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Refai MY, Elazzazy AM, Desouky SE, Abu-Elghait M, Fayed EA, Alajel SM, Alajlan AA, Albureikan MO, Nakayama J. Interception of Epoxide ring to quorum sensing system in Enterococcus faecalis and Staphylococcus aureus. AMB Express 2023; 13:126. [PMID: 37946062 PMCID: PMC10636001 DOI: 10.1186/s13568-023-01633-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2023] [Accepted: 10/27/2023] [Indexed: 11/12/2023] Open
Abstract
Quorum sensing inhibitor (QSI) has been attracting attention as anti-virulence agent which disarms pathogens of their virulence rather than killing them. QSI marking cyclic peptide-mediated QS in Gram-positive bacteria is an effective tool to overcome the crisis of antibiotic-dependent chemotherapy due to the emergence of drug resistance strain, e.g., methicillin resistant Staphylococcus aureus (MRSA) and Vancomycin resistant Enterococci (VRE). From a semi-large-scale screening thus far carried out, two Epoxide compounds, Ambuic acid and Synerazol, have been found to efficiently block agr and fsr QS systems, suggesting that the Epoxide group is involved in the mode of action of these QSIs. To address this notion, known natural Epoxide compounds, Cerulenin and Fosfomycin were examined for QSI activity for the agr and fsr systems in addition to in silico and SAR studies. As a result, most of investigated Epoxide containing antibiotics correlatively interfere with QSI activity for the agr and fsr systems under sublethal concentrations.
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Affiliation(s)
- Mohammed Y Refai
- Department of Biological Science, College of Science, University of Jeddah, Jeddah, Saudi Arabia
| | - Ahmed M Elazzazy
- Department of Biological Science, College of Science, University of Jeddah, Jeddah, Saudi Arabia
| | - Said E Desouky
- Laboratory of Microbial Technology, Division of Systems Bioengineering, Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School, Kyushu University, 819-0395, Fukuoka, Japan
- Department of Botany and Microbiology, Faculty of Science, Al-Azhar University, 11884, Cairo, Egypt
| | - Mohammed Abu-Elghait
- Department of Botany and Microbiology, Faculty of Science, Al-Azhar University, 11884, Cairo, Egypt.
| | - Eman A Fayed
- Department of Pharmaceutical Organic Chemistry, Faculty of Pharmacy (Girls), Al-Azhar University, 11754, Cairo, Egypt
| | - Sulaiman M Alajel
- Reference Laboratory for Microbiology, Executive Department of Reference Laboratories, Research and Laboratories Sector, Saudi Food and Drug Authority (SFDA), Riyadh, Saudi Arabia
| | - Abdullah A Alajlan
- Microbial Identification Division, Reference Laboratory for Microbiology, Executive Department of Reference Laboratories, Research and Laboratories Sector, Saudi Food and Drug Authority (SFDA), Riyadh, Saudi Arabia
| | - Mona O Albureikan
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, 21589, Jeddah, Saudi Arabia
| | - Jiro Nakayama
- Laboratory of Microbial Technology, Division of Systems Bioengineering, Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School, Kyushu University, 819-0395, Fukuoka, Japan
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Demonstration of the role of cell wall homeostasis in Staphylococcus aureus growth and the action of bactericidal antibiotics. Proc Natl Acad Sci U S A 2021; 118:2106022118. [PMID: 34716264 PMCID: PMC8612353 DOI: 10.1073/pnas.2106022118] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 09/02/2021] [Indexed: 12/29/2022] Open
Abstract
Bacterial cell wall peptidoglycan is essential, maintaining both cellular integrity and morphology, in the face of internal turgor pressure. Peptidoglycan synthesis is important, as it is targeted by cell wall antibiotics, including methicillin and vancomycin. Here, we have used the major human pathogen Staphylococcus aureus to elucidate both the cell wall dynamic processes essential for growth (life) and the bactericidal effects of cell wall antibiotics (death) based on the principle of coordinated peptidoglycan synthesis and hydrolysis. The death of S. aureus due to depletion of the essential, two-component and positive regulatory system for peptidoglycan hydrolase activity (WalKR) is prevented by addition of otherwise bactericidal cell wall antibiotics, resulting in stasis. In contrast, cell wall antibiotics kill via the activity of peptidoglycan hydrolases in the absence of concomitant synthesis. Both methicillin and vancomycin treatment lead to the appearance of perforating holes throughout the cell wall due to peptidoglycan hydrolases. Methicillin alone also results in plasmolysis and misshapen septa with the involvement of the major peptidoglycan hydrolase Atl, a process that is inhibited by vancomycin. The bactericidal effect of vancomycin involves the peptidoglycan hydrolase SagB. In the presence of cell wall antibiotics, the inhibition of peptidoglycan hydrolase activity using the inhibitor complestatin results in reduced killing, while, conversely, the deregulation of hydrolase activity via loss of wall teichoic acids increases the death rate. For S. aureus, the independent regulation of cell wall synthesis and hydrolysis can lead to cell growth, death, or stasis, with implications for the development of new control regimes for this important pathogen.
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Troudi A, Pagès JM, Brunel JM. Chemical Highlights Supporting the Role of Lipid A in Efficient Biological Adaptation of Gram-Negative Bacteria to External Stresses. J Med Chem 2021; 64:1816-1834. [PMID: 33538159 DOI: 10.1021/acs.jmedchem.0c02185] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The outer membrane (OM) of Gram-negative bacteria provides an efficient barrier against external noxious compounds such as antimicrobial agents. Associated with drug target modification, it contributes to the overall failure of chemotherapy. In the complex OM architecture, Lipid A plays an essential role by anchoring the lipopolysaccharide in the membrane and ensuring the spatial organization between lipids, proteins, and sugars. Currently, the targets of almost all antibiotics are intracellularly located and require translocation across membranes. We report herein an integrated view of Lipid A synthesis, membrane assembly, a structure comparison at the molecular structure level of numerous Gram-negative bacterial species, as well as its recent use as a target for original antibacterial molecules. This review paves the way for a new vision of a key membrane component that acts during bacterial adaptation to environmental stresses and for the development of new weapons against microbial resistance to usual antibiotics.
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Affiliation(s)
- Azza Troudi
- UMR-MD1, U1261, Aix Marseille Université, INSERM, SSA, MCT, 13385 Marseille, France.,Laboratory of Microorganisms and Active Biomolecules, Department of Biology, Faculty of Sciences of Tunis, University of Tunis El Manar, Tunis 1008, Tunisia
| | - Jean Marie Pagès
- UMR-MD1, U1261, Aix Marseille Université, INSERM, SSA, MCT, 13385 Marseille, France
| | - Jean Michel Brunel
- UMR-MD1, U1261, Aix Marseille Université, INSERM, SSA, MCT, 13385 Marseille, France
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Pishchany G, Kolter R. On the possible ecological roles of antimicrobials. Mol Microbiol 2020; 113:580-587. [PMID: 31975454 DOI: 10.1111/mmi.14471] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 01/13/2020] [Accepted: 01/17/2020] [Indexed: 12/29/2022]
Abstract
The Introduction of antibiotics into the clinical use in the middle of the 20th century had a profound impact on modern medicine and human wellbeing. The contribution of these wonder molecules to public health and science is hard to overestimate. Much research has informed our understanding of antibiotic mechanisms of action and resistance at inhibitory concentrations in the lab and in the clinic. Antibiotics, however, are not a human invention as most of them are either natural products produced by soil microorganisms or semisynthetic derivatives of natural products. Because we use antibiotics to inhibit the bacterial growth, it is generally assumed that growth inhibition is also their primary ecological function in the environment. Nevertheless, multiple studies point to diverse nonlethal effects that are exhibited at lower levels of antibiotics. Here we review accumulating evidence of antibiosis and of alternative functions of antibiotics exhibited at subinhibitory concentrations. We also speculate on how these effects might alter phenotypes, fitness, and community composition of microbes in the context of the environment and suggest directions for future research.
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Affiliation(s)
- Gleb Pishchany
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA
| | - Roberto Kolter
- Department of Microbiology, Harvard Medical School, Boston, MA, USA
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Dolzani L, Milan A, Scocchi M, Lagatolla C, Bressan R, Benincasa M. Sub-MIC effects of a proline-rich antibacterial peptide on clinical isolates of Acinetobacter baumannii. J Med Microbiol 2019; 68:1253-1265. [PMID: 31215857 DOI: 10.1099/jmm.0.001028] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
INTRODUCTION Acinetobacter baumannii is one of the most important nosocomial pathogens, mainly due to its ability to accumulate antibiotic-resistances and to persist in the hospital environment - characteristics related to biofilm production. It is well-known that A. baumannii is inhibited by the proline-rich peptide Bac7(1-35), but its putative effects at sub-MICs were never considered. AIMS We examined the sub-MIC effect of Bac7(1-35) on the growth rate, resistance induction and some A. baumannii features linked to virulence. METHODOLOGY Growth kinetics in the presence of sub-MICs of Bac7(1-35) were evaluated spectrophotometrically. Peptide uptake was quantified by cytometric analysis. The ability of Bac7(1-35) to interfere with biofilm production was investigated by the crystal violet method and confocal microscopy. Bacterial motility was observed at the interphase between a layer of a semi-solid medium and the polystyrene bottom of a Petri dish. The induction of resistance was evaluated after serial passages with sub-MICs of the peptide. RESULTS Although the MIC of Bac7(1-35) was between 2-4 µM for all tested strains, its effect on the growth rate at sub-MICs was strain-dependent and correlated with the amount of peptide internalized by each strain. Sub-MICs of Bac7(1-35) induced a strongly strain-dependent effect on biofilm formation and reduced motility in almost all strains, but interestingly the peptide did not induce resistance. CONCLUSION Bac7(1-35) is internalized into A. baumannii and is able to inhibit biofilm formation and bacterial motility, without inducing resistance. This study stresses the importance of considering possible effects that antimicrobials could have at sub-MICs, mimicking a common condition during antibiotic treatment.
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Affiliation(s)
- Lucilla Dolzani
- Department of Life Sciences, University of Trieste, Trieste, Italy
| | - Annalisa Milan
- Department of Life Sciences, University of Trieste, Trieste, Italy
| | - Marco Scocchi
- Department of Life Sciences, University of Trieste, Trieste, Italy
| | | | - Raffaela Bressan
- Department of Life Sciences, University of Trieste, Trieste, Italy
| | - Monica Benincasa
- Department of Life Sciences, University of Trieste, Trieste, Italy
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Rohinishree YS, Negi PS. Effect of licorice extract on cell viability, biofilm formation and exotoxin production by Staphylococcus aureus. Journal of Food Science and Technology 2015; 53:1092-100. [PMID: 27162389 DOI: 10.1007/s13197-015-2131-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Revised: 11/29/2015] [Accepted: 12/01/2015] [Indexed: 12/22/2022]
Abstract
Staphylococcus aureus is one of the most significant clinical pathogen, as it causes infections to humans and animals. Even though several antibiotics and other treatments have been used to control S. aureus infections and intoxication, bacterium is able to adapt, survive and produces exotoxins. Licorice (Glycyrrhiza glabra L.) has been used traditionally in various medicinal (antimicrobial) preparations, and Glycyrrhizic acid (GA) is the major active constituents present in it. In the present investigation the effect of licorice extract on methicillin susceptible S. aureus (FRI 722) and methicillin resistant S. aureus (ATCC 43300) growth and toxin production was studied. The MIC of licorice extract was found to be 0.25 and 2.5 mg GA ml(-1) against S. aureus FRI 722 and S. aureus ATCC 43300, respectively. Inhibition of biofilm formation was observed even at very low concentration (25 μg GA ml(-1)). Gradual decrease in expression and production of exotoxins such as α and β hemolysins and enterotoxin B was observed with the increasing concentrations of licorice extract, however, suboptimal concentration induced the expression of some of the virulence genes. This study indicated efficacy of licorice extract in controlling growth and pathogenicity of both methicillin susceptible and methicillin resistant S. aureus, however, the mechanisms of survival and toxin production at suboptimal concentration needs further study.
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Affiliation(s)
- Yadahalli Shrihari Rohinishree
- Fruit and Vegetable Technology Department, Council of Scientific and Industrial Research- Central Food Technological Research Institute, Mysore, 570 020 India
| | - Pradeep Singh Negi
- Fruit and Vegetable Technology Department, Council of Scientific and Industrial Research- Central Food Technological Research Institute, Mysore, 570 020 India
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Kaneti G, Meir O, Mor A. Controlling bacterial infections by inhibiting proton-dependent processes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015; 1858:995-1003. [PMID: 26522076 DOI: 10.1016/j.bbamem.2015.10.022] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 10/20/2015] [Accepted: 10/27/2015] [Indexed: 12/15/2022]
Abstract
Bacterial resistance to antibiotics is recognized as one of the greatest threats in modern healthcare, taking a staggering toll worldwide. New approaches for controlling bacterial infections must be designed, eventually combining multiple strategies for complimentary therapies. This review explores an old/new paradigm for multi-targeted antibacterial therapy, focused at disturbing bacterial cytoplasmic membrane functions at sub minimal inhibitory concentrations, namely through superficial physical alterations of the bilayer, thereby perturbing transmembrane signals transduction. Such a paradigm may have the advantage of fighting the infection while avoiding many of the known resistance mechanisms. This article is part of a Special Issue entitled: Antimicrobial peptides edited by Karl Lohner and Kai Hilpert.
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Affiliation(s)
- Galoz Kaneti
- Department of Biotechnology & Food Engineering, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Ohad Meir
- Department of Biotechnology & Food Engineering, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Amram Mor
- Department of Biotechnology & Food Engineering, Technion-Israel Institute of Technology, Haifa 32000, Israel.
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Ammer E, Nietzsche S, Rien C, Kühnl A, Mader T, Heller R, Sauerbrei A, Henke A. The anti-obesity drug orlistat reveals anti-viral activity. Med Microbiol Immunol 2015; 204:635-45. [DOI: 10.1007/s00430-015-0391-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Accepted: 02/06/2015] [Indexed: 12/28/2022]
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Andersson DI, Hughes D. Microbiological effects of sublethal levels of antibiotics. Nat Rev Microbiol 2014; 12:465-78. [DOI: 10.1038/nrmicro3270] [Citation(s) in RCA: 986] [Impact Index Per Article: 98.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Potent sub-MIC effect of GSK1322322 and other peptide deformylase inhibitors on in vitro growth of Staphylococcus aureus. Antimicrob Agents Chemother 2013; 58:290-6. [PMID: 24165188 DOI: 10.1128/aac.01292-13] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Peptide deformylase (PDF), a clinically unexploited antibacterial target, plays an essential role in protein maturation. PDF inhibitors, therefore, represent a new antibiotic class with a unique mode of action that provides an alternative therapy for the treatment of infections caused by drug-resistant pathogens, including methicillin-resistant Staphylococcus aureus (MRSA). GSK1322322 is a novel PDF inhibitor that is in phase II clinical development for the treatment of lower respiratory tract and skin infections. We have discovered that PDF inhibitors can prevent S. aureus in vitro growth for up to 6 h at concentrations 8- to 32-fold below their MICs. This phenomenon seems specific to PDF inhibitors, as none of the antimicrobial agents with alternative mechanisms of action tested show such a potent and widespread effect. It also appears limited to S. aureus, as PDF inhibitors do not show such an inhibition of growth at sub-MIC levels in Streptococcus pneumoniae or Haemophilus influenzae. Analysis of the effect of GSK1322322 on the early growth of 100 randomly selected S. aureus strains showed that concentrations equal to or below 1/8× MIC inhibited growth of 91% of the strains tested for 6 h, while the corresponding amount of moxifloxacin or linezolid only affected the growth of 1% and 6% of strains, respectively. Furthermore, the sub-MIC effect demonstrated by GSK1322322 appears more substantial on those strains at the higher end of the MIC spectrum. These effects may impact the clinical efficacy of GSK1322322 in serious infections caused by multidrug-resistant S. aureus.
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Shafreen RB, Pandian SK. Molecular modeling and simulation of FabG, an enzyme involved in the fatty acid pathway of Streptococcus pyogenes. J Mol Graph Model 2013; 45:1-12. [DOI: 10.1016/j.jmgm.2013.07.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Revised: 07/28/2013] [Accepted: 07/30/2013] [Indexed: 12/18/2022]
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12
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Inhibition of fatty acid synthase by amentoflavone reduces coxsackievirus B3 replication. Arch Virol 2011; 157:259-69. [DOI: 10.1007/s00705-011-1164-z] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2011] [Accepted: 10/27/2011] [Indexed: 10/15/2022]
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Surfactants, aromatic and isoprenoid compounds, and fatty acid biosynthesis inhibitors suppress Staphylococcus aureus production of toxic shock syndrome toxin 1. Antimicrob Agents Chemother 2009; 53:1898-906. [PMID: 19223628 DOI: 10.1128/aac.01293-08] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Menstrual toxic shock syndrome is a rare but potentially life-threatening illness manifest through the actions of Staphylococcus aureus toxic shock syndrome toxin 1 (TSST-1). Previous studies have shown that tampon additives can influence staphylococcal TSST-1 production. We report here on the TSST-1-suppressing activity of 34 compounds that are commonly used additives in the pharmaceutical, food, and perfume industries. Many of the tested chemicals had a minimal impact on the growth of S. aureus and yet were potent inhibitors of TSST-1 production. The TSST-1-reducing compounds included surfactants with an ether, amide, or amine linkage to their fatty acid moiety (e.g., myreth-3-myristate, Laureth-3, disodium lauroamphodiacetate, disodium lauramido monoethanolamido, sodium lauriminodipropionic acid, and triethanolamine laureth sulfate); aromatic compounds (e.g. phenylethyl and benzyl alcohols); and several isoprenoids and related compounds (e.g., terpineol and menthol). The membrane-targeting and -altering effects of the TSST-1-suppressing compounds led us to assess the activity of molecules that are known to inhibit fatty acid biosynthesis (e.g., cerulenin, triclosan, and hexachlorophene). These compounds also reduced S. aureus TSST-1 production. This study suggests that more additives than previously recognized inhibit the production of TSST-1.
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Effects of subinhibitory concentrations of antibiotics on SOS and DNA repair gene expression in Staphylococcus aureus. Antimicrob Agents Chemother 2008; 52:3394-7. [PMID: 18591271 DOI: 10.1128/aac.01599-07] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Reporter clones of Staphylococcus aureus with different SOS response- and DNA repair-associated promoter-lux gene fusion constructs were constructed to study the effects of sub-MICs of antibiotics on the transcription of the SOS and methyl mismatch repair (MMR) genes. Fluoroquinolones (FQs) upmodulated both the SOS and the MMR genes. The patterns of antibiotic-induced transcriptional modulation were altered in FQ-resistant mutants.
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Yim G, Huimi Wang H, Davies FRS J. Antibiotics as signalling molecules. Philos Trans R Soc Lond B Biol Sci 2007; 362:1195-200. [PMID: 17360275 PMCID: PMC2435582 DOI: 10.1098/rstb.2007.2044] [Citation(s) in RCA: 325] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
We present the argument that the majority of low-molecular-weight organic compounds made and secreted by microbes play roles as cell-signalling molecules in the environment. Of the large number of compounds isolated to date, only a small fraction have been shown to possess useful therapeutic antibiotic activity. However, most microbial metabolites modulate gene transcription at low concentrations, and this is proposed to be the primary effect of the compounds in the maintenance of microbial communities in the environment. Thus, microbial metabolites constitute a large collection of cell-signalling molecules that regulate gene expression in microbial populations and possibly the interactions of these populations with the surrounding organisms.
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Sibbald MJJB, Ziebandt AK, Engelmann S, Hecker M, de Jong A, Harmsen HJM, Raangs GC, Stokroos I, Arends JP, Dubois JYF, van Dijl JM. Mapping the pathways to staphylococcal pathogenesis by comparative secretomics. Microbiol Mol Biol Rev 2006; 70:755-88. [PMID: 16959968 PMCID: PMC1594592 DOI: 10.1128/mmbr.00008-06] [Citation(s) in RCA: 201] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The gram-positive bacterium Staphylococcus aureus is a frequent component of the human microbial flora that can turn into a dangerous pathogen. As such, this organism is capable of infecting almost every tissue and organ system in the human body. It does so by actively exporting a variety of virulence factors to the cell surface and extracellular milieu. Upon reaching their respective destinations, these virulence factors have pivotal roles in the colonization and subversion of the human host. It is therefore of major importance to obtain a clear understanding of the protein transport pathways that are active in S. aureus. The present review aims to provide a state-of-the-art roadmap of staphylococcal secretomes, which include both protein transport pathways and the extracytoplasmic proteins of these organisms. Specifically, an overview is presented of the exported virulence factors, pathways for protein transport, signals for cellular protein retention or secretion, and the exoproteomes of different S. aureus isolates. The focus is on S. aureus, but comparisons with Staphylococcus epidermidis and other gram-positive bacteria, such as Bacillus subtilis, are included where appropriate. Importantly, the results of genomic and proteomic studies on S. aureus secretomes are integrated through a comparative "secretomics" approach, resulting in the first definition of the core and variant secretomes of this bacterium. While the core secretome seems to be largely employed for general housekeeping functions which are necessary to thrive in particular niches provided by the human host, the variant secretome seems to contain the "gadgets" that S. aureus needs to conquer these well-protected niches.
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Affiliation(s)
- M J J B Sibbald
- Department of Medical Microbiology, University Medical Centre Groningen, Groningen, The Netherlands
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Davies J, Spiegelman GB, Yim G. The world of subinhibitory antibiotic concentrations. Curr Opin Microbiol 2006; 9:445-53. [PMID: 16942902 DOI: 10.1016/j.mib.2006.08.006] [Citation(s) in RCA: 478] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2006] [Accepted: 08/11/2006] [Indexed: 12/25/2022]
Abstract
Although antibiotics have long been known to have multiple effects on bacterial cells at low concentrations, it is only with the advent of genome transcription analyses that these activities have been studied in detail at the level of cell metabolism. It has been shown that all antibiotics, regardless of their receptors and mode of action, exhibit the phenomenon of hormesis and provoke considerable transcription activation at low concentrations. These analyses should be of value in providing information on antibiotic side-effects, in bioactive natural product discovery and antibiotic mode-of-action studies.
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Affiliation(s)
- Julian Davies
- Department of Microbiology and Immunology, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia V6T 01Z3, Canada.
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