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Ersoy SC, Gonçalves B, Cavaco G, Manna AC, Sobral RG, Nast CC, Proctor RA, Chambers HF, Cheung A, Bayer AS. Influence of Sodium Bicarbonate on Wall Teichoic Acid Synthesis and β-Lactam Sensitization in NaHCO 3-Responsive and Nonresponsive Methicillin-Resistant Staphylococcus aureus. Microbiol Spectr 2022; 10:e0342222. [PMID: 36377886 PMCID: PMC9769754 DOI: 10.1128/spectrum.03422-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 10/13/2022] [Indexed: 11/16/2022] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) strains pose major treatment challenges due to their innate resistance to most β-lactams under standard in vitro antimicrobial susceptibility testing conditions. A novel phenotype among MRSA, termed "NaHCO3 responsiveness," where certain strains display increased susceptibility to β-lactams in the presence of NaHCO3, has been identified among a relatively large proportion of MRSA isolates. One underlying mechanism of NaHCO3 responsiveness appears to be related to decreased expression and altered functionality of several genes and proteins involved in cell wall synthesis and maturation. Here, we studied the impact of NaHCO3 on wall teichoic acid (WTA) synthesis, a process intimately linked to peptidoglycan (PG) synthesis and functionality, in NaHCO3-responsive versus -nonresponsive MRSA isolates. NaHCO3 sensitized responsive MRSA strains to cefuroxime, a specific penicillin-binding protein 2 (PBP2)-inhibitory β-lactam known to synergize with early WTA synthesis inhibitors (e.g., ticlopidine). Combining cefuroxime with ticlopidine with or without NaHCO3 suggested that these latter two agents target the same step in WTA synthesis. Further, NaHCO3 decreased the abundance and molecular weight of WTA only in responsive strains. Additionally, NaHCO3 stimulated increased autolysis and aberrant cell division in responsive strains, two phenotypes associated with disruption of WTA synthesis. Of note, studies of key genes involved in the WTA biosynthetic pathway (e.g., tarO, tarG, dltA, and fmtA) indicated that the inhibitory impact of NaHCO3 on WTA biosynthesis in responsive strains likely occurred posttranslationally. IMPORTANCE MRSA is generally viewed as resistant to standard β-lactam antibiotics. However, a NaHCO3-responsive phenotype is observed in a substantial proportion of clinical MRSA strains in vitro, i.e., isolates which demonstrate enhanced susceptibility to standard β-lactam antibiotics (e.g., oxacillin) in the presence of NaHCO3. This phenotype correlates with increased MRSA clearance in vivo by standard β-lactam antibiotics, suggesting that patients with infections caused by such MRSA strains might be amenable to treatment with β-lactams. The mechanism(s) behind this phenotype is not fully understood but appears to involve mecA-PBP2a production and maturation axes. Our study adds significantly to this body of knowledge in terms of additional mechanistic targets of NaHCO3 in selected MRSA strains. This investigation demonstrates that NaHCO3 has direct impacts on S. aureus wall teichoic acid biosynthesis in NaHCO3-responsive MRSA. These findings provide an additional target for new agents being designed to synergistically kill MRSA using β-lactam antibiotics.
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Affiliation(s)
| | - Barbara Gonçalves
- Laboratory of Molecular Microbiology of Bacterial Pathogens, UCIBIO, Applied Molecular Biosciences Unit, Department of Life Sciences, Nova School of Science and Technology, Universidade Nova de Lisboa, Caparica, Portugal
- Associate Laboratory i4HB, Institute for Health and Bioeconomy, Nova School of Science and Technology, Universidade Nova de Lisboa, Caparica, Portugal
| | - Gonçalo Cavaco
- Laboratory of Molecular Microbiology of Bacterial Pathogens, UCIBIO, Applied Molecular Biosciences Unit, Department of Life Sciences, Nova School of Science and Technology, Universidade Nova de Lisboa, Caparica, Portugal
- Associate Laboratory i4HB, Institute for Health and Bioeconomy, Nova School of Science and Technology, Universidade Nova de Lisboa, Caparica, Portugal
| | - Adhar C. Manna
- Department of Microbiology & Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Rita G. Sobral
- Laboratory of Molecular Microbiology of Bacterial Pathogens, UCIBIO, Applied Molecular Biosciences Unit, Department of Life Sciences, Nova School of Science and Technology, Universidade Nova de Lisboa, Caparica, Portugal
- Associate Laboratory i4HB, Institute for Health and Bioeconomy, Nova School of Science and Technology, Universidade Nova de Lisboa, Caparica, Portugal
| | - Cynthia C. Nast
- Cedars-Sinai Medical Center, Los Angeles, California, USA
- Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Richard A. Proctor
- Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
- Department of Medical Microbiology/Immunology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
| | | | - Ambrose Cheung
- Department of Microbiology & Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Arnold S. Bayer
- The Lundquist Institute, Torrance, California, USA
- Geffen School of Medicine at UCLA, Los Angeles, California, USA
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Wang M, Buist G, van Dijl JM. Staphylococcus aureus cell wall maintenance - the multifaceted roles of peptidoglycan hydrolases in bacterial growth, fitness, and virulence. FEMS Microbiol Rev 2022; 46:6604383. [PMID: 35675307 PMCID: PMC9616470 DOI: 10.1093/femsre/fuac025] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 04/22/2022] [Accepted: 05/25/2022] [Indexed: 01/07/2023] Open
Abstract
Staphylococcus aureus is an important human and livestock pathogen that is well-protected against environmental insults by a thick cell wall. Accordingly, the wall is a major target of present-day antimicrobial therapy. Unfortunately, S. aureus has mastered the art of antimicrobial resistance, as underscored by the global spread of methicillin-resistant S. aureus (MRSA). The major cell wall component is peptidoglycan. Importantly, the peptidoglycan network is not only vital for cell wall function, but it also represents a bacterial Achilles' heel. In particular, this network is continuously opened by no less than 18 different peptidoglycan hydrolases (PGHs) encoded by the S. aureus core genome, which facilitate bacterial growth and division. This focuses attention on the specific functions executed by these enzymes, their subcellular localization, their control at the transcriptional and post-transcriptional levels, their contributions to staphylococcal virulence and their overall importance in bacterial homeostasis. As highlighted in the present review, our understanding of the different aspects of PGH function in S. aureus has been substantially increased over recent years. This is important because it opens up new possibilities to exploit PGHs as innovative targets for next-generation antimicrobials, passive or active immunization strategies, or even to engineer them into effective antimicrobial agents.
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Affiliation(s)
- Min Wang
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, PO Box 30001, 9700 RB Groningen, the Netherlands
| | | | - Jan Maarten van Dijl
- Corresponding author: Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O. box 30001, HPC EB80, 9700 RB Groningen, the Netherlands, Tel. +31-50-3615187; Fax. +31-50-3619105; E-mail:
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3
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Korobov VP, Lemkina LM, Polyudova TV. The Mechanism of Antibacterial Action of the Lantibiotic Warnerin. Microbiology (Reading) 2022. [DOI: 10.1134/s0026261722020059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Fan W, Sun Q, Li Y, Tay FR, Fan B. Synergistic mechanism of Ag +-Zn 2+ in anti-bacterial activity against Enterococcus faecalis and its application against dentin infection. J Nanobiotechnology 2018; 16:10. [PMID: 29386060 PMCID: PMC5793365 DOI: 10.1186/s12951-018-0336-3] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 01/19/2018] [Indexed: 01/21/2023] Open
Abstract
Background Ag+ and Zn2+ have already been used in combinations to obtain both enhanced antibacterial effect and low cytotoxicity. Despite this, it is still unclear how the Zn2+ co-works with Ag+ in the synergistic antibacterial activity. The main purposes of this study were to investigate the co-work pattern and optimum ratio between Ag+ and Zn2+ in their synergistic antibacterial activity against E. faecalis, the possible mechanisms behind this synergy and the primary application of optimum Ag+–Zn2+ co-work pattern against the E. faecalis biofilm on dentin. A serial of Ag+–Zn2+ atomic combination ratios were tested on both planktonic and biofilm-resident E. faecalis on dentin, their antibacterial efficiency was calculated and optimum ratio determined. And the cytotoxicity of various Ag+–Zn2+ atomic ratios was tested on MC3T3-E1 Cells. The role of Zn2+ in Ag+–Zn2+co-work was evaluated using a Zn2+ pretreatment study and membrane potential—permeability measurement. Results The results showed that the synergistically promoted antibacterial effect of Ag+–Zn2+ combinations was Zn2+ amount-dependent with the 1:9 and 1:12 Ag+–Zn2+ atomic ratios showing the most powerful ability against both planktonic and biofilm-resident E. faecalis. This co-work could likely be attributed to the depolarization of E. faecalis cell membrane by the addition of Zn2+. The cytotoxicity of the Ag+–Zn2+ atomic ratios of 1:9 and 1:12 was much lower than 2% chlorhexidine. Conclusions The Ag+–Zn2+ atomic ratios of 1:9 and 1:12 demonstrated similar strong ability against E. faecalis biofilm on dentin but much lower cytotoxicity than 2% chlorhexidine. New medications containing optimum Ag+–Zn2+ atomic ratios higher than 1:6, such as 1:9 or 1:12, could be developed against E. faecalis infection in root canals of teeth or any other parts of human body.
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Affiliation(s)
- Wei Fan
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory of Oral Biomedicine, Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan, People's Republic of China
| | - Qing Sun
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory of Oral Biomedicine, Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan, People's Republic of China
| | - Yanyun Li
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory of Oral Biomedicine, Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan, People's Republic of China
| | - Franklin R Tay
- Department of Endodontics, The Dental College of Georgia, Augusta University, Augusta, GA, USA
| | - Bing Fan
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory of Oral Biomedicine, Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan, People's Republic of China.
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McLeod FSA, Simmonds RS. Penicillin facilitates the entry of antisense constructs into Streptococcus mutans. FEMS Microbiol Lett 2013; 349:25-31. [PMID: 24111714 DOI: 10.1111/1574-6968.12286] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Accepted: 09/13/2013] [Indexed: 12/01/2022] Open
Abstract
Antisense oligonucleotides (AS-ODN) target genes in a sequence-specific manner inhibit gene function and have potential use as antimicrobial agents. Cell barriers, such as peptidoglycan, cell surface proteins and lipopolysaccharide membranes, prevent delivery of AS-ODN into the bacterial cell, limiting their use as an effective treatment option. The β-lactam antibiotic penicillin was examined for its ability to deliver phosphorothioate oligodeoxyribonucleotides (PS-ODNs) and γ(32) P-ODN into Streptococcus mutans OMZ175. Treatment of lag-phase S. mutans OMZ175 cells with penicillin and FBA (PS-ODN targeting the fructose-biphosphate aldolase gene), resulted in prolonged suppression of growth (> 24 h) and fba expression (656.9 ± 194.4-fold decrease at 5 h). Suppression of both cell growth and fba expression corresponded with a greater amount of γ(32) P-ODN becoming cell associated, with a maximum γ(32) P-ODN concentration per cell achieved 5 h after penicillin treatment (6.50 ± 1.39 × 10(8) molecules per CFU). This study confirms that for S. mutans OMZ175, the peptidoglycan layer acts as a major barrier preventing AS-ODN penetration and suggests that the use of agents such as penicillin that interfere with peptidoglycan integrity can significantly increase the uptake of PS-ODN by these cells.
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Affiliation(s)
- Felicity S A McLeod
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
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Yadav S, Joshi S, Qadar Pasha MA, Pasha S. Antimicrobial activity and mode of action of novel, N-terminal tagged tetra-peptidomimetics. MEDCHEMCOMM 2013. [DOI: 10.1039/c3md20311e] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Biswas R, Martinez RE, Göhring N, Schlag M, Josten M, Xia G, Hegler F, Gekeler C, Gleske AK, Götz F, Sahl HG, Kappler A, Peschel A. Proton-binding capacity of Staphylococcus aureus wall teichoic acid and its role in controlling autolysin activity. PLoS One 2012; 7:e41415. [PMID: 22911791 PMCID: PMC3402425 DOI: 10.1371/journal.pone.0041415] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2011] [Accepted: 06/26/2012] [Indexed: 11/18/2022] Open
Abstract
Wall teichoic acid (WTA) or related polyanionic cell wall glycopolymers are produced by most gram-positive bacterial species and have been implicated in various cellular functions. WTA and the proton gradient across bacterial membranes are known to control the activity of autolysins but the molecular details of these interactions are poorly understood. We demonstrate that WTA contributes substantially to the proton-binding capacity of Staphylococcus aureus cell walls and controls autolysis largely via the major autolysin AtlA whose activity is known to decline at acidic pH values. Compounds that increase or decrease the activity of the respiratory chain, a main source of protons in the cell wall, modulated autolysis rates in WTA-producing cells but did not affect the augmented autolytic activity observed in a WTA-deficient mutant. We propose that WTA represents a cation-exchanger like mesh in the gram-positive cell envelopes that is required for creating a locally acidified milieu to govern the pH-dependent activity of autolysins.
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Affiliation(s)
- Raja Biswas
- Interfaculty Institute of Microbiology and Infection Medicine, Cellular and Molecular Microbiology, University of Tübingen, Tübingen, Germany
| | - Raul E. Martinez
- Center for Applied Geoscience, Geomicrobiology, University of Tübingen, Tübingen, Germany
| | - Nadine Göhring
- Interfaculty Institute of Microbiology and Infection Medicine, Cellular and Molecular Microbiology, University of Tübingen, Tübingen, Germany
| | - Martin Schlag
- Interfaculty Institute of Microbiology and Infection Medicine, Microbial Genetics, University of Tübingen, Tübingen, Germany
| | - Michaele Josten
- Institute for Medical Microbiology, Immunology and Parasitology (IMMIP), Pharmaceutical Microbiology Unit, University of Bonn, Bonn, Germany
| | - Guoqing Xia
- Interfaculty Institute of Microbiology and Infection Medicine, Cellular and Molecular Microbiology, University of Tübingen, Tübingen, Germany
| | - Florian Hegler
- Center for Applied Geoscience, Geomicrobiology, University of Tübingen, Tübingen, Germany
| | - Cordula Gekeler
- Interfaculty Institute of Microbiology and Infection Medicine, Cellular and Molecular Microbiology, University of Tübingen, Tübingen, Germany
| | - Anne-Kathrin Gleske
- Interfaculty Institute of Microbiology and Infection Medicine, Cellular and Molecular Microbiology, University of Tübingen, Tübingen, Germany
| | - Friedrich Götz
- Interfaculty Institute of Microbiology and Infection Medicine, Microbial Genetics, University of Tübingen, Tübingen, Germany
| | - Hans-Georg Sahl
- Institute for Medical Microbiology, Immunology and Parasitology (IMMIP), Pharmaceutical Microbiology Unit, University of Bonn, Bonn, Germany
| | - Andreas Kappler
- Center for Applied Geoscience, Geomicrobiology, University of Tübingen, Tübingen, Germany
| | - Andreas Peschel
- Interfaculty Institute of Microbiology and Infection Medicine, Cellular and Molecular Microbiology, University of Tübingen, Tübingen, Germany
- * E-mail:
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8
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C-terminal amino acids of alpha-melanocyte-stimulating hormone are requisite for its antibacterial activity against Staphylococcus aureus. Antimicrob Agents Chemother 2011; 55:1920-9. [PMID: 21282427 DOI: 10.1128/aac.00957-10] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Alpha-melanocyte-stimulating hormone (α-MSH) is an endogenous neuropeptide that is known for its anti-inflammatory and antipyretic activities. We recently demonstrated that α-MSH possesses staphylocidal activity and causes bacterial membrane damage. To understand the role of its amino acid sequences in the staphylocidal mechanism, in the present study we investigated the antimicrobial activities of different fragments of α-MSH, i.e., α-MSH(6-13), α-MSH(11-13), and α-MSH(1-5), and compared them with that of the entire peptide. Our results showed that peptides containing the C-terminal region of α-MSH, namely, α-MSH(6-13) and α-MSH(11-13), efficiently killed >90% of both methicillin-sensitive and -resistant Staphylococcus aureus cells in the micromolar range and ∼50% of these cells in the nanomolar range; their efficiency was comparable to that of the entire α-MSH, whereas the peptide containing the N-terminal region, α-MSH(1-5), was found to be ineffective against S. aureus. The antimicrobial activity of α-MSH and its C-terminal fragments was not affected by the presence of NaCl or even divalent cations such as Ca2+ and Mg2+. Similar to the case for the parent peptide, α-MSH(6-13) and α-MSH(11-13) also depolarized and permeabilized Staphylococcus cells (∼70 to 80% of the cells were depolarized and lysed after 2 h of peptide exposure at micromolar concentrations). Furthermore, scanning and transmission electron microscopy showed remarkable morphological and ultrastructural changes on S. aureus cell surface due to exposure to α-MSH-based peptides. Thus, our observations indicate that C-terminal fragments of α-MSH retain the antimicrobial activity of entire peptide and that their mechanism of action is similar to that of full-length peptide. These observations are important and are critical in the rational design of α-MSH-based therapeutics with optimal efficacy.
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Barrett-Jolley R, Lewis R, Fallman R, Mobasheri A. The emerging chondrocyte channelome. Front Physiol 2010; 1:135. [PMID: 21423376 PMCID: PMC3059965 DOI: 10.3389/fphys.2010.00135] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2010] [Accepted: 09/09/2010] [Indexed: 11/18/2022] Open
Abstract
Chondrocytes are the resident cells of articular cartilage and are responsible for synthesizing a range of collagenous and non-collagenous extracellular matrix macromolecules. Whilst chondrocytes exist at low densities in the tissue (1-10% of the total tissue volume in mature cartilage) they are extremely active cells and are capable of responding to a range of mechanical and biochemical stimuli. These responses are necessary for the maintenance of viable cartilage and may be compromised in inflammatory diseases such as arthritis. Although chondrocytes are non-excitable cells their plasma membrane contains a rich complement of ion channels. This diverse channelome appears to be as complex as one might expect to find in excitable cells although, in the case of chondrocytes, their functions are far less well understood. The ion channels so far identified in chondrocytes include potassium channels (K(ATP), BK, K(v), and SK), sodium channels (epithelial sodium channels, voltage activated sodium channels), transient receptor potential calcium or non-selective cation channels and chloride channels. In this review we describe this emerging channelome and discuss the possible functions of a range of chondrocyte ion channels.
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Affiliation(s)
- Richard Barrett-Jolley
- Musculoskeletal Research Group, Department of Comparative Molecular Medicine, School of Veterinary Science, University of LiverpoolLiverpool, UK
| | - Rebecca Lewis
- Musculoskeletal Research Group, Department of Comparative Molecular Medicine, School of Veterinary Science, University of LiverpoolLiverpool, UK
| | - Rebecca Fallman
- Musculoskeletal Research Group, Department of Comparative Molecular Medicine, School of Veterinary Science, University of LiverpoolLiverpool, UK
| | - Ali Mobasheri
- Musculoskeletal Research Group, Division of Veterinary Medicine, School of Veterinary Medicine and Science, Faculty of Medicine and Health Sciences, University of NottinghamNottingham, Leicestershire, UK
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10
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Krupovic M, Daugelavicius R, Bamford DH. Polymyxin B induces lysis of marine pseudoalteromonads. Antimicrob Agents Chemother 2007; 51:3908-14. [PMID: 17709471 PMCID: PMC2151463 DOI: 10.1128/aac.00449-07] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Polymyxin B (PMB) is a cationic antibiotic that interacts with the envelopes of gram-negative bacterial cells. The therapeutic use of PMB was abandoned for a long time due to its undesirable side effects; however, the spread of resistance to currently used antibiotics has forced the reevaluation of PMB for clinical use. Previous studies have used enteric bacteria to examine the mode of PMB action, resulting in a somewhat limited understanding of this process. This study examined the effects of PMB on marine pseudoalteromonads and demonstrates that the frequently accepted view that "what is true for Escherichia coli is true for all bacteria" does not hold true. We show here that in contrast to the growth inhibition observed for enteric bacteria, PMB induces lysis of pseudoalteromonads, which is not prevented by high concentrations of divalent cations. Furthermore, we demonstrate that a high membrane voltage is required for the interaction of PMB with the cytoplasmic membranes of pseudoalteromonads, further elucidating the mechanisms by which PMB interacts with the cell envelopes of those gram-negative bacteria.
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Affiliation(s)
- Mart Krupovic
- Department of Biological and Environmental Sciences, 00014 University of Helsinki, Finland
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11
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Salzberg LI, Helmann JD. An antibiotic-inducible cell wall-associated protein that protects Bacillus subtilis from autolysis. J Bacteriol 2007; 189:4671-80. [PMID: 17483219 PMCID: PMC1913437 DOI: 10.1128/jb.00403-07] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In Bacillus subtilis, antibiotics that impair cell wall synthesis induce a characteristic stress response including the sigma(W) and sigma(M) regulons and the previously uncharacterized yoeB gene. Here we demonstrate that YoeB is a cell wall-associated protein with weak sequence similarity to a noncatalytic domain of class B penicillin-binding proteins. A yoeB-null mutant exhibits an increased rate of autolysis in response to cell wall-targeting antibiotics or nutrient depletion. This phenotype does not appear to be correlated with gross alterations in peptidoglycan structure or levels of autolysins. Promoter dissection experiments define a minimal region necessary for antibiotic-mediated induction of yoeB, and this region is highly conserved preceding yoeB homologs in close relatives of B. subtilis. These results support a model in which induction of YoeB in response to cell envelope stress decreases the activity of autolysins and thereby reduces the rate of antibiotic-dependent cell death.
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Affiliation(s)
- Letal I Salzberg
- Department of Microbiology, 370 Wing Hall, Cornell University, Ithaca, NY 14853, USA
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Abstract
Programmed cell death (PCD) is a genetically determined process of cellular suicide that is activated in response to cellular stress or damage, as well as in response to the developmental signals in multicellular organisms. Although historically studied in eukaryotes, it has been proposed that PCD also functions in prokaryotes, either during the developmental life cycle of certain bacteria or to remove damaged cells from a population in response to a wide variety of stresses. This review will examine several putative examples of bacterial PCD and summarize what is known about the molecular components of these systems.
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Affiliation(s)
- Kelly C Rice
- Department of Microbiology, Molecular Biology and Biochemistry, University of Idaho, Moscow, ID 83844-3052, USA
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