201
|
Koppen BC, Mulder PPG, de Boer L, Riool M, Drijfhout JW, Zaat SAJ. Synergistic microbicidal effect of cationic antimicrobial peptides and teicoplanin against planktonic and biofilm-encased Staphylococcus aureus. Int J Antimicrob Agents 2018; 53:143-151. [PMID: 30315918 DOI: 10.1016/j.ijantimicag.2018.10.002] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Revised: 09/07/2018] [Accepted: 10/06/2018] [Indexed: 12/11/2022]
Abstract
Antibiotic resistance and biofilm formation are the main reasons for failure in treatment of bacterial infections. This study aimed to identify synergistic combinations of conventional antibiotics and novel synthetic antimicrobial and antibiofilm peptides (SAAPs) inspired by the structures of the natural human cationic peptides LL-37 and thrombocidin-1 (TC-1). The LL-37-inspired lead peptide SAAP-148 was combined with antibiotics of different classes against Staphylococcus aureus, and showed synergy with teicoplanin. Synergy with teicoplanin was also observed with LL-37, the LL-37-inspired SAAP-276 and the TC-1-inspired TC84. Interestingly, no synergy was observed against Staphylococcus epidermidis. Furthermore, teicoplanin combined with SAAP-148 or SAAP-276 showed strong interaction against S. aureus biofilms. The dltABCD operon and the mprF gene in S. aureus conferred resistance to LL-37, but SAAP-148 proved to be indifferently potent against wild-type, ΔdltA and ΔmprF S. aureus strains. When used alone, relatively high concentrations of both LL-37 and teicoplanin (30-120 µM and 4-32 mg/L, respectively) were required to kill S. aureus. Resistance to LL-37 in S. aureus was overcome by combined use of teicoplanin and LL-37. Thus, teicoplanin potentiates peptide LL-37, enhancing the efficacy of the innate defence, and combining the novel peptides with teicoplanin offers potential for enhanced efficacy of treatment of S. aureus infections, including biofilms.
Collapse
Affiliation(s)
- Bruce C Koppen
- Department of Medical Microbiology, Amsterdam Infection and Immunity Institute, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Patrick P G Mulder
- Department of Medical Microbiology, Amsterdam Infection and Immunity Institute, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Leonie de Boer
- Department of Medical Microbiology, Amsterdam Infection and Immunity Institute, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Martijn Riool
- Department of Medical Microbiology, Amsterdam Infection and Immunity Institute, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Jan W Drijfhout
- Department of Immunohaematology and Blood Transfusion, Leiden University Medical Centre, Leiden, The Netherlands
| | - Sebastian A J Zaat
- Department of Medical Microbiology, Amsterdam Infection and Immunity Institute, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands.
| |
Collapse
|
202
|
van Hensbergen VP, Movert E, de Maat V, Lüchtenborg C, Le Breton Y, Lambeau G, Payré C, Henningham A, Nizet V, van Strijp JAG, Brügger B, Carlsson F, McIver KS, van Sorge NM. Streptococcal Lancefield polysaccharides are critical cell wall determinants for human Group IIA secreted phospholipase A2 to exert its bactericidal effects. PLoS Pathog 2018; 14:e1007348. [PMID: 30321240 PMCID: PMC6201954 DOI: 10.1371/journal.ppat.1007348] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 10/25/2018] [Accepted: 09/20/2018] [Indexed: 12/21/2022] Open
Abstract
Human Group IIA secreted phospholipase A2 (hGIIA) is an acute phase protein with bactericidal activity against Gram-positive bacteria. Infection models in hGIIA transgenic mice have suggested the importance of hGIIA as an innate defense mechanism against the human pathogens Group A Streptococcus (GAS) and Group B Streptococcus (GBS). Compared to other Gram-positive bacteria, GAS is remarkably resistant to hGIIA activity. To identify GAS resistance mechanisms, we exposed a highly saturated GAS M1 transposon library to recombinant hGIIA and compared relative mutant abundance with library input through transposon-sequencing (Tn-seq). Based on transposon prevalence in the output library, we identified nine genes, including dltA and lytR, conferring increased hGIIA susceptibility. In addition, seven genes conferred increased hGIIA resistance, which included two genes, gacH and gacI that are located within the Group A Carbohydrate (GAC) gene cluster. Using GAS 5448 wild-type and the isogenic gacI mutant and gacI-complemented strains, we demonstrate that loss of the GAC N-acetylglucosamine (GlcNAc) side chain in the ΔgacI mutant increases hGIIA resistance approximately 10-fold, a phenotype that is conserved across different GAS serotypes. Increased resistance is associated with delayed penetration of hGIIA through the cell wall. Correspondingly, loss of the Lancefield Group B Carbohydrate (GBC) rendered GBS significantly more resistant to hGIIA-mediated killing. This suggests that the streptococcal Lancefield antigens, which are critical determinants for streptococcal physiology and virulence, are required for the bactericidal enzyme hGIIA to exert its bactericidal function.
Collapse
Affiliation(s)
- Vincent P. van Hensbergen
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Elin Movert
- Department of Experimental Medical Science, Section for Immunology, Lund University, Lund, Sweden
| | - Vincent de Maat
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | | | - Yoann Le Breton
- Department of Cell Biology & Molecular Genetics and Maryland Pathogen Research Institute, University of Maryland, College Park, MD, United States of America
| | - Gérard Lambeau
- Université Côte d'Azur, CNRS, Institut de Pharmacologie Moléculaire et Cellulaire, Department of Biochemistry, Valbonne, France
| | - Christine Payré
- Université Côte d'Azur, CNRS, Institut de Pharmacologie Moléculaire et Cellulaire, Department of Biochemistry, Valbonne, France
| | - Anna Henningham
- Department of Pediatrics and Skaggs School of Pharmacy & Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA, United States of America
| | - Victor Nizet
- Department of Pediatrics and Skaggs School of Pharmacy & Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA, United States of America
- Skaggs School of Pharmacy & Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA, United States of America
| | - Jos A. G. van Strijp
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Britta Brügger
- Heidelberg University, Biochemistry Center (BZH), Heidelberg, Germany
| | - Fredric Carlsson
- Department of Experimental Medical Science, Section for Immunology, Lund University, Lund, Sweden
- Department of Biology, Section for Molecular Cell Biology, Lund University, Lund, Sweden
| | - Kevin S. McIver
- Department of Cell Biology & Molecular Genetics and Maryland Pathogen Research Institute, University of Maryland, College Park, MD, United States of America
| | - Nina M. van Sorge
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| |
Collapse
|
203
|
Abstract
Membrane-bound O-acyltransferases (MBOATs) are a superfamily of integral transmembrane enzymes that are found in all kingdoms of life1. In bacteria, MBOATs modify protective cell-surface polymers. In vertebrates, some MBOAT enzymes-such as acyl-coenzyme A:cholesterol acyltransferase and diacylglycerol acyltransferase 1-are responsible for lipid biosynthesis or phospholipid remodelling2,3. Other MBOATs, including porcupine, hedgehog acyltransferase and ghrelin acyltransferase, catalyse essential lipid modifications of secreted proteins such as Wnt, hedgehog and ghrelin, respectively4-10. Although many MBOAT proteins are important drug targets, little is known about their molecular architecture and functional mechanisms. Here we present crystal structures of DltB, an MBOAT responsible for the D-alanylation of cell-wall teichoic acid in Gram-positive bacteria11-16, both alone and in complex with the D-alanyl donor protein DltC. DltB contains a ring of 11 peripheral transmembrane helices, which shield a highly conserved extracellular structural funnel extending into the middle of the lipid bilayer. The conserved catalytic histidine residue is located at the bottom of this funnel and is connected to the intracellular DltC through a narrow tunnel. Mutation of either the catalytic histidine or the DltC-binding site of DltB abolishes the D-alanylation of lipoteichoic acid and sensitizes the Gram-positive bacterium Bacillus subtilis to cell-wall stress, which suggests cross-membrane catalysis involving the tunnel. Structure-guided sequence comparison among DltB and vertebrate MBOATs reveals a conserved structural core and suggests that MBOATs from different organisms have similar catalytic mechanisms. Our structures provide a template for understanding structure-function relationships in MBOATs and for developing therapeutic MBOAT inhibitors.
Collapse
|
204
|
Fong R, Kajihara K, Chen M, Hotzel I, Mariathasan S, Hazenbos WL, Lupardus PJ. Structural investigation of human S. aureus-targeting antibodies that bind wall teichoic acid. MAbs 2018; 10:979-991. [PMID: 30102105 PMCID: PMC6204806 DOI: 10.1080/19420862.2018.1501252] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Infections caused by methicillin-resistant Staphylococcus aureus (MRSA) are a growing health threat worldwide. Efforts to identify novel antibodies that target S. aureus cell surface antigens are a promising direction in the development of antibiotics that can halt MRSA infection. We biochemically and structurally characterized three patient-derived MRSA-targeting antibodies that bind to wall teichoic acid (WTA), which is a polyanionic surface glycopolymer. In S. aureus, WTA exists in both α- and β-forms, based on the stereochemistry of attachment of a N-acetylglucosamine residue to the repeating phosphoribitol sugar unit. We identified a panel of antibodies cloned from human patients that specifically recognize the α or β form of WTA, and can bind with high affinity to pathogenic wild-type strains of S. aureus bacteria. To investigate how the β-WTA specific antibodies interact with their target epitope, we determined the X-ray crystal structures of the three β-WTA specific antibodies, 4462, 4497, and 6078 (Protein Data Bank IDs 6DWI, 6DWA, and 6DW2, respectively), bound to a synthetic WTA epitope. These structures reveal that all three of these antibodies, while utilizing distinct antibody complementarity-determining region sequences and conformations to interact with β-WTA, fulfill two recognition principles: binding to the β-GlcNAc pyranose core and triangulation of WTA phosphate residues with polar contacts. These studies reveal the molecular basis for targeting a unique S. aureus cell surface epitope and highlight the power of human patient-based antibody discovery techniques for finding novel pathogen-targeting therapeutics.
Collapse
Affiliation(s)
- Rina Fong
- Department of Structural Biology, Genentech, South San Francisco, CA, USA,Departments of Infectious Diseases, Genentech, South San Francisco, CA, USA,Departments of Antibody Engineering, Genentech, South San Francisco, CA, USA
| | - Kimberly Kajihara
- Department of Structural Biology, Genentech, South San Francisco, CA, USA,Departments of Infectious Diseases, Genentech, South San Francisco, CA, USA,Departments of Antibody Engineering, Genentech, South San Francisco, CA, USA
| | - Matthew Chen
- Department of Structural Biology, Genentech, South San Francisco, CA, USA,Departments of Infectious Diseases, Genentech, South San Francisco, CA, USA,Departments of Antibody Engineering, Genentech, South San Francisco, CA, USA
| | - Isidro Hotzel
- Department of Structural Biology, Genentech, South San Francisco, CA, USA,Departments of Infectious Diseases, Genentech, South San Francisco, CA, USA,Departments of Antibody Engineering, Genentech, South San Francisco, CA, USA
| | - Sanjeev Mariathasan
- Department of Structural Biology, Genentech, South San Francisco, CA, USA,Departments of Infectious Diseases, Genentech, South San Francisco, CA, USA,Departments of Antibody Engineering, Genentech, South San Francisco, CA, USA
| | - Wouter L.W. Hazenbos
- Department of Structural Biology, Genentech, South San Francisco, CA, USA,Departments of Infectious Diseases, Genentech, South San Francisco, CA, USA,Departments of Antibody Engineering, Genentech, South San Francisco, CA, USA
| | - Patrick J. Lupardus
- Department of Structural Biology, Genentech, South San Francisco, CA, USA,Departments of Infectious Diseases, Genentech, South San Francisco, CA, USA,Departments of Antibody Engineering, Genentech, South San Francisco, CA, USA,CONTACT Patrick J. Lupardus Department of Structural Biology, Genentech, South San Francisco, CA, USA
| |
Collapse
|
205
|
Wassmann CS, Lund LC, Thorsing M, Lauritzen SP, Kolmos HJ, Kallipolitis BH, Klitgaard JK. Molecular mechanisms of thioridazine resistance in Staphylococcus aureus. PLoS One 2018; 13:e0201767. [PMID: 30089175 PMCID: PMC6082566 DOI: 10.1371/journal.pone.0201767] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Accepted: 07/20/2018] [Indexed: 11/18/2022] Open
Abstract
Staphylococcus aureus has developed resistance towards the most commonly used anti-staphylococcal antibiotics. Therefore, there is an urgent need to find new treatment opportunities. A new approach relies on the use of helper compounds, which are able to potentiate the effect of antibiotics. A well-studied helper compound is thioridazine, which potentiates the effect of the β-lactam antibiotic dicloxacillin against Methicillin-resistant Staphylococcus aureus (MRSA). In order to identify thioridazine's mechanism of action and how it potentiates the effect of dicloxacillin, we generated thioridazine resistant strains of MRSA USA300 by serial passage experiments. Selected strains were whole-genome sequenced to find mutations causing thioridazine resistance. Genes observed to be mutated were attempted deleted in MRSA USA300. The cls gene encoding a cardiolipin synthase important for synthesis of the membrane lipid cardiolipin was found to be mutated in thioridazine resistant strains. Deletion of this gene resulted in a two-fold increased Minimum inhibitory concentrations (MIC) value for thioridazine compared to the wild type and decreased susceptibility similar to the thioridazine resistant strains. Since cardiolipin likely plays a role in resistance towards thioridazine, it might also be important for the mechanism of action behind the potentiating effect of thioridazine. TDZ is known to intercalate into the membrane and we show here that TDZ can depolarize the plasma membrane. However, our results indicate that the membrane potential reducing effect of TDZ is independent of the resistance mechanism.
Collapse
Affiliation(s)
| | - Lars Christian Lund
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Mette Thorsing
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Sabrina Prehn Lauritzen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Hans Jørn Kolmos
- Institute of Clinical Research, Research Unit of Clinical Microbiology, University of Southern Denmark, Odense, Denmark
| | | | - Janne Kudsk Klitgaard
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
- Institute of Clinical Research, Research Unit of Clinical Microbiology, University of Southern Denmark, Odense, Denmark
- * E-mail:
| |
Collapse
|
206
|
Peroxisome Proliferator-Activated Receptor γ Is Essential for the Resolution of Staphylococcus aureus Skin Infections. Cell Host Microbe 2018; 24:261-270.e4. [PMID: 30057172 DOI: 10.1016/j.chom.2018.07.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 12/05/2017] [Accepted: 07/03/2018] [Indexed: 11/22/2022]
Abstract
Skin/soft tissue infections (SSTIs) caused by methicillin-resistant Staphylococcus aureus (MRSA) represent serious healthcare burdens worldwide. The host initially controls these infections with a pro-inflammatory infiltrate. However, once established, MRSA viability remains constant. To clear established MRSA SSTIs, the host must transition into the post-inflammatory resolution phase marked by infiltration of alternatively activated macrophages. Here we show that the host nuclear receptor, peroxisome proliferation activator receptor γ (PPARγ), is essential for this transition and MRSA clearance. Chemical PPARγ inhibition or genetic ablation of PPARγ in myeloid cells results in an extended inflammatory phase and exacerbated MRSA SSTIs. Conversely, treating mice with PPARγ agonists hastens the onset of the resolution phase and improves MRSA clearance in a myeloid-dependent fashion. The resolving fibrotic abscess lacks abundant glucose and oxygen but is replete with antimicrobial peptides, which together contribute to MRSA clearance. Thus, PPARγ agonists may serve as viable treatment options for complicated MRSA SSTIs.
Collapse
|
207
|
Moravej H, Moravej Z, Yazdanparast M, Heiat M, Mirhosseini A, Moosazadeh Moghaddam M, Mirnejad R. Antimicrobial Peptides: Features, Action, and Their Resistance Mechanisms in Bacteria. Microb Drug Resist 2018; 24:747-767. [PMID: 29957118 DOI: 10.1089/mdr.2017.0392] [Citation(s) in RCA: 189] [Impact Index Per Article: 31.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
In recent years, because of increased resistance to conventional antimicrobials, many researchers have started to study the synthesis of new antibiotics to control the disease-causing effects of infectious pathogens. Antimicrobial peptides (AMPs) are among the newest antibiotics; these peptides are integral compounds in all kinds of organisms and play a significant role in microbial ecology, and critically contribute to the innate immunity of organisms by destroying invading microorganisms. Moreover, AMPs may encourage cells to produce chemokines, stimulate angiogenesis, accelerate wound healing, and influence programmed cell death in multicellular organisms. Bacteria differ in their inherent susceptibility and resistance mechanisms to these peptides when responding to the antimicrobial effects of AMPs. Generally, the development of AMP resistance mechanisms is driven by direct competition between bacterial species, and host and pathogen interactions. Several studies have shown diverse mechanisms of bacterial resistance to AMPs, for example, some bacteria produce proteases and trapping proteins; some modify cell surface charge, change membrane fluidity, and activate efflux pumps; and some species make use of biofilms and exopolymers, and develop sensing systems by selective gene expression. A closer understanding of bacterial resistance mechanisms may help in developing novel therapeutic approaches for the treatment of infections caused by pathogenic organisms that are successful in developing extensive resistance to AMPs. Based on these observations, this review discusses the properties of AMPs, their targeting mechanisms, and bacterial resistance mechanisms against AMPs.
Collapse
Affiliation(s)
- Hoda Moravej
- 1 Molecular Biology Research Center, Systems Biology and Poisoning Institute, Baqiyatallah University of Medical Sciences , Tehran, Iran
| | - Zahra Moravej
- 2 Department of Hepatitis and AIDS, Pasteur Institute of Iran , Tehran, Iran
| | - Maryam Yazdanparast
- 3 Department of Pharmacology, Experimental Medicine Research Center, School of Medicine, Tehran University of Medical Sciences , Tehran, Iran
| | - Mohammad Heiat
- 4 Applied Biotechnology Research Center, Baqiyatallah University of Medical Sciences , Tehran, Iran
| | - Ali Mirhosseini
- 5 Applied Microbiology Research Center, Systems Biology and Poisoning Institute, Baqiyatallah University of Medical Sciences , Tehran, Iran
| | | | - Reza Mirnejad
- 1 Molecular Biology Research Center, Systems Biology and Poisoning Institute, Baqiyatallah University of Medical Sciences , Tehran, Iran
| |
Collapse
|
208
|
Exposure of Staphylococcus aureus to Targocil Blocks Translocation of the Major Autolysin Atl across the Membrane, Resulting in a Significant Decrease in Autolysis. Antimicrob Agents Chemother 2018; 62:AAC.00323-18. [PMID: 29735561 DOI: 10.1128/aac.00323-18] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Accepted: 04/29/2018] [Indexed: 11/20/2022] Open
Abstract
Peptidoglycan (PG) and wall teichoic acid (WTA) are the major staphylococcal cell wall components, and WTA biosynthesis has recently been explored for drug development. Targocil is a novel agent that targets the TarG subunit of the WTA translocase (TarGH) that transports WTA across the membrane to the wall. Previously we showed that targocil treatment of a methicillin-susceptible Staphylococcus aureus strain led to a rapid shut down of cellular autolysis. Targocil II, which targets the TarH subunit of TarGH, also resulted in a drastic decrease in autolysis. Here, we address the mechanism of targocil-mediated decreased autolysis. The mechanism is WTA dependent since targocil treatment decreased autolysis in methicillin-resistant strains but not in a WTA-deficient mutant. Similar to cellular autolysis, autolysin-retaining crude cell walls isolated from targocil-treated cells had vastly decreased autolytic activity compared to those from untreated cells. Purified cell walls from control and targocil-treated cells, which lack autolytic activity, were similarly susceptible to lysozyme and lysostaphin and had similar O-acetyl contents, indicating that targocil treatment did not grossly alter PG structure and chemistry. Purified cell walls from targocil-treated cells were highly susceptible to autolysin extracts, supporting the notion that targocil treatment led to decreased autolysin in the crude cell walls. Quantitative real-time PCR analysis revealed that the decrease in autolysis in the targocil-exposed cells was not due to transcriptional repression of the autolysin genes atl, lytM, lytN, and sle1 Zymographic analysis of peptidoglycan hydrolase profiles showed a deficiency of cell surface autolysins in targocil-treated cells but higher activity in cell membrane fractions. Here, we propose that the untranslocated WTA molecules in the targocil-exposed cells sequester Atl at the membrane, resulting in significantly decreased autolysis.
Collapse
|
209
|
Ma Z, Lasek-Nesselquist E, Lu J, Schneider R, Shah R, Oliva G, Pata J, McDonough K, Pai MP, Rose WE, Sakoulas G, Malik M. Characterization of genetic changes associated with daptomycin nonsusceptibility in Staphylococcus aureus. PLoS One 2018; 13:e0198366. [PMID: 29879195 PMCID: PMC5991675 DOI: 10.1371/journal.pone.0198366] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 05/17/2018] [Indexed: 11/25/2022] Open
Abstract
The extensive use of daptomycin (DAP) for treatment of methicillin-resistant Staphylococcus aureus (MRSA) infections in the last decade has led to the emergence of DAP non-susceptible (DNS) Staphylococcus aureus strains. A better understanding of the molecular changes underlying DAP-non-susceptibility is required for early diagnosis and intervention with alternate combination therapies. The phenotypic changes associated with DNS strains have been well established. However, the genotypic changes—especially the kinetics of expression of the genes responsible for DAP-non-susceptibility are not well understood. In this study, we used three clinically derived isogenic pairs of DAP-susceptible (DAP-S) and DNS S. aureus strains to study gene expression profiles with the objective of identifying the potential genotypic changes associated with DAP-nonsusceptibility. We determined the expression profiles of genes involved in cell membrane (CM) charge, autolysis, cell wall (CW) synthesis, and penicillin binding proteins in DAP-S and DNS isogenic pairs. Our results demonstrate characteristic expression profiles for mprF, dltABCD, vraS, femB, and pbp2a genes, which are common to all the DNS S. aureus strains tested. Whole genome sequencing of DAP-S and DNS clinical isolates of S. aureus showed non-synonymous mutations in all DNS strains in genes involved in CM charge, CM composition, CW thickness and CW composition. To conclude, this study unravels some of the complex molecular changes involved in the development of DAP-nonsusceptibility by demonstrating distinct differences in gene expression profiles and mutations in the DNS S. aureus strains. This knowledge will aid in rapid identification of DNS S. aureus in clinical settings.
Collapse
Affiliation(s)
- Zhuo Ma
- Albany College of Pharmacy and Health Sciences, Albany, New York, United States of America
| | - Erica Lasek-Nesselquist
- Wadsworth Center, New York State Department of Health, Albany, New York, United States of America
| | - Jackson Lu
- Albany College of Pharmacy and Health Sciences, Albany, New York, United States of America
| | - Ryan Schneider
- Wadsworth Center, New York State Department of Health, Albany, New York, United States of America
| | - Riddhi Shah
- Albany College of Pharmacy and Health Sciences, Albany, New York, United States of America
| | - George Oliva
- Albany College of Pharmacy and Health Sciences, Albany, New York, United States of America
| | - Janice Pata
- Wadsworth Center, New York State Department of Health, Albany, New York, United States of America
| | - Kathleen McDonough
- Wadsworth Center, New York State Department of Health, Albany, New York, United States of America
| | - Manjunath P. Pai
- Albany College of Pharmacy and Health Sciences, Albany, New York, United States of America
| | - Warren E. Rose
- Universtiy of Wisconsin-Madison, School of Pharmacy, Madison, Wisconsin, United States of America
| | - George Sakoulas
- Center for Immunity, Infection & Inflammation, UCSD School of Medicine, La Jolla, California, United States of America
| | - Meenakshi Malik
- Albany College of Pharmacy and Health Sciences, Albany, New York, United States of America
- * E-mail:
| |
Collapse
|
210
|
Chen YE, Fischbach MA, Belkaid Y. Skin microbiota-host interactions. Nature 2018; 553:427-436. [PMID: 29364286 DOI: 10.1038/nature25177] [Citation(s) in RCA: 390] [Impact Index Per Article: 65.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Accepted: 11/28/2017] [Indexed: 12/23/2022]
Abstract
The skin is a complex and dynamic ecosystem that is inhabited by bacteria, archaea, fungi and viruses. These microbes-collectively referred to as the skin microbiota-are fundamental to skin physiology and immunity. Interactions between skin microbes and the host can fall anywhere along the continuum between mutualism and pathogenicity. In this Review, we highlight how host-microbe interactions depend heavily on context, including the state of immune activation, host genetic predisposition, barrier status, microbe localization, and microbe-microbe interactions. We focus on how context shapes the complex dialogue between skin microbes and the host, and the consequences of this dialogue for health and disease.
Collapse
Affiliation(s)
- Y Erin Chen
- Department of Dermatology, University of California San Francisco, San Francisco, California, USA.,Department of Bioengineering and ChEM-H, Stanford University, Stanford, California, USA
| | - Michael A Fischbach
- Department of Bioengineering and ChEM-H, Stanford University, Stanford, California, USA
| | - Yasmine Belkaid
- NIAID Microbiome Program, National Institute of Allergy and Infectious Disease, NIH, Bethesda, Maryland, USA.,Mucosal Immunology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Disease, NIH, Bethesda, Maryland, USA
| |
Collapse
|
211
|
Salt-Induced Stress Stimulates a Lipoteichoic Acid-Specific Three-Component Glycosylation System in Staphylococcus aureus. J Bacteriol 2018; 200:JB.00017-18. [PMID: 29632092 DOI: 10.1128/jb.00017-18] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 04/03/2018] [Indexed: 01/01/2023] Open
Abstract
Lipoteichoic acid (LTA) in Staphylococcus aureus is a poly-glycerophosphate polymer anchored to the outer surface of the cell membrane. LTA has numerous roles in cell envelope physiology, including regulating cell autolysis, coordinating cell division, and adapting to environmental growth conditions. LTA is often further modified with substituents, including d-alanine and glycosyl groups, to alter cellular function. While the genetic determinants of d-alanylation have been largely defined, the route of LTA glycosylation and its role in cell envelope physiology have remained unknown, in part due to the low levels of basal LTA glycosylation in S. aureus We demonstrate here that S. aureus utilizes a membrane-associated three-component glycosylation system composed of an undecaprenol (Und) N-acetylglucosamine (GlcNAc) charging enzyme (CsbB; SAOUHSC_00713), a putative flippase to transport loaded substrate to the outside surface of the cell (GtcA; SAOUHSC_02722), and finally an LTA-specific glycosyltransferase that adds α-GlcNAc moieties to LTA (YfhO; SAOUHSC_01213). We demonstrate that this system is specific for LTA with no cross recognition of the structurally similar polyribitol phosphate containing wall teichoic acids. We show that while wild-type S. aureus LTA has only a trace of GlcNAcylated LTA under normal growth conditions, amounts are raised upon either overexpressing CsbB, reducing endogenous d-alanylation activity, expressing the cell envelope stress responsive alternative sigma factor SigB, or by exposure to environmental stress-inducing culture conditions, including growth media containing high levels of sodium chloride.IMPORTANCE The role of glycosylation in the structure and function of Staphylococcus aureus lipoteichoic acid (LTA) is largely unknown. By defining key components of the LTA three-component glycosylation pathway and uncovering stress-induced regulation by the alternative sigma factor SigB, the role of N-acetylglucosamine tailoring during adaptation to environmental stresses can now be elucidated. As the dlt and glycosylation pathways compete for the same sites on LTA and induction of glycosylation results in decreased d-alanylation, the interplay between the two modification systems holds implications for resistance to antibiotics and antimicrobial peptides.
Collapse
|
212
|
Zheng Y, He L, Asiamah TK, Otto M. Colonization of medical devices by staphylococci. Environ Microbiol 2018; 20:3141-3153. [PMID: 29633455 DOI: 10.1111/1462-2920.14129] [Citation(s) in RCA: 88] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 03/16/2018] [Accepted: 04/03/2018] [Indexed: 12/19/2022]
Abstract
The use of medical devices in modern medicine is constantly increasing. Despite the multiple precautionary strategies that are being employed in hospitals, which include increased hygiene and sterilization measures, bacterial infections on these devices still happen frequently. Staphylococci are among the major causes of medical device infection. This is mostly due to the strong capacity of those bacteria to form device-associated biofilms, which provide resistance to chemical and physical treatments as well as attacks by the host's immune system. Biofilm development is a multistep process with specific factors participating in each step. It is tightly regulated to provide a balance between biofilm expansion and detachment. Detachment from a biofilm on a medical device can lead to severe systemic infection, such as bacteremia and sepsis. While our understanding of staphylococcal biofilm formation has increased significantly and staphylococcal biofilm formation on medical devices is among the best understood biofilm-associated infections, the extensive effort put in preclinical studies with the goal to find novel therapies against staphylococcal device-associated infections has not yet resulted in efficient, applicable therapeutic options for that difficult-to-treat type of disease.
Collapse
Affiliation(s)
- Yue Zheng
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, U.S. National Institutes of Health, Bethesda, MD, USA
| | - Lei He
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, U.S. National Institutes of Health, Bethesda, MD, USA
| | - Titus K Asiamah
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, U.S. National Institutes of Health, Bethesda, MD, USA
| | - Michael Otto
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, U.S. National Institutes of Health, Bethesda, MD, USA
| |
Collapse
|
213
|
Reduced Susceptibility to Antiseptics Is Conferred by Heterologous Housekeeping Genes. Microb Drug Resist 2018; 24:105-112. [DOI: 10.1089/mdr.2017.0105] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
|
214
|
Vickery CR, Wood BM, Morris HG, Losick R, Walker S. Reconstitution of Staphylococcus aureus Lipoteichoic Acid Synthase Activity Identifies Congo Red as a Selective Inhibitor. J Am Chem Soc 2018; 140:876-879. [PMID: 29300473 PMCID: PMC5856125 DOI: 10.1021/jacs.7b11704] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Lipoteichoic acid (LTA) is an anionic surface polymer that is essential for normal growth of Staphylococcus aureus, making the LTA polymerase, LTA synthase (LtaS), a proposed drug target for combating Staphylococcal infections. LtaS is a polytopic membrane protein with five membrane-spanning helices and an extracellular domain, and it uses phosphatidylglycerol to assemble a glycerol phosphate chain on a glycosylated diacylglycerol membrane anchor. We report here the first reconstitution of LtaS polymerization activity and show that the azo dye Congo red inhibits this enzyme both in vitro and in cells. Related azo dyes and the previously reported LtaS inhibitor 1771 have weak or no in vitro inhibitory activity. Synthetic lethality with mutant strains known to be nonviable in the absence of LTA confirms selective inhibition by Congo red. As the only validated LtaS inhibitor, Congo red can serve as a probe to understand how inhibiting lipoteichoic acid biosynthesis affects cell physiology and may also guide the discovery of more potent inhibitors for use in treating S. aureus infections.
Collapse
Affiliation(s)
- Christopher R. Vickery
- Department of Microbiology and Immunobiology, Harvard University, 77 Avenue Louis Pasteur, Boston, Massachusetts 02115, United States
| | - B. McKay Wood
- Department of Microbiology and Immunobiology, Harvard University, 77 Avenue Louis Pasteur, Boston, Massachusetts 02115, United States
| | - Heidi G. Morris
- Department of Microbiology and Immunobiology, Harvard University, 77 Avenue Louis Pasteur, Boston, Massachusetts 02115, United States
| | - Richard Losick
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Suzanne Walker
- Department of Microbiology and Immunobiology, Harvard University, 77 Avenue Louis Pasteur, Boston, Massachusetts 02115, United States
| |
Collapse
|
215
|
Ultrastructural damage in Streptococcus mutans incubated with saliva and histatin 5. Arch Oral Biol 2018; 87:226-234. [PMID: 29328950 DOI: 10.1016/j.archoralbio.2018.01.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Revised: 12/15/2017] [Accepted: 01/07/2018] [Indexed: 12/11/2022]
Abstract
OBJECTIVE To study the ultrastructural alterations induced in Streptococcus mutans (ATCC 25175) incubated with saliva, saliva plus histatin 5 and histatin 5. METHODS S. mutans incubated with saliva histatin 5 or a combination of both were morphologically analyzed and counted. The results were expressed as (CFU)ml-1. Ultrastructural damage was evaluated by transmission electron microscopy. Ultrastructural localization of histatin 5 was examined using immunogold labeling. Apoptotic cell death was determined by flow cytometry (TUNEL). RESULTS A decrease in the bacteria numbers was observed after incubation with saliva, saliva with histatin 5 or histatin 5 compared to the control group (p<0.0001). Ultrastructural damage in S. mutans incubated with saliva was found in the cell wall. Saliva plus histatin 5 induced a cytoplasmic granular pattern and decreased the distance between the plasma membrane bilayers, also found after incubation with histatin 5, together with pyknotic nucleoids. Histatin 5 was localized on the bacterial cell walls, plasma membranes, cytoplasm and nucleoids. Apoptosis was found in the bacteria incubated with saliva (63.9%), saliva plus histatin 5 (71.4%) and histatin 5 (29.3%). Apoptosis in the control bacteria was 0.2%. CONCLUSIONS Antibacterial activity against S. mutans and the morphological description of damage induced by saliva and histatin 5 was demonstrated. Pyknotic nucleoids observed in S. mutans exposed to saliva, saliva plus histatin 5 and histatin 5 could be an apoptosis-like death mechanism. The knowledge of the damage generated by histatin 5 and its intracellular localization could favor the design of an ideal peptide as a therapeutic agent.
Collapse
|
216
|
Müller A, Grein F, Otto A, Gries K, Orlov D, Zarubaev V, Girard M, Sher X, Shamova O, Roemer T, François P, Becher D, Schneider T, Sahl HG. Differential daptomycin resistance development in Staphylococcus aureus strains with active and mutated gra regulatory systems. Int J Med Microbiol 2017; 308:335-348. [PMID: 29429584 DOI: 10.1016/j.ijmm.2017.12.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Revised: 12/13/2017] [Accepted: 12/18/2017] [Indexed: 02/03/2023] Open
Abstract
The first-in-class lipopeptide antibiotic daptomycin (DAP) is highly active against Gram-positive pathogens including ß-lactam and glycopeptide resistant strains. Its molecular mode of action remains enigmatic, since a defined target has not been identified so far and multiple effects, primarily on the cell envelope have been observed. Reduced DAP susceptibility has been described in S. aureus and enterococci after prolonged treatment courses. In line with its pleiotropic antibiotic activities, a unique, defined molecular mechanism of resistance has not emerged, instead non-susceptibility appears often accompanied by alterations in membrane composition and changes in cell wall homeostasis. We compared S. aureus strains HG001 and SG511, which differ primarily in the functionality of the histidine kinase GraS, to evaluate the impact of the GraRS regulatory system on the development of DAP non-susceptibility. After extensive serial passing, both DAPR variants reached a minimal inhibitory concentration of 31 μg/ml and shared some phenotypic characteristics (e.g. thicker cell wall, reduced autolysis). However, based on comprehensive analysis of the underlying genetic, transcriptomic and proteomic changes, we found that both strains took different routes to achieve DAP resistance. Our study highlights the impressive genetic and physiological capacity of S. aureus to counteract pleiotropic activities of cell wall- and membrane-active compounds even when a major cell wall regulatory system is dysfunctional.
Collapse
Affiliation(s)
- Anna Müller
- Institute for Pharmaceutical Microbiology, University Hospital Bonn, University of Bonn, Bonn, Germany; German Center for Infection Research (DZIF), partner site Bonn-Cologne, Bonn.
| | - Fabian Grein
- Institute for Pharmaceutical Microbiology, University Hospital Bonn, University of Bonn, Bonn, Germany; German Center for Infection Research (DZIF), partner site Bonn-Cologne, Bonn
| | - Andreas Otto
- Institute for Microbiology, University of Greifswald, Greifswald, Germany
| | - Kathrin Gries
- Institute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, University of Bonn, Bonn, Germany
| | - Dmitriy Orlov
- Institute for Experimental Medicine, Saint Petersburg, Russia; Saint Petersburg University, Saint Petersburg, Russia
| | - Vladimir Zarubaev
- Pasteur Institute of Epidemiology and Microbiology, Saint Petersburg Russia
| | - Myriam Girard
- Genomic Research Laboratory, Department of Medical Specialties, University Hospitals of Geneva, University of Geneva, Geneva, Switzerland
| | - Xinwei Sher
- Merck & Co., Infectious Diseases, Kenilworth, NJ, USA
| | - Olga Shamova
- Institute for Experimental Medicine, Saint Petersburg, Russia; Saint Petersburg University, Saint Petersburg, Russia
| | | | - Patrice François
- Genomic Research Laboratory, Department of Medical Specialties, University Hospitals of Geneva, University of Geneva, Geneva, Switzerland
| | - Dörte Becher
- Institute for Microbiology, University of Greifswald, Greifswald, Germany
| | - Tanja Schneider
- Institute for Pharmaceutical Microbiology, University Hospital Bonn, University of Bonn, Bonn, Germany; German Center for Infection Research (DZIF), partner site Bonn-Cologne, Bonn
| | - Hans-Georg Sahl
- German Center for Infection Research (DZIF), partner site Bonn-Cologne, Bonn; Institute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, University of Bonn, Bonn, Germany
| |
Collapse
|
217
|
Lewis ML, Surewaard BGJ. Neutrophil evasion strategies by Streptococcus pneumoniae and Staphylococcus aureus. Cell Tissue Res 2017; 371:489-503. [PMID: 29204747 DOI: 10.1007/s00441-017-2737-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 11/06/2017] [Indexed: 02/05/2023]
Abstract
Humans are well equipped to defend themselves against bacteria. The innate immune system employs diverse mechanisms to recognize, control and initiate a response that can destroy millions of different microbes. Microbes that evade the sophisticated innate immune system are able to escape detection and could become pathogens. The pathogens Streptococcus pneumoniae and Staphylococcus aureus are particularly successful due to the development of a wide variety of virulence strategies for bacterial pathogenesis and they invest significant efforts towards mechanisms that allow for neutrophil evasion. Neutrophils are a primary cellular defense and can rapidly kill invading microbes, which is an indispensable function for maintaining host health. This review compares the key features of Streptococcus pneumoniae and Staphylococcus aureus in epidemiology, with a specific focus on virulence mechanisms utilized to evade neutrophils in bacterial pathogenesis. It is important to understand the complex interactions between pathogenic bacteria and neutrophils so that we can disrupt the ability of pathogens to cause disease.
Collapse
Affiliation(s)
- Megan L Lewis
- Department of Physiology & Pharmacology, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
| | - Bas G J Surewaard
- Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AB, Canada. .,Department of Medical Microbiology, University Medical Centre, Utrecht, Netherlands.
| |
Collapse
|
218
|
Plotkin BJ, Konakieva MI. Attenuation of antimicrobial activity by the human steroid hormones. Steroids 2017; 128:120-127. [PMID: 28951169 DOI: 10.1016/j.steroids.2017.09.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 08/28/2017] [Accepted: 09/20/2017] [Indexed: 11/16/2022]
Abstract
Upon entering the human host, Staphylococcus aureus is exposed to endogenous steroid hormones. The interaction between S. aureus and dehydroepiandosterone (DHEA) results in an increased resistance to the host cationic defense peptide, β-1 defensin, as well as vancomycin and other antibiotics that have a positive charge. The increased resistance to vancomycin is phenotypic and appears to correlate with a DHEA-mediated alteration in cell surface architecture. DHEA-mediated cell surface changes include alterations in: cell surface charge, surface hydrophobicity, capsule production, and carotenoid production. In addition, exposure to DHEA results in decreased resistance to lysis by Triton X-100 and lysozyme, indicating activation of murien hydrolase activity. We propose that DHEA is an interspecies quorum-like signal that triggers innate phenotypic host survival strategies in S. aureus that include increased carotenoid production and increased vancomycin resistance. Furthermore, this DHEA-mediated survival system may share the cholesterol-squalene pathway shown to be statin sensitive thus, providing a potential pathway for drug targeting.
Collapse
Affiliation(s)
- Balbina J Plotkin
- Department of Microbiology and Immunology, Midwestern University, Downers Grove, IL 60515, United States.
| | - Monika I Konakieva
- Department of Chemistry, American University, Washington, DC 20016, United States.
| |
Collapse
|
219
|
Horn J, Stelzner K, Rudel T, Fraunholz M. Inside job: Staphylococcus aureus host-pathogen interactions. Int J Med Microbiol 2017; 308:607-624. [PMID: 29217333 DOI: 10.1016/j.ijmm.2017.11.009] [Citation(s) in RCA: 136] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 11/17/2017] [Accepted: 11/21/2017] [Indexed: 12/21/2022] Open
Abstract
Staphylococcus aureus is a notorious opportunistic pathogen causing a plethora of diseases. Recent research established that once phagocytosed by neutrophils and macrophages, a certain percentage of S. aureus is able to survive within these phagocytes which thereby even may contribute to dissemination of the pathogen. S. aureus further induces its uptake by otherwise non-phagocytic cells and the ensuing intracellular cytotoxicity is suggested to lead to tissue destruction, whereas bacterial persistence within cells is thought to lead to immune evasion and chronicity of infections. We here review recent work on the S. aureus host pathogen interactions with a focus on the intracellular survival of the pathogen.
Collapse
Affiliation(s)
- Jessica Horn
- Chair of Microbiology, Biocenter, University of Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Kathrin Stelzner
- Chair of Microbiology, Biocenter, University of Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Thomas Rudel
- Chair of Microbiology, Biocenter, University of Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Martin Fraunholz
- Chair of Microbiology, Biocenter, University of Würzburg, Am Hubland, 97074 Würzburg, Germany.
| |
Collapse
|
220
|
Grayczyk JP, Harvey CJ, Laczkovich I, Alonzo F. A Lipoylated Metabolic Protein Released by Staphylococcus aureus Suppresses Macrophage Activation. Cell Host Microbe 2017; 22:678-687.e9. [PMID: 29056428 PMCID: PMC5683407 DOI: 10.1016/j.chom.2017.09.004] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Revised: 07/29/2017] [Accepted: 09/08/2017] [Indexed: 11/30/2022]
Abstract
The virulence factors of pathogenic microbes often have single functions that permit immune suppression. However, a proportion possess multiple activities and are considered moonlighting proteins. By examining secreted virulence factors of Staphylococcus aureus, we determine that the bacterial lipoic acid synthetase LipA suppresses macrophage activation. LipA is known to modify the E2 subunit of the metabolic enzyme complex pyruvate dehydrogenase (E2-PDH) with a fatty acid derivative, lipoic acid, yielding the metabolic protein lipoyl-E2-PDH. We demonstrate that lipoyl-E2-PDH is also released by S. aureus and moonlights as a macrophage immunosuppressant by reducing Toll-like receptor 1/2 (TLR1/2) activation by bacterial lipopeptides. A LipA-deficient strain induces heightened pro-inflammatory cytokine production, which is diminished in the absence of TLR2. During murine systemic infection, LipA suppresses pro-inflammatory macrophage activation, rendering these cells inefficient at controlling infection. These observations suggest that bacterial metabolism and immune evasion are linked by virtue of this moonlighting protein.
Collapse
Affiliation(s)
- James P Grayczyk
- Department of Microbiology and Immunology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL 60153, USA
| | - Cameron J Harvey
- Department of Microbiology and Immunology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL 60153, USA
| | - Irina Laczkovich
- Department of Microbiology and Immunology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL 60153, USA
| | - Francis Alonzo
- Department of Microbiology and Immunology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL 60153, USA.
| |
Collapse
|
221
|
Nam EY, Yang SJ, Kim ES, Cho JE, Park KH, Jung SI, Yoon N, Kim DM, Lee CS, Jang HC, Park Y, Lee KS, Kwak YG, Lee JH, Park SY, Hwang JH, Kim M, Song KH, Kim HB. Emergence of Daptomycin-Nonsusceptible Methicillin-Resistant Staphylococcus aureus Clinical Isolates Among Daptomycin-Naive Patients in Korea. Microb Drug Resist 2017; 24:534-541. [PMID: 29863982 DOI: 10.1089/mdr.2017.0212] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
This study was conducted to assess emergence of daptomycin-nonsusceptible (DAP-NS) phenotype in DAP-naive patients with invasive Staphylococcus aureus (ISA) infections in Korea. A total of 208 S. aureus clinical isolates were selected from a previous prospective study on ISA infections and evaluated for DAP-NS. Although DAP has never been introduced in Korea, five DAP-NS S. aureus strains (2.4%) were identified among 208 S. aureus strains collected from ISA infections. The DAP-NS phenotype was observed only in methicillin-resistant S. aureus (MRSA) strains, but not in methicillin-susceptible S. aureus strains. One DAP-NS MRSA strain belonged to sequence type 72 (ST72) and four were ST5 MRSA strains, three of which were heteroresistant vancomycin (VAN)-intermediate S. aureus. All these five DAP-NS MRSA strains were from healthcare-associated infections without prior exposure to VAN within 30 days. While the ST72 MRSA strain exhibited DAP-NS phenotype via charge repulsion mechanism, four ST5 DAP-NS S. aureus strains had charge-independent DAP-NS mechanism. None of the five DAP-NS strains displayed significant increase in cell wall thickness, indicating that altered cell wall thickness was not associated with the observed DAP-NS phenotype.
Collapse
Affiliation(s)
- Eun Young Nam
- 1 Department of Internal Medicine, Seoul National University Bundang Hospital , Seongnam, Republic of Korea.,2 Department of Internal Medicine, Seoul National University College of Medicine , Seoul, Republic of Korea
| | - Soo-Jin Yang
- 3 School of Bioresources and Bioscience, Chung-Ang University , Anseong, Republic of Korea
| | - Eu Suk Kim
- 1 Department of Internal Medicine, Seoul National University Bundang Hospital , Seongnam, Republic of Korea.,2 Department of Internal Medicine, Seoul National University College of Medicine , Seoul, Republic of Korea
| | - Jeong Eun Cho
- 1 Department of Internal Medicine, Seoul National University Bundang Hospital , Seongnam, Republic of Korea
| | - Kyung-Hwa Park
- 4 Department of Internal Medicine, Chonnam National University Hospital , Gwangju, Republic of Korea
| | - Sook-In Jung
- 4 Department of Internal Medicine, Chonnam National University Hospital , Gwangju, Republic of Korea
| | - Nara Yoon
- 5 Department of Internal Medicine, Chosun University Hospital , Gwangju, Republic of Korea
| | - Dong-Min Kim
- 5 Department of Internal Medicine, Chosun University Hospital , Gwangju, Republic of Korea
| | - Chang-Seop Lee
- 6 Department of Internal Medicine, Chonbuk National University , Jeonju, Republic of Korea
| | - Hee-Chang Jang
- 7 Department of Internal Medicine, Chonnam National University Hwasun Hospital , Hwasun, Republic of Korea
| | - Yoonseon Park
- 8 Department of Internal Medicine, National Health Insurance Corporation Ilsan Hospital , Goyang, Republic of Korea
| | - Kkot Sil Lee
- 9 Department of Internal Medicine, Myongji Hospital , Goyang, Republic of Korea
| | - Yee Gyung Kwak
- 10 Department of Internal Medicine, Inje University Ilsan Paik Hospital , Goyang, Republic of Korea
| | - Jae Hoon Lee
- 11 Department of Internal Medicine, Wonkwang University Hospital , Iksan, Republic of Korea
| | - Seong Yeon Park
- 12 Department of Internal Medicine, Dongguk University Ilsan Hospital , Goyang, Republic of Korea
| | - Joo-Hee Hwang
- 1 Department of Internal Medicine, Seoul National University Bundang Hospital , Seongnam, Republic of Korea.,2 Department of Internal Medicine, Seoul National University College of Medicine , Seoul, Republic of Korea
| | - Moonsuk Kim
- 1 Department of Internal Medicine, Seoul National University Bundang Hospital , Seongnam, Republic of Korea.,2 Department of Internal Medicine, Seoul National University College of Medicine , Seoul, Republic of Korea
| | - Kyoung-Ho Song
- 1 Department of Internal Medicine, Seoul National University Bundang Hospital , Seongnam, Republic of Korea.,2 Department of Internal Medicine, Seoul National University College of Medicine , Seoul, Republic of Korea
| | - Hong Bin Kim
- 1 Department of Internal Medicine, Seoul National University Bundang Hospital , Seongnam, Republic of Korea.,2 Department of Internal Medicine, Seoul National University College of Medicine , Seoul, Republic of Korea
| |
Collapse
|
222
|
Impact of cell wall peptidoglycan O- acetylation on the pathogenesis of Staphylococcus aureus in septic arthritis. Int J Med Microbiol 2017; 307:388-397. [DOI: 10.1016/j.ijmm.2017.08.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Revised: 07/18/2017] [Accepted: 08/04/2017] [Indexed: 02/02/2023] Open
|
223
|
Abstract
Lysozyme is a cornerstone of innate immunity. The canonical mechanism for bacterial killing by lysozyme occurs through the hydrolysis of cell wall peptidoglycan (PG). Conventional type (c-type) lysozymes are also highly cationic and can kill certain bacteria independently of PG hydrolytic activity. Reflecting the ongoing arms race between host and invading microorganisms, both gram-positive and gram-negative bacteria have evolved mechanisms to thwart killing by lysozyme. In addition to its direct antimicrobial role, more recent evidence has shown that lysozyme modulates the host immune response to infection. The degradation and lysis of bacteria by lysozyme enhance the release of bacterial products, including PG, that activate pattern recognition receptors in host cells. Yet paradoxically, lysozyme is important for the resolution of inflammation at mucosal sites. This review will highlight recent advances in our understanding of the diverse mechanisms that bacteria use to protect themselves against lysozyme, the intriguing immunomodulatory function of lysozyme, and the relationship between these features in the context of infection.
Collapse
Affiliation(s)
- Stephanie A. Ragland
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, Virginia, United States of America
| | - Alison K. Criss
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, Virginia, United States of America
- * E-mail:
| |
Collapse
|
224
|
Langer MN, Blodkamp S, Bayerbach M, Feßler AT, de Buhr N, Gutsmann T, Kreienbrock L, Schwarz S, von Köckritz-Blickwede M. Testing cathelicidin susceptibility of bacterial mastitis isolates: Technical challenges and data output for clinical isolates. Vet Microbiol 2017; 210:107-115. [PMID: 29103679 DOI: 10.1016/j.vetmic.2017.08.022] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2017] [Accepted: 08/29/2017] [Indexed: 12/11/2022]
Abstract
Bovine mastitis caused by bacterial pathogens, such as Staphylococcus (S.) aureus and Escherichia (E.) coli, is a major economic problem in dairy industry. In order to limit the presence of multi-resistant bacteria in bovine mastitis, alternatives for the treatment with antibiotics are urgently needed. Antimicrobial peptides (AMPs) have recently been discussed as a potential new strategy against bacterial infections. They are key players in the innate immune system, as they can directly act against microorganisms or modulate the immune system. The aim of our study was to test S. aureus and E. coli mastitis isolates for their susceptibility to the bovine cathelicidins, BMAP-27 and BMAP-28. Susceptibility testing was performed in analogy to the broth microdilution criteria described by the Clinical and Laboratory Standard Institute (CLSI) to determine MICs of 50 clinical S. aureus and 50 clinical E. coli isolates for BMAP-27 and BMAP-28. Based on the repetitive testing of four well-selected reference strains, the homogeneity of MIC variances for each peptide as well as the effect of temperature, oxygen level and plastic polymers on MIC testing was determined. Statistical analysis revealed not only strong peptide-specific variances, but also strain-specific variances in the technical procedure. Finally, using this technique, susceptibility testing of the field isolates revealed statistically significant peptide-specific differences in the MICs. While BMAP-27 showed lower MICs for E. coli, BMAP-28 showed lower MICs for S. aureus. However, these results clearly illustrate the need of susceptibility testing of AMPs on several unrelated strains and not only on one selected test organism.
Collapse
Affiliation(s)
- Melissa N Langer
- Institute for Physiological Chemistry, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany; Research Center for Emerging Infections and Zoonoses (RIZ), University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
| | - Stefanie Blodkamp
- Institute for Physiological Chemistry, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
| | - Martin Bayerbach
- Institute for Biometry, Epidemiology and Information Processing, WHO-Collaborating Center for Research and Training for Health at the Human-Animal-Environment Interface, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
| | - Andrea T Feßler
- Institute of Microbiology and Epizootics, Center for Infection Medicine, Department of Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
| | - Nicole de Buhr
- Institute for Physiological Chemistry, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany; Research Center for Emerging Infections and Zoonoses (RIZ), University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
| | - Thomas Gutsmann
- Research Group Biophysics, Research Centre Borstel, Borstel, Germany
| | - Lothar Kreienbrock
- Institute for Biometry, Epidemiology and Information Processing, WHO-Collaborating Center for Research and Training for Health at the Human-Animal-Environment Interface, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
| | - Stefan Schwarz
- Institute of Microbiology and Epizootics, Center for Infection Medicine, Department of Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
| | - Maren von Köckritz-Blickwede
- Institute for Physiological Chemistry, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany; Research Center for Emerging Infections and Zoonoses (RIZ), University of Veterinary Medicine Hannover, Foundation, Hannover, Germany.
| |
Collapse
|
225
|
Inhibition of the ATP Synthase Eliminates the Intrinsic Resistance of Staphylococcus aureus towards Polymyxins. mBio 2017; 8:mBio.01114-17. [PMID: 28874470 PMCID: PMC5587909 DOI: 10.1128/mbio.01114-17] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Staphylococcus aureus is intrinsically resistant to polymyxins (polymyxin B and colistin), an important class of cationic antimicrobial peptides used in treatment of Gram-negative bacterial infections. To understand the mechanisms underlying intrinsic polymyxin resistance in S. aureus, we screened the Nebraska Transposon Mutant Library established in S. aureus strain JE2 for increased susceptibility to polymyxin B. Nineteen mutants displayed at least 2-fold reductions in MIC, while the greatest reductions (8-fold) were observed for mutants with inactivation of either graS, graR, vraF, or vraG or the subunits of the ATP synthase (atpA, atpB, atpG, or atpH), which during respiration is the main source of energy. Inactivation of atpA also conferred hypersusceptibility to colistin and the aminoglycoside gentamicin, whereas susceptibilities to nisin, gallidermin, bacitracin, vancomycin, ciprofloxacin, linezolid, daptomycin, and oxacillin were unchanged. ATP synthase activity is known to be inhibited by oligomycin A, and the presence of this compound increased polymyxin B-mediated killing of S. aureus Our results demonstrate that the ATP synthase contributes to intrinsic resistance of S. aureus towards polymyxins and that inhibition of the ATP synthase sensitizes S. aureus to this group of compounds. These findings show that by modulation of bacterial metabolism, new classes of antibiotics may show efficacy against pathogens towards which they were previously considered inapplicable. In light of the need for new treatment options for infections with serious pathogens like S. aureus, this approach may pave the way for novel applications of existing antibiotics.IMPORTANCE Bacterial pathogens that cause disease in humans remain a serious threat to public health, and antibiotics are still our primary weapon in treating bacterial diseases. The ability to eradicate bacterial infections is critically challenged by development of resistance to all clinically available antibiotics. Polymyxins constitute an important class of antibiotics for treatment of infections caused by Gram-negative pathogens, whereas Gram-positive bacteria remain largely insusceptible towards class of antibiotics. Here we performed a whole-genome screen among nonessential genes for polymyxin intrinsic resistance determinants in Staphylococcus aureus We found that the ATP synthase is important for polymyxin susceptibility and that inhibition of the ATP synthase sensitizes S. aureus towards polymyxins. Our study provides novel insights into the mechanisms that limit polymyxin activity against S. aureus and provides valuable targets for inhibitors to potentially enable the use of polymyxins against S. aureus and other Gram-positive pathogens.
Collapse
|
226
|
Kamar R, Réjasse A, Jéhanno I, Attieh Z, Courtin P, Chapot-Chartier MP, Nielsen-Leroux C, Lereclus D, El Chamy L, Kallassy M, Sanchis-Borja V. DltX of Bacillus thuringiensis Is Essential for D-Alanylation of Teichoic Acids and Resistance to Antimicrobial Response in Insects. Front Microbiol 2017; 8:1437. [PMID: 28824570 PMCID: PMC5541007 DOI: 10.3389/fmicb.2017.01437] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Accepted: 07/14/2017] [Indexed: 11/13/2022] Open
Abstract
The dlt operon of Gram-positive bacteria is required for the incorporation of D-alanine esters into cell wall-associated teichoic acids (TAs). Addition of D-alanine to TAs reduces the negative charge of the cell envelope thereby preventing cationic antimicrobial peptides (CAMPs) from reaching their target of action on the bacterial surface. In most gram-positive bacteria, this operon consists of five genes dltXABCD but the involvement of the first ORF (dltX) encoding a small protein of unknown function, has never been investigated. The aim of this study was to establish whether this protein is involved in the D-alanylation process in Bacillus thuringiensis. We, therefore constructed an in frame deletion mutant of dltX, without affecting the expression of the other genes of the operon. The growth characteristics of the dltX mutant and those of the wild type strain were similar under standard in vitro conditions. However, disruption of dltX drastically impaired the resistance of B. thuringiensis to CAMPs and significantly attenuated its virulence in two insect species. Moreover, high-performance liquid chromatography studies showed that the dltX mutant was devoid of D-alanine, and electrophoretic mobility measurements indicated that the cells carried a higher negative surface charge. Scanning electron microscopy experiments showed morphological alterations of these mutant bacteria, suggesting that depletion of D-alanine from TAs affects cell wall structure. Our findings suggest that DltX is essential for the incorporation of D-alanyl esters into TAs. Therefore, DltX plays a direct role in the resistance to CAMPs, thus contributing to the survival of B. thuringiensis in insects. To our knowledge, this work is the first report examining the involvement of dltX in the D-alanylation of TAs.
Collapse
Affiliation(s)
- Rita Kamar
- INRA, UMR1319 MicalisJouy-en-Josas, France.,AgroParisTech, UMR MicalisJouy-en-Josas, France.,Laboratoire de Génétique de la Drosophile et Virulence Microbienne, Université Saint-JosephBeirut, Lebanon
| | - Agnès Réjasse
- INRA, UMR1319 MicalisJouy-en-Josas, France.,AgroParisTech, UMR MicalisJouy-en-Josas, France
| | - Isabelle Jéhanno
- INRA, UMR1319 MicalisJouy-en-Josas, France.,AgroParisTech, UMR MicalisJouy-en-Josas, France
| | - Zaynoun Attieh
- Laboratoire de Génétique de la Drosophile et Virulence Microbienne, Université Saint-JosephBeirut, Lebanon
| | - Pascal Courtin
- INRA, UMR1319 MicalisJouy-en-Josas, France.,AgroParisTech, UMR MicalisJouy-en-Josas, France
| | | | | | - Didier Lereclus
- INRA, UMR1319 MicalisJouy-en-Josas, France.,AgroParisTech, UMR MicalisJouy-en-Josas, France
| | - Laure El Chamy
- Laboratoire de Génétique de la Drosophile et Virulence Microbienne, Université Saint-JosephBeirut, Lebanon
| | - Mireille Kallassy
- Laboratoire de Génétique de la Drosophile et Virulence Microbienne, Université Saint-JosephBeirut, Lebanon
| | - Vincent Sanchis-Borja
- INRA, UMR1319 MicalisJouy-en-Josas, France.,AgroParisTech, UMR MicalisJouy-en-Josas, France
| |
Collapse
|
227
|
Sabaté Brescó M, Harris LG, Thompson K, Stanic B, Morgenstern M, O'Mahony L, Richards RG, Moriarty TF. Pathogenic Mechanisms and Host Interactions in Staphylococcus epidermidis Device-Related Infection. Front Microbiol 2017; 8:1401. [PMID: 28824556 PMCID: PMC5539136 DOI: 10.3389/fmicb.2017.01401] [Citation(s) in RCA: 117] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 07/11/2017] [Indexed: 12/25/2022] Open
Abstract
Staphylococcus epidermidis is a permanent member of the normal human microbiota, commonly found on skin and mucous membranes. By adhering to tissue surface moieties of the host via specific adhesins, S. epidermidis is capable of establishing a lifelong commensal relationship with humans that begins early in life. In its role as a commensal organism, S. epidermidis is thought to provide benefits to human host, including out-competing more virulent pathogens. However, largely due to its capacity to form biofilm on implanted foreign bodies, S. epidermidis has emerged as an important opportunistic pathogen in patients receiving medical devices. S. epidermidis causes approximately 20% of all orthopedic device-related infections (ODRIs), increasing up to 50% in late-developing infections. Despite this prevalence, it remains underrepresented in the scientific literature, in particular lagging behind the study of the S. aureus. This review aims to provide an overview of the interactions of S. epidermidis with the human host, both as a commensal and as a pathogen. The mechanisms retained by S. epidermidis that enable colonization of human skin as well as invasive infection, will be described, with a particular focus upon biofilm formation. The host immune responses to these infections are also described, including how S. epidermidis seems to trigger low levels of pro-inflammatory cytokines and high levels of interleukin-10, which may contribute to the sub-acute and persistent nature often associated with these infections. The adaptive immune response to S. epidermidis remains poorly described, and represents an area which may provide significant new discoveries in the coming years.
Collapse
Affiliation(s)
- Marina Sabaté Brescó
- Musculoskeletal Infection, AO Research Institute DavosDavos, Switzerland.,Molecular Immunology, Swiss Institute of Allergy and Asthma Research, University of ZurichDavos, Switzerland
| | - Llinos G Harris
- Microbiology and Infectious Diseases, Institute of Life Science, Swansea University Medical SchoolSwansea, United Kingdom
| | - Keith Thompson
- Musculoskeletal Infection, AO Research Institute DavosDavos, Switzerland
| | - Barbara Stanic
- Musculoskeletal Infection, AO Research Institute DavosDavos, Switzerland
| | - Mario Morgenstern
- Department of Orthopedic and Trauma Surgery, University Hospital BaselBasel, Switzerland
| | - Liam O'Mahony
- Molecular Immunology, Swiss Institute of Allergy and Asthma Research, University of ZurichDavos, Switzerland
| | - R Geoff Richards
- Musculoskeletal Infection, AO Research Institute DavosDavos, Switzerland
| | - T Fintan Moriarty
- Musculoskeletal Infection, AO Research Institute DavosDavos, Switzerland
| |
Collapse
|
228
|
Pensinger DA, Schaenzer AJ, Sauer JD. Do Shoot the Messenger: PASTA Kinases as Virulence Determinants and Antibiotic Targets. Trends Microbiol 2017; 26:56-69. [PMID: 28734616 DOI: 10.1016/j.tim.2017.06.010] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 06/15/2017] [Accepted: 06/27/2017] [Indexed: 01/14/2023]
Abstract
All domains of life utilize protein phosphorylation as a mechanism of signal transduction. In bacteria, protein phosphorylation was classically thought to be mediated exclusively by histidine kinases as part of two-component signaling systems. However, it is now well appreciated that eukaryotic-like serine/threonine kinases (eSTKs) control essential processes in bacteria. A subset of eSTKs are single-pass transmembrane proteins that have extracellular penicillin-binding-protein and serine/threonine kinase-associated (PASTA) domains which bind muropeptides. In a variety of important pathogens, PASTA kinases have been implicated in regulating biofilms, antibiotic resistance, and ultimately virulence. Although there are limited examples of direct regulation of virulence factors, PASTA kinases are critical for virulence due to their roles in regulating bacterial physiology in the context of stress. This review focuses on the role of PASTA kinases in virulence for a variety of important Gram-positive pathogens and concludes with a discussion of current efforts to develop kinase inhibitors as novel antimicrobials.
Collapse
Affiliation(s)
- Daniel A Pensinger
- Microbiology Doctoral Training Program, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53706, USA; Department of Medical Microbiology and Immunology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Adam J Schaenzer
- Department of Medical Microbiology and Immunology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53706, USA; Molecular and Cellular Pharmacology Doctoral Training Program, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - John-Demian Sauer
- Microbiology Doctoral Training Program, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53706, USA; Department of Medical Microbiology and Immunology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53706, USA; Molecular and Cellular Pharmacology Doctoral Training Program, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53706, USA.
| |
Collapse
|
229
|
Guerra FE, Borgogna TR, Patel DM, Sward EW, Voyich JM. Epic Immune Battles of History: Neutrophils vs. Staphylococcus aureus. Front Cell Infect Microbiol 2017; 7:286. [PMID: 28713774 PMCID: PMC5491559 DOI: 10.3389/fcimb.2017.00286] [Citation(s) in RCA: 98] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 06/12/2017] [Indexed: 12/23/2022] Open
Abstract
Neutrophils are the most abundant leukocytes in human blood and the first line of defense after bacteria have breached the epithelial barriers. After migration to a site of infection, neutrophils engage and expose invading microorganisms to antimicrobial peptides and proteins, as well as reactive oxygen species, as part of their bactericidal arsenal. Ideally, neutrophils ingest bacteria to prevent damage to surrounding cells and tissues, kill invading microorganisms with antimicrobial mechanisms, undergo programmed cell death to minimize inflammation, and are cleared away by macrophages. Staphylococcus aureus (S. aureus) is a prevalent Gram-positive bacterium that is a common commensal and causes a wide range of diseases from skin infections to endocarditis. Since its discovery, S. aureus has been a formidable neutrophil foe that has challenged the efficacy of this professional assassin. Indeed, proper clearance of S. aureus by neutrophils is essential to positive infection outcome, and S. aureus has developed mechanisms to evade neutrophil killing. Herein, we will review mechanisms used by S. aureus to modulate and evade neutrophil bactericidal mechanisms including priming, activation, chemotaxis, production of reactive oxygen species, and resolution of infection. We will also highlight how S. aureus uses sensory/regulatory systems to tailor production of virulence factors specifically to the triggering signal, e.g., neutrophils and defensins. To conclude, we will provide an overview of therapeutic approaches that may potentially enhance neutrophil antimicrobial functions.
Collapse
Affiliation(s)
- Fermin E Guerra
- Department of Microbiology and Immunology, Montana State UniversityBozeman, MT, United States
| | - Timothy R Borgogna
- Department of Microbiology and Immunology, Montana State UniversityBozeman, MT, United States
| | - Delisha M Patel
- Department of Microbiology and Immunology, Montana State UniversityBozeman, MT, United States
| | - Eli W Sward
- Department of Microbiology and Immunology, Montana State UniversityBozeman, MT, United States
| | - Jovanka M Voyich
- Department of Microbiology and Immunology, Montana State UniversityBozeman, MT, United States
| |
Collapse
|
230
|
Zapotoczna M, Forde É, Hogan S, Humphreys H, O'Gara JP, Fitzgerald-Hughes D, Devocelle M, O'Neill E. Eradication of Staphylococcus aureus Biofilm Infections Using Synthetic Antimicrobial Peptides. J Infect Dis 2017; 215:975-983. [PMID: 28453851 DOI: 10.1093/infdis/jix062] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Accepted: 01/24/2017] [Indexed: 12/15/2022] Open
Abstract
Here, we demonstrate that antimicrobial peptides (AMPs) are an effective antibiofilm treatment when applied as catheter lock solutions (CLSs) against S. aureus biofilm infections. The activity of synthetic AMPs (Bac8c, HB43, P18, Omiganan, WMR, Ranalexin, and Polyphemusin) was measured against early and mature biofilms produced by methicillin-resistant S. aureus and methicillin-susceptible S. aureus isolates from patients with device-related infections grown under in vivo-relevant biofilm conditions. The cytotoxic and hemolytic activities of the AMPs against human cells and their immunomodulatory potential in human blood were also characterized. The D-Bac8c2,5Leu variant emerged as the most effective AMP during in vitro studies and was also highly effective in eradicating S. aureus biofilm infection when used in a CLS rat central venous catheter infection model. These data support the potential use of D-Bac8c2,5Leu, alone or in combination with other AMPs, in the treatment of S. aureus intravenous catheter infections.
Collapse
Affiliation(s)
- Marta Zapotoczna
- Department of Clinical Microbiology, Education and Research Centre at Beaumont Hospital, Ireland
| | - Éanna Forde
- Department of Clinical Microbiology, Education and Research Centre at Beaumont Hospital, Ireland.,Centre for Synthesis and Chemical Biology, Department of Pharmaceutical and Medicinal Chemistry, Royal College of Surgeons, Ireland
| | - Siobhan Hogan
- Department of Clinical Microbiology, Education and Research Centre at Beaumont Hospital, Ireland
| | - Hilary Humphreys
- Department of Clinical Microbiology, Education and Research Centre at Beaumont Hospital, Ireland.,Department of Microbiology, Beaumont Hospital, Beaumont Road, Dublin, Ireland
| | - James P O'Gara
- Department of Microbiology, Connolly Hospital, Dublin, Ireland
| | | | - Marc Devocelle
- Centre for Synthesis and Chemical Biology, Department of Pharmaceutical and Medicinal Chemistry, Royal College of Surgeons, Ireland
| | - Eoghan O'Neill
- Department of Clinical Microbiology, Education and Research Centre at Beaumont Hospital, Ireland.,Department of Microbiology, School of Natural Sciences, National University of Ireland, Galway, Ireland
| |
Collapse
|
231
|
Gimblet C, Meisel JS, Loesche MA, Cole SD, Horwinski J, Novais FO, Misic AM, Bradley CW, Beiting DP, Rankin SC, Carvalho LP, Carvalho EM, Scott P, Grice EA. Cutaneous Leishmaniasis Induces a Transmissible Dysbiotic Skin Microbiota that Promotes Skin Inflammation. Cell Host Microbe 2017; 22:13-24.e4. [PMID: 28669672 DOI: 10.1016/j.chom.2017.06.006] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2017] [Revised: 05/09/2017] [Accepted: 06/08/2017] [Indexed: 12/15/2022]
Abstract
Skin microbiota can impact allergic and autoimmune responses, wound healing, and anti-microbial defense. We investigated the role of skin microbiota in cutaneous leishmaniasis and found that human patients infected with Leishmania braziliensis develop dysbiotic skin microbiota, characterized by increases in the abundance of Staphylococcus and/or Streptococcus. Mice infected with L. major exhibit similar changes depending upon disease severity. Importantly, this dysbiosis is not limited to the lesion site, but is transmissible to normal skin distant from the infection site and to skin from co-housed naive mice. This observation allowed us to test whether a pre-existing dysbiotic skin microbiota influences disease, and we found that challenging dysbiotic naive mice with L. major or testing for contact hypersensitivity results in exacerbated skin inflammatory responses. These findings demonstrate that a dysbiotic skin microbiota is not only a consequence of tissue stress, but also enhances inflammation, which has implications for many inflammatory cutaneous diseases.
Collapse
Affiliation(s)
- Ciara Gimblet
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jacquelyn S Meisel
- Department of Dermatology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Michael A Loesche
- Department of Dermatology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Stephen D Cole
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Joseph Horwinski
- Department of Dermatology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Fernanda O Novais
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Ana M Misic
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Charles W Bradley
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Daniel P Beiting
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Shelley C Rankin
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Lucas P Carvalho
- Centro de Pesquisas Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador 40296-710, Brazil; Serviço de Imunologia, Complexo Hospitalar Prof. Edgard Santos, Universidade Federal da Bahia, Salvador 40170-115, Brazil; Instituto Nacional de Ciências e Tecnologia-Doenças Tropicais, Salvador 40110-160, Brazil
| | - Edgar M Carvalho
- Centro de Pesquisas Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador 40296-710, Brazil; Serviço de Imunologia, Complexo Hospitalar Prof. Edgard Santos, Universidade Federal da Bahia, Salvador 40170-115, Brazil; Instituto Nacional de Ciências e Tecnologia-Doenças Tropicais, Salvador 40110-160, Brazil
| | - Phillip Scott
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
| | - Elizabeth A Grice
- Department of Dermatology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
| |
Collapse
|
232
|
Mathur H, Field D, Rea MC, Cotter PD, Hill C, Ross RP. Bacteriocin-Antimicrobial Synergy: A Medical and Food Perspective. Front Microbiol 2017; 8:1205. [PMID: 28706513 PMCID: PMC5489601 DOI: 10.3389/fmicb.2017.01205] [Citation(s) in RCA: 123] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 06/14/2017] [Indexed: 12/18/2022] Open
Abstract
The continuing emergence of multi-drug resistant pathogens has sparked an interest in seeking alternative therapeutic options. Antimicrobial combinatorial therapy is one such avenue. A number of studies have been conducted, involving combinations of bacteriocins with other antimicrobials, to circumvent the development of antimicrobial resistance and/or increase antimicrobial potency. Such bacteriocin-antimicrobial combinations could have tremendous value, in terms of reducing the likelihood of resistance development due to the involvement of two distinct mechanisms of antimicrobial action. Furthermore, antimicrobial synergistic interactions may also have potential financial implications in terms of decreasing the costs of treatment by reducing the concentration of an expensive antimicrobial and utilizing it in combination with an inexpensive one. In addition, combinatorial therapies with bacteriocins can broaden antimicrobial spectra and/or result in a reduction in the concentration of an antibiotic required for effective treatments to the extent that potentially toxic or adverse side effects can be reduced or eliminated. Here, we review studies in which bacteriocins were found to be effective in combination with other antimicrobials, with a view to targeting clinical and/or food-borne pathogens. Furthermore, we discuss some of the bottlenecks which are currently hindering the development of bacteriocins as viable therapeutic options, as well as addressing the need to exercise caution when attempting to predict clinical outcomes of bacteriocin-antimicrobial combinations.
Collapse
Affiliation(s)
- Harsh Mathur
- Teagasc Food Research Centre, MooreparkCork, Ireland.,APC Microbiome Institute, University College CorkCork, Ireland
| | - Des Field
- APC Microbiome Institute, University College CorkCork, Ireland.,School of Microbiology, University College CorkCork, Ireland
| | - Mary C Rea
- Teagasc Food Research Centre, MooreparkCork, Ireland.,APC Microbiome Institute, University College CorkCork, Ireland
| | - Paul D Cotter
- Teagasc Food Research Centre, MooreparkCork, Ireland.,APC Microbiome Institute, University College CorkCork, Ireland
| | - Colin Hill
- APC Microbiome Institute, University College CorkCork, Ireland.,School of Microbiology, University College CorkCork, Ireland
| | - R Paul Ross
- APC Microbiome Institute, University College CorkCork, Ireland.,School of Microbiology, University College CorkCork, Ireland
| |
Collapse
|
233
|
Yan X, Gu S, Shi Y, Cui X, Wen S, Ge J. The effect of emodin on Staphylococcus aureus strains in planktonic form and biofilm formation in vitro. Arch Microbiol 2017; 199:1267-1275. [PMID: 28616631 DOI: 10.1007/s00203-017-1396-8] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Revised: 05/06/2017] [Accepted: 06/05/2017] [Indexed: 10/19/2022]
Abstract
Staphylococcus aureus (S. aureus) is a Gram-positive pathogen and forms biofilm easily. Bacteria inside biofilms display an increased resistance to antibiotics and disinfectants. The objective of the current study was to assess the antimicrobial activities of emodin, 1,2,8-trihydroxy-6-methylanthraquinone, an anthraquinone derivative isolated from Polygonum cuspidatum and Rheum palmatum, against S. aureus CMCC26003 grown in planktonic and biofilm cultures in vitro. In addition, a possible synergistic effect between emodin and berberine chloride was evaluated. As quantified by crystal violet method, emodin significantly decreased S. aureus biofilm growth in a dose-dependent manner. The above findings were further supported by scanning electron microscopy. Moreover, the present study demonstrated that sub-MICs emodin obviously intervened the release of extracellular DNA and inhibited expression of the biofilm-related genes (cidA, icaA, dltB, agrA, sortaseA and sarA) by real-time RT-PCR. These results revealed a promising application for emodin as a therapeutic agent and an effective strategy to prevent S. aureus biofilm-related infections.
Collapse
Affiliation(s)
- Xin Yan
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, 150030, People's Republic of China
| | - Shanshan Gu
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, 150030, People's Republic of China
| | - Yunjia Shi
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, 150030, People's Republic of China
| | - Xingyang Cui
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, 150030, People's Republic of China
| | - Shanshan Wen
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, 150030, People's Republic of China
| | - Junwei Ge
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, 150030, People's Republic of China.
| |
Collapse
|
234
|
Kaplan A, Lee MW, Wolf AJ, Limon JJ, Becker CA, Ding M, Murali R, Lee EY, Liu GY, Wong GCL, Underhill DM. Direct Antimicrobial Activity of IFN-β. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2017; 198:4036-4045. [PMID: 28411186 PMCID: PMC5469413 DOI: 10.4049/jimmunol.1601226] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Accepted: 03/10/2017] [Indexed: 01/08/2023]
Abstract
Type I IFNs are a cytokine family essential for antiviral defense. More recently, type I IFNs were shown to be important during bacterial infections. In this article, we show that, in addition to known cytokine functions, IFN-β is antimicrobial. Parts of the IFN-β molecular surface (especially helix 4) are cationic and amphipathic, both classic characteristics of antimicrobial peptides, and we observed that IFN-β can directly kill Staphylococcus aureus Further, a mutant S. aureus that is more sensitive to antimicrobial peptides was killed more efficiently by IFN-β than was the wild-type S. aureus, and immunoblotting showed that IFN-β interacts with the bacterial cell surface. To determine whether specific parts of IFN-β are antimicrobial, we synthesized IFN-β helix 4 and found that it is sufficient to permeate model prokaryotic membranes using synchrotron x-ray diffraction and that it is sufficient to kill S. aureus These results suggest that, in addition to its well-known signaling activity, IFN-β may be directly antimicrobial and be part of a growing family of cytokines and chemokines, called kinocidins, that also have antimicrobial properties.
Collapse
Affiliation(s)
- Amber Kaplan
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095
| | - Michelle W Lee
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA 90095
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095
- California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA 90095
| | - Andrea J Wolf
- F. Widjaja Foundation Inflammatory Bowel and Immunobiology Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048
| | - Jose J Limon
- F. Widjaja Foundation Inflammatory Bowel and Immunobiology Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048
| | - Courtney A Becker
- F. Widjaja Foundation Inflammatory Bowel and Immunobiology Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048
| | - Minna Ding
- F. Widjaja Foundation Inflammatory Bowel and Immunobiology Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048
| | - Ramachandran Murali
- Research Division of Immunology, Cedars-Sinai Medical Center, Los Angeles, CA 90048; and
| | - Ernest Y Lee
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA 90095
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095
- California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA 90095
| | - George Y Liu
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095
- Division of Pediatric Infectious Diseases, Cedars-Sinai Medical Center, Los Angeles, CA 90048
| | - Gerard C L Wong
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA 90095;
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095
- California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA 90095
| | - David M Underhill
- F. Widjaja Foundation Inflammatory Bowel and Immunobiology Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048;
- Research Division of Immunology, Cedars-Sinai Medical Center, Los Angeles, CA 90048; and
| |
Collapse
|
235
|
Quantitation of wall teichoic acid in Staphylococcus aureus by direct measurement of monomeric units using LC-MS/MS. Anal Biochem 2017; 518:9-15. [DOI: 10.1016/j.ab.2016.10.027] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Revised: 10/19/2016] [Accepted: 10/30/2016] [Indexed: 11/24/2022]
|
236
|
Kang KM, Mishra NN, Park KT, Lee GY, Park YH, Bayer AS, Yang SJ. Phenotypic and genotypic correlates of daptomycin-resistant methicillin-susceptible Staphylococcus aureus clinical isolates. J Microbiol 2017; 55:153-159. [PMID: 28120188 DOI: 10.1007/s12275-017-6509-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Revised: 11/23/2016] [Accepted: 11/24/2016] [Indexed: 12/28/2022]
Abstract
Daptomycin (DAP) has potent activity in vitro and in vivo against both methicillin-susceptible Staphylococcus aureus (MSSA) and methicillin-resistant S. aureus (MRSA) strains. DAP-resistance (DAP-R) in S. aureus has been mainly observed in MRSA strains, and has been linked to single nucleotide polymorphisms (SNPs) within the mprF gene leading to altered cell membrane (CM) phospholipid (PL) profiles, enhanced positive surface charge, and changes in CM fluidity. The current study was designed to delineate whether these same genotypic and phenotypic perturbations are demonstrated in clinically-derived DAP-R MSSA strains. We used three isogenic DAP-susceptible (DAP-S)/DAP-R strainpairs and compared: (i) presence of mprF SNPs, (ii) temporal expression profiles of the two key determinants (mprF and dltABCD) of net positive surface charge, (iii) increased production of mprF-dependent lysinylated-phosphatidylglycerol (L-PG), (iv) positive surface charge assays, and (v) susceptibility to cationic host defense peptides (HDPs) of neutrophil and platelet origins. Similar to prior data in MRSA, DAP-R (vs DAP-S) MSSA strains exhibited hallmark hot-spot SNPs in mprF, enhanced and dysregulated expression of both mprF and dltA, L-PG overproduction, HDP resistance and enhanced positive surface charge profiles. However, in contrast to most DAP-R MRSA strains, there were no changes in CM fluidity seen. Thus, charge repulsion via mprF-and dlt-mediated enhancement of positive surface charge may be the main mechanism to explain DAP-R in MSSA strains.
Collapse
Affiliation(s)
- Kyoung-Mi Kang
- School of Bioresources and Bioscience, Chung-Ang University, Gyeonggi-do, 17546, Republic of Korea
| | - Nagendra N Mishra
- Division of Infectious Diseases, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, USA.,The David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Kun Taek Park
- Department of Veterinary Microbiology, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, 08826, Republic of Korea
| | - Gi-Yong Lee
- School of Bioresources and Bioscience, Chung-Ang University, Gyeonggi-do, 17546, Republic of Korea
| | - Yong Ho Park
- Department of Veterinary Microbiology, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, 08826, Republic of Korea
| | - Arnold S Bayer
- Division of Infectious Diseases, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, USA.,The David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Soo-Jin Yang
- School of Bioresources and Bioscience, Chung-Ang University, Gyeonggi-do, 17546, Republic of Korea.
| |
Collapse
|
237
|
Wanner S, Schade J, Keinhörster D, Weller N, George SE, Kull L, Bauer J, Grau T, Winstel V, Stoy H, Kretschmer D, Kolata J, Wolz C, Bröker BM, Weidenmaier C. Wall teichoic acids mediate increased virulence in Staphylococcus aureus. Nat Microbiol 2017; 2:16257. [DOI: 10.1038/nmicrobiol.2016.257] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Accepted: 11/28/2016] [Indexed: 12/15/2022]
|
238
|
Bastos P, Trindade F, da Costa J, Ferreira R, Vitorino R. Human Antimicrobial Peptides in Bodily Fluids: Current Knowledge and Therapeutic Perspectives in the Postantibiotic Era. Med Res Rev 2017; 38:101-146. [PMID: 28094448 PMCID: PMC7168463 DOI: 10.1002/med.21435] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Revised: 11/04/2016] [Accepted: 11/14/2016] [Indexed: 12/12/2022]
Abstract
Antimicrobial peptides (AMPs) are an integral part of the innate immune defense mechanism of many organisms. Due to the alarming increase of resistance to antimicrobial therapeutics, a growing interest in alternative antimicrobial agents has led to the exploitation of AMPs, both synthetic and isolated from natural sources. Thus, many peptide-based drugs have been the focus of increasing attention by many researchers not only in identifying novel AMPs, but in defining mechanisms of antimicrobial peptide activity as well. Herein, we review the available strategies for the identification of AMPs in human body fluids and their mechanism(s) of action. In addition, an overview of the distribution of AMPs across different human body fluids is provided, as well as its relation with microorganisms and infectious conditions.
Collapse
Affiliation(s)
- Paulo Bastos
- Department of Medical Sciences, iBiMED-Institute for Research in Biomedicine, University of Aveiro, Aveiro, Portugal
| | - Fábio Trindade
- Department of Medical Sciences, iBiMED-Institute for Research in Biomedicine, University of Aveiro, Aveiro, Portugal.,Unidade de Investigação Cardiovascular, Departamento de Cirurgia e Fisiologia, Faculdade de Medicina, Universidade do Porto, Porto, Portugal
| | - João da Costa
- Department of Chemistry, CESAM, University of Aveiro, Aveiro, Portugal
| | - Rita Ferreira
- Department of Chemistry, QOPNA, Mass Spectrometry Center, University of Aveiro, Aveiro, Portugal
| | - Rui Vitorino
- Department of Medical Sciences, iBiMED-Institute for Research in Biomedicine, University of Aveiro, Aveiro, Portugal.,Unidade de Investigação Cardiovascular, Departamento de Cirurgia e Fisiologia, Faculdade de Medicina, Universidade do Porto, Porto, Portugal
| |
Collapse
|
239
|
Kawada-Matsuo M, Komatsuzawa H. Role of Streptococcus mutans two-component systems in antimicrobial peptide resistance in the oral cavity. JAPANESE DENTAL SCIENCE REVIEW 2017; 53:86-94. [PMID: 28725299 PMCID: PMC5501732 DOI: 10.1016/j.jdsr.2016.12.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Revised: 10/14/2016] [Accepted: 12/08/2016] [Indexed: 01/24/2023] Open
Abstract
Approximately 100 trillion microorganisms exist in the oral cavity. For the commensal bacteria of the oral cavity, it is important to adapt to environmental stimuli, including human- or bacteria-derived antimicrobial agents. Recently, bacterial-specific signal transduction regulatory systems, called two-component systems (TCSs), which appear to be focused on sensing and adapting to the environment, were discovered. Streptococcus mutans is an oral commensal bacteria and is also known as a cariogenic bacteria. Although the virulence factors of S. mutans have been well demonstrated, the mechanism underlying the adaptation of the species to the oral cavity is poorly understood. S. mutans UA159 has 15 sets of TCSs. Among them, several have been demonstrated to be involved in acid tolerance, competence and biofilm formation. Recently, together with our findings, it was demonstrated that 5 TCSs were involved in resistance to antimicrobial agents. Furthermore, another TCS was associated with the production of bacteriocin. Six of 15 TCSs are associated with antimicrobial agents, implying that S. mutans can survive in the oral cavity by resisting various antimicrobial peptides. In this review, we highlight the role of antimicrobial peptides in the oral cavity.
Collapse
Affiliation(s)
- Miki Kawada-Matsuo
- Department of Oral Microbiology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890-8544, Japan
| | - Hitoshi Komatsuzawa
- Department of Oral Microbiology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890-8544, Japan
| |
Collapse
|
240
|
|
241
|
Vestergaard M, Leng B, Haaber J, Bojer MS, Vegge CS, Ingmer H. Genome-Wide Identification of Antimicrobial Intrinsic Resistance Determinants in Staphylococcus aureus. Front Microbiol 2016; 7:2018. [PMID: 28066345 PMCID: PMC5165250 DOI: 10.3389/fmicb.2016.02018] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Accepted: 12/02/2016] [Indexed: 11/24/2022] Open
Abstract
The emergence of antimicrobial resistance severely threatens our ability to treat bacterial infections. While acquired resistance has received considerable attention, relatively little is known of intrinsic resistance that allows bacteria to naturally withstand antimicrobials. Gene products that confer intrinsic resistance to antimicrobial agents may be explored for alternative antimicrobial therapies, by potentiating the efficacy of existing antimicrobials. In this study, we identified the intrinsic resistome to a broad spectrum of antimicrobials in the human pathogen, Staphylococcus aureus. We screened the Nebraska Transposon Mutant Library of 1920 single-gene inactivations in S. aureus strain JE2, for increased susceptibility to the anti-staphylococcal antimicrobials (ciprofloxacin, oxacillin, linezolid, fosfomycin, daptomycin, mupirocin, vancomycin, and gentamicin). Sixty-eight mutants were confirmed by E-test to display at least twofold increased susceptibility to one or more antimicrobial agents. The majority of the identified genes have not previously been associated with antimicrobial susceptibility in S. aureus. For example, inactivation of genes encoding for subunits of the ATP synthase, atpA, atpB, atpG and atpH, reduced the minimum inhibitory concentration (MIC) of gentamicin 16-fold. To elucidate the potential of the screen, we examined treatment efficacy in the Galleria mellonella infection model. Gentamicin efficacy was significantly improved, when treating larvae infected with the atpA mutant compared to wild type cells with gentamicin at a clinically relevant concentration. Our results demonstrate that many gene products contribute to the intrinsic antimicrobial resistance of S. aureus. Knowledge of these intrinsic resistance determinants provides alternative targets for compounds that may potentiate the efficacy of existing antimicrobial agents against this important pathogen.
Collapse
Affiliation(s)
- Martin Vestergaard
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen Frederiksberg, Denmark
| | - Bingfeng Leng
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen Frederiksberg, Denmark
| | - Jakob Haaber
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen Frederiksberg, Denmark
| | - Martin S Bojer
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen Frederiksberg, Denmark
| | - Christina S Vegge
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen Frederiksberg, Denmark
| | - Hanne Ingmer
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen Frederiksberg, Denmark
| |
Collapse
|
242
|
Matano LM, Morris HG, Wood BM, Meredith TC, Walker S. Accelerating the discovery of antibacterial compounds using pathway-directed whole cell screening. Bioorg Med Chem 2016; 24:6307-6314. [PMID: 27594549 PMCID: PMC5180449 DOI: 10.1016/j.bmc.2016.08.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Revised: 07/28/2016] [Accepted: 08/03/2016] [Indexed: 12/17/2022]
Abstract
Since the introduction of penicillin into the clinic in 1942, antibiotics have saved the lives of millions of people around the world. While penicillin and other traditional broad spectrum antibiotics were effective as monotherapies, the inexorable spread of antibiotic resistance has made alternative therapeutic approaches necessary. Compound combinations are increasingly seen as attractive options. Such combinations may include: lethal compounds; synthetically lethal compounds; or administering a lethal compound with a nonlethal compound that targets a virulence factor or a resistance factor. Regardless of the therapeutic strategy, high throughput screening is a key approach to discover potential leads. Unfortunately, the discovery of biologically active compounds that inhibit a desired pathway can be a very slow process, and an inordinate amount of time is often spent following up on compounds that do not have the desired biological activity. Here we describe a pathway-directed high throughput screening paradigm that combines the advantages of target-based and whole cell screens while minimizing the disadvantages. By exploiting this paradigm, it is possible to rapidly identify biologically active compounds that inhibit a pathway of interest. We describe some previous successful applications of this paradigm and report the discovery of a new class of d-alanylation inhibitors that may be useful as components of compound combinations to treat methicillin-resistant Staphylococcus aureus (MRSA).
Collapse
Affiliation(s)
- Leigh M Matano
- Department of Microbiology and Immunobiology, 4 Blackfan Circle, Boston, MA 02115, USA
| | - Heidi G Morris
- Department of Microbiology and Immunobiology, 4 Blackfan Circle, Boston, MA 02115, USA
| | - B McKay Wood
- Department of Microbiology and Immunobiology, 4 Blackfan Circle, Boston, MA 02115, USA
| | - Timothy C Meredith
- Department of Biochemistry and Molecular Biology, 206 South Frear Laboratory, University Park, PA 16802, USA.
| | - Suzanne Walker
- Department of Microbiology and Immunobiology, 4 Blackfan Circle, Boston, MA 02115, USA.
| |
Collapse
|
243
|
Sobhanifar S, Worrall LJ, King DT, Wasney GA, Baumann L, Gale RT, Nosella M, Brown ED, Withers SG, Strynadka NCJ. Structure and Mechanism of Staphylococcus aureus TarS, the Wall Teichoic Acid β-glycosyltransferase Involved in Methicillin Resistance. PLoS Pathog 2016; 12:e1006067. [PMID: 27973583 PMCID: PMC5156392 DOI: 10.1371/journal.ppat.1006067] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Accepted: 11/15/2016] [Indexed: 01/05/2023] Open
Abstract
In recent years, there has been a growing interest in teichoic acids as targets for antibiotic drug design against major clinical pathogens such as Staphylococcus aureus, reflecting the disquieting increase in antibiotic resistance and the historical success of bacterial cell wall components as drug targets. It is now becoming clear that β-O-GlcNAcylation of S. aureus wall teichoic acids plays a major role in both pathogenicity and antibiotic resistance. Here we present the first structure of S. aureus TarS, the enzyme responsible for polyribitol phosphate β-O-GlcNAcylation. Using a divide and conquer strategy, we obtained crystal structures of various TarS constructs, mapping high resolution overlapping N-terminal and C-terminal structures onto a lower resolution full-length structure that resulted in a high resolution view of the entire enzyme. Using the N-terminal structure that encapsulates the catalytic domain, we furthermore captured several snapshots of TarS, including the native structure, the UDP-GlcNAc donor complex, and the UDP product complex. These structures along with structure-guided mutants allowed us to elucidate various catalytic features and identify key active site residues and catalytic loop rearrangements that provide a valuable platform for anti-MRSA drug design. We furthermore observed for the first time the presence of a trimerization domain composed of stacked carbohydrate binding modules, commonly observed in starch active enzymes, but adapted here for a poly sugar-phosphate glycosyltransferase. Historically, β-lactam class antibiotics such as methicillin have been very successful in the treatment of bacterial infections, effectively destroying bacteria by rupturing their cell walls while posing little harm to the human organism. In recent years, however, the alarming emergence of Methicillin Resistant S. aureus or MRSA has resulted in a world-wide health crisis, calling on new strategies to combat pathogenesis and antibiotic resistance. As such, understanding the pathways and players that orchestrate resistance is important for overcoming these mechanisms and restoring our powerful β-lactam antibiotic arsenal. In this article we describe the crystal structure of TarS, an enzyme responsible for the glycosylation of wall teichoic acid polymers of the S. aureus cell wall, a process that has been shown to be specifically responsible for methicillin resistance in MRSA. TarS is therefore a promising drug target whose inhibition in combinational therapies would result in MRSA re-sensitization to β-lactam antibiotics. Here we present the first structure of TarS together with several snap-shots of its substrate/product complexes, and elucidate important catalytic features that are valuable for rational drug design efforts to combat resistance in MRSA.
Collapse
Affiliation(s)
- Solmaz Sobhanifar
- Department of Biochemistry and Center for Blood Research, University of British Columbia, Vancouver, British Columbia, Canada
| | - Liam J. Worrall
- Department of Biochemistry and Center for Blood Research, University of British Columbia, Vancouver, British Columbia, Canada
| | - Dustin T. King
- Department of Biochemistry and Center for Blood Research, University of British Columbia, Vancouver, British Columbia, Canada
| | - Gregory A. Wasney
- Department of Biochemistry and Center for Blood Research, University of British Columbia, Vancouver, British Columbia, Canada
| | - Lars Baumann
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia, Canada
| | - Robert T. Gale
- Department of Chemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
| | - Michael Nosella
- Department of Biochemistry and Center for Blood Research, University of British Columbia, Vancouver, British Columbia, Canada
| | - Eric D. Brown
- Department of Chemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
| | - Stephen G. Withers
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia, Canada
| | - Natalie C. J. Strynadka
- Department of Biochemistry and Center for Blood Research, University of British Columbia, Vancouver, British Columbia, Canada
- * E-mail:
| |
Collapse
|
244
|
Abstract
Antimicrobial peptides (AMPs), also known as host defense peptides, are small naturally occurring microbicidal molecules produced by the host innate immune response that function as a first line of defense to kill pathogenic microorganisms by inducing deleterious cell membrane damage. AMPs also possess signaling and chemoattractant activities and can modulate the innate immune response to enhance protective immunity or suppress inflammation. Human pathogens have evolved defense molecules and strategies to counter and survive the AMPs released by host immune cells such as neutrophils and macrophages. Here, we review the various mechanisms used by human bacterial pathogens to resist AMP-mediated killing, including surface charge modification, active efflux, alteration of membrane fluidity, inactivation by proteolytic digestion, and entrapment by surface proteins and polysaccharides. Enhanced understanding of AMP resistance at the molecular level may offer insight into the mechanisms of bacterial pathogenesis and augment the discovery of novel therapeutic targets and drug design for the treatment of recalcitrant multidrug-resistant bacterial infections.
Collapse
|
245
|
Rauch C, Cherkaoui M, Egan S, Leigh J. The bio-physics of condensation of divalent cations into the bacterial wall has implications for growth of Gram-positive bacteria. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1859:282-288. [PMID: 27940173 DOI: 10.1016/j.bbamem.2016.12.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Revised: 11/30/2016] [Accepted: 12/06/2016] [Indexed: 10/20/2022]
Abstract
BACKGROUND The anionic-polyelectrolyte nature of the wall of Gram-positive bacteria has long been suspected to be involved in homeostasis of essential cations and bacterial growth. A better understanding of the coupling between the biophysics and the biology of the wall is essential to understand some key features at play in ion-homeostasis in this living system. METHODS We consider the wall as a polyelectrolyte gel and balance the long-range electrostatic repulsion within this structure against the penalty entropy required to condense cations around wall polyelectrolytes. The resulting equations define how cations interact physically with the wall and the characteristic time required for a cation to leave the wall and enter into the bacterium to enable its usage for bacterial metabolism and growth. RESULTS The model was challenged against experimental data regarding growth of Gram-positive bacteria in the presence of varying concentration of divalent ions. The model explains qualitatively and quantitatively how divalent cations interact with the wall as well as how the biophysical properties of the wall impact on bacterial growth (in particular the initiation of bacterial growth). CONCLUSION The interplay between polymer biophysics and the biology of Gram positive bacteria is defined for the first time as a new set of variables that contribute to the kinetics of bacterial growth. GENERAL SIGNIFICANCE Providing an understanding of how bacteria capture essential metal cations in way that does not follow usual binding laws has implications when considering the control of such organisms and their ability to survive and grow in extreme environments.
Collapse
Affiliation(s)
- Cyril Rauch
- School of Veterinary Medicine and Science, University of Nottingham, College Road, Sutton Bonington, LE12 5RD, UK.
| | - Mohammed Cherkaoui
- School of Veterinary Medicine and Science, University of Nottingham, College Road, Sutton Bonington, LE12 5RD, UK
| | - Sharon Egan
- School of Veterinary Medicine and Science, University of Nottingham, College Road, Sutton Bonington, LE12 5RD, UK
| | - James Leigh
- School of Veterinary Medicine and Science, University of Nottingham, College Road, Sutton Bonington, LE12 5RD, UK
| |
Collapse
|
246
|
Myers CL, Li FKK, Koo BM, El-Halfawy OM, French S, Gross CA, Strynadka NCJ, Brown ED. Identification of Two Phosphate Starvation-induced Wall Teichoic Acid Hydrolases Provides First Insights into the Degradative Pathway of a Key Bacterial Cell Wall Component. J Biol Chem 2016; 291:26066-26082. [PMID: 27780866 PMCID: PMC5207077 DOI: 10.1074/jbc.m116.760447] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Revised: 10/22/2016] [Indexed: 11/06/2022] Open
Abstract
The cell wall of most Gram-positive bacteria contains equal amounts of peptidoglycan and the phosphate-rich glycopolymer wall teichoic acid (WTA). During phosphate-limited growth of the Gram-positive model organism Bacillus subtilis 168, WTA is lost from the cell wall in a response mediated by the PhoPR two-component system, which regulates genes involved in phosphate conservation and acquisition. It has been thought that WTA provides a phosphate source to sustain growth during starvation conditions; however, WTA degradative pathways have not been described for this or any condition of bacterial growth. Here, we uncover roles for the Bacillus subtilis PhoP regulon genes glpQ and phoD as encoding secreted phosphodiesterases that function in WTA metabolism during phosphate starvation. Unlike the parent 168 strain, ΔglpQ or ΔphoD mutants retained WTA and ceased growth upon phosphate limitation. Characterization of GlpQ and PhoD enzymatic activities, in addition to X-ray crystal structures of GlpQ, revealed distinct mechanisms of WTA depolymerization for the two enzymes; GlpQ catalyzes exolytic cleavage of individual monomer units, and PhoD catalyzes endo-hydrolysis at nonspecific sites throughout the polymer. The combination of these activities appears requisite for the utilization of WTA as a phosphate reserve. Phenotypic characterization of the ΔglpQ and ΔphoD mutants revealed altered cell morphologies and effects on autolytic activity and antibiotic susceptibilities that, unexpectedly, also occurred in phosphate-replete conditions. Our findings offer novel insight into the B. subtilis phosphate starvation response and implicate WTA hydrolase activity as a determinant of functional properties of the Gram-positive cell envelope.
Collapse
Affiliation(s)
- Cullen L Myers
- From the Department of Biochemistry and Biomedical Sciences and
- Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario L8N 3Z5, Canada
| | - Franco K K Li
- the Department of Biochemistry and Center for Blood Research, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Byoung-Mo Koo
- the Department of Microbiology and Immunology, University of California at San Francisco, San Francisco, California 94158
| | - Omar M El-Halfawy
- From the Department of Biochemistry and Biomedical Sciences and
- Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario L8N 3Z5, Canada
| | - Shawn French
- From the Department of Biochemistry and Biomedical Sciences and
- Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario L8N 3Z5, Canada
| | - Carol A Gross
- the Department of Microbiology and Immunology, University of California at San Francisco, San Francisco, California 94158
| | - Natalie C J Strynadka
- the Department of Biochemistry and Center for Blood Research, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Eric D Brown
- From the Department of Biochemistry and Biomedical Sciences and
- Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario L8N 3Z5, Canada
| |
Collapse
|
247
|
Yang X, Huang E, Yousef AE. Brevibacillin, a cationic lipopeptide that binds to lipoteichoic acid and subsequently disrupts cytoplasmic membrane of Staphylococcus aureus. Microbiol Res 2016; 195:18-23. [PMID: 28024522 DOI: 10.1016/j.micres.2016.11.002] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 11/01/2016] [Accepted: 11/05/2016] [Indexed: 11/16/2022]
Abstract
Brevibacillin is a newly-discovered antimicrobial lipopeptide produced by Brevibacillus laterosporus OSY-I1. It is active against Gram-positive bacteria, including antibiotic resistant strains. This research was initiated to investigate the mechanism of action of brevibacillin against an indicator strain, Staphylococcus aureus ATCC 6538. Results of the study proved that brevibacillin binds to lipoteichoic acid (LTA) on cell wall before interacting with cell membrane. Additionally, brevibacillin disrupts S. aureus cytoplasmic membrane by increasing its permeability, depolarization and potassium leakage. Therefore, cytoplasmic membrane serves as a major target for brevibacillin. Despite the presence of multiple sites on S. aureus cell envelope, scanning electron microscope observation didn't reveal evidence of cell lysis or any morphological defects in cells treated with brevibacillin. Based on the results of this study, we propose that the electrostatic interaction between the cationic brevibacillin and the anionic LTA helped the accumulation of the antimicrobial agent at cell surface; this was followed by translocation of the lipopeptide to the cytoplasmic membrane and disrupting its vital functions.
Collapse
Affiliation(s)
- Xu Yang
- Department of Food Science and Technology, The Ohio State University, Columbus, OH, United States
| | - En Huang
- Department of Environmental and Occupational Health, University of Arkansas for Medical Sciences, Little Rock, AR, United States
| | - Ahmed E Yousef
- Department of Food Science and Technology, The Ohio State University, Columbus, OH, United States; Department of Microbiology, The Ohio State University, Columbus, OH, United States.
| |
Collapse
|
248
|
Enhancing productivity for cascade biotransformation of styrene to (S)-vicinal diol with biphasic system in hollow fiber membrane bioreactor. Appl Microbiol Biotechnol 2016; 101:1857-1868. [DOI: 10.1007/s00253-016-7954-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 10/17/2016] [Accepted: 10/21/2016] [Indexed: 11/27/2022]
|
249
|
Xu T, Han J, Zhang J, Chen J, Wu N, Zhang W, Zhang Y. Absence of Protoheme IX Farnesyltransferase CtaB Causes Virulence Attenuation but Enhances Pigment Production and Persister Survival in MRSA. Front Microbiol 2016; 7:1625. [PMID: 27822202 PMCID: PMC5076432 DOI: 10.3389/fmicb.2016.01625] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 09/29/2016] [Indexed: 02/05/2023] Open
Abstract
The membrane protein CtaB in S. aureus is a protoheme IX farnesyltransferase involved in the synthesis of the heme containing terminal oxidases of bacterial respiratory chain. In this study, to assess the role of CtaB in S. aureus virulence, pigment production, and persister formation, we constructed a ctaB mutant in the methicillin-resistant Staphylococcus aureus (MRSA) strain USA500. We found that deletion of ctaB attenuated growth and virulence in mice but enhanced pigment production and formation of quinolone tolerant persister cells in stationary phase. RNA-seq analysis showed that deletion of ctaB caused decreased transcription of several virulence genes including RNAIII which is consistent with its virulence attenuation. In addition, transcription of 20 ribosomal genes and 24 genes involved in amino acid biosynthesis was significantly down-regulated in the ctaB knockout mutant compared with the parent strain. These findings suggest the importance of heme biosynthesis in virulence and persister formation of S. aureus.
Collapse
Affiliation(s)
- Tao Xu
- Key Laboratory of Medical Molecular Virology, Huashan Hospital, Shanghai Medical College of Fudan UniversityShanghai, China
| | - Jian Han
- Department of Pathogenic Biology, School of Basic Medical Sciences, Lanzhou UniversityLanzhou, China
| | - Jia Zhang
- Key Laboratory of Medical Molecular Virology, Huashan Hospital, Shanghai Medical College of Fudan UniversityShanghai, China
| | - Jiazhen Chen
- Key Laboratory of Medical Molecular Virology, Huashan Hospital, Shanghai Medical College of Fudan UniversityShanghai, China
| | - Nan Wu
- Key Laboratory of Medical Molecular Virology, Huashan Hospital, Shanghai Medical College of Fudan UniversityShanghai, China
| | - Wenhong Zhang
- Key Laboratory of Medical Molecular Virology, Huashan Hospital, Shanghai Medical College of Fudan UniversityShanghai, China
| | - Ying Zhang
- Key Laboratory of Medical Molecular Virology, Huashan Hospital, Shanghai Medical College of Fudan UniversityShanghai, China
- Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins UniversityBaltimore, MD, USA
| |
Collapse
|
250
|
Omardien S, Brul S, Zaat SAJ. Antimicrobial Activity of Cationic Antimicrobial Peptides against Gram-Positives: Current Progress Made in Understanding the Mode of Action and the Response of Bacteria. Front Cell Dev Biol 2016; 4:111. [PMID: 27790614 PMCID: PMC5063857 DOI: 10.3389/fcell.2016.00111] [Citation(s) in RCA: 115] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2016] [Accepted: 09/21/2016] [Indexed: 01/11/2023] Open
Abstract
Antimicrobial peptides (AMPs) have been proposed as a novel class of antimicrobials that could aid the fight against antibiotic resistant bacteria. The mode of action of AMPs as acting on the bacterial cytoplasmic membrane has often been presented as an enigma and there are doubts whether the membrane is the sole target of AMPs. Progress has been made in clarifying the possible targets of these peptides, which is reported in this review with as focus gram-positive vegetative cells and spores. Numerical estimates are discussed to evaluate the possibility that targets, other than the membrane, could play a role in susceptibility to AMPs. Concerns about possible resistance that bacteria might develop to AMPs are addressed. Proteomics, transcriptomics, and other molecular techniques are reviewed in the context of explaining the response of bacteria to the presence of AMPs and to predict what resistance strategies might be. Emergent mechanisms are cell envelope stress responses as well as enzymes able to degrade and/or specifically bind (and thus inactivate) AMPs. Further studies are needed to address the broadness of the AMP resistance and stress responses observed.
Collapse
Affiliation(s)
- Soraya Omardien
- Department of Molecular Biology and Microbial Food Safety, Swammerdam Institute for Life Sciences, University of Amsterdam Amsterdam, Netherlands
| | - Stanley Brul
- Department of Molecular Biology and Microbial Food Safety, Swammerdam Institute for Life Sciences, University of Amsterdam Amsterdam, Netherlands
| | - Sebastian A J Zaat
- Department of Medical Microbiology, Center for Infection and Immunity Amsterdam, Academic Medical Center, University of Amsterdam Amsterdam, Netherlands
| |
Collapse
|