1
|
Mascary JB, Bordeau V, Nicolas I, Verdier MC, Rocheteau P, Cattoir V. Intracellular activity and in vivo efficacy in a mouse model of septic arthritis of the novel pseudopeptide Pep16 against Staphylococcus aureus clinical isolates. JAC Antimicrob Resist 2024; 6:dlae025. [PMID: 38410249 PMCID: PMC10895697 DOI: 10.1093/jacamr/dlae025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Accepted: 02/02/2024] [Indexed: 02/28/2024] Open
Abstract
Objectives Assessing the therapeutic potential of a novel antimicrobial pseudopeptide, Pep16, both in vitro and in vivo for the treatment of septic arthritis caused by Staphylococcus aureus. Methods Seven clinical isolates of S. aureus (two MRSA and five MSSA) were studied. MICs of Pep16 and comparators (vancomycin, teicoplanin, daptomycin and levofloxacin) were determined through the broth microdilution method. The intracellular activity of Pep16 and levofloxacin was assessed in two models of infection using non-professional (osteoblasts MG-63) or professional (macrophages THP-1) phagocytic cells. A mouse model of septic arthritis was used to evaluate the in vivo efficacy of Pep16 and vancomycin. A preliminary pharmacokinetic (PK) analysis was performed by measuring plasma concentrations using LC-MS/MS following a single subcutaneous injection of Pep16 (10 mg/kg). Results MICs of Pep16 were consistently at 8 mg/L for all clinical isolates of S. aureus (2- to 32-fold higher to those of comparators) while MBC/MIC ratios confirmed its bactericidal activity. Both Pep16 and levofloxacin (when used at 2 × MIC) significantly reduced the bacterial load of all tested isolates (two MSSA and two MRSA) within both osteoblasts and macrophages. In MSSA-infected mice, Pep16 demonstrated a significant (∼10-fold) reduction on bacterial loads in knee joints. PK analysis following a single subcutaneous administration of Pep16 revealed a gradual increase in plasma concentrations, reaching a peak of 5.6 mg/L at 12 h. Conclusions Pep16 is a promising option for the treatment of septic arthritis due to S. aureus, particularly owing to its robust intracellular activity.
Collapse
Affiliation(s)
- Jean-Baptiste Mascary
- Inserm U1230 BRM (Bacterial RNAs and Medicine), Université de Rennes, Rennes, France
- SAS Olgram, Bréhan, France
| | - Valérie Bordeau
- Inserm U1230 BRM (Bacterial RNAs and Medicine), Université de Rennes, Rennes, France
| | | | | | | | - Vincent Cattoir
- CHU de Rennes, Service de Bactériologie-Hygiène hospitalière, 2 rue Henri Le Guilloux, 35033 Rennes, France
- CNR de la Résistance aux Antibiotiques (laboratoire associé 'Entérocoques'), CHU de Rennes, Rennes, France
| |
Collapse
|
2
|
Fermon L, Burel A, Ostyn E, Dréano S, Bondon A, Chevance S, Pinel-Marie ML. Mechanism of action of sprG1-encoded type I toxins in Staphylococcus aureus: from membrane alterations to mesosome-like structures formation and bacterial lysis. Front Microbiol 2023; 14:1275849. [PMID: 37854335 PMCID: PMC10579593 DOI: 10.3389/fmicb.2023.1275849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Accepted: 09/11/2023] [Indexed: 10/20/2023] Open
Abstract
sprG1/SprF1 is a type I toxin-antitoxin system located on Staphylococcus aureus prophage. It has previously been shown that the two toxins, SprG131 and SprG144, encoded by the sprG1 gene, are two membrane-associated peptides structured in a single α-helix. Overexpression of these two peptides leads to growth inhibition and even S. aureus death. In this study, we investigated the involvement of each peptide in this toxicity, the sequence requirements necessary for SprG131 toxicity, and the mechanism of action of these two peptides. Our findings show that both peptides, when expressed individually, are able to stop growth, with higher toxicity observed for SprG131. The combination of a hydrophobic domain and a charged domain located only at the C-terminus is necessary for this toxicity, likely to retain the orientation of the transmembrane domain. A net cationic charge for SprG131 is not essential to induce a growth defect in S. aureus. Furthermore, we established a chronology of toxic events following overexpression to gain insights into the mode of action of SprG144 and SprG131. We demonstrated that mesosome-like structures are already formed when membrane is depolarized, about 20 min after peptides induction. This membrane depolarization occurs concomitantly with a depletion of intracellular ATP, leading to S. aureus growth arrest. Moreover, we hypothesized that SprG144 and SprG131 do not form large pores in the S. aureus membrane, as ATP is not excreted into the extracellular medium, and membrane permeabilization is delayed relative to membrane depolarization. The next challenge is to identify the conditions under which SprG144 and SprG131 are naturally expressed, and to uncover their potential roles during staphylococcal growth, colonization, and infection.
Collapse
Affiliation(s)
- Laurence Fermon
- Univ Rennes, INSERM, BRM – UMR_S 1230, Rennes, France
- Univ Rennes, CNRS, ISCR – UMR 6226, Rennes, France
| | - Agnès Burel
- Univ Rennes, CNRS, INSERM, BIOSIT – UAR 3480, US_S 018, Rennes, France
| | - Emeline Ostyn
- Univ Rennes, INSERM, BRM – UMR_S 1230, Rennes, France
| | | | | | | | | |
Collapse
|
3
|
Investigation of the Mechanism and Chemistry Underlying Staphylococcus aureus ' Ability to Inhibit Pseudomonas aeruginosa Growth In Vitro. J Bacteriol 2022; 204:e0017422. [PMID: 36218351 DOI: 10.1128/jb.00174-22] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Pseudomonas aeruginosa inhibits or eradicates Staphylococcus aureus in most in vitro settings. Nonetheless, P. aeruginosa and S. aureus are commonly isolated from chronically infected, nonhealing wounds and lungs of people with cystic fibrosis (CF). Therefore, we hypothesized that S. aureus could protect itself from P. aeruginosa through glucose-derived metabolites, such as small organic acids, preventing it from being eradicated. This in vitro study demonstrated that S. aureus populations, in the presence of glucose, secrete one or more substances that efficiently eradicate P. aeruginosa in a concentration-dependent manner. These substances had a molecular mass lower than three kDa, were hydrophilic, heat- and proteinase-resistant, and demonstrated a pH-dependent effect. Nuclear magnetic resonance analysis identified acetoin, acetic acid, and oligopeptides or cyclic peptides in glucose-grown S. aureus supernatants. All the tested wild-type and clinical S. aureus strain inhibited P. aeruginosa growth. Thus, we proposed a model in which a cocktail of these compounds, produced by established S. aureus populations in glucose presence, facilitated these two species' coexistence in chronic infections. IMPORTANCE Chronic infections affect a growing part of the population and are associated with high societal and personal costs. Multiple bacterial species are often present in these infections, and multispecies infections are considered more severe than single-species infections. Staphylococcus aureus and Pseudomonas aeruginosa often coexist in chronic infections. However, the interactions between these two species and their coexistence in chronic infections are not fully understood. By exploring in vitro interactions, we found a novel S. aureus-mediated inhibition of P. aeruginosa, and we suggested a model of the coexistence of the two species in chronic infections. With this study, we enhanced our understanding of the pathogenesis of chronic multispecies infections, which is crucial to paving the way for developing improved treatment strategies.
Collapse
|
4
|
Qiu J, Zhai Y, Wei M, Zheng C, Jiao X. Toxin–antitoxin systems: Classification, biological roles, and applications. Microbiol Res 2022; 264:127159. [DOI: 10.1016/j.micres.2022.127159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2022] [Revised: 08/02/2022] [Accepted: 08/03/2022] [Indexed: 11/28/2022]
|
5
|
Yadavalli SS, Yuan J. Bacterial Small Membrane Proteins: the Swiss Army Knife of Regulators at the Lipid Bilayer. J Bacteriol 2022; 204:e0034421. [PMID: 34516282 PMCID: PMC8765417 DOI: 10.1128/jb.00344-21] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Small membrane proteins represent a subset of recently discovered small proteins (≤100 amino acids), which are a ubiquitous class of emerging regulators underlying bacterial adaptation to environmental stressors. Until relatively recently, small open reading frames encoding these proteins were not designated genes in genome annotations. Therefore, our understanding of small protein biology was primarily limited to a few candidates associated with previously characterized larger partner proteins. Following the first systematic analyses of small proteins in Escherichia coli over a decade ago, numerous small proteins across different bacteria have been uncovered. An estimated one-third of these newly discovered proteins in E. coli are localized to the cell membrane, where they may interact with distinct groups of membrane proteins, such as signal receptors, transporters, and enzymes, and affect their activities. Recently, there has been considerable progress in functionally characterizing small membrane protein regulators aided by innovative tools adapted specifically to study small proteins. Our review covers prototypical proteins that modulate a broad range of cellular processes, such as transport, signal transduction, stress response, respiration, cell division, sporulation, and membrane stability. Thus, small membrane proteins represent a versatile group of physiology regulators at the membrane and the whole cell. Additionally, small membrane proteins have the potential for clinical applications, where some of the proteins may act as antibacterial agents themselves while others serve as alternative drug targets for the development of novel antimicrobials.
Collapse
Affiliation(s)
- Srujana S. Yadavalli
- Waksman Institute of Microbiology, Rutgers University, Piscataway, New Jersey, USA
- Department of Genetics, Rutgers University, Piscataway, New Jersey, USA
| | - Jing Yuan
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
- LOEWE Center for Synthetic Microbiology (SYNMIKRO), Marburg, Germany
| |
Collapse
|
6
|
Nonin-Lecomte S, Fermon L, Felden B, Pinel-Marie ML. Bacterial Type I Toxins: Folding and Membrane Interactions. Toxins (Basel) 2021; 13:toxins13070490. [PMID: 34357962 PMCID: PMC8309996 DOI: 10.3390/toxins13070490] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 07/08/2021] [Accepted: 07/09/2021] [Indexed: 11/16/2022] Open
Abstract
Bacterial type I toxin-antitoxin systems are two-component genetic modules that encode a stable toxic protein whose ectopic overexpression can lead to growth arrest or cell death, and an unstable RNA antitoxin that inhibits toxin translation during growth. These systems are widely spread among bacterial species. Type I antitoxins are cis- or trans-encoded antisense small RNAs that interact with toxin-encoding mRNAs by pairing, thereby inhibiting toxin mRNA translation and/or inducing its degradation. Under environmental stress conditions, the up-regulation of the toxin and/or the antitoxin degradation by specific RNases promote toxin translation. Most type I toxins are small hydrophobic peptides with a predicted α-helical transmembrane domain that induces membrane depolarization and/or permeabilization followed by a decrease of intracellular ATP, leading to plasmid maintenance, growth adaptation to environmental stresses, or persister cell formation. In this review, we describe the current state of the art on the folding and the membrane interactions of these membrane-associated type I toxins from either Gram-negative or Gram-positive bacteria and establish a chronology of their toxic effects on the bacterial cell. This review also includes novel structural results obtained by NMR concerning the sprG1-encoded membrane peptides that belong to the sprG1/SprF1 type I TA system expressed in Staphylococcus aureus and discusses the putative membrane interactions allowing the lysis of competing bacteria and host cells.
Collapse
Affiliation(s)
| | - Laurence Fermon
- BRM (Bacterial Regulatory RNAs and Medicine), Inserm, UMR_S 1230, Université de Rennes 1, 35000 Rennes, France; (L.F.); (B.F.)
| | - Brice Felden
- BRM (Bacterial Regulatory RNAs and Medicine), Inserm, UMR_S 1230, Université de Rennes 1, 35000 Rennes, France; (L.F.); (B.F.)
| | - Marie-Laure Pinel-Marie
- BRM (Bacterial Regulatory RNAs and Medicine), Inserm, UMR_S 1230, Université de Rennes 1, 35000 Rennes, France; (L.F.); (B.F.)
- Correspondence:
| |
Collapse
|
7
|
Targeting Type II Toxin-Antitoxin Systems as Antibacterial Strategies. Toxins (Basel) 2020; 12:toxins12090568. [PMID: 32899634 PMCID: PMC7551001 DOI: 10.3390/toxins12090568] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 08/31/2020] [Accepted: 08/31/2020] [Indexed: 12/13/2022] Open
Abstract
The identification of novel targets for antimicrobial agents is crucial for combating infectious diseases caused by evolving bacterial pathogens. Components of bacterial toxin–antitoxin (TA) systems have been recognized as promising therapeutic targets. These widespread genetic modules are usually composed of two genes that encode a toxic protein targeting an essential cellular process and an antitoxin that counteracts the activity of the toxin. Uncontrolled toxin expression may elicit a bactericidal effect, so they may be considered “intracellular molecular bombs” that can lead to elimination of their host cells. Based on the molecular nature of antitoxins and their mode of interaction with toxins, TA systems have been classified into six groups. The most prevalent are type II TA systems. Due to their ubiquity among clinical isolates of pathogenic bacteria and the essential processes targeted, they are promising candidates for the development of novel antimicrobial strategies. In this review, we describe the distribution of type II TA systems in clinically relevant human pathogens, examine how these systems could be developed as the targets for novel antibacterials, and discuss possible undesirable effects of such therapeutic intervention, such as the induction of persister cells, biofilm formation and toxicity to eukaryotic cells.
Collapse
|
8
|
Weaver K. The Fst/Ldr Family of Type I TA System Toxins: Potential Roles in Stress Response, Metabolism and Pathogenesis. Toxins (Basel) 2020; 12:toxins12080474. [PMID: 32722354 PMCID: PMC7472228 DOI: 10.3390/toxins12080474] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 07/20/2020] [Accepted: 07/23/2020] [Indexed: 12/27/2022] Open
Abstract
The parpAD1 locus was the first type I toxin-antitoxin (TA) system described in Gram-positive bacteria and was later determined to be the founding member of a widely distributed family of plasmid- and chromosomally encoded TA systems. Indeed, homology searches revealed that the toxin component, FstpAD1, is a member of the Fst/Ldr superfamily of peptide toxins found in both Gram-positive and Gram-negative bacteria. Regulation of the Fst and Ldr toxins is distinct in their respective Gram-positive and Gram-negative hosts, but the effects of ectopic over-expression are similar. While, the plasmid versions of these systems appear to play the canonical role of post-segregational killing stability mechanisms, the function of the chromosomal systems remains largely obscure. At least one member of the family has been suggested to play a role in pathogenesis in Staphylococcus aureus, while the regulation of several others appear to be tightly integrated with genes involved in sugar metabolism. After a brief discussion of the regulation and function of the foundational parpAD1 locus, this review will focus on the current information available on potential roles of the chromosomal homologs.
Collapse
Affiliation(s)
- Keith Weaver
- Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion, SD 57069, USA
| |
Collapse
|
9
|
Garai P, Blanc‐Potard A. Uncovering small membrane proteins in pathogenic bacteria: Regulatory functions and therapeutic potential. Mol Microbiol 2020; 114:710-720. [DOI: 10.1111/mmi.14564] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Revised: 06/19/2020] [Accepted: 06/20/2020] [Indexed: 01/01/2023]
Affiliation(s)
- Preeti Garai
- Laboratory of Pathogen‐Host Interactions Université de MontpellierCNRS‐UMR5235 Montpellier France
| | - Anne Blanc‐Potard
- Laboratory of Pathogen‐Host Interactions Université de MontpellierCNRS‐UMR5235 Montpellier France
| |
Collapse
|
10
|
Towards Exploring Toxin-Antitoxin Systems in Geobacillus: A Screen for Type II Toxin-Antitoxin System Families in a Thermophilic Genus. Int J Mol Sci 2019; 20:ijms20235869. [PMID: 31771094 PMCID: PMC6929052 DOI: 10.3390/ijms20235869] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2019] [Revised: 11/12/2019] [Accepted: 11/20/2019] [Indexed: 12/19/2022] Open
Abstract
The toxin-antitoxin (TA) systems have been attracting attention due to their role in regulating stress responses in prokaryotes and their biotechnological potential. Much recognition has been given to type II TA system of mesophiles, while thermophiles have received merely limited attention. Here, we are presenting the putative type II TA families encoded on the genomes of four Geobacillus strains. We employed the TA finder tool to mine for TA-coding genes and manually curated the results using protein domain analysis tools. We also used the NCBI BLAST, Operon Mapper, ProOpDB, and sequence alignment tools to reveal the geobacilli TA features. We identified 28 putative TA pairs, distributed over eight TA families. Among the identified TAs, 15 represent putative novel toxins and antitoxins, belonging to the MazEF, MNT-HEPN, ParDE, RelBE, and XRE-COG2856 TA families. We also identified a potentially new TA composite, AbrB-ParE. Furthermore, we are suggesting the Geobacillus acetyltransferase TA (GacTA) family, which potentially represents one of the unique TA families with a reverse gene order. Moreover, we are proposing a hypothesis on the xre-cog2856 gene expression regulation, which seems to involve the c-di-AMP. This study aims for highlighting the significance of studying TAs in Geobacillus and facilitating future experimental research.
Collapse
|
11
|
Germain-Amiot N, Augagneur Y, Camberlein E, Nicolas I, Lecureur V, Rouillon A, Felden B. A novel Staphylococcus aureus cis-trans type I toxin-antitoxin module with dual effects on bacteria and host cells. Nucleic Acids Res 2019; 47:1759-1773. [PMID: 30544243 PMCID: PMC6393315 DOI: 10.1093/nar/gky1257] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Revised: 11/29/2018] [Accepted: 12/05/2018] [Indexed: 12/16/2022] Open
Abstract
Bacterial type I toxin–antitoxin (TA) systems are widespread, and consist of a stable toxic peptide whose expression is monitored by a labile RNA antitoxin. We characterized Staphylococcus aureus SprA2/SprA2AS module, which shares nucleotide similarities with the SprA1/SprA1AS TA system. We demonstrated that SprA2/SprA2AS encodes a functional type I TA system, with the cis-encoded SprA2AS antitoxin acting in trans to prevent ribosomal loading onto SprA2 RNA. We proved that both TA systems are distinct, with no cross-regulation between the antitoxins in vitro or in vivo. SprA2 expresses PepA2, a toxic peptide which internally triggers bacterial death. Conversely, although PepA2 does not affect bacteria when it is present in the extracellular medium, it is highly toxic to other host cells such as polymorphonuclear neutrophils and erythrocytes. Finally, we showed that SprA2AS expression is lowered during osmotic shock and stringent response, which indicates that the system responds to specific triggers. Therefore, the SprA2/SprA2AS module is not redundant with SprA1/SprA1AS, and its PepA2 peptide exhibits an original dual mode of action against bacteria and host cells. This suggests an altruistic behavior for S. aureus in which clones producing PepA2 in vivo shall die as they induce cytotoxicity, thereby promoting the success of the community.
Collapse
Affiliation(s)
- Noëlla Germain-Amiot
- Université de Rennes 1, Inserm, BRM (Bacterial Regulatory RNAs and Medicine) UMR_S 1230, 35000 Rennes, France
| | - Yoann Augagneur
- Université de Rennes 1, Inserm, BRM (Bacterial Regulatory RNAs and Medicine) UMR_S 1230, 35000 Rennes, France
| | - Emilie Camberlein
- Université de Rennes 1, Inserm, BRM (Bacterial Regulatory RNAs and Medicine) UMR_S 1230, 35000 Rennes, France
| | - Irène Nicolas
- Université de Rennes 1, Inserm, BRM (Bacterial Regulatory RNAs and Medicine) UMR_S 1230, 35000 Rennes, France
| | - Valérie Lecureur
- Université de Rennes 1, CHU Rennes, Inserm, EHESP, Irset (Institut de recherche en santé, environnement et travail) UMR_S 1085, 35000 Rennes, France
| | - Astrid Rouillon
- Université de Rennes 1, Inserm, BRM (Bacterial Regulatory RNAs and Medicine) UMR_S 1230, 35000 Rennes, France
| | - Brice Felden
- Université de Rennes 1, Inserm, BRM (Bacterial Regulatory RNAs and Medicine) UMR_S 1230, 35000 Rennes, France
| |
Collapse
|
12
|
Nicolas I, Bordeau V, Bondon A, Baudy-Floc’h M, Felden B. Novel antibiotics effective against gram-positive and -negative multi-resistant bacteria with limited resistance. PLoS Biol 2019; 17:e3000337. [PMID: 31287812 PMCID: PMC6615598 DOI: 10.1371/journal.pbio.3000337] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Accepted: 06/06/2019] [Indexed: 12/29/2022] Open
Abstract
Antibiotics are a medical wonder, but an increasing frequency of resistance among most human pathogens is rendering them ineffective. If this trend continues, the consequences for public health and for the general community could be catastrophic. The current clinical pipeline, however, is very limited and is dominated by derivatives of established classes, the "me too" compounds. Here, we have exploited our recent identification of a bacterial toxin to transform it into antibiotics active on multidrug-resistant (MDR) gram-positive and -negative bacterial pathogens. We generated a new family of peptidomimetics-cyclic heptapseudopeptides-inspired from a natural bacterial peptide. Out of the 4 peptides studied, 2 are effective against methicillin-resistant Staphylococcus aureus (MRSA) in mild and severe sepsis mouse models without exhibiting toxicity on human erythrocytes and kidney cells, zebrafish embryos, and mice. These new compounds are safe at their active doses and above, without nephrotoxicity. Efficacy was also demonstrated against Pseudomonas aeruginosa and MRSA in a mouse skin infection model. Importantly, these compounds did not result in resistance after serial passages for 2 weeks and 4 or 6 days' exposure in mice. Activity of heptapseudopeptides was explained by the ability of unnatural amino acids to strengthen dynamic association with bacterial lipid bilayers and to induce membrane permeability, leading to bacterial death. Based on structure determination, we showed that cationic domains surrounded by an extended hydrophobic core could improve bactericidal activity. Because 2 peptide analogs, Pep 16 and Pep19, are effective against both MRSA and P. aeruginosa in severe sepsis and skin infection models, respectively, we believe that these peptidomimetics are promising lead candidates for drug development. We have identified potential therapeutic agents that can provide alternative treatments against antimicrobial resistance. Because the compounds are potential leads for therapeutic development, the next step is to start phase I clinical trials.
Collapse
Affiliation(s)
- Irène Nicolas
- University of Rennes, Inserm, BRM [Bacterial Regulatory RNAs and Medicine] UMR_S 1230, Rue du Professeur Léon Bernard, France
- University of Rennes, CNRS, ISCR–UMR 6226, France
| | - Valérie Bordeau
- University of Rennes, Inserm, BRM [Bacterial Regulatory RNAs and Medicine] UMR_S 1230, Rue du Professeur Léon Bernard, France
| | | | | | - Brice Felden
- University of Rennes, Inserm, BRM [Bacterial Regulatory RNAs and Medicine] UMR_S 1230, Rue du Professeur Léon Bernard, France
| |
Collapse
|
13
|
Soutourina O. Type I Toxin-Antitoxin Systems in Clostridia. Toxins (Basel) 2019; 11:toxins11050253. [PMID: 31064056 PMCID: PMC6563280 DOI: 10.3390/toxins11050253] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 04/30/2019] [Accepted: 05/02/2019] [Indexed: 12/20/2022] Open
Abstract
Type I toxin-antitoxin (TA) modules are abundant in both bacterial plasmids and chromosomes and usually encode a small hydrophobic toxic protein and an antisense RNA acting as an antitoxin. The RNA antitoxin neutralizes toxin mRNA by inhibiting its translation and/or promoting its degradation. This review summarizes our current knowledge of the type I TA modules identified in Clostridia species focusing on the recent findings in the human pathogen Clostridium difficile. More than ten functional type I TA modules have been identified in the genome of this emerging enteropathogen that could potentially contribute to its fitness and success inside the host. Despite the absence of sequence homology, the comparison of these newly identified type I TA modules with previously studied systems in other Gram-positive bacteria, i.e., Bacillus subtilis and Staphylococcus aureus, revealed some important common traits. These include the conservation of characteristic sequence features for small hydrophobic toxic proteins, the localization of several type I TA within prophage or prophage-like regions and strong connections with stress response. Potential functions in the stabilization of genome regions, adaptations to stress conditions and interactions with CRISPR-Cas defence system, as well as promising applications of TA for genome-editing and antimicrobial developments are discussed.
Collapse
Affiliation(s)
- Olga Soutourina
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette CEDEX, France.
| |
Collapse
|
14
|
Mosbah A, Delavenne E, Souissi Y, Mahjoubi M, Jéhan P, Le Yondre N, Cherif A, Bondon A, Mounier J, Baudy-Floc'h M, Le Blay G. Novel Antifungal Compounds, Spermine-Like and Short Cyclic Polylactates, Produced by Lactobacillus harbinensis K.V9.3.1Np in Yogurt. Front Microbiol 2018; 9:2252. [PMID: 30356746 PMCID: PMC6189402 DOI: 10.3389/fmicb.2018.02252] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Accepted: 09/04/2018] [Indexed: 01/05/2023] Open
Abstract
Lactobacillus harbinensis K.V9.3.1Np was described as endowed with high antifungal activity. Most of the studies associated this activity to the produced organic acids, i.e., lactic acid, acetic acid, and hexanoic acid. The aim of this study was to purify and identify, other not yet described, antifungal molecules produced by L. harbinensis K.V9.3.1Np when used in yogurt fermentation. Active compounds were extracted through several extraction processes using organic solvents and protein precipitation. The fractions of interest were purified using flash chromatography and preparative HPLC for specific characterization. The bioactive compounds identification was performed using Nuclear Magnetic Resonance and Mass Spectrometry. Activity tests against Penicillium expansum and Yarrowia lipolytica showed that the active compounds from L. harbinensis K.V9.3.1Np are benzoic acid and a polyamine identified as a spermine analog, which has not been reported earlier. However, the highest activity was shown by a mixture of short (n = 2–5) polycyclic lactates. Our overall results demonstrate the efficiency of the proposed extraction/purification approach. The new compounds described here have promising antifungal activities but further studies are still needed to decipher their mode of action and production pathways. Even though, they present an interesting potential application in food, feed, as well as, in pharmaceutical industries and could serve as alternative to chemical additives.
Collapse
Affiliation(s)
- Amor Mosbah
- CNRS, ISCR-UMR 6226, Université de Rennes 1, Rennes, France.,BVBGR-LR11ES31, ISBST, Université de la Manouba, Biotechpole Sidi Thabet, Ariana, Tunisia
| | - Emilie Delavenne
- UEB, EA3882, SFR148 ScInBioS, ESIAB, Technopôle Brest-Iroise, Plouzané, France.,Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, Université de Brest, Plouzané, France
| | - Yasmine Souissi
- BVBGR-LR11ES31, ISBST, Université de la Manouba, Biotechpole Sidi Thabet, Ariana, Tunisia
| | - Mouna Mahjoubi
- BVBGR-LR11ES31, ISBST, Université de la Manouba, Biotechpole Sidi Thabet, Ariana, Tunisia
| | | | | | - Ameur Cherif
- BVBGR-LR11ES31, ISBST, Université de la Manouba, Biotechpole Sidi Thabet, Ariana, Tunisia
| | - Arnaud Bondon
- CNRS, ISCR-UMR 6226, Université de Rennes 1, Rennes, France
| | - Jérôme Mounier
- UEB, EA3882, SFR148 ScInBioS, ESIAB, Technopôle Brest-Iroise, Plouzané, France.,Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, Université de Brest, Plouzané, France
| | | | - Gwenaelle Le Blay
- UEB, EA3882, SFR148 ScInBioS, ESIAB, Technopôle Brest-Iroise, Plouzané, France.,Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, Université de Brest, Plouzané, France.,Laboratoire des Sciences de l'Environnement Marin, UMR 6539, Université de Brest, Université Européenne de Bretagne, Institut Universitaire Européen de la Mer, Plouzané, France
| |
Collapse
|
15
|
Laurencin M, Simon M, Fleury Y, Baudy-Floc'h M, Bondon A, Legrand B. Selectivity Modulation and Structure of α/aza-β3
Cyclic Antimicrobial Peptides. Chemistry 2018; 24:6191-6201. [DOI: 10.1002/chem.201800152] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Indexed: 12/26/2022]
Affiliation(s)
| | - Matthieu Simon
- Institut des Biomolécules Max Mousseron (IBMM); Univ Montpellier, CNRS, UM, ENSCM; 15 Avenue Charles Flahault 34093 Montpellier Cedex 5 France
- Université de Rennes, CNRS; ISCR-UMR 6226; 35000 Rennes France
| | - Yannick Fleury
- Chimie Marines, IUEM; Université de Brest, EA 3884; 6 rue de l'Université 29000 Quimper France
| | | | - Arnaud Bondon
- Université de Rennes, CNRS; ISCR-UMR 6226; 35000 Rennes France
| | - Baptiste Legrand
- Institut des Biomolécules Max Mousseron (IBMM); Univ Montpellier, CNRS, UM, ENSCM; 15 Avenue Charles Flahault 34093 Montpellier Cedex 5 France
- Université de Rennes, CNRS; ISCR-UMR 6226; 35000 Rennes France
| |
Collapse
|
16
|
Duval M, Cossart P. Small bacterial and phagic proteins: an updated view on a rapidly moving field. Curr Opin Microbiol 2017; 39:81-88. [PMID: 29111488 DOI: 10.1016/j.mib.2017.09.010] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Accepted: 09/17/2017] [Indexed: 01/21/2023]
Abstract
Small proteins, that is, polypeptides of 50 amino acids (aa) or less, are increasingly recognized as important regulators in bacteria. Secreted or not, their small size make them versatile proteins, involved in a wide range of processes. They may allow bacteria to sense and to respond to stresses, to send signals and communicate, and to modulate infections. Bacteriophages also produce small proteins to influence lysogeny/lysis decisions. In this review, we update the present view on small proteins functions, and discuss their possible applications.
Collapse
Affiliation(s)
- Mélodie Duval
- Unité des Interactions Bactéries-Cellules, Institut Pasteur, Paris F-75015, France; Institut National de la Santé et de la Recherche Médicale, U604, Paris F-75015, France; Institut National de la Recherche Agronomique, Unité Sous Contrat 2020, Paris F-75015, France.
| | - Pascale Cossart
- Unité des Interactions Bactéries-Cellules, Institut Pasteur, Paris F-75015, France; Institut National de la Santé et de la Recherche Médicale, U604, Paris F-75015, France; Institut National de la Recherche Agronomique, Unité Sous Contrat 2020, Paris F-75015, France.
| |
Collapse
|
17
|
Structure, Biology, and Therapeutic Application of Toxin-Antitoxin Systems in Pathogenic Bacteria. Toxins (Basel) 2016; 8:toxins8100305. [PMID: 27782085 PMCID: PMC5086665 DOI: 10.3390/toxins8100305] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Revised: 10/17/2016] [Accepted: 10/18/2016] [Indexed: 01/09/2023] Open
Abstract
Bacterial toxin–antitoxin (TA) systems have received increasing attention for their diverse identities, structures, and functional implications in cell cycle arrest and survival against environmental stresses such as nutrient deficiency, antibiotic treatments, and immune system attacks. In this review, we describe the biological functions and the auto-regulatory mechanisms of six different types of TA systems, among which the type II TA system has been most extensively studied. The functions of type II toxins include mRNA/tRNA cleavage, gyrase/ribosome poison, and protein phosphorylation, which can be neutralized by their cognate antitoxins. We mainly explore the similar but divergent structures of type II TA proteins from 12 important pathogenic bacteria, including various aspects of protein–protein interactions. Accumulating knowledge about the structure–function correlation of TA systems from pathogenic bacteria has facilitated a novel strategy to develop antibiotic drugs that target specific pathogens. These molecules could increase the intrinsic activity of the toxin by artificially interfering with the intermolecular network of the TA systems.
Collapse
|
18
|
Schuster CF, Bertram R. Toxin-Antitoxin Systems of Staphylococcus aureus. Toxins (Basel) 2016; 8:E140. [PMID: 27164142 PMCID: PMC4885055 DOI: 10.3390/toxins8050140] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2016] [Revised: 04/21/2016] [Accepted: 04/25/2016] [Indexed: 01/02/2023] Open
Abstract
Toxin-antitoxin (TA) systems are small genetic elements found in the majority of prokaryotes. They encode toxin proteins that interfere with vital cellular functions and are counteracted by antitoxins. Dependent on the chemical nature of the antitoxins (protein or RNA) and how they control the activity of the toxin, TA systems are currently divided into six different types. Genes comprising the TA types I, II and III have been identified in Staphylococcus aureus. MazF, the toxin of the mazEF locus is a sequence-specific RNase that cleaves a number of transcripts, including those encoding pathogenicity factors. Two yefM-yoeB paralogs represent two independent, but auto-regulated TA systems that give rise to ribosome-dependent RNases. In addition, omega/epsilon/zeta constitutes a tripartite TA system that supposedly plays a role in the stabilization of resistance factors. The SprA1/SprA1AS and SprF1/SprG1 systems are post-transcriptionally regulated by RNA antitoxins and encode small membrane damaging proteins. TA systems controlled by interaction between toxin protein and antitoxin RNA have been identified in S. aureus in silico, but not yet experimentally proven. A closer inspection of possible links between TA systems and S. aureus pathophysiology will reveal, if these genetic loci may represent druggable targets. The modification of a staphylococcal TA toxin to a cyclopeptide antibiotic highlights the potential of TA systems as rather untapped sources of drug discovery.
Collapse
Affiliation(s)
- Christopher F Schuster
- Section of Microbiology & MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, UK.
| | - Ralph Bertram
- Interfakultäres Institut für Mikrobiologie und Infektionsmedizin, Lehrbereich Mikrobielle Genetik, University of Tübingen, 72076 Tübingen, Germany.
- Klinikum Nürnberg Medical School GmbH, Research Department, Paracelsus Medical University, 90419 Nuremberg, Germany.
| |
Collapse
|
19
|
Brielle R, Pinel-Marie ML, Felden B. Linking bacterial type I toxins with their actions. Curr Opin Microbiol 2016; 30:114-121. [PMID: 26874964 DOI: 10.1016/j.mib.2016.01.009] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Revised: 01/18/2016] [Accepted: 01/19/2016] [Indexed: 01/12/2023]
Abstract
Bacterial type I toxin-antitoxin systems consist of stable toxin-encoding mRNAs whose expression is counteracted by unstable RNA antitoxins. Accumulating evidence suggests that these players belong to broad regulatory networks influencing overall bacterial physiology. The majority of known transmembrane type I toxic peptides have conserved structural characteristics. However, recent studies demonstrated that their mechanisms of toxicity are diverse and complex. To better assess the current state of the art, type I toxins can be grouped into two classes according to their location and mechanisms of action: membrane-associated toxins acting by pore formation and/or by nucleoid condensation; and cytosolic toxins inducing nucleic acid cleavage. This classification will evolve as a result of future investigations.
Collapse
Affiliation(s)
- Régine Brielle
- Inserm U835-Upres EA2311, Pharmaceutical Biochemistry Lab, University of Rennes 1, 2 av. du Prof. Léon Bernard, 35000 Rennes, France
| | - Marie-Laure Pinel-Marie
- Inserm U835-Upres EA2311, Pharmaceutical Biochemistry Lab, University of Rennes 1, 2 av. du Prof. Léon Bernard, 35000 Rennes, France.
| | - Brice Felden
- Inserm U835-Upres EA2311, Pharmaceutical Biochemistry Lab, University of Rennes 1, 2 av. du Prof. Léon Bernard, 35000 Rennes, France.
| |
Collapse
|
20
|
Nigro E, Colavita I, Sarnataro D, Scudiero O, Zambrano G, Granata V, Daniele A, Carotenuto A, Galdiero S, Folliero V, Galdiero M, Urbanowicz RA, Ball JK, Salvatore F, Pessi A. An ancestral host defence peptide within human β-defensin 3 recapitulates the antibacterial and antiviral activity of the full-length molecule. Sci Rep 2015; 5:18450. [PMID: 26688341 PMCID: PMC4685272 DOI: 10.1038/srep18450] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Accepted: 11/09/2015] [Indexed: 12/21/2022] Open
Abstract
Host defence peptides (HDPs) are critical components of innate immunity. Despite their diversity, they share common features including a structural signature, designated "γ-core motif". We reasoned that for each HDPs evolved from an ancestral γ-core, the latter should be the evolutionary starting point of the molecule, i.e. it should represent a structural scaffold for the modular construction of the full-length molecule, and possess biological properties. We explored the γ-core of human β-defensin 3 (HBD3) and found that it: (a) is the folding nucleus of HBD3; (b) folds rapidly and is stable in human serum; (c) displays antibacterial activity; (d) binds to CD98, which mediates HBD3 internalization in eukaryotic cells; (e) exerts antiviral activity against human immunodeficiency virus and herpes simplex virus; and (f) is not toxic to human cells. These results demonstrate that the γ-core within HBD3 is the ancestral core of the full-length molecule and is a viable HDP per se, since it is endowed with the most important biological features of HBD3. Notably, the small, stable scaffold of the HBD3 γ-core can be exploited to design disease-specific antimicrobial agents.
Collapse
Affiliation(s)
- Ersilia Nigro
- CEINGE-Biotecnologie Avanzate, Via Gaetano Salvatore 486, 80145 Napoli, Italy
| | - Irene Colavita
- CEINGE-Biotecnologie Avanzate, Via Gaetano Salvatore 486, 80145 Napoli, Italy
| | - Daniela Sarnataro
- CEINGE-Biotecnologie Avanzate, Via Gaetano Salvatore 486, 80145 Napoli, Italy.,Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Via Sergio Pansini 5, 80131 Napoli, Italy
| | - Olga Scudiero
- CEINGE-Biotecnologie Avanzate, Via Gaetano Salvatore 486, 80145 Napoli, Italy.,Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Via Sergio Pansini 5, 80131 Napoli, Italy
| | - Gerardo Zambrano
- CEINGE-Biotecnologie Avanzate, Via Gaetano Salvatore 486, 80145 Napoli, Italy
| | - Vincenzo Granata
- CEINGE-Biotecnologie Avanzate, Via Gaetano Salvatore 486, 80145 Napoli, Italy
| | - Aurora Daniele
- CEINGE-Biotecnologie Avanzate, Via Gaetano Salvatore 486, 80145 Napoli, Italy.,Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, Second University of Naples, Via Vivaldi 43, 81100 Caserta, Italy
| | - Alfonso Carotenuto
- Department of Pharmacy, University of Naples Federico II, Via Domenico Montesano 49, 80131 Napoli, Italy
| | - Stefania Galdiero
- Department of Pharmacy, University of Naples Federico II, Via Domenico Montesano 49, 80131 Napoli, Italy.,Institute of Biostructures and Bioimages, CNR, Naples, Italy
| | - Veronica Folliero
- Department of Experimental Medicine, Second University of Naples, Via Costantinopoli, 16, 80138 Napoli, Italy
| | - Massimiliano Galdiero
- Department of Experimental Medicine, Second University of Naples, Via Costantinopoli, 16, 80138 Napoli, Italy
| | - Richard A Urbanowicz
- The School of Life Sciences and the Nottingham Digestive Diseases Centre Biomedical Research Unit, The University of Nottingham, Queen's Medical Centre, Nottingham NG7 2UH, United Kingdom
| | - Jonathan K Ball
- The School of Life Sciences and the Nottingham Digestive Diseases Centre Biomedical Research Unit, The University of Nottingham, Queen's Medical Centre, Nottingham NG7 2UH, United Kingdom
| | - Francesco Salvatore
- CEINGE-Biotecnologie Avanzate, Via Gaetano Salvatore 486, 80145 Napoli, Italy.,IRCCS-SDN Foundation, Via Emanuele Gianturco 113, 80142 Napoli, Italy
| | - Antonello Pessi
- CEINGE-Biotecnologie Avanzate, Via Gaetano Salvatore 486, 80145 Napoli, Italy
| |
Collapse
|