1
|
Neha, Verma C, Kaur N. Fluorenone-naphthyl encapsulated dual sensor for recognition of F - and Hg 2+: Syngenetic effect with drug sobisis and molecular docking studies. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2025; 325:125042. [PMID: 39232312 DOI: 10.1016/j.saa.2024.125042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Revised: 07/22/2024] [Accepted: 08/24/2024] [Indexed: 09/06/2024]
Abstract
A novel fluorenone-naphthyl pendant sensor (FTU) possessing thiourea functionality has been synthesized via a simple condensation method and utilized for the recognition of F- and Hg2+ ions in the solution of CH3CN. The addition of F- and Hg2+ ions to the FTU solution led to the appearance of red-shifted absorption bands at 340 and 315 nm, respectively. On the other hand, in the fluorescence spectrum, the two-fold decrease in fluorescence intensity of probe FTU was observed with F- ions; while complete quenching of the fluorescence intensity was noticed with Hg2+ ions at 423 nm. The limit of detection values of F- and Hg2+ ions were found to be 1.02 & 29.1 nM, respectively, measured by UV-vis studies and 0.0185 & 0.81 nM, respectively, measured by fluorescence studies, which are less than recommended by WHO. DFT computational assessments and 1H NMR titration experiments pointed to F- induced deprotonation of thiourea NH signals. However, the chelation-enhanced quenching effect (CHEQ) was held responsible for fluorescence quenching with Hg2+ addition. Moreover, the in-situ formed FTU + F- complex was utilized for secondary sensing of drug sobisis. Furthermore, the real-world applicability of sensor FTU has been successfully scrutinized for the recognition of F- ions in the toothpaste samples. In addition, molecular docking studies revealed that FTU exhibited excellent antibacterial potency towards different gram-positive as well as negative strains.
Collapse
Affiliation(s)
- Neha
- Department of Chemistry, Panjab University, Chandigarh 160014, India
| | - Chetan Verma
- Department of Chemistry, Panjab University, Chandigarh 160014, India
| | - Navneet Kaur
- Department of Chemistry, Panjab University, Chandigarh 160014, India.
| |
Collapse
|
2
|
Savitskii MV, Moskaleva NE, Brito A, Markin PA, Zigangirova NA, Soloveva AV, Sheremet AB, Bondareva NE, Lubenec NL, Tagliaro F, Tarasov VV, Tatzhikova KA, Appolonova SA. Pharmacokinetics, tissue distribution, bioavailability and excretion of the anti-virulence drug Fluorothiazinon in rats and rabbits. J Antibiot (Tokyo) 2024; 77:382-388. [PMID: 38491136 DOI: 10.1038/s41429-024-00719-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 01/15/2024] [Accepted: 03/06/2024] [Indexed: 03/18/2024]
Abstract
Growing antimicrobial resistance has accelerated the development of anti-virulence drugs to suppress bacterial toxicity without affecting cell viability. Fluorothiazinon (FT), an anti-virulence, type three secretion system and flagella motility inhibitor which has shown promise to suppress drug-resistant pathogens having the potential to enhance the efficacy of commonly prescribed antibiotics when used in combination. In this study we characterized the pharmacokinetics, tissue distribution, bioavailability and excretion of FT in rats and rabbits. FT presented a dose-proportional linear increase in the blood of rats. Tissue distribution profiling confirmed that FT distributes to all organs being substantially higher than in the blood of rats. The bioavailability of FT was higher when administered with starch than with water implying FT should be ideally dosed with food. FT was primarily excreted in the feces in rats and rabbits while negligible amounts are recovered from the urine.
Collapse
Affiliation(s)
- Mark V Savitskii
- Laboratory of Pharmacokinetics and Metabolomic Analysis, Institute of Translational Medicine and Biotechnology, Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russian Federation
- Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russian Federation
- Unit of Forensic Medicine, Department of Diagnostics and Public Health, University of Verona, Verona, Italy
| | - Natalia E Moskaleva
- Laboratory of Pharmacokinetics and Metabolomic Analysis, Institute of Translational Medicine and Biotechnology, Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russian Federation.
- World Class Research Center Digital Biodesign and Personalized Healthcare, Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russian Federation.
| | - Alex Brito
- Laboratory of Pharmacokinetics and Metabolomic Analysis, Institute of Translational Medicine and Biotechnology, Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russian Federation
| | - Pavel A Markin
- Laboratory of Pharmacokinetics and Metabolomic Analysis, Institute of Translational Medicine and Biotechnology, Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russian Federation
| | - Nailya A Zigangirova
- National Research Center for Epidemiology and Microbiology named after N. F. Gamaleya, Russian Health Ministry, Moscow, Russian Federation
| | - Anna V Soloveva
- National Research Center for Epidemiology and Microbiology named after N. F. Gamaleya, Russian Health Ministry, Moscow, Russian Federation
| | - Anna B Sheremet
- National Research Center for Epidemiology and Microbiology named after N. F. Gamaleya, Russian Health Ministry, Moscow, Russian Federation
| | - Natalia E Bondareva
- National Research Center for Epidemiology and Microbiology named after N. F. Gamaleya, Russian Health Ministry, Moscow, Russian Federation
| | - Nadezhda L Lubenec
- National Research Center for Epidemiology and Microbiology named after N. F. Gamaleya, Russian Health Ministry, Moscow, Russian Federation
| | - Franco Tagliaro
- Laboratory of Pharmacokinetics and Metabolomic Analysis, Institute of Translational Medicine and Biotechnology, Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russian Federation
- Unit of Forensic Medicine, Department of Diagnostics and Public Health, University of Verona, Verona, Italy
| | - Vadim V Tarasov
- Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russian Federation
| | - Kristina A Tatzhikova
- Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russian Federation
| | - Svetlana A Appolonova
- Laboratory of Pharmacokinetics and Metabolomic Analysis, Institute of Translational Medicine and Biotechnology, Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russian Federation
- Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russian Federation
| |
Collapse
|
3
|
Flacht L, Lunelli M, Kaszuba K, Chen ZA, Reilly FJO, Rappsilber J, Kosinski J, Kolbe M. Integrative structural analysis of the type III secretion system needle complex from Shigella flexneri. Protein Sci 2023; 32:e4595. [PMID: 36790757 PMCID: PMC10019453 DOI: 10.1002/pro.4595] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 01/31/2023] [Accepted: 02/09/2023] [Indexed: 02/16/2023]
Abstract
The type III secretion system (T3SS) is a large, transmembrane protein machinery used by various pathogenic gram-negative bacteria to transport virulence factors into the host cell during infection. Understanding the structure of T3SSs is crucial for future developments of therapeutics that could target this system. However, much of the knowledge about the structure of T3SS is available only for Salmonella, and it is unclear how this large assembly is conserved across species. Here, we combined cryo-electron microscopy, cross-linking mass spectrometry, and integrative modeling to determine the structure of the T3SS needle complex from Shigella flexneri. We show that the Shigella T3SS exhibits unique features distinguishing it from other structurally characterized T3SSs. The secretin pore complex adopts a new fold of its C-terminal S domain and the pilotin MxiM[SctG] locates around the outer surface of the pore. The export apparatus structure exhibits a conserved pseudohelical arrangement but includes the N-terminal domain of the SpaS[SctU] subunit, which was not present in any of the previously published virulence-related T3SS structures. Similar to other T3SSs, however, the apparatus is anchored within the needle complex by a network of flexible linkers that either adjust conformation to connect to equivalent patches on the secretin oligomer or bind distinct surface patches at the same height of the export apparatus. The conserved and unique features delineated by our analysis highlight the necessity to analyze T3SS in a species-specific manner, in order to fully understand the underlying molecular mechanisms of these systems. The structure of the type III secretion system from Shigella flexneri delineates conserved and unique features, which could be used for the development of broad-range therapeutics.
Collapse
Affiliation(s)
- Lara Flacht
- Department for Structural Infection BiologyCenter for Structural Systems Biology (CSSB) & Helmholtz Centre for Infection Research (HZI)HamburgGermany
- Dynamics of Viral Structures, Leibniz Institute for Virology (LIV)HamburgGermany
| | - Michele Lunelli
- Department for Structural Infection BiologyCenter for Structural Systems Biology (CSSB) & Helmholtz Centre for Infection Research (HZI)HamburgGermany
| | - Karol Kaszuba
- Department for Structural Infection BiologyCenter for Structural Systems Biology (CSSB) & Helmholtz Centre for Infection Research (HZI)HamburgGermany
- Centre for Structural Systems Biology (CSSB) & European Molecular Biology Laboratory (EMBL)HamburgGermany
| | - Zhuo Angel Chen
- Technische Universität Berlin, Institute of Biotechnology, Chair of BioanalyticsBerlinGermany
| | - Francis J. O'. Reilly
- Technische Universität Berlin, Institute of Biotechnology, Chair of BioanalyticsBerlinGermany
| | - Juri Rappsilber
- Technische Universität Berlin, Institute of Biotechnology, Chair of BioanalyticsBerlinGermany
- University of Edinburgh, Wellcome Centre for Cell BiologyEdinburghUK
| | - Jan Kosinski
- Centre for Structural Systems Biology (CSSB) & European Molecular Biology Laboratory (EMBL)HamburgGermany
- Structural and Computational Biology Unit, European Molecular Biology LaboratoryHeidelbergGermany
| | - Michael Kolbe
- Department for Structural Infection BiologyCenter for Structural Systems Biology (CSSB) & Helmholtz Centre for Infection Research (HZI)HamburgGermany
- MIN‐FacultyUniversity HamburgHamburgGermany
| |
Collapse
|
4
|
Research Progress on Small Molecular Inhibitors of the Type 3 Secretion System. Molecules 2022; 27:molecules27238348. [PMID: 36500441 PMCID: PMC9740592 DOI: 10.3390/molecules27238348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 11/22/2022] [Accepted: 11/23/2022] [Indexed: 12/05/2022] Open
Abstract
The overuse of antibiotics has led to severe bacterial drug resistance. Blocking pathogen virulence devices is a highly effective approach to combating bacterial resistance worldwide. Type three secretion systems (T3SSs) are significant virulence factors in Gram-negative pathogens. Inhibition of these systems can effectively weaken infection whilst having no significant effect on bacterial growth. Therefore, T3SS inhibitors may be a powerful weapon against resistance in Gram-negative bacteria, and there has been increasing interest in the research and development of T3SS inhibitors. This review outlines several reported small-molecule inhibitors of the T3SS, covering those of synthetic and natural origin, including their sources, structures, and mechanisms of action.
Collapse
|
5
|
PopB-PcrV Interactions Are Essential for Pore Formation in the Pseudomonas aeruginosa Type III Secretion System Translocon. mBio 2022; 13:e0238122. [PMID: 36154276 PMCID: PMC9600203 DOI: 10.1128/mbio.02381-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The type III secretion system (T3SS) is a syringe-like virulence factor that delivers bacterial proteins directly into the cytoplasm of host cells. An essential component of the system is the translocon, which creates a pore in the host cell membrane through which proteins are injected. In Pseudomonas aeruginosa, the translocation pore is formed by proteins PopB and PopD and attaches to the T3SS needle via the needle tip protein PcrV. The structure and stoichiometry of the multimeric pore are unknown. We took a genetic approach to map contact points within the system by taking advantage of the fact that the translocator proteins of P. aeruginosa and the related Aeromonas hydrophila T3SS are incompatible and cannot be freely exchanged. We created chimeric versions of P. aeruginosa PopB and A. hydrophila AopB to intentionally disrupt and restore protein-protein interactions. We identified a chimeric B-translocator that specifically disrupts an interaction with the needle tip protein. This disruption did not affect membrane insertion of the B-translocator but did prevent formation of the translocation pore, arguing that the needle tip protein drives the formation of the translocation pore. IMPORTANCE Type III secretion systems are integral to the pathogenesis of many Gram-negative bacterial pathogens. A hallmark of these secretion systems is that they deliver effector proteins vectorially into the targeted host cell via a translocation pore. The translocon is crucial for T3SS function, but it has proven difficult to study biochemically and structurally. Here, we used a genetic approach to identify protein-protein contacts among translocator proteins that are important for function. This genetic approach allowed us to specifically break a contact between the translocator PopB and the T3SS needle tip protein PcrV. Breaking this contact allowed us to determine, for the first time, that the needle tip actively participates in the assembly of the translocation pore by the membrane-bound pore-forming translocator proteins. Our study therefore both expands our knowledge of the network of functionally important interactions among translocator proteins and illuminates a new step in the assembly of this critical host cell interface.
Collapse
|
6
|
Lin IT, Tulman ER, Geary SJ, Zhou X. A gatekeeper protein contributes to T3SS2 function via interaction with an ATPase in Vibrio parahaemolyticus. Microbiol Res 2021; 252:126857. [PMID: 34481262 DOI: 10.1016/j.micres.2021.126857] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 07/26/2021] [Accepted: 08/21/2021] [Indexed: 01/22/2023]
Abstract
Assembly of a functional type III secretion system (T3SS) requires intricate protein-protein interactions in many bacterial species. In Vibrio parahaemolyticus, the leading cause of seafood-associated diarrheal illnesses, the gatekeeper protein VgpA is essential for T3SS2 to secrete its substrates. However, it is unknown if VgpA interacts with other core elements of T3SS2 to mediate its substrate secretion. Through bacterial two-hybrid (BACTH) analysis, we now show that VgpA physically interacts with VscN2 (an ATPase essential for T3SS function) and six other hypothetical proteins. Mutation of isoleucine to alanine at residue 175 of VgpA (VgpAI175A) abolished its ability to interact with VscN2. Importantly, complementation of a VgpA nonsense mutant (vgpA') with VgpAI175A did not restore the ability of T3SS2 to secrete substrates, demonstrating that VgpA-VscN2 interaction is critical for the function of T3SS2. Bacterial cell fractionation and mass spectrometry analyses showed that vgpA' resulted in significant alterations of T3SS2 protein abundance in multiple bacterial cell fractions. Particularly, VscN2 abundance in the inner membrane fraction and VscC2 abundance in the outer membrane fraction are significantly reduced in vgpA' compared to those in WT. These results demonstrated that VgpA contributes to T3SS2 function via its interaction with VscN2 and possibly by affecting subcellular distribution of T3SS2 proteins.
Collapse
Affiliation(s)
- I-Ting Lin
- Department of Pathobiology and Veterinary Science, University of Connecticut, Storrs, CT, 06269, USA
| | - Edan R Tulman
- Department of Pathobiology and Veterinary Science, University of Connecticut, Storrs, CT, 06269, USA; Center of Excellence for Vaccine Research, University of Connecticut, CT, 06269, USA
| | - Steve J Geary
- Department of Pathobiology and Veterinary Science, University of Connecticut, Storrs, CT, 06269, USA; Center of Excellence for Vaccine Research, University of Connecticut, CT, 06269, USA
| | - Xiaohui Zhou
- Department of Pathobiology and Veterinary Science, University of Connecticut, Storrs, CT, 06269, USA.
| |
Collapse
|
7
|
Swietnicki W. Secretory System Components as Potential Prophylactic Targets for Bacterial Pathogens. Biomolecules 2021; 11:892. [PMID: 34203937 PMCID: PMC8232601 DOI: 10.3390/biom11060892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 06/13/2021] [Accepted: 06/14/2021] [Indexed: 01/18/2023] Open
Abstract
Bacterial secretory systems are essential for virulence in human pathogens. The systems have become a target of alternative antibacterial strategies based on small molecules and antibodies. Strategies to use components of the systems to design prophylactics have been less publicized despite vaccines being the preferred solution to dealing with bacterial infections. In the current review, strategies to design vaccines against selected pathogens are presented and connected to the biology of the system. The examples are given for Y. pestis, S. enterica, B. anthracis, S. flexneri, and other human pathogens, and discussed in terms of effectiveness and long-term protection.
Collapse
Affiliation(s)
- Wieslaw Swietnicki
- Department of Immunology of Infectious Diseases, Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, ul. R. Weigla 12, 53-114 Wroclaw, Poland
| |
Collapse
|
8
|
Sebbane F, Lemaître N. Antibiotic Therapy of Plague: A Review. Biomolecules 2021; 11:724. [PMID: 34065940 PMCID: PMC8151713 DOI: 10.3390/biom11050724] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 05/04/2021] [Accepted: 05/07/2021] [Indexed: 12/15/2022] Open
Abstract
Plague-a deadly disease caused by the bacterium Yersinia pestis-is still an international public health concern. There are three main clinical forms: bubonic plague, septicemic plague, and pulmonary plague. In all three forms, the symptoms appear suddenly and progress very rapidly. Early antibiotic therapy is essential for countering the disease. Several classes of antibiotics (e.g., tetracyclines, fluoroquinolones, aminoglycosides, sulfonamides, chloramphenicol, rifamycin, and β-lactams) are active in vitro against the majority of Y. pestis strains and have demonstrated efficacy in various animal models. However, some discrepancies have been reported. Hence, health authorities have approved and recommended several drugs for prophylactic or curative use. Only monotherapy is currently recommended; combination therapy has not shown any benefits in preclinical studies or case reports. Concerns about the emergence of multidrug-resistant strains of Y. pestis have led to the development of new classes of antibiotics and other therapeutics (e.g., LpxC inhibitors, cationic peptides, antivirulence drugs, predatory bacteria, phages, immunotherapy, host-directed therapy, and nutritional immunity). It is difficult to know which of the currently available treatments or therapeutics in development will be most effective for a given form of plague. This is due to the lack of standardization in preclinical studies, conflicting data from case reports, and the small number of clinical trials performed to date.
Collapse
Affiliation(s)
- Florent Sebbane
- Univ. Lille, Inserm, CNRS, Institut Pasteur Lille, U1019—UMR 9017—CIIL—Center for Infection and Immunity of Lille, F-59000 Lille, France
| | - Nadine Lemaître
- Univ. Lille, Inserm, CNRS, Institut Pasteur Lille, U1019—UMR 9017—CIIL—Center for Infection and Immunity of Lille, F-59000 Lille, France
- Laboratoire de Bactériologie-Hygiène, Centre Hospitalier Universitaire Amiens Picardie, UR 4294, Agents Infectieux, Résistance et Chimiothérapie (AGIR), Université de Picardie Jules Verne, F-80000 Amiens, France
| |
Collapse
|
9
|
Cortés-Avalos D, Martínez-Pérez N, Ortiz-Moncada MA, Juárez-González A, Baños-Vargas AA, Estrada-de Los Santos P, Pérez-Rueda E, Ibarra JA. An update of the unceasingly growing and diverse AraC/XylS family of transcriptional activators. FEMS Microbiol Rev 2021; 45:6219864. [PMID: 33837749 DOI: 10.1093/femsre/fuab020] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 03/31/2021] [Indexed: 01/09/2023] Open
Abstract
Transcriptional factors play an important role in gene regulation in all organisms, especially in Bacteria. Here special emphasis is placed in the AraC/XylS family of transcriptional regulators. This is one of the most abundant as many predicted members have been identified and more members are added because more bacterial genomes are sequenced. Given the way more experimental evidence has mounded in the past decades, we decided to update the information about this captivating family of proteins. Using bioinformatics tools on all the data available for experimentally characterized members of this family, we found that many members that display a similar functional classification can be clustered together and in some cases they have a similar regulatory scheme. A proposal for grouping these proteins is also discussed. Additionally, an analysis of surveyed proteins in bacterial genomes is presented. Altogether, the current review presents a panoramic view into this family and we hope it helps to stimulate future research in the field.
Collapse
Affiliation(s)
- Daniel Cortés-Avalos
- Laboratorio de Genética Microbiana, Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Ciudad de México, México
| | - Noemy Martínez-Pérez
- Instituto de Investigaciones en Matemáticas Aplicadas y en Sistemas, Universidad Nacional Autónoma de México, Unidad Académica Yucatán, Mérida, Yucatán, México
| | - Mario A Ortiz-Moncada
- Laboratorio de Genética Microbiana, Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Ciudad de México, México
| | - Aylin Juárez-González
- Laboratorio de Genética Microbiana, Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Ciudad de México, México
| | - Arturo A Baños-Vargas
- Laboratorio de Genética Microbiana, Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Ciudad de México, México
| | - Paulina Estrada-de Los Santos
- Laboratorio de Biotecnología Microbiana, Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Ciudad de México, México
| | - Ernesto Pérez-Rueda
- Instituto de Investigaciones en Matemáticas Aplicadas y en Sistemas, Universidad Nacional Autónoma de México, Unidad Académica Yucatán, Mérida, Yucatán, México.,Facultad de Ciencias, Centro de Genómica y Bioinformática, Universidad Mayor, Santiago, Chile
| | - J Antonio Ibarra
- Laboratorio de Genética Microbiana, Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Ciudad de México, México
| |
Collapse
|
10
|
A high-throughput cell-based assay pipeline for the preclinical development of bacterial DsbA inhibitors as antivirulence therapeutics. Sci Rep 2021; 11:1569. [PMID: 33452354 PMCID: PMC7810732 DOI: 10.1038/s41598-021-81007-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 12/17/2020] [Indexed: 11/23/2022] Open
Abstract
Antibiotics are failing fast, and the development pipeline remains alarmingly dry. New drug research and development is being urged by world health officials, with new antibacterials against multidrug-resistant Gram-negative pathogens as the highest priority. Antivirulence drugs, which inhibit bacterial pathogenicity factors, are a class of promising antibacterials, however, their development is stifled by lack of standardised preclinical testing akin to what guides antibiotic development. The lack of established target-specific microbiological assays amenable to high-throughput, often means that cell-based testing of virulence inhibitors is absent from the discovery (hit-to-lead) phase, only to be employed at later-stages of lead optimization. Here, we address this by establishing a pipeline of bacterial cell-based assays developed for the identification and early preclinical evaluation of DsbA inhibitors, previously identified by biophysical and biochemical assays. Inhibitors of DsbA block oxidative protein folding required for virulence factor folding in pathogens. Here we use existing Escherichia coli DsbA inhibitors and uropathogenic E. coli (UPEC) as a model pathogen, to demonstrate that the combination of a cell-based sulfotransferase assay and a motility assay (both DsbA reporter assays), modified for a higher throughput format, can provide a robust and target-specific platform for the identification and evaluation of DsbA inhibitors.
Collapse
|
11
|
Cryo-EM structure of the EspA filament from enteropathogenic Escherichia coli: Revealing the mechanism of effector translocation in the T3SS. Structure 2021; 29:479-487.e4. [PMID: 33453150 DOI: 10.1016/j.str.2020.12.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 11/22/2020] [Accepted: 12/16/2020] [Indexed: 02/02/2023]
Abstract
The type III secretion system (T3SS) is a virulence mechanism employed by Gram-negative pathogens. The T3SS forms a proteinaceous channel that projects a needle into the extracellular medium where it interacts with the host cell to deliver virulence factors. Enteropathogenic Escherichia coli (EPEC) is unique in adopting a needle extension to the T3SS-a filament formed by EspA-which is absolutely required for efficient colonization of the gut. Here, we describe the cryoelectron microscopy structure of native EspA filaments from EPEC at 3.6-Å resolution. Within the filament, positively charged residues adjacent to a hydrophobic groove line the lumen of the filament in a spiral manner, suggesting a mechanism of substrate translocation mediated via electrostatics. Using structure-guided mutagenesis, in vivo studies corroborate the role of these residues in secretion and translocation function. The high-resolution structure of the EspA filament could aid in structure-guided drug design of antivirulence therapeutics.
Collapse
|
12
|
Identification of Small Molecules Blocking the Pseudomonas aeruginosa type III Secretion System Protein PcrV. Biomolecules 2021; 11:biom11010055. [PMID: 33406810 PMCID: PMC7824769 DOI: 10.3390/biom11010055] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 12/21/2020] [Accepted: 12/29/2020] [Indexed: 01/09/2023] Open
Abstract
Pseudomonas aeruginosa is an opportunistic bacterial pathogen that employs its type III secretion system (T3SS) during the acute phase of infection to translocate cytotoxins into the host cell cytoplasm to evade the immune system. The PcrV protein is located at the tip of the T3SS, facilitates the integration of pore-forming proteins into the eukaryotic cell membrane, and is required for translocation of cytotoxins into the host cell. In this study, we used surface plasmon resonance screening to identify small molecule binders of PcrV. A follow-up structure-activity relationship analysis resulted in PcrV binders that protect macrophages in a P. aeruginosa cell-based infection assay. Treatment of P. aeruginosa infections is challenging due to acquired, intrinsic, and adaptive resistance in addition to a broad arsenal of virulence systems such as the T3SS. Virulence blocking molecules targeting PcrV constitute valuable starting points for development of next generation antibacterials to treat infections caused by P. aeruginosa.
Collapse
|
13
|
Current Knowledge and Future Directions in Developing Strategies to Combat Pseudomonas aeruginosa Infection. J Mol Biol 2020; 432:5509-5528. [PMID: 32750389 DOI: 10.1016/j.jmb.2020.07.021] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 07/17/2020] [Accepted: 07/22/2020] [Indexed: 12/21/2022]
Abstract
In the face of growing antimicrobial resistance, there is an urgent need for the development of effective strategies to target Pseudomonas aeruginosa. This metabolically versatile bacterium can cause a wide range of severe opportunistic infections in patients with serious underlying medical conditions, such as those with burns, surgical wounds or people with cystic fibrosis. Many of the key adaptations that arise in this organism during infection are centered on core metabolism and virulence factor synthesis. Interfering with these processes may provide a new strategy to combat infection which could be combined with conventional antibiotics. This review will provide an overview of the most recent work that has advanced our understanding of P. aeruginosa infection. Strategies that exploit this recent knowledge to combat infection will be highlighted alongside potential alternative therapeutic options and their limitations.
Collapse
|
14
|
Abstract
The independent naming of components of injectisome-type type III secretion systems in different bacterial species has resulted in considerable confusion, impeding accessibility of the literature and hindering communication between scientists of the same field. A unified nomenclature had been proposed by Hueck more than 20 years ago. It found little attention for many years, but usage was sparked again by recent reviews and an international type III secretion meeting in 2016. Here, we propose that the field consistently switches to an extended version of this nomenclature to be no longer lost in translation.
Collapse
|
15
|
Gajdács M, Spengler G. The Role of Drug Repurposing in the Development of Novel Antimicrobial Drugs: Non-Antibiotic Pharmacological Agents as Quorum Sensing-Inhibitors. Antibiotics (Basel) 2019; 8:E270. [PMID: 31861228 PMCID: PMC6963710 DOI: 10.3390/antibiotics8040270] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2019] [Revised: 12/11/2019] [Accepted: 12/12/2019] [Indexed: 02/06/2023] Open
Abstract
Background: The emergence of multidrug-resistant organisms (MDROs) is a global public health issue, severely hindering clinicians in administering appropriate antimicrobial therapy. Drug repurposing is a drug development strategy, during which new pharmacological applications are identified for already approved drugs. From the viewpoint of the development of virulence inhibitors, inhibition of quorum sensing (QS) is a promising route because various important features in bacterial physiology and virulence are mediated by QS-dependent gene expression. Methods: Forty-five pharmacological agents, encompassing a wide variety of different chemical structures and mechanisms of action, were tested during our experiments. The antibacterial activity of the compounds was tested using the broth microdilution method. Screening and semi-quantitative assessment of QS-inhibition by the compounds was performed using QS-signal molecule-producing and indicator strains. Results: Fourteen pharmaceutical agents showed antibacterial activity in the tested concentration range, while eight drugs (namely 5-fluorouracil, metamizole-sodium, cisplatin, methotrexate, bleomycin, promethazine, chlorpromazine, and thioridazine) showed dose-dependent QS-inhibitory activity in the in vitro model systems applied during the experiments. Conclusions: Virulence inhibitors represent an attractive alternative strategy to combat bacterial pathogens more efficiently. Some of the tested compounds could be considered potential QS-inhibitory agents, warranting further experiments involving additional model systems to establish the extent of their efficacy.
Collapse
Affiliation(s)
- Márió Gajdács
- Department of Medical Microbiology and Immunobiology, Faculty of Medicine, University of Szeged, Dóm tér 10, 6720 Szeged, Hungary
- Department of Pharmacodynamics and Biopharmacy, Faculty of Pharmacy, University of Szeged, Eötvös utca 6, 6720 Szeged, Hungary;
| | - Gabriella Spengler
- Department of Pharmacodynamics and Biopharmacy, Faculty of Pharmacy, University of Szeged, Eötvös utca 6, 6720 Szeged, Hungary;
| |
Collapse
|