIF), Partner Site Tuebingen, Tuebingen, Germany.,Department of Pediatrics, Kinderklinik Muenchen Schwabing, Klinikum Schwabing, StKM GmbH und Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
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McCallin S, Sarker SA, Sultana S, Oechslin F, Brüssow H. Metagenome analysis of Russian and Georgian Pyophage cocktails and a placebo-controlled safety trial of single phage versus phage cocktail in healthy Staphylococcus aureus carriers. Environ Microbiol 2018; 20:3278-3293. [PMID: 30051571 DOI: 10.1111/1462-2920.14310] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 06/11/2018] [Indexed: 01/30/2023]
Abstract
Bacteriophage therapy is a commonly used treatment for Staphylococcus aureus infections in countries of the former Soviet Union, using both single phages and phage cocktails. The scarce data available on Eastern phage cocktails prompted an investigation into commercially-available Pyophage cocktails from two different manufacturers used to treat skin and wound infections. Comparison of the metagenomic composition of two Pyophage products from Georgia and Russia revealed substantial differences in phage-types targeting Escherichia, Enterococcus, Salmonella, Pseudomonas aeruginosa and Proteus, therefore indicating multiple strategies for composing phage cocktails against these bacterial pathogens. Closely-related Kayvirus-like Myoviruses were, however, a shared component against S. aureus within all products, except for the inclusion of a secondary S. aureus Podovirus in one Microgen cocktail. Metagenomic analysis also revealed the presence of several probable prophage sequences but detected no genetic safety risks in terms of virulence factors or antibiotic resistance genes. The safety of broad-spectrum cocktails was tested by comparing the effects of nasal and oral exposure to Eliava Pyophage, a monospecies counterpart and placebo in healthy human carriers of S. aureus. The lack of adverse effects in any treatment groups supports the clinical safety of S. aureus phages administered as a single phage or as phage cocktail.
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Affiliation(s)
- Shawna McCallin
- Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland
| | - Shafiqul A Sarker
- International Centre for Diarrhoeal Diseases Research, Bangladesh (icddr,b), Dhaka, Bangladesh
| | - Shamima Sultana
- International Centre for Diarrhoeal Diseases Research, Bangladesh (icddr,b), Dhaka, Bangladesh
| | - Frank Oechslin
- Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland
| | - Harald Brüssow
- Laboratory of Gene Technology, Department of Biosystems, KU Leuven, Leuven, Belgium
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MntC-Dependent Manganese Transport Is Essential for Staphylococcus aureus Oxidative Stress Resistance and Virulence. mSphere 2018; 3:3/4/e00336-18. [PMID: 30021878 PMCID: PMC6052334 DOI: 10.1128/msphere.00336-18] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Work outlined in this report demonstrated that MntC-dependent manganese transport is required for S. aureus virulence. These study results support the model that MntC-specific antibodies elicited by a vaccine have the potential to disrupt S. aureus manganese transport and thus abrogate to its virulence. Staphylococcus aureus is a human pathogen that has developed several approaches to evade the immune system, including a strategy to resist oxidative killing by phagocytes. This resistance is mediated by production of superoxide dismutase (SOD) enzymes which use manganese as a cofactor. S. aureus encodes two manganese ion transporters, MntABC and MntH, and a possible Nramp family manganese transporter, exemplified by S. aureus N315 SA1432. Their relative contributions to manganese transport have not been well defined in clinically relevant isolates. For this purpose, insertional inactivation mutations were introduced into mntC, mntH, and SA1432 individually and in combination. mntC was necessary for full resistance to methyl viologen, a compound that generates intracellular free radicals. In contrast, strains with an intact mntH gene had a minimal increase in resistance that was revealed only in mntC strains, and no change was observed upon mutation of SA1432 in strains lacking both mntC and mntH. Similarly, MntC alone was required for high cellular SOD activity. In addition, mntC strains were attenuated in a murine sepsis model. To further link these observations to manganese transport, an S. aureus MntC protein lacking manganese binding activity was designed, expressed, and purified. While circular dichroism experiments demonstrated that the secondary and tertiary structures of this protein were unaltered, a defect in manganese binding was confirmed by isothermal titration calorimetry. Unlike complementation with wild-type mntC, introduction of the manganese-binding defective allele into the chromosome of an mntC strain did not restore resistance to oxidative stress or virulence. Collectively, these results underscore the importance of MntC-dependent manganese transport in S. aureus oxidative stress resistance and virulence. IMPORTANCE Work outlined in this report demonstrated that MntC-dependent manganese transport is required for S. aureus virulence. These study results support the model that MntC-specific antibodies elicited by a vaccine have the potential to disrupt S. aureus manganese transport and thus abrogate to its virulence.
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27
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Chung M, Borges V, Gomes JP, de Lencastre H, Tomasz A. Phenotypic signatures and genetic determinants of oxacillin tolerance in a laboratory mutant of Staphylococcus aureus. PLoS One 2018; 13:e0199707. [PMID: 29969476 PMCID: PMC6029783 DOI: 10.1371/journal.pone.0199707] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Accepted: 06/12/2018] [Indexed: 11/18/2022] Open
Abstract
Addition of β-lactam antibiotics to growing cultures of bacteria inhibit synthesis of the bacterial cell wall peptidoglycan accompanied by killing (loss of viable titer) and lysis (physical disintegration) of the cells. However, it has also been well established that these antibiotics are not effective in killing non-growing or slow-growing bacteria and the mechanism of this "antibiotic tolerance" is not well understood. In this study, we report on the genetic basis and phenotypic properties of an antibiotic tolerant derivative of the methicillin susceptible S. aureus strain 27s. Cultures were exposed to "pulses" of high concentrations of oxacillin followed by outgrowth of the surviving bacteria. This procedure quickly selected for antibiotic tolerant mutants with an increased ability to survive antibiotic treatment without increase in the MIC value for the antibiotic. Such mutants also exhibited longer lag phase, decreased lysis, virtually no change in antibiotic susceptibilities, cross tolerance to D-cycloserine and vancomycin, and increase in biofilm formation in the presence of high concentrations of oxacillin. Whole genome sequencing showed that these altered properties were linked to mutations in the atl and gdpP genes.
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Affiliation(s)
- Marilyn Chung
- Laboratory of Microbiology & Infectious Diseases, The Rockefeller University, New York, New York, United States of America
| | - Vitor Borges
- Bioinformatics Unit, Department of Infectious Diseases, National Institute of Health, Lisboa, Portugal
| | - João Paulo Gomes
- Bioinformatics Unit, Department of Infectious Diseases, National Institute of Health, Lisboa, Portugal
| | - Herminia de Lencastre
- Laboratory of Molecular Genetics, Instituto de Tecnologia Química e Biológica António Xavier (ITQB) da Universidade Nova de Lisboa, Oeiras, Portugal
| | - Alexander Tomasz
- Laboratory of Microbiology & Infectious Diseases, The Rockefeller University, New York, New York, United States of America
- * E-mail:
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28
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Whole-Genome Sequencing and Genetic Analysis Reveal Novel Stress Responses to Individual Constituents of Essential Oils in Escherichia coli. Appl Environ Microbiol 2018; 84:AEM.02538-17. [PMID: 29374037 DOI: 10.1128/aem.02538-17] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Accepted: 01/21/2018] [Indexed: 11/20/2022] Open
Abstract
Food preservation by the use of essential oils (EOs) is being extensively studied because of the antimicrobial properties of their individual constituents (ICs). Three resistant mutants (termed CAR, CIT, and LIM) of Escherichia coli MG1655 were selected by subculturing with the ICs carvacrol, citral, and (+)-limonene oxide, respectively. These derivative strains showed increased MIC values of ICs and concomitantly enhanced resistance to various antibiotics (ampicillin, trimethoprim, chloramphenicol, tetracycline, kanamycin, novobiocin, norfloxacin, cephalexin, and nalidixic acid) compared to those for the parental strain (wild type [WT]). Whole-genome sequencing (WGS) of these hyperresistant strains permitted the identification of single nucleotide polymorphisms (SNPs) and deletions in comparison to the WT. In order to analyze the contribution of these mutations to the increased antimicrobial resistance detected in hyperresistant strains, derivative strains were constructed by allelic reversion. A role of the SoxR D137Y missense mutation in CAR was confirmed by growth in the presence of some ICs and antibiotics and by its tolerance to ICs but not to lethal heat treatments. In CIT, increased resistance relied on contributions by several detected SNPs, resulting in a frameshift in MarR and an in-frame GyrB ΔG157 mutation. Finally, both the insertion resulting in an AcrR frameshift and large chromosomal deletions found in LIM were correlated with the hyperresistant phenotype of this strain. The nature of the obtained mutants suggests intriguing links to cellular defense mechanisms previously implicated in antibiotic resistance.IMPORTANCE The antimicrobial efficacy of ICs has been proven over the years, together with their potential to improve traditional heat treatments by reducing treatment intensity and, consequently, adverse effects on food quality. However, the mechanisms of bacterial inactivation by ICs are still not well understood, in contrast to antibiotics. We performed WGS of three E. coli strains that are hyperresistant to ICs. The information provided detailed insight into the mechanisms of bacterial resistance arising from exposure to carvacrol, citral, and (+)-limonene oxide. Future experiments will undoubtedly yield additional insights into genes and pathways contributing to the acquisition of endogenous resistance to ICs.
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29
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Kang MS, Lim HS, Oh JS, Lim YJ, Wuertz-Kozak K, Harro JM, Shirtliff ME, Achermann Y. Antimicrobial activity of Lactobacillus salivarius and Lactobacillus fermentum against Staphylococcus aureus. Pathog Dis 2017; 75:2966468. [DOI: 10.1093/femspd/ftx009] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Accepted: 01/25/2017] [Indexed: 12/20/2022] Open
Affiliation(s)
- Mi-Sun Kang
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland-Baltimore, Baltimore, 21201 MD, USA
- Oradentics Research Institute, Seoul 06157, South Korea
| | - Hae-Soon Lim
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland-Baltimore, Baltimore, 21201 MD, USA
- Dental Science Research Institute, Chonnam National University, Gwangju 61186, South Korea
- Department of Dental Education, School of Dentistry, Chonnam National University, Gwangju 61186, South Korea
| | - Jong-Suk Oh
- Department of Microbiology, School of Medicine, Chonnam National University, Gwangju 61469, South Korea
| | - You-jin Lim
- Department of Nursing, Gwangju Health University, Gwangju 62287, South Korea
| | - Karin Wuertz-Kozak
- Institute for Biomechanics, ETH Zurich, 8093 Zurich, Switzerland
- Schön Clinic Munich Harlaching, Spine Center, Academic Teaching Hospital and Spine Research, Institute of the Paracelsus Medical University 5020 Salzburg (Austria), 81547 Munich, Germany
- Department of Health Sciences, University of Potsdam, 14469 Potsdam, Deutschland
| | - Janette M. Harro
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland-Baltimore, Baltimore, 21201 MD, USA
| | - Mark E. Shirtliff
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland-Baltimore, Baltimore, 21201 MD, USA
- Department of Microbiology and Immunology, School of Medicine, University of Maryland—Baltimore, Baltimore, 21201 MD, USA
| | - Yvonne Achermann
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland-Baltimore, Baltimore, 21201 MD, USA
- Department of Infectious Diseases, University and University Hospital Zurich, 8091 Zurich, Switzerland
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30
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Affiliation(s)
- Tatyana A Sysoeva
- Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708, USA
| | - Briana M Burton
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
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31
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Broekema NM, Larsen IV, Naruzawa ES, Filutowicz M, Kolb AW, Teixeira LBC, Brandt CR. A Mouse Model of Multi-Drug Resistant Staphylococcus aureus-induced Ocular Disease. ACTA ACUST UNITED AC 2016; 4. [PMID: 27896297 PMCID: PMC5123590 DOI: 10.13188/2334-2838.1000026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Staphylococcus aureus infection of the cornea is a significant threat to vision. The percentage of bacterial isolates resistant to antibiotics is increasing as is the percentage of infections caused by methicillin resistant isolates. There is a critical need for additional therapeutic approaches and their development will require the use of animal models to test efficacy. Two mouse models of S. aureus keratitis have been described but only quantified stromal keratitis (corneal clouding and perforation). We have extended these models using the methicillin resistant S. aureus USA300 LAC strain and show that eyelid inflammation and swelling (blepharitis) and corneal neovascularization can be quantified. This expanded model should prove useful in assessing additional effects of antibacterial therapies and additional pathological mechanisms involved in bacterial ocular infection.
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Affiliation(s)
| | - Inna V Larsen
- Department of Ophthalmology and Visual Sciences, School of Medicine and Public Health, University of Wisconsin-Madison, Wisconsin, USA
| | | | - Marcin Filutowicz
- Amebagone, Inc.; Department of Bacteriology, University of Wisconsin-Madison, Wisconsin, USA
| | - Aaron W Kolb
- Department of Ophthalmology and Visual Sciences, School of Medicine and Public Health, University of Wisconsin-Madison, Wisconsin, USA
| | - Leandro B C Teixeira
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Wisconsin, USA
| | - Curtis R Brandt
- Department of Ophthalmology and Visual Sciences, School of Medicine and Public Health, University of Wisconsin-Madison, Wisconsin, USA; Department of Medical Microbiology and Immunology, School of Medicine and Public Health, University of Wisconsin-Madison, Wisconsin, USA; McPherson Eye Research Institute - University of Wisconsin-Madison, Wisconsin, USA
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32
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Bacterial viruses enable their host to acquire antibiotic resistance genes from neighbouring cells. Nat Commun 2016; 7:13333. [PMID: 27819286 PMCID: PMC5103068 DOI: 10.1038/ncomms13333] [Citation(s) in RCA: 129] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 09/23/2016] [Indexed: 12/29/2022] Open
Abstract
Prophages are quiescent viruses located in the chromosomes of bacteria. In the human pathogen, Staphylococcus aureus, prophages are omnipresent and are believed to be responsible for the spread of some antibiotic resistance genes. Here we demonstrate that release of phages from a subpopulation of S. aureus cells enables the intact, prophage-containing population to acquire beneficial genes from competing, phage-susceptible strains present in the same environment. Phage infection kills competitor cells and bits of their DNA are occasionally captured in viral transducing particles. Return of such particles to the prophage-containing population can drive the transfer of genes encoding potentially useful traits such as antibiotic resistance. This process, which can be viewed as 'auto-transduction', allows S. aureus to efficiently acquire antibiotic resistance both in vitro and in an in vivo virulence model (wax moth larvae) and enables it to proliferate under strong antibiotic selection pressure. Our results may help to explain the rapid exchange of antibiotic resistance genes observed in S. aureus.
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33
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Schubert J, Podkowik M, Bystroń J, Bania J. Production of staphylococcal enterotoxins in microbial broth and milk by Staphylococcus aureus strains harboring seh gene. Int J Food Microbiol 2016; 235:36-45. [DOI: 10.1016/j.ijfoodmicro.2016.06.043] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Revised: 05/25/2016] [Accepted: 06/29/2016] [Indexed: 11/30/2022]
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Rifampin Resistance rpoB Alleles or Multicopy Thioredoxin/Thioredoxin Reductase Suppresses the Lethality of Disruption of the Global Stress Regulator spx in Staphylococcus aureus. J Bacteriol 2016; 198:2719-31. [PMID: 27432833 DOI: 10.1128/jb.00261-16] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 07/14/2016] [Indexed: 12/25/2022] Open
Abstract
UNLABELLED Staphylococcus aureus is capable of causing a remarkable spectrum of disease, ranging from mild skin eruptions to life-threatening infections. The survival and pathogenic potential of S. aureus depend partly on its ability to sense and respond to changes in its environment. Spx is a thiol/oxidative stress sensor that interacts with the C-terminal domain of the RNA polymerase RpoA subunit, leading to changes in gene expression that help sustain viability under various conditions. Using genetic and deep-sequencing methods, we show that spx is essential in S. aureus and that a previously reported Δspx strain harbored suppressor mutations that allowed it to grow without spx One of these mutations is a single missense mutation in rpoB (a P-to-L change at position 519 encoded by rpoB [rpoB-P519L]) that conferred high-level resistance to rifampin. This mutation alone was found to be sufficient to bypass the requirement for spx The generation of rifampin resistance libraries led to the discovery of an additional rpoB mutation, R484H, which supported strains with the spx disruption. Other rifampin resistance mutations either failed to support the Δspx mutant or were recovered at unexpectedly low frequencies in genetic transduction experiments. The amino acid residues encoded by rpoB-P519L and -R484H map in close spatial proximity and comprise a highly conserved region of RpoB. We also discovered that multicopy expression of either trxA (encoding thioredoxin) or trxB (encoding thioredoxin reductase) supports strains with the deletion of spx Our results reveal intriguing properties, especially of RNA polymerase, that compensate for the loss of an essential gene that is a key mediator of diverse processes in S. aureus, including redox and thiol homeostasis, antibiotic resistance, growth, and metabolism. IMPORTANCE The survival and pathogenicity of S. aureus depend on complex genetic programs. An objective for combating this insidious organism entails dissecting genetic regulatory circuits and discovering promising new targets for therapeutic intervention. In this study, we discovered that Spx, an RNA polymerase-interacting stress regulator implicated in many stress responses in S. aureus, including responses to oxidative and cell wall antibiotics, is essential. We describe two mechanisms that suppress the lethality of spx disruption. One mechanism highlights how only certain rifampin resistance-encoding alleles of RpoB confer new properties on RNA polymerase, with important mechanistic implications. We describe additional stress conditions where the loss of spx is deleterious, thereby highlighting Spx as a multifaceted regulator and attractive drug discovery target.
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35
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Genomic Signatures of Experimental Adaptation to Antimicrobial Peptides in Staphylococcus aureus. G3-GENES GENOMES GENETICS 2016; 6:1535-9. [PMID: 27172179 PMCID: PMC4889650 DOI: 10.1534/g3.115.023622] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The evolution of resistance against antimicrobial peptides has long been considered unlikely due to their mechanism of action, yet experimental selection with antimicrobial peptides (AMPs) results in rapid evolution of resistance in several species of bacteria. Although numerous studies have utilized mutant screens to identify loci that determine AMP susceptibility, there is a dearth of data concerning the genomic changes that accompany experimental evolution of AMP resistance. Using genome resequencing, we analyzed the mutations that arose during experimental evolution of resistance to the cationic AMPs iseganan, melittin, and pexiganan, as well as to a combination of melittin and pexiganan, or to the aminoglycoside antibiotic streptomycin. Analysis of 17 independently replicated Staphylococcus aureus selection lines, including unselected controls, showed that each AMP selected for mutations at distinct loci. We identify mutations in genes involved in the synthesis and maintenance of the cell envelope. These include genes previously identified from mutant screens for AMP resistance, and genes involved in the response to AMPs and cell-wall-active antibiotics. Furthermore, transposon insertion mutants were used to verify that a number of the identified genes are directly involved in determining AMP susceptibility. Strains selected for AMP resistance under controlled experimental evolution displayed consistent AMP-specific mutations in genes that determine AMP susceptibility. This suggests that different routes to evolve resistance are favored within a controlled genetic background.
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36
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Coburn PS, Wiskur BJ, Miller FC, LaGrow AL, Astley RA, Elliott MH, Callegan MC. Bloodstream-To-Eye Infections Are Facilitated by Outer Blood-Retinal Barrier Dysfunction. PLoS One 2016; 11:e0154560. [PMID: 27195776 PMCID: PMC4873292 DOI: 10.1371/journal.pone.0154560] [Citation(s) in RCA: 19] [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: 03/07/2016] [Accepted: 04/15/2016] [Indexed: 12/30/2022] Open
Abstract
The blood-retinal barrier (BRB) functions to maintain the immune privilege of the eye, which is necessary for normal vision. The outer BRB is formed by tightly-associated retinal pigment epithelial (RPE) cells which limit transport within the retinal environment, maintaining retinal function and viability. Retinal microvascular complications and RPE dysfunction resulting from diabetes and diabetic retinopathy cause permeability changes in the BRB that compromise barrier function. Diabetes is the major predisposing condition underlying endogenous bacterial endophthalmitis (EBE), a blinding intraocular infection resulting from bacterial invasion of the eye from the bloodstream. However, significant numbers of EBE cases occur in non-diabetics. In this work, we hypothesized that dysfunction of the outer BRB may be associated with EBE development. To disrupt the RPE component of the outer BRB in vivo, sodium iodate (NaIO3) was administered to C57BL/6J mice. NaIO3-treated and untreated mice were intravenously injected with 108 colony forming units (cfu) of Staphylococcus aureus or Klebsiella pneumoniae. At 4 and 6 days postinfection, EBE was observed in NaIO3-treated mice after infection with K. pneumoniae and S. aureus, although the incidence was higher following S. aureus infection. Invasion of the eye was observed in control mice following S. aureus infection, but not in control mice following K. pneumoniae infection. Immunohistochemistry and FITC-dextran conjugate transmigration assays of human RPE barriers after infection with an exoprotein-deficient agr/sar mutant of S. aureus suggested that S. aureus exoproteins may be required for the loss of the tight junction protein, ZO-1, and for permeability of this in vitro barrier. Our results support the clinical findings that for both pathogens, complications which result in BRB permeability increase the likelihood of bacterial transmigration from the bloodstream into the eye. For S. aureus, however, BRB permeability is not required for the development of EBE, but toxin production may facilitate EBE pathogenesis.
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Affiliation(s)
- Phillip S. Coburn
- Department of Ophthalmology, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - Brandt J. Wiskur
- Oklahoma Center for Neuroscience, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - Frederick C. Miller
- Department of Cell Biology, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
- Department of Family and Preventative Medicine, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - Austin L. LaGrow
- Department of Ophthalmology, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - Roger A. Astley
- Department of Ophthalmology, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - Michael H. Elliott
- Department of Ophthalmology, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
- Oklahoma Center for Neuroscience, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
- Department of Physiology, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - Michelle C. Callegan
- Department of Ophthalmology, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
- Oklahoma Center for Neuroscience, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
- Department of Microbiology and Immunology, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
- * E-mail:
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Stach CS, Vu BG, Merriman JA, Herrera A, Cahill MP, Schlievert PM, Salgado-Pabón W. Novel Tissue Level Effects of the Staphylococcus aureus Enterotoxin Gene Cluster Are Essential for Infective Endocarditis. PLoS One 2016; 11:e0154762. [PMID: 27124393 PMCID: PMC4849672 DOI: 10.1371/journal.pone.0154762] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Accepted: 04/18/2016] [Indexed: 01/01/2023] Open
Abstract
Background Superantigens are indispensable virulence factors for Staphylococcus aureus in disease causation. Superantigens stimulate massive immune cell activation, leading to toxic shock syndrome (TSS) and contributing to other illnesses. However, superantigens differ in their capacities to induce body-wide effects. For many, their production, at least as tested in vitro, is not high enough to reach the circulation, or the proteins are not efficient in crossing epithelial and endothelial barriers, thus remaining within tissues or localized on mucosal surfaces where they exert only local effects. In this study, we address the role of TSS toxin-1 (TSST-1) and most importantly the enterotoxin gene cluster (egc) in infective endocarditis and sepsis, gaining insights into the body-wide versus local effects of superantigens. Methods We examined S. aureus TSST-1 gene (tstH) and egc deletion strains in the rabbit model of infective endocarditis and sepsis. Importantly, we also assessed the ability of commercial human intravenous immunoglobulin (IVIG) plus vancomycin to alter the course of infective endocarditis and sepsis. Results TSST-1 contributed to infective endocarditis vegetations and lethal sepsis, while superantigens of the egc, a cluster with uncharacterized functions in S. aureus infections, promoted vegetation formation in infective endocarditis. IVIG plus vancomycin prevented lethality and stroke development in infective endocarditis and sepsis. Conclusions Our studies support the local tissue effects of egc superantigens for establishment and progression of infective endocarditis providing evidence for their role in life-threatening illnesses. In contrast, TSST-1 contributes to both infective endocarditis and lethal sepsis. IVIG may be a useful adjunct therapy for infective endocarditis and sepsis.
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Affiliation(s)
- Christopher S. Stach
- Department of Microbiology, University of Iowa Carver College of Medicine, Iowa City, IA, 52242, United States of America
| | - Bao G. Vu
- Department of Microbiology, University of Iowa Carver College of Medicine, Iowa City, IA, 52242, United States of America
| | - Joseph A. Merriman
- Department of Microbiology, University of Iowa Carver College of Medicine, Iowa City, IA, 52242, United States of America
| | - Alfa Herrera
- Department of Microbiology, University of Iowa Carver College of Medicine, Iowa City, IA, 52242, United States of America
| | - Michael P. Cahill
- Department of Microbiology, University of Iowa Carver College of Medicine, Iowa City, IA, 52242, United States of America
| | - Patrick M. Schlievert
- Department of Microbiology, University of Iowa Carver College of Medicine, Iowa City, IA, 52242, United States of America
- * E-mail:
| | - Wilmara Salgado-Pabón
- Department of Microbiology, University of Iowa Carver College of Medicine, Iowa City, IA, 52242, United States of America
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Warne B, Harkins CP, Harris SR, Vatsiou A, Stanley-Wall N, Parkhill J, Peacock SJ, Palmer T, Holden MTG. The Ess/Type VII secretion system of Staphylococcus aureus shows unexpected genetic diversity. BMC Genomics 2016; 17:222. [PMID: 26969225 PMCID: PMC4788903 DOI: 10.1186/s12864-016-2426-7] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 02/01/2016] [Indexed: 02/03/2023] Open
Abstract
Background Type VII protein secretion (T7SS) is a specialised system for excreting extracellular proteins across bacterial cell membranes and has been associated with virulence in Staphylococcus aureus. The genetic diversity of the ess locus, which encodes the T7SS, and the functions of proteins encoded within it are poorly understood. Results We used whole genome sequence data from 153 isolates representative of the diversity of the species to investigate the genetic variability of T7SS across S. aureus. The ess loci were found to comprise of four distinct modules based on gene content and relative conservation. Modules 1 and 4, comprising of the 5’ and 3’ modules of the ess locus, contained the most conserved clusters of genes across the species. Module 1 contained genes encoding the secreted protein EsxA, and the EsaAB and EssAB components of the T7SS machinery, and Module 4 contained two functionally uncharacterized conserved membrane proteins. Across the species four variants of Module 2 were identified containing the essC gene, each of which was associated with a specific group of downstream genes. The most diverse module of the ess locus was Module 3 comprising a highly variable arrangement of hypothetical proteins. RNA-Seq was performed on representatives of the four Module 2 variants and demonstrated strain-specific differences in the levels of transcription in the conserved Module 1 components and transcriptional linkage Module 2, and provided evidence of the expression of genes the variable regions of the ess loci. Conclusions The ess locus of S. aureus exhibits modularity and organisational variation across the species and transcriptional variation. In silico analysis of ess loci encoded hypothetical proteins identified potential novel secreted substrates for the T7SS. The considerable variety in operon arrangement between otherwise closely related isolates provides strong evidence for recombination at this locus. Comparison of these recombination regions with each other, and with the genomes of other Staphylococcal species, failed to identify evidence of intra- and inter-species recombination, however the analysis identified a novel T7SS in another pathogenic staphylococci, Staphylococcus lugdunensis. Electronic supplementary material The online version of this article (doi:10.1186/s12864-016-2426-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Ben Warne
- The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 15A, UK.,University of Cambridge, Addenbrooke's Hospital, Cambridge, CB2 0QQ, UK
| | - Catriona P Harkins
- Division of Molecular Microbiology, College of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK.,School of Medicine, University of St Andrews, St Andrews, KY16 9TF, UK
| | - Simon R Harris
- The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 15A, UK
| | - Alexandra Vatsiou
- School of Medicine, University of St Andrews, St Andrews, KY16 9TF, UK
| | - Nicola Stanley-Wall
- Division of Molecular Microbiology, College of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK
| | - Julian Parkhill
- The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 15A, UK
| | - Sharon J Peacock
- The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 15A, UK.,University of Cambridge, Addenbrooke's Hospital, Cambridge, CB2 0QQ, UK
| | - Tracy Palmer
- Division of Molecular Microbiology, College of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK.
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Beltrame CO, Côrtes MF, Bonelli RR, Côrrea ABDA, Botelho AMN, Américo MA, Fracalanzza SEL, Figueiredo AMS. Inactivation of the Autolysis-Related Genes lrgB and yycI in Staphylococcus aureus Increases Cell Lysis-Dependent eDNA Release and Enhances Biofilm Development In Vitro and In Vivo. PLoS One 2015; 10:e0138924. [PMID: 26406329 PMCID: PMC4583396 DOI: 10.1371/journal.pone.0138924] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Accepted: 09/04/2015] [Indexed: 11/19/2022] Open
Abstract
Staphylococcus aureus ica-independent biofilms are multifactorial in nature, and various bacterial proteins have been associated with biofilm development, including fibronectin-binding proteins A and B, protein A, surface protein SasG, proteases, and some autolysins. The role of extracellular DNA (eDNA) has also been demonstrated in some S. aureus biofilms. Here, we constructed a Tn551 library, and the screening identified two genes that affected biofilm formation, lrgB and yycI. The repressive effect of both genes on the development of biofilm was also confirmed in knockout strains constructed by allelic recombination. In contrast, the superexpression of either lrgB or yycI by a cadmium-inducible promoter led to a decrease in biofilm accumulation. Indeed, a significant increase in the cell-lysis dependent eDNA release was detected when lrgB or yycI were inactivated, explaining the enhanced biofilm formed by these mutants. In fact, lrgB and yycI genes belong to distinct operons that repress bacterial autolysis through very different mechanisms. LrgB is associated with the synthesis of phage holin/anti-holin analogues, while YycI participates in the activation/repression of the two-component system YycGF (WalKR). Our in vivo data suggest that autolysins activation lead to increased bacterial virulence in the foreign body animal model since a higher number of attached cells was recovered from the implanted catheters inoculated with lrgB or yycI knockout mutants.
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Affiliation(s)
- Cristiana Ossaille Beltrame
- Universidade Federal do Rio de Janeiro, Instituto de Microbiologia Paulo de Góes, Departamento de Microbiologia Médica, Rio de Janeiro, RJ, Brazil
| | - Marina Farrel Côrtes
- Universidade Federal do Rio de Janeiro, Instituto de Microbiologia Paulo de Góes, Departamento de Microbiologia Médica, Rio de Janeiro, RJ, Brazil
| | - Raquel Regina Bonelli
- Universidade Federal do Rio de Janeiro, Instituto de Microbiologia Paulo de Góes, Departamento de Microbiologia Médica, Rio de Janeiro, RJ, Brazil
| | - Ana Beatriz de Almeida Côrrea
- Universidade Federal do Rio de Janeiro, Instituto de Microbiologia Paulo de Góes, Departamento de Microbiologia Médica, Rio de Janeiro, RJ, Brazil
| | - Ana Maria Nunes Botelho
- Universidade Federal do Rio de Janeiro, Instituto de Microbiologia Paulo de Góes, Departamento de Microbiologia Médica, Rio de Janeiro, RJ, Brazil
| | - Marco Antônio Américo
- Universidade Federal do Rio de Janeiro, Instituto de Microbiologia Paulo de Góes, Departamento de Microbiologia Médica, Rio de Janeiro, RJ, Brazil
| | - Sérgio Eduardo Longo Fracalanzza
- Universidade Federal do Rio de Janeiro, Instituto de Microbiologia Paulo de Góes, Departamento de Microbiologia Médica, Rio de Janeiro, RJ, Brazil
| | - Agnes Marie Sá Figueiredo
- Universidade Federal do Rio de Janeiro, Instituto de Microbiologia Paulo de Góes, Departamento de Microbiologia Médica, Rio de Janeiro, RJ, Brazil
- * E-mail:
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Andrey DO, Jousselin A, Villanueva M, Renzoni A, Monod A, Barras C, Rodriguez N, Kelley WL. Impact of the Regulators SigB, Rot, SarA and sarS on the Toxic Shock Tst Promoter and TSST-1 Expression in Staphylococcus aureus. PLoS One 2015; 10:e0135579. [PMID: 26275216 PMCID: PMC4537247 DOI: 10.1371/journal.pone.0135579] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Accepted: 07/24/2015] [Indexed: 12/21/2022] Open
Abstract
Staphylococcus aureus is an important pathogen manifesting virulence through diverse disease forms, ranging from acute skin infections to life-threatening bacteremia or systemic toxic shock syndromes. In the latter case, the prototypical superantigen is TSST-1 (Toxic Shock Syndrome Toxin 1), encoded by tst(H), and carried on a mobile genetic element that is not present in all S. aureus strains. Transcriptional regulation of tst is only partially understood. In this study, we dissected the role of sarA, sarS (sarH1), RNAIII, rot, and the alternative stress sigma factor sigB (σB). By examining tst promoter regulation predominantly in the context of its native sequence within the SaPI1 pathogenicity island of strain RN4282, we discovered that σB emerged as a particularly important tst regulator. We did not detect a consensus σB site within the tst promoter, and thus the effect of σB is likely indirect. We found that σB strongly repressed the expression of the toxin via at least two distinct regulatory pathways dependent upon sarA and agr. Furthermore rot, a member of SarA family, was shown to repress tst expression when overexpressed, although its deletion had no consistent measurable effect. We could not find any detectable effect of sarS, either by deletion or overexpression, suggesting that this regulator plays a minimal role in TSST-1 expression except when combined with disruption of sarA. Collectively, our results extend our understanding of complex multifactorial regulation of tst, revealing several layers of negative regulation. In addition to environmental stimuli thought to impact TSST-1 production, these findings support a model whereby sporadic mutation in a few key negative regulators can profoundly affect and enhance TSST-1 expression.
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Affiliation(s)
- Diego O. Andrey
- Service of Infectious Diseases, University Hospital and Medical School of Geneva, 4 rue Gabrielle-Perret-Gentil, CH-1211 Geneva 14, Switzerland
| | - Ambre Jousselin
- Department of Microbiology and Molecular Medicine, University Hospital and Medical School of Geneva, 1 rue Michel-Servet, CH-1211 Geneva, Switzerland
| | - Maite Villanueva
- Department of Microbiology and Molecular Medicine, University Hospital and Medical School of Geneva, 1 rue Michel-Servet, CH-1211 Geneva, Switzerland
| | - Adriana Renzoni
- Service of Infectious Diseases, University Hospital and Medical School of Geneva, 4 rue Gabrielle-Perret-Gentil, CH-1211 Geneva 14, Switzerland
| | - Antoinette Monod
- Service of Infectious Diseases, University Hospital and Medical School of Geneva, 4 rue Gabrielle-Perret-Gentil, CH-1211 Geneva 14, Switzerland
| | - Christine Barras
- Service of Infectious Diseases, University Hospital and Medical School of Geneva, 4 rue Gabrielle-Perret-Gentil, CH-1211 Geneva 14, Switzerland
| | - Natalia Rodriguez
- Department of Microbiology and Molecular Medicine, University Hospital and Medical School of Geneva, 1 rue Michel-Servet, CH-1211 Geneva, Switzerland
| | - William L. Kelley
- Department of Microbiology and Molecular Medicine, University Hospital and Medical School of Geneva, 1 rue Michel-Servet, CH-1211 Geneva, Switzerland
- * E-mail:
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Land AD, Hogan P, Fritz S, Levin PA. Phenotypic Variation Is Almost Entirely Independent of the Host-Pathogen Relationship in Clinical Isolates of S. aureus. PLoS One 2015; 10:e0129670. [PMID: 26098551 PMCID: PMC4476556 DOI: 10.1371/journal.pone.0129670] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Accepted: 05/12/2015] [Indexed: 11/18/2022] Open
Abstract
Background A key feature of Staphylococcus aureus biology is its ability to switch from an apparently benign colonizer of ~30% of the population to a cutaneous pathogen, to a deadly invasive pathogen. Little is known about the mechanisms driving this transition or the propensity of different S. aureus strains to engender different types of host-pathogen interactions. At the same time, significant weight has been given to the role of specific in vitro phenotypes in S. aureus virulence. Biofilm formation, hemolysis and pigment formation have all been associated with virulence in mice. Design To determine if there is a correlation between in vitro phenotype and the three types of host-pathogen relationships commonly exhibited by S. aureus in the context of its natural human host, we assayed 300 clinical isolates for phenotypes implicated in virulence including hemolysis, sensitivity to autolysis, and biofilm formation. For comparative purposes, we also assayed phenotype in 9 domesticated S. aureus strains routinely used for analysis of virulence determinants in laboratory settings. Results Strikingly, the clinical strains exhibited significant phenotypic uniformity in each of the assays evaluated in this study. One exception was a small, but significant, correlation between an increased propensity for biofilm formation and isolation from skin and soft tissue infections (SSTIs). In contrast, we observed a high degree of phenotypic variation between common laboratory strains that exhibit virulence in mouse models. These data suggest the existence of significant evolutionary pressure on the S. aureus genome and highlight a role for host factors as a strong determinant of the host-pathogen relationship. In addition, the high degree of variation between laboratory strains emphasizes the need for caution when applying data obtained in one lab strain to the analysis of another.
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Affiliation(s)
- Adrian D. Land
- Department of Biology, Washington University in Saint Louis, Saint Louis, Missouri, United States of America
| | - Patrick Hogan
- Department of Pediatrics, Washington University School of Medicine, St Louis, Missouri, United States of America
| | - Stephanie Fritz
- Department of Pediatrics, Washington University School of Medicine, St Louis, Missouri, United States of America
| | - Petra Anne Levin
- Department of Biology, Washington University in Saint Louis, Saint Louis, Missouri, United States of America
- * E-mail:
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Enhancing DNA electro-transformation efficiency on a clinical Staphylococcus capitis isolate. J Microbiol Methods 2014; 109:25-30. [PMID: 25477024 DOI: 10.1016/j.mimet.2014.11.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Revised: 11/21/2014] [Accepted: 11/21/2014] [Indexed: 12/18/2022]
Abstract
Clinical staphylococcus isolates possess a stronger restriction-modification (RM) barrier than laboratory strains. Clinical isolates are therefore more resistant to acceptance of foreign genetic material than laboratory strains, as their restriction systems more readily recognize and destroy foreign DNA. This stronger barrier consequently restricts genetic studies to a small number of domestic strains that are capable of accepting foreign DNA. In this study, an isolate of Staphylococcus capitis, obtained from the blood of a very low birth-weight baby, was transformed with a shuttle vector, pBT2. Optimal conditions for electro-transformation were as follows: cells were harvested at mid-log phase, electro-competent cells were prepared; cells were pre-treated at 55°C for 1min; 3μg of plasmid DNA was mixed with 70-80μL of competent cells (3-4×10(10)cells/mL) at 20°C in 0.5M sucrose, 10% glycerol; and electroporation was conducted using 2.1kV/cm field strength with a 0.1cm gap. Compared to the conventional method, which involves DNA electroporation of Staphylococcus aureus RN4220 as an intermediate strain to overcome the restriction barrier, our proposed approach exhibits a higher level (3 log10 units) of transformation efficiency. Heat treatment was used to temporarily inactivate the recipient RM barrier. Other important parameters contributing to improved electro-transformation efficiency were growth stage for cell harvesting, the quantity of DNA, the transformation temperature and field strength. The approach described here may facilitate genetic manipulations of this opportunistic pathogen.
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β-Lactam resistance in methicillin-resistant Staphylococcus aureus USA300 is increased by inactivation of the ClpXP protease. Antimicrob Agents Chemother 2014; 58:4593-603. [PMID: 24867990 DOI: 10.1128/aac.02802-14] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) has acquired the mecA gene encoding a peptidoglycan transpeptidase, penicillin binding protein 2a (PBP2a), which has decreased affinity for β-lactams. Quickly spreading and highly virulent community-acquired (CA) MRSA strains recently emerged as a frequent cause of infection in individuals without exposure to the health care system. In this study, we found that the inactivation of the components of the ClpXP protease substantially increased the β-lactam resistance level of a CA-MRSA USA300 strain, suggesting that the proteolytic activity of ClpXP controls one or more pathways modulating β-lactam resistance. These pathways do not involve the control of mecA expression, as the cellular levels of PBP2a were unaltered in the clp mutants. An analysis of the cell envelope properties of the clpX and clpP mutants revealed a number of distinct phenotypes that may contribute to the enhanced β-lactam tolerance. Both mutants displayed significantly thicker cell walls, increased peptidoglycan cross-linking, and altered composition of monomeric muropeptide species compared to those of the wild types. Moreover, changes in Sle1-mediated peptidoglycan hydrolysis and altered processing of the major autolysin Atl were observed in the clp mutants. In conclusion, the results presented here point to an important role for the ClpXP protease in controlling cell wall metabolism and add novel insights into the molecular factors that determine strain-dependent β-lactam resistance.
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Restriction-Modification Systems as a Barrier for Genetic Manipulation of Staphylococcus aureus. Methods Mol Biol 2014; 1373:9-23. [PMID: 25646604 DOI: 10.1007/7651_2014_180] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Genetic manipulation is a powerful approach to study fundamental aspects of bacterial physiology, metabolism, and pathogenesis. Most Staphylococcus aureus strains are remarkably difficult to genetically manipulate as they possess strong host defense mechanisms that protect bacteria from cellular invasion by foreign DNA. In S. aureus these bacterial "immunity" mechanisms against invading genomes are mainly associated with restriction-modification systems. To date, prokaryotic restriction-modification systems are classified into four different types (Type I-IV), all of which have been found in the sequenced S. aureus genomes. This chapter describes the roles, classification, mechanisms of action of different types of restriction-modification systems and the recent advances in the biology of restriction and modification in S. aureus.
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The giant protein Ebh is a determinant of Staphylococcus aureus cell size and complement resistance. J Bacteriol 2013; 196:971-81. [PMID: 24363342 DOI: 10.1128/jb.01366-13] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Staphylococcus aureus USA300, the clonal type associated with epidemic community-acquired methicillin-resistant S. aureus (MRSA) infections, displays the giant protein Ebh on its surface. Mutations that disrupt the ebh reading frame increase the volume of staphylococcal cells and alter the cross wall, a membrane-enclosed peptidoglycan synthesis and assembly compartment. S. aureus ebh variants display increased sensitivity to oxacillin (methicillin) as well as susceptibility to complement-mediated killing. Mutations in ebh are associated with reduced survival of mutant staphylococci in blood and diminished virulence in mice. We propose that Ebh, following its secretion into the cross wall, contributes to the characteristic cell growth and envelope assembly pathways of S. aureus, thereby enabling complement resistance and the pathogenesis of staphylococcal infections.
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