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Gao Y, Xie R, Chen Y, Yang B, Wang M, Hua L, Wang X, Wang W, Wang N, Ge H, Ma J. Structural basis for substrate recognition by a S-adenosylhomocysteine hydrolase Lpg2021 from Legionella pneumophila. Int J Biol Macromol 2024; 270:132289. [PMID: 38735607 DOI: 10.1016/j.ijbiomac.2024.132289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2024] [Revised: 04/24/2024] [Accepted: 05/09/2024] [Indexed: 05/14/2024]
Abstract
S-Adenosyl-l-homocysteine hydrolase (SAHH) is a crucial enzyme that governs S-adenosyl methionine (SAM)-dependent methylation reactions within cells and regulates the intracellular concentration of SAH. Legionella pneumophila, the causative pathogen of Legionnaires' disease, encodes Lpg2021, which is the first identified dimeric SAHH in bacteria and is a promising target for drug development. Here, we report the structure of Lpg2021 in its ligand-free state and in complexes with adenine (ADE), adenosine (ADO), and 3-Deazaneplanocin A (DZNep). X-ray crystallography, isothermal titration calorimetry (ITC), and molecular docking were used to elucidate the binding mechanisms of Lpg2021 to its substrates and inhibitors. Virtual screening was performed to identify potential Lpg2021 inhibitors. This study contributes a novel perspective to the understanding of SAHH evolution and establishes a structural framework for designing specific inhibitors targeting pathogenic Legionella pneumophila SAHH.
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Affiliation(s)
- Yongshan Gao
- Institute of Health Sciences and Technology, Institutes of Material Science and Information Technology, Anhui University, Hefei 230601, China; School of Resources and Environmental Engineering, Anhui University, Hefei 230601, China
| | - Rao Xie
- Institute of Health Sciences and Technology, Institutes of Material Science and Information Technology, Anhui University, Hefei 230601, China
| | - Yanan Chen
- Institute of Health Sciences and Technology, Institutes of Material Science and Information Technology, Anhui University, Hefei 230601, China
| | - Beibei Yang
- Institute of Health Sciences and Technology, Institutes of Material Science and Information Technology, Anhui University, Hefei 230601, China
| | - Min Wang
- Institute of Health Sciences and Technology, Institutes of Material Science and Information Technology, Anhui University, Hefei 230601, China
| | - Lan Hua
- Institute of Health Sciences and Technology, Institutes of Material Science and Information Technology, Anhui University, Hefei 230601, China
| | - Xu Wang
- Institute of Health Sciences and Technology, Institutes of Material Science and Information Technology, Anhui University, Hefei 230601, China
| | - Weiqiang Wang
- Institute of Health Sciences and Technology, Institutes of Material Science and Information Technology, Anhui University, Hefei 230601, China
| | - Na Wang
- Institute of Health Sciences and Technology, Institutes of Material Science and Information Technology, Anhui University, Hefei 230601, China.
| | - Honghua Ge
- Institute of Health Sciences and Technology, Institutes of Material Science and Information Technology, Anhui University, Hefei 230601, China.
| | - Jinming Ma
- Institute of Health Sciences and Technology, Institutes of Material Science and Information Technology, Anhui University, Hefei 230601, China.
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2
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Auranofin inhibits virulence pathways in Pseudomonas aeruginosa. Bioorg Med Chem 2023; 79:117167. [PMID: 36682225 DOI: 10.1016/j.bmc.2023.117167] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 12/18/2022] [Accepted: 01/09/2023] [Indexed: 01/13/2023]
Abstract
Pseudomonas aeruginosa is widely attributed as the leading cause of hospital-acquired infections. Due to intrinsic antibiotic resistance mechanisms and the ability to form biofilms, P. aeruginosa infections are challenging to treat. P. aeruginosa employs multiple virulence mechanisms to establish infections, many of which are controlled by the global virulence regulator Vfr. An attractive strategy to combat P. aeruginosa infections is thus the use of anti-virulence compounds. Here, we report the discovery that FDA-approved drug auranofin attenuates virulence pathways in P. aeruginosa, including quorum sensing (QS) and Type IV pili (TFP). We show that auranofin acts via multiple targets, one of which being Vfr. Consistent with inhibition of QS and TFP expression, we show that auranofin attenuates biofilm maturation, and when used in combination with colistin, displays strong synergy in eradicating P. aeruginosa biofilms. Auranofin may have immediate applications as an anti-virulence drug against P. aeruginosa infections.
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3
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Barik K, Arya PK, Singh AK, Kumar A. Potential therapeutic targets for combating Mycoplasma genitalium. 3 Biotech 2023; 13:9. [PMID: 36532859 PMCID: PMC9755450 DOI: 10.1007/s13205-022-03423-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Accepted: 12/05/2022] [Indexed: 12/23/2022] Open
Abstract
Mycoplasma genitalium (M. genitalium) has emerged as a sexually transmitted infection (STI) all over the world in the last three decades. It has been identified as a cause of male urethritis, and there is now evidence that it also causes cervicitis and pelvic inflammatory disease in women. However, the precise role of M. genitalium in diseases such as pelvic inflammatory disease, and infertility is unknown, and more research is required. It is a slow-growing organism, and with the advent of the nucleic acid amplification test (NAAT), more studies are being conducted and knowledge about the pathogenicity of this organism is being elucidated. The accumulation of data has improved our understanding of the pathogen and its role in disease transmission. Despite the widespread use of single-dose azithromycin in the sexual health field, M. genitalium is known to rapidly develop antibiotic resistance. As a result, the media frequently refer to this pathogen as the "new STI superbug." Despite their rarity, antibiotics available today have serious side effects. As the cure rates for first-line antimicrobials have decreased, it is now a challenge to determine the effective antimicrobial therapy. In this review, we summarise recent M. genitalium research and investigate potential therapeutic targets for combating this pathogen.
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Affiliation(s)
- Krishnendu Barik
- Department of Bioinformatics, Central University of South Bihar, Gaya, 824236 India
| | - Praffulla Kumar Arya
- Department of Bioinformatics, Central University of South Bihar, Gaya, 824236 India
| | - Ajay Kumar Singh
- Department of Bioinformatics, Central University of South Bihar, Gaya, 824236 India
| | - Anil Kumar
- Department of Bioinformatics, Central University of South Bihar, Gaya, 824236 India
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4
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Yam JKH, Aung TT, Chua SL, Cheng Y, Kohli GS, Zhou J, Constancias F, Liu Y, Cai Z, Salido MMS, Drautz-Moses DI, Rice SA, Schuster SC, Boo ZZ, Wu B, Kjelleberg S, Tolker-Nielsen T, Lakshminarayanan R, Beuerman RW, Yang L, Givskov M. Elevated c-di-GMP Levels and Expression of the Type III Secretion System Promote Corneal Infection by Pseudomonas aeruginosa. Infect Immun 2022; 90:e0006122. [PMID: 35913171 PMCID: PMC9387266 DOI: 10.1128/iai.00061-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 07/07/2022] [Indexed: 01/18/2023] Open
Abstract
Pseudomonas aeruginosa is generally believed to establish biofilm-associated infections under the regulation of the secondary messenger c-di-GMP. To evaluate P. aeruginosa biofilm physiology during ocular infections, comparative transcriptomic analysis was performed on wild-type P. aeruginosa PAO1, a ΔwspF mutant strain (high c-di-GMP levels), and a plac-yhjH-containing strain (low c-di-GMP levels) from mouse corneal infection, as well as in vitro biofilm and planktonic cultures. The c-di-GMP content in P. aeruginosa during corneal infection was monitored using a fluorescent c-di-GMP reporter strain. Biofilm-related genes were induced in in vivo PAO1 compared to in vitro planktonic bacteria. Several diguanylate cyclases and phosphodiesterases were commonly regulated in in vivo PAO1 and in vitro biofilm compared to in vitro planktonic bacteria. Several exopolysaccharide genes and motility genes were induced and downregulated, respectively, in in vivo PAO1 and the in vivo ΔwspF mutant compared to the in vivo plac-yhjH-containing strain. Elevation of c-di-GMP levels in P. aeruginosa began as early as 2 h postinfection. The ΔwspF mutant was less susceptible to host clearance than the plac-yhjH-containing strain and could suppress host immune responses. The type III secretion system (T3SS) was induced in in vivo PAO1 compared to in vitro biofilm bacteria. A ΔwspF mutant with a defective T3SS was more susceptible to host clearance than a ΔwspF mutant with a functional T3SS. Our study suggests that elevated intracellular c-di-GMP levels and T3SS activity in P. aeruginosa are necessary for establishment of infection and modulation of host immune responses in mouse cornea.
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Affiliation(s)
- Joey Kuok Hoong Yam
- Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore, Singapore
| | - Thet Tun Aung
- Ocular Infections and Anti-Microbials Research Group, Singapore Eye Research Institute, Singapore, Singapore
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, National University Health System, Singapore, Singapore
| | - Song Lin Chua
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hong Kong
| | - Yingying Cheng
- Forensics Genomics International (FGI), BGI-Shenzhen, Shenzhen, China
| | - Gurjeet Singh Kohli
- Alfred Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, Germany
| | - Jianuan Zhou
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, China
| | | | - Yang Liu
- School of Medicine, Southern University of Science and Technology, Shenzhen, Guangdong Province, China
| | - Zhao Cai
- School of Medicine, Southern University of Science and Technology, Shenzhen, Guangdong Province, China
| | - May Margarette Santillan Salido
- Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore, Singapore
| | - Daniela I. Drautz-Moses
- Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore, Singapore
| | - Scott A. Rice
- Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore, Singapore
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
- CSIRO, Agriculture and Food, Microbiomes for One Systems Health, Canberra, Australia
| | - Stephan Christoph Schuster
- Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore, Singapore
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Zhao Zhi Boo
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Bin Wu
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Staffan Kjelleberg
- Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore, Singapore
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
- School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Tim Tolker-Nielsen
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Rajamani Lakshminarayanan
- Ocular Infections and Anti-Microbials Research Group, Singapore Eye Research Institute, Singapore, Singapore
- Department of Pharmacy, National University of Singapore, Singapore, Singapore
- Academic Clinical Program in Ophthalmology and Visual Sciences Academic Clinical Program, Duke-NUS Medical School, Singapore, Singapore
| | - Roger W. Beuerman
- Ocular Infections and Anti-Microbials Research Group, Singapore Eye Research Institute, Singapore, Singapore
- SRP Neuroscience and Behavioural Disorders and Emerging Infectious Diseases, Duke-NUS, Singapore, Singapore
- Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- Department of Ophthalmology, The University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Liang Yang
- School of Medicine, Southern University of Science and Technology, Shenzhen, Guangdong Province, China
| | - Michael Givskov
- Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore, Singapore
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
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5
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Liu Z, Zhao Y, Sossah FL, Okorley BA, Amoako DG, Liu P, Sheng H, Li D, Li Y. Characterization, Pathogenicity, Phylogeny, and Comparative Genomic Analysis of Pseudomonas tolaasii Strains Isolated from Various Mushrooms in China. PHYTOPATHOLOGY 2022; 112:521-534. [PMID: 34293910 DOI: 10.1094/phyto-12-20-0550-r] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Since 2016, devastating bacterial blotch affecting the fruiting bodies of Agaricus bisporus, Cordyceps militaris, Flammulina filiformis, and Pleurotus ostreatus in China has caused severe economic losses. We isolated 102 bacterial strains and characterized them polyphasically. We identified the causal agent as Pseudomonas tolaasii and confirmed the pathogenicity of the strains. A host range test further confirmed the pathogen's ability to infect multiple hosts. This is the first report in China of bacterial blotch in C. militaris caused by P. tolaasii. Whole-genome sequences were generated for three strains: Pt11 (6.48 Mb), Pt51 (6.63 Mb), and Pt53 (6.80 Mb), and pangenome analysis was performed with 13 other publicly accessible P. tolaasii genomes to determine their genetic diversity, virulence, antibiotic resistance, and mobile genetic elements. The pangenome of P. tolaasii is open, and many more gene families are likely to emerge with further genome sequencing. Multilocus sequence analysis using the sequences of four common housekeeping genes (glns, gyrB, rpoB, and rpoD) showed high genetic variability among the P. tolaasii strains, with 115 strains clustered into a monophyletic group. The P. tolaasii strains possess various genes for secretion systems, virulence factors, carbohydrate-active enzymes, toxins, secondary metabolites, and antimicrobial resistance genes that are associated with pathogenesis and adapted to different environments. The myriad of insertion sequences, integrons, prophages, and genome islands encoded in the strains may contribute to genome plasticity, virulence, and antibiotic resistance. These findings advance understanding of the determinants of virulence, which can be targeted for the effective control of bacterial blotch disease.
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Affiliation(s)
- Zhenghui Liu
- Engineering Research Center of Chinese Ministry of Education for Edible and Medicinal Fungi, Jilin Agricultural University, Changchun 130118, China
- Department of Plant Protection, Shenyang Agricultural University, Shenyang 110866, China
| | - Yitong Zhao
- Engineering Research Center of Chinese Ministry of Education for Edible and Medicinal Fungi, Jilin Agricultural University, Changchun 130118, China
| | - Frederick L Sossah
- Engineering Research Center of Chinese Ministry of Education for Edible and Medicinal Fungi, Jilin Agricultural University, Changchun 130118, China
| | - Benjamin A Okorley
- Engineering Research Center of Chinese Ministry of Education for Edible and Medicinal Fungi, Jilin Agricultural University, Changchun 130118, China
- Crop Science Department, University of Ghana, Legon, Accra, Ghana
| | - Daniel G Amoako
- Antimicrobial Research Unit, College of Health Sciences, University of KwaZulu-Natal, Durban 4000, South Africa
| | - Peibin Liu
- Engineering Research Center of Chinese Ministry of Education for Edible and Medicinal Fungi, Jilin Agricultural University, Changchun 130118, China
| | - Hongyan Sheng
- Department of Plant Pathology, Washington State University, Pullman, WA 99164-6430, U.S.A
| | - Dan Li
- Engineering Research Center of Chinese Ministry of Education for Edible and Medicinal Fungi, Jilin Agricultural University, Changchun 130118, China
- Internationally Cooperative Research Center of China for New Germplasm Breeding of Edible Mushroom, Ministry of Science and Technology, Jilin Agricultural University, Changchun 130118, China
| | - Yu Li
- Engineering Research Center of Chinese Ministry of Education for Edible and Medicinal Fungi, Jilin Agricultural University, Changchun 130118, China
- Internationally Cooperative Research Center of China for New Germplasm Breeding of Edible Mushroom, Ministry of Science and Technology, Jilin Agricultural University, Changchun 130118, China
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6
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Castillo-Juárez I, Blancas-Luciano BE, García-Contreras R, Fernández-Presas AM. Antimicrobial peptides properties beyond growth inhibition and bacterial killing. PeerJ 2022; 10:e12667. [PMID: 35116194 PMCID: PMC8785659 DOI: 10.7717/peerj.12667] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 12/01/2021] [Indexed: 01/07/2023] Open
Abstract
Antimicrobial peptides (AMPs) are versatile molecules with broad antimicrobial activity produced by representatives of the three domains of life. Also, there are derivatives of AMPs and artificial short peptides that can inhibit microbial growth. Beyond killing microbes, AMPs at grow sub-inhibitory concentrations also exhibit anti-virulence activity against critical pathogenic bacteria, including ESKAPE pathogens. Anti-virulence therapies are an alternative to antibiotics since they do not directly affect viability and growth, and they are considered less likely to generate resistance. Bacterial biofilms significantly increase antibiotic resistance and are linked to establishing chronic infections. Various AMPs can kill biofilm cells and eradicate infections in animal models. However, some can inhibit biofilm formation and promote dispersal at sub-growth inhibitory concentrations. These examples are discussed here, along with those of peptides that inhibit the expression of traits controlled by quorum sensing, such as the production of exoproteases, phenazines, surfactants, toxins, among others. In addition, specific targets that are determinants of virulence include secretion systems (type II, III, and VI) responsible for releasing effector proteins toxic to eukaryotic cells. This review summarizes the current knowledge on the anti-virulence properties of AMPs and the future directions of their research.
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Affiliation(s)
- Israel Castillo-Juárez
- Laboratorio de Fitoquímica, Posgrado de Botánica, Colegio de Postgraduados, Texcoco, Estado de México, Mexico
| | - Blanca Esther Blancas-Luciano
- Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico City, Mexico
| | - Rodolfo García-Contreras
- Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico City, Mexico
| | - Ana María Fernández-Presas
- Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico City, Mexico
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7
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Identification of Translocation Inhibitors Targeting the Type III Secretion System of Enteropathogenic Escherichia coli. Antimicrob Agents Chemother 2021; 65:e0095821. [PMID: 34543097 DOI: 10.1128/aac.00958-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Infections with enteropathogenic Escherichia coli (EPEC) cause severe diarrhea in children. The noninvasive bacteria adhere to enterocytes of the small intestine and use a type III secretion system (T3SS) to inject effector proteins into host cells to modify and exploit cellular processes in favor of bacterial survival and replication. Several studies have shown that the T3SSs of bacterial pathogens are essential for virulence. Furthermore, the loss of T3SS-mediated effector translocation results in increased immune recognition and clearance of the bacteria. The T3SS is, therefore, considered a promising target for antivirulence strategies and novel therapeutics development. Here, we report the results of a high-throughput screening assay based on the translocation of the EPEC effector protein Tir (translocated intimin receptor). Using this assay, we screened more than 13,000 small molecular compounds of six different compound libraries and identified three substances which showed a significant dose-dependent effect on translocation without adverse effects on bacterial or eukaryotic cell viability. In addition, these substances reduced bacterial binding to host cells, effector-dependent cell detachment, and abolished attaching and effacing lesion formation without affecting the expression of components of the T3SS or associated effector proteins. Moreover, no effects of the inhibitors on bacterial motility or Shiga-toxin expression were observed. In summary, we have identified three new compounds that strongly inhibit T3SS-mediated translocation of effectors into mammalian cells, which could be valuable as lead substances for treating EPEC and enterohemorrhagic E. coli infections.
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8
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Conners R, McLaren M, Łapińska U, Sanders K, Stone MRL, Blaskovich MAT, Pagliara S, Daum B, Rakonjac J, Gold VAM. CryoEM structure of the outer membrane secretin channel pIV from the f1 filamentous bacteriophage. Nat Commun 2021; 12:6316. [PMID: 34728631 PMCID: PMC8563730 DOI: 10.1038/s41467-021-26610-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 10/13/2021] [Indexed: 11/09/2022] Open
Abstract
The Ff family of filamentous bacteriophages infect gram-negative bacteria, but do not cause lysis of their host cell. Instead, new virions are extruded via the phage-encoded pIV protein, which has homology with bacterial secretins. Here, we determine the structure of pIV from the f1 filamentous bacteriophage at 2.7 Å resolution by cryo-electron microscopy, the first near-atomic structure of a phage secretin. Fifteen f1 pIV subunits assemble to form a gated channel in the bacterial outer membrane, with associated soluble domains projecting into the periplasm. We model channel opening and propose a mechanism for phage egress. By single-cell microfluidics experiments, we demonstrate the potential for secretins such as pIV to be used as adjuvants to increase the uptake and efficacy of antibiotics in bacteria. Finally, we compare the f1 pIV structure to its homologues to reveal similarities and differences between phage and bacterial secretins.
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Affiliation(s)
- Rebecca Conners
- Living Systems Institute, University of Exeter, Exeter, UK
- College of Life and Environmental Sciences, Geoffrey Pope, University of Exeter, Exeter, UK
| | - Mathew McLaren
- Living Systems Institute, University of Exeter, Exeter, UK
- College of Life and Environmental Sciences, Geoffrey Pope, University of Exeter, Exeter, UK
| | - Urszula Łapińska
- Living Systems Institute, University of Exeter, Exeter, UK
- College of Life and Environmental Sciences, Geoffrey Pope, University of Exeter, Exeter, UK
| | - Kelly Sanders
- Living Systems Institute, University of Exeter, Exeter, UK
- College of Life and Environmental Sciences, Geoffrey Pope, University of Exeter, Exeter, UK
| | - M Rhia L Stone
- Centre for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
| | - Mark A T Blaskovich
- Centre for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
| | - Stefano Pagliara
- Living Systems Institute, University of Exeter, Exeter, UK
- College of Life and Environmental Sciences, Geoffrey Pope, University of Exeter, Exeter, UK
| | - Bertram Daum
- Living Systems Institute, University of Exeter, Exeter, UK
- College of Life and Environmental Sciences, Geoffrey Pope, University of Exeter, Exeter, UK
| | - Jasna Rakonjac
- School of Fundamental Sciences, Massey University, Palmerston North, New Zealand
| | - Vicki A M Gold
- Living Systems Institute, University of Exeter, Exeter, UK.
- College of Life and Environmental Sciences, Geoffrey Pope, University of Exeter, Exeter, UK.
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9
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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.
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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.
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10
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Biswas S, Wu C, van der Donk WA. The Antimicrobial Activity of the Glycocin Sublancin Is Dependent on an Active Phosphoenolpyruvate-Sugar Phosphotransferase System. ACS Infect Dis 2021; 7:2402-2412. [PMID: 34242010 DOI: 10.1021/acsinfecdis.1c00157] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Antimicrobial resistance is a global challenge that is compounded by the limited number of available targets. Glycocins are antimicrobial glycopeptides that are believed to have novel targets. Previous studies have shown that the mechanism of action of the glycocin sublancin 168 involves the glucose uptake system. The phosphoenolpyruvate:sugar phosphotransferase system (PTS) phosphorylates the C6 hydroxyl group on glucose during import. Since sublancin carries a glucose on a Cys on an exposed loop, we investigated whether phosphorylation of this glucose might be involved in its mechanism of action by replacement with xylose. Surprisingly, the xylose analog was more active than wild-type sublancin and still required the glucose PTS for activity. Overexpression of the individual components of the PTS rendered cells more sensitive to sublancin, and their resistance frequency was considerably decreased. These observations suggest that sublancin is activated in some form by the glucose PTS or that sublancin imparts a deleterious gain-of-function on the PTS. Superresolution microscopy studies with fluorescent sublancin and fluorescently labeled PTS proteins revealed localization of both at the poles of cells. Resistant mutants raised under conditions that would minimize mutation of the PTS revealed mutations in FliQ, a protein involved in the flagellar protein export process. Overexpression of FliQ lead to decreased sensitivity of cells to sublancin. Collectively, these findings enforce a model in which the PTS is required for sublancin activity, either by inducing a deleterious gain-of-function or by activating or transporting sublancin.
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11
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Fatoba AJ, Okpeku M, Adeleke MA. Subtractive Genomics Approach for Identification of Novel Therapeutic Drug Targets in Mycoplasma genitalium. Pathogens 2021; 10:pathogens10080921. [PMID: 34451385 PMCID: PMC8402164 DOI: 10.3390/pathogens10080921] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 07/09/2021] [Accepted: 07/11/2021] [Indexed: 12/14/2022] Open
Abstract
Mycoplasma genitalium infection is a sexually transmitted infection that causes urethritis, cervicitis, and pelvic inflammatory disease (PID) in men and women. The global rise in antimicrobial resistance against recommended antibiotics for the treatment of M. genitalium infection has triggered the need to explore novel drug targets against this pathogen. The application of a bioinformatics approach through subtractive genomics has proven highly instrumental in predicting novel therapeutic targets against a pathogen. This study aimed to identify essential and non-homologous proteins with unique metabolic pathways in the pathogen that could serve as novel drug targets. Based on this, a manual comparison of the metabolic pathways of M. genitalium and the human host was done, generating nine pathogen-specific metabolic pathways. Additionally, the analysis of the whole proteome of M. genitalium using different bioinformatics databases generated 21 essential, non-homologous, and cytoplasmic proteins involved in nine pathogen-specific metabolic pathways. The further screening of these 21 cytoplasmic proteins in the DrugBank database generated 13 druggable proteins, which showed similarity with FDA-approved and experimental small-molecule drugs. A total of seven proteins that are involved in seven different pathogen-specific metabolic pathways were finally selected as novel putative drug targets after further analysis. Therefore, these proposed drug targets could aid in the design of potent drugs that may inhibit the functionality of these pathogen-specific metabolic pathways and, as such, lead to the eradication of this pathogen.
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Zigangirova NA, Nesterenko LN, Sheremet AB, Soloveva AV, Luyksaar SI, Zayakin ES, Balunets DV, Gintsburg AL. Fluorothiazinon, a small-molecular inhibitor of T3SS, suppresses salmonella oral infection in mice. J Antibiot (Tokyo) 2021; 74:244-254. [PMID: 33479520 DOI: 10.1038/s41429-020-00396-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 11/05/2020] [Accepted: 11/18/2020] [Indexed: 01/29/2023]
Abstract
Therapeutic strategies that target bacterial virulence have received considerable attention. The type III secretion system (T3SS) is important for bacterial virulence and represents an attractive therapeutic target. Recently, we developed a new small-molecule inhibitor belonging to a class 2,4-disubstituted-4H-[1,3,4]-thiadiazine-5-ones, Fluorothiazinon (FT-previously called CL-55). FT effectively suppressed T3SS of Chlamydia spp., Pseudomonas aeruginosa, and Salmonella without affecting bacterial growth in vitro. FT was previously characterized by low toxicity, stability, and therapeutic efficacy in animal models. Salmonella T3SS inhibition by FT was studied using in vitro assays for effector proteins detection and estimation of salmonella replication in peritoneal macrophages. The antibacterial effect of FT in vivo was investigated in murine models of salmonella chronic systemic and acute infection. Oral administration of the virulent strain of Salmonella enterica serovar Typhimurium to mice-induced chronic systemic infection with the pathogen persistence in different lymphoid organs such as spleens, Peyer's plaques, and mesenteric lymph nodes. We found that FT suppressed orally induced salmonella infection both with therapeutic and prophylactic administration. Treatment by FT at a dose of 50 mg/kg for 4 days starting from day 7 post-infection (therapy) as well as for 4 days before infection (prevention) led to practically complete eradication of salmonella in mice. FT shows a strong potential for antibacterial therapy and could be used as a substance in the design of antibacterial drugs for pharmaceutical intervention including therapy of antibiotic-resistant infections.
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Affiliation(s)
- Nailya A Zigangirova
- Gamaleya National Research Center of Epidemiology and Microbiology, Ministry of Health Russian Federation, Gamaleya str.18, Moscow, 123098, Russia.
| | - Ludmila N Nesterenko
- Gamaleya National Research Center of Epidemiology and Microbiology, Ministry of Health Russian Federation, Gamaleya str.18, Moscow, 123098, Russia
| | - Anna B Sheremet
- Gamaleya National Research Center of Epidemiology and Microbiology, Ministry of Health Russian Federation, Gamaleya str.18, Moscow, 123098, Russia
| | - Anna V Soloveva
- Gamaleya National Research Center of Epidemiology and Microbiology, Ministry of Health Russian Federation, Gamaleya str.18, Moscow, 123098, Russia
| | - Sergey I Luyksaar
- Gamaleya National Research Center of Epidemiology and Microbiology, Ministry of Health Russian Federation, Gamaleya str.18, Moscow, 123098, Russia
| | - Egor S Zayakin
- Gamaleya National Research Center of Epidemiology and Microbiology, Ministry of Health Russian Federation, Gamaleya str.18, Moscow, 123098, Russia
| | - Denis V Balunets
- Gamaleya National Research Center of Epidemiology and Microbiology, Ministry of Health Russian Federation, Gamaleya str.18, Moscow, 123098, Russia
| | - Alexandr L Gintsburg
- Gamaleya National Research Center of Epidemiology and Microbiology, Ministry of Health Russian Federation, Gamaleya str.18, Moscow, 123098, Russia
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Matthews-Palmer TRS, Gonzalez-Rodriguez N, Calcraft T, Lagercrantz S, Zachs T, Yu XJ, Grabe GJ, Holden DW, Nans A, Rosenthal PB, Rouse SL, Beeby M. Structure of the cytoplasmic domain of SctV (SsaV) from the Salmonella SPI-2 injectisome and implications for a pH sensing mechanism. J Struct Biol 2021; 213:107729. [PMID: 33774138 PMCID: PMC8223533 DOI: 10.1016/j.jsb.2021.107729] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 03/19/2021] [Accepted: 03/20/2021] [Indexed: 12/22/2022]
Abstract
CryoEM of a full-length type III secretion system SctV resolves cytoplasmic but not transmembrane domains. MD simulations show SctV protomers flexibly hinge. Acidification expands the SctV ring by altering interprotomer interactions.
Bacterial type III secretion systems assemble the axial structures of both injectisomes and flagella. Injectisome type III secretion systems subsequently secrete effector proteins through their hollow needle into a host, requiring co-ordination. In the Salmonella enterica serovar Typhimurium SPI-2 injectisome, this switch is triggered by sensing the neutral pH of the host cytoplasm. Central to specificity switching is a nonameric SctV protein with an N-terminal transmembrane domain and a toroidal C-terminal cytoplasmic domain. A ‘gatekeeper’ complex interacts with the SctV cytoplasmic domain in a pH dependent manner, facilitating translocon secretion while repressing effector secretion through a poorly understood mechanism. To better understand the role of SctV in SPI-2 translocon-effector specificity switching, we purified full-length SctV and determined its toroidal cytoplasmic region’s structure using cryo-EM. Structural comparisons and molecular dynamics simulations revealed that the cytoplasmic torus is stabilized by its core subdomain 3, about which subdomains 2 and 4 hinge, varying the flexible outside cleft implicated in gatekeeper and substrate binding. In light of patterns of surface conservation, deprotonation, and structural motion, the location of previously identified critical residues suggest that gatekeeper binds a cleft buried between neighboring subdomain 4s. Simulations suggest that a local pH change from 5 to 7.2 stabilizes the subdomain 3 hinge and narrows the central aperture of the nonameric torus. Our results are consistent with a model of local pH sensing at SctV, where pH-dependent dynamics of SctV cytoplasmic domain affect binding of gatekeeper complex.
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Affiliation(s)
| | | | - Thomas Calcraft
- Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom; Structural Biology of Cells and Viruses Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Signe Lagercrantz
- Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Tobias Zachs
- Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Xiu-Jun Yu
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, United Kingdom
| | - Grzegorz J Grabe
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, United Kingdom
| | - David W Holden
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, United Kingdom
| | - Andrea Nans
- Structural Biology of Cells and Viruses Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Peter B Rosenthal
- Structural Biology of Cells and Viruses Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Sarah L Rouse
- Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom.
| | - Morgan Beeby
- Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom.
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14
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The Shigella Type III Secretion System: An Overview from Top to Bottom. Microorganisms 2021; 9:microorganisms9020451. [PMID: 33671545 PMCID: PMC7926512 DOI: 10.3390/microorganisms9020451] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 02/16/2021] [Accepted: 02/18/2021] [Indexed: 12/16/2022] Open
Abstract
Shigella comprises four species of human-restricted pathogens causing bacillary dysentery. While Shigella possesses multiple genetic loci contributing to virulence, a type III secretion system (T3SS) is its primary virulence factor. The Shigella T3SS nanomachine consists of four major assemblies: the cytoplasmic sorting platform; the envelope-spanning core/basal body; an exposed needle; and a needle-associated tip complex with associated translocon that is inserted into host cell membranes. The initial subversion of host cell activities is carried out by the effector functions of the invasion plasmid antigen (Ipa) translocator proteins, with the cell ultimately being controlled by dedicated effector proteins that are injected into the host cytoplasm though the translocon. Much of the information now available on the T3SS injectisome has been accumulated through collective studies on the T3SS from three systems, those of Shigella flexneri, Salmonella typhimurium and Yersinia enterocolitica/Yersinia pestis. In this review, we will touch upon the important features of the T3SS injectisome that have come to light because of research in the Shigella and closely related systems. We will also briefly highlight some of the strategies being considered to target the Shigella T3SS for disease prevention.
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15
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Hofmann L, Hirsch M, Ruthstein S. Advances in Understanding of the Copper Homeostasis in Pseudomonas aeruginosa. Int J Mol Sci 2021; 22:2050. [PMID: 33669570 PMCID: PMC7922089 DOI: 10.3390/ijms22042050] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Revised: 02/10/2021] [Accepted: 02/15/2021] [Indexed: 12/12/2022] Open
Abstract
Thirty-five thousand people die as a result of more than 2.8 million antibiotic-resistant infections in the United States of America per year. Pseudomonas aeruginosa (P. aeruginosa) is classified a serious threat, the second-highest threat category of the U.S. Department of Health and Human Services. Among others, the World Health Organization (WHO) encourages the discovery and development of novel antibiotic classes with new targets and mechanisms of action without cross-resistance to existing classes. To find potential new target sites in pathogenic bacteria, such as P. aeruginosa, it is inevitable to fully understand the molecular mechanism of homeostasis, metabolism, regulation, growth, and resistances thereof. P. aeruginosa maintains a sophisticated copper defense cascade comprising three stages, resembling those of public safety organizations. These stages include copper scavenging, first responder, and second responder. Similar mechanisms are found in numerous pathogens. Here we compare the copper-dependent transcription regulators cueR and copRS of Escherichia coli (E. coli) and P. aeruginosa. Further, phylogenetic analysis and structural modelling of mexPQ-opmE reveal that this efflux pump is unlikely to be involved in the copper export of P. aeruginosa. Altogether, we present current understandings of the copper homeostasis in P. aeruginosa and potential new target sites for antimicrobial agents or a combinatorial drug regimen in the fight against multidrug resistant pathogens.
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Affiliation(s)
| | | | - Sharon Ruthstein
- Institute of Nanotechnology and Advanced Materials & Department of Chemistry, Faculty of Exact Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel; (L.H.); (M.H.)
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16
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Stoica C, Cox G. Old problems and new solutions: antibiotic alternatives in food animal production. Can J Microbiol 2021; 67:427-444. [PMID: 33606564 DOI: 10.1139/cjm-2020-0601] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The antimicrobial resistance crisis is a Global Health challenge that impacts humans, animals, and the environment alike. In response to increased demands for animal protein and by-products, there has been a substantial increase in the use of antimicrobial agents in the animal industry. Indeed, they are extensively used to prevent, control, and (or) treat disease in animals. In addition to infection control, in-feed supplementation with antimicrobials became common practice for growth promotion of livestock. Unfortunately, the global overuse of antimicrobials has contributed to the emergence and spread of resistance. As such, many countries have implemented policies and approaches to eliminate the use of antimicrobials as growth promoters in food animals, which necessitates the need for alternate and One Health strategies to maintain animal health and welfare. This review summarizes the antimicrobial resistance crisis from Global Health and One Health perspectives. In addition, we outline examples of potential alternate strategies to circumvent antimicrobial use in animal husbandry practices, including antivirulence agents, bacteriophages, and nutritional measures to control bacterial pathogens. Overall, these alternate strategies require further research and development efforts, including assessment of efficacy and the associated development, manufacturing, and labor costs.
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Affiliation(s)
- Celine Stoica
- Department of Molecular and Cellular Biology, College of Biological Sciences, University of Guelph, 50 Stone Road East, Guelph, ON N1G 2W1, Canada.,Department of Molecular and Cellular Biology, College of Biological Sciences, University of Guelph, 50 Stone Road East, Guelph, ON N1G 2W1, Canada
| | - Georgina Cox
- Department of Molecular and Cellular Biology, College of Biological Sciences, University of Guelph, 50 Stone Road East, Guelph, ON N1G 2W1, Canada.,Department of Molecular and Cellular Biology, College of Biological Sciences, University of Guelph, 50 Stone Road East, Guelph, ON N1G 2W1, Canada
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Kumar M, Sarma DK, Shubham S, Kumawat M, Verma V, Nina PB, JP D, Kumar S, Singh B, Tiwari RR. Futuristic Non-antibiotic Therapies to Combat Antibiotic Resistance: A Review. Front Microbiol 2021; 12:609459. [PMID: 33574807 PMCID: PMC7870489 DOI: 10.3389/fmicb.2021.609459] [Citation(s) in RCA: 64] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 01/04/2021] [Indexed: 12/26/2022] Open
Abstract
The looming problem of resistance to antibiotics in microorganisms is a global health concern. The drug-resistant microorganisms originating from anthropogenic sources and commercial livestock farming have posed serious environmental and health challenges. Antibiotic-resistant genes constituting the environmental "resistome" get transferred to human and veterinary pathogens. Hence, deciphering the origin, mechanism and extreme of transfer of these genetic factors into pathogens is extremely important to develop not only the therapeutic interventions to curtail the infections, but also the strategies to avert the menace of microbial drug-resistance. Clinicians, researchers and policymakers should jointly come up to develop the strategies to prevent superfluous exposure of pathogens to antibiotics in non-clinical settings. This article highlights the present scenario of increasing antimicrobial-resistance in pathogenic bacteria and the clinical importance of unconventional or non-antibiotic therapies to thwart the infectious pathogenic microorganisms.
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Affiliation(s)
- Manoj Kumar
- ICMR-National Institute for Research in Environmental Health, Bhopal, India
| | | | - Swasti Shubham
- ICMR-National Institute for Research in Environmental Health, Bhopal, India
| | - Manoj Kumawat
- ICMR-National Institute for Research in Environmental Health, Bhopal, India
| | - Vinod Verma
- Stem Cell Research Centre, Department of Hematology, SGPGIMS, Lucknow, India
| | | | - Devraj JP
- ICMR- National Institute of Nutrition, Hyderabad, India
| | - Santosh Kumar
- ICMR- National Institute of Nutrition, Hyderabad, India
| | - Birbal Singh
- ICAR-Indian Veterinary Research Institute, Regional Station, Palampur, India
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18
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Bacterial virulence mediated by orthogonal post-translational modification. Nat Chem Biol 2020; 16:1043-1051. [PMID: 32943788 DOI: 10.1038/s41589-020-0638-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 07/30/2020] [Indexed: 12/28/2022]
Abstract
Many bacterial pathogens secrete virulence factors, also known as effector proteins, directly into host cells. These effectors suppress pro-inflammatory host signaling while promoting bacterial infection. A particularly interesting subset of effectors post-translationally modify host proteins using novel chemistry that is not otherwise found in the mammalian proteome, which we refer to as 'orthogonal post-translational modification' (oPTM). In this Review, we profile oPTM chemistry for effectors that catalyze serine/threonine acetylation, phosphate β-elimination, phosphoribosyl-linked ubiquitination, glutamine deamidation, phosphocholination, cysteine methylation, arginine N-acetylglucosaminylation, and glutamine ADP-ribosylation on host proteins. AMPylation, a PTM that could be considered orthogonal until only recently, is also discussed. We further highlight known cellular targets of oPTMs and their resulting biological consequences. Developing a complete understanding of oPTMs and the host cell processes they hijack will illuminate critical steps in the infection process, which can be harnessed for a variety of therapeutic, diagnostic, and synthetic applications.
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19
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Chemical Targeting and Manipulation of Type III Secretion in the Phytopathogen Xanthomonas campestris for Control of Disease. Appl Environ Microbiol 2020; 86:AEM.02349-19. [PMID: 31732574 PMCID: PMC6974632 DOI: 10.1128/aem.02349-19] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 11/07/2019] [Indexed: 12/21/2022] Open
Abstract
The bacterium Xanthomonas campestris pv. campestris is known to cause black rot disease in many socioeconomically important vegetable crops worldwide. The management and control of black rot disease have been tackled with chemical and host resistance methods with variable success. This has motivated the development of alternative methods for preventing this disease. Here, we identify a set of novel small molecules capable of inhibiting X. campestris pv. campestris virulence, which may represent leading compounds for the further development of antivirulence agents that could be used in the control of black rot disease. Xanthomonas campestris pv. campestris is the causative agent of black rot disease in crucifer plants. This Gram-negative bacterium utilizes the type III secretion system (T3SS), encoded by the hrp gene cluster, to aid in its resistance to host defenses and the ability to cause disease. The T3SS injects a set of proteins known as effectors into host cells that come into contact with the bacterium. The T3SS is essential for the virulence and hypersensitive response (HR) of X. campestris pv. campestris, making it a potential target for disease control strategies. Using a unique and straightforward high-throughput screening method, we examined a large collection of diverse small molecules for their potential to modulate the T3SS without affecting the growth of X. campestris pv. campestris. Screening of 13,129 different compounds identified 10 small molecules that had a significant inhibitory influence on T3SS. Moreover, reverse transcription-quantitative PCR (qRT-PCR) assays demonstrated that all 10 compounds repress the expression of the hrp genes. Interestingly, the effect of these small molecules on hrp genes may be through the HpaS and ColS sensor kinase proteins that are key to the regulation of the T3SS in planta. Five of the compounds were also capable of inhibiting X. campestris pv. campestris virulence in a Chinese radish leaf-clipping assay. Furthermore, seven of the small molecules significantly weakened the HR in nonhost pepper plants challenged with X. campestris pv. campestris. Taken together, these small molecules may provide potential tool compounds for the further development of antivirulence agents that could be used in disease control of the plant pathogen X. campestris pv. campestris. IMPORTANCE The bacterium Xanthomonas campestris pv. campestris is known to cause black rot disease in many socioeconomically important vegetable crops worldwide. The management and control of black rot disease have been tackled with chemical and host resistance methods with variable success. This has motivated the development of alternative methods for preventing this disease. Here, we identify a set of novel small molecules capable of inhibiting X. campestris pv. campestris virulence, which may represent leading compounds for the further development of antivirulence agents that could be used in the control of black rot disease.
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20
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Zhang X, Gao R, Liu Y, Cong Y, Zhang D, Zhang Y, Yang X, Lu C, Shen Y. Anti-virulence activities of biflavonoids from Mesua ferrea L. flower. Drug Discov Ther 2019; 13:222-227. [PMID: 31534074 DOI: 10.5582/ddt.2019.01053] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Based on the anti-virulence activity on Salmonella, the ethyl acetate extract (EAE) of Mesua ferrea flower was investigated for its chemical constituents. Ten purified compounds were identified and assayed for their inhibitory activity against Type III secretion system (T3SS) by polyacrylamide gel electrophoresis (SDS-PAGE) and Western blots experiments. We found the biflavonoids, rhusflavanone and mesuaferrone B, exhibited inhibitory effects on the secretion of Salmonella pathogenicity island 1 (SPI-1) effector proteins (SipA, B, C and D) without effecting the bacterial growth. In addition, 5, 6, 6'-trihydroxy-[1,1'-biphenyl]-3,3'-dicarboxylic acid (6) is a new natural product from M. ferrea flower.
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Affiliation(s)
- Xiaochun Zhang
- Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences, Shandong University
| | - Rongrong Gao
- Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences, Shandong University
| | - Yan Liu
- Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences, Shandong University
| | - Yuhe Cong
- Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences, Shandong University
| | - Dongdong Zhang
- Key Laboratory of Economic Plants and Biotechnology, Kunming Institute of Botany, Chinese Academy of Sciences
| | - Yu Zhang
- Key Laboratory of Economic Plants and Biotechnology, Kunming Institute of Botany, Chinese Academy of Sciences
| | - Xuefei Yang
- Key Laboratory of Economic Plants and Biotechnology, Kunming Institute of Botany, Chinese Academy of Sciences
| | - Chunhua Lu
- Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences, Shandong University
| | - Yuemao Shen
- Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences, Shandong University
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21
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Abstract
Antibiotic resistance is a major public health threat that has stimulated the scientific community to search for nontraditional therapeutic targets. Because virulence, but not the growth, of many Gram-negative bacterial pathogens depends on the multicomponent type three secretion system injectisome (T3SSi), the T3SSi has been an attractive target for identifying small molecules, peptides, and monoclonal antibodies that inhibit its function to render the pathogen avirulent. While many small-molecule lead compounds have been identified in whole-cell-based high-throughput screens (HTSs), only a few protein targets of these compounds are known; such knowledge is an important step to developing more potent and specific inhibitors. Evaluation of the efficacy of compounds in animal studies is ongoing. Some efforts involving the development of antibodies and vaccines that target the T3SSi are further along and include an antibody that is currently in phase II clinical trials. Continued research into these antivirulence therapies, used alone or in combination with traditional antibiotics, requires combined efforts from both pharmaceutical companies and academic labs.
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22
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Slater SL, Sågfors AM, Pollard DJ, Ruano-Gallego D, Frankel G. The Type III Secretion System of Pathogenic Escherichia coli. Curr Top Microbiol Immunol 2019; 416:51-72. [PMID: 30088147 DOI: 10.1007/82_2018_116] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Infection with enteropathogenic and enterohaemorrhagic Escherichia coli (EPEC and EHEC), enteroinvasive E. coli (EIEC) and Shigella relies on the elaboration of a type III secretion system (T3SS). Few strains also encode a second T3SS, named ETT2. Through the integration of coordinated intracellular and extracellular cues, the modular T3SS is assembled within the bacterial cell wall, as well as the plasma membrane of the host cell. As such, the T3SS serves as a conduit, allowing the chaperone-regulated translocation of effector proteins directly into the host cytosol to subvert eukaryotic cell processes. Recent technological advances revealed high structural resolution of the T3SS apparatus and how it could be exploited to treat enteric disease. This chapter summarises the current knowledge of the structure and function of the E. coli T3SSs.
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Affiliation(s)
- Sabrina L Slater
- Department of Life Sciences, MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, UK
| | - Agnes M Sågfors
- Department of Life Sciences, MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, UK
| | - Dominic J Pollard
- Department of Life Sciences, MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, UK
| | - David Ruano-Gallego
- Department of Life Sciences, MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, UK
| | - Gad Frankel
- Department of Life Sciences, MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, UK.
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23
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El Qaidi S, Zhu C, McDonald P, Roy A, Maity PK, Rane D, Perera C, Hardwidge PR. High-Throughput Screening for Bacterial Glycosyltransferase Inhibitors. Front Cell Infect Microbiol 2018; 8:435. [PMID: 30619781 PMCID: PMC6305410 DOI: 10.3389/fcimb.2018.00435] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Accepted: 12/05/2018] [Indexed: 11/25/2022] Open
Abstract
The enteropathogenic and enterohemorrhagic Escherichia coli NleB proteins as well as the Salmonella enterica SseK proteins are type III secretion system effectors that function as glycosyltransferase enzymes to post-translationally modify host substrates on arginine residues. This modification is unusual because it occurs on the guanidinium groups of arginines, which are poor nucleophiles, and is distinct from the activity of the mammalian O-linked N-acetylglucosaminyltransferase. We conducted high-throughput screening assays to identify small molecules that inhibit NleB/SseK activity. Two compounds, 100066N and 102644N, both significantly inhibited NleB1, SseK1, and SseK2 activities. Addition of these compounds to cultured mammalian cells was sufficient to inhibit NleB1 glycosylation of the tumor necrosis factor receptor type 1-associated DEATH domain protein. These compounds were also capable of inhibiting Salmonella enterica strain ATCC 14028 replication in mouse macrophage-like cells. Neither inhibitor was significantly toxic to mammalian cells, nor showed in vitro cross-reactivity with the mammalian O-linked N-acetylglucosaminyltransferase. These compounds or derivatives generated from medicinal chemistry refinements may have utility as a potential alternative therapeutic strategy to antibiotics or as reagents to further the study of bacterial glycosyltransferases.
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Affiliation(s)
- Samir El Qaidi
- College of Veterinary Medicine, Kansas State University, Manhattan, KS, United States
| | - Congrui Zhu
- College of Veterinary Medicine, Kansas State University, Manhattan, KS, United States
| | - Peter McDonald
- High Throughput Screening Laboratory, University of Kansas, Lawrence, KS, United States
| | - Anuradha Roy
- High Throughput Screening Laboratory, University of Kansas, Lawrence, KS, United States
| | - Pradip Kumar Maity
- Synthetic Chemical Biology Core Laboratory, University of Kansas, Lawrence, KS, United States
| | - Digamber Rane
- Synthetic Chemical Biology Core Laboratory, University of Kansas, Lawrence, KS, United States
| | - Chamani Perera
- Synthetic Chemical Biology Core Laboratory, University of Kansas, Lawrence, KS, United States
| | - Philip R Hardwidge
- College of Veterinary Medicine, Kansas State University, Manhattan, KS, United States
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Lakemeyer M, Zhao W, Mandl FA, Hammann P, Sieber SA. Thinking Outside the Box-Novel Antibacterials To Tackle the Resistance Crisis. Angew Chem Int Ed Engl 2018; 57:14440-14475. [PMID: 29939462 DOI: 10.1002/anie.201804971] [Citation(s) in RCA: 101] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2018] [Indexed: 12/13/2022]
Abstract
The public view on antibiotics as reliable medicines changed when reports about "resistant superbugs" appeared in the news. While reasons for this resistance development are easily spotted, solutions for re-establishing effective antibiotics are still in their infancy. This Review encompasses several aspects of the antibiotic development pipeline from very early strategies to mature drugs. An interdisciplinary overview is given of methods suitable for mining novel antibiotics and strategies discussed to unravel their modes of action. Select examples of antibiotics recently identified by using these platforms not only illustrate the efficiency of these measures, but also highlight promising clinical candidates with therapeutic potential. Furthermore, the concept of molecules that disarm pathogens by addressing gatekeepers of virulence will be covered. The Review concludes with an evaluation of antibacterials currently in clinical development. Overall, this Review aims to connect select innovative antimicrobial approaches to stimulate interdisciplinary partnerships between chemists from academia and industry.
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Affiliation(s)
- Markus Lakemeyer
- Department of Chemistry, Chair of Organic Chemistry II, Center for Integrated Protein Science (CIPSM), Technische Universität München, Lichtenbergstrasse 4, 85747, Garching, Germany
| | - Weining Zhao
- Department of Chemistry, Chair of Organic Chemistry II, Center for Integrated Protein Science (CIPSM), Technische Universität München, Lichtenbergstrasse 4, 85747, Garching, Germany
| | - Franziska A Mandl
- Department of Chemistry, Chair of Organic Chemistry II, Center for Integrated Protein Science (CIPSM), Technische Universität München, Lichtenbergstrasse 4, 85747, Garching, Germany
| | - Peter Hammann
- R&D Therapeutic Area Infectious Diseases, Sanofi-Aventis (Deutschland) GmbH, Industriepark Höchst, 65926, Frankfurt am Main, Germany
| | - Stephan A Sieber
- Department of Chemistry, Chair of Organic Chemistry II, Center for Integrated Protein Science (CIPSM), Technische Universität München, Lichtenbergstrasse 4, 85747, Garching, Germany
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Lakemeyer M, Zhao W, Mandl FA, Hammann P, Sieber SA. Über bisherige Denkweisen hinaus - neue Wirkstoffe zur Überwindung der Antibiotika-Krise. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201804971] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Markus Lakemeyer
- Fakultät für Chemie; Lehrstuhl für Organische Chemie II, Center for Integrated Protein Science (CIPSM); Technische Universität München; Lichtenbergstraße 4 85747 Garching Deutschland
| | - Weining Zhao
- Fakultät für Chemie; Lehrstuhl für Organische Chemie II, Center for Integrated Protein Science (CIPSM); Technische Universität München; Lichtenbergstraße 4 85747 Garching Deutschland
| | - Franziska A. Mandl
- Fakultät für Chemie; Lehrstuhl für Organische Chemie II, Center for Integrated Protein Science (CIPSM); Technische Universität München; Lichtenbergstraße 4 85747 Garching Deutschland
| | - Peter Hammann
- R&D Therapeutic Area Infectious Diseases; Sanofi-Aventis (Deutschland) GmbH; Industriepark Höchst 65926 Frankfurt am Main Deutschland
| | - Stephan A. Sieber
- Fakultät für Chemie; Lehrstuhl für Organische Chemie II, Center for Integrated Protein Science (CIPSM); Technische Universität München; Lichtenbergstraße 4 85747 Garching Deutschland
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26
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Wagner S, Grin I, Malmsheimer S, Singh N, Torres-Vargas CE, Westerhausen S. Bacterial type III secretion systems: a complex device for the delivery of bacterial effector proteins into eukaryotic host cells. FEMS Microbiol Lett 2018; 365:5068689. [PMID: 30107569 PMCID: PMC6140923 DOI: 10.1093/femsle/fny201] [Citation(s) in RCA: 113] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 08/08/2018] [Indexed: 12/21/2022] Open
Abstract
Virulence-associated type III secretion systems (T3SS) serve the injection of bacterial effector proteins into eukaryotic host cells. They are able to secrete a great diversity of substrate proteins in order to modulate host cell function, and have evolved to sense host cell contact and to inject their substrates through a translocon pore in the host cell membrane. T3SS substrates contain an N-terminal signal sequence and often a chaperone-binding domain for cognate T3SS chaperones. These signals guide the substrates to the machine where substrates are unfolded and handed over to the secretion channel formed by the transmembrane domains of the export apparatus components and by the needle filament. Secretion itself is driven by the proton motive force across the bacterial inner membrane. The needle filament measures 20-150 nm in length and is crowned by a needle tip that mediates host-cell sensing. Secretion through T3SS is a highly regulated process with early, intermediate and late substrates. A strict secretion hierarchy is required to build an injectisome capable of reaching, sensing and penetrating the host cell membrane, before host cell-acting effector proteins are deployed. Here, we review the recent progress on elucidating the assembly, structure and function of T3SS injectisomes.
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Affiliation(s)
- Samuel Wagner
- University of Tübingen, Interfaculty Institute of Microbiology and Infection Medicine (IMIT), Elfriede-Aulhorn-Str. 6, 72076 Tübingen, Germany
- German Center for Infection Research (DZIF), partner-site Tübingen, Elfriede-Aulhorn-Str. 6, 72076 Tübingen, Germany
| | - Iwan Grin
- University of Tübingen, Interfaculty Institute of Microbiology and Infection Medicine (IMIT), Elfriede-Aulhorn-Str. 6, 72076 Tübingen, Germany
| | - Silke Malmsheimer
- University of Tübingen, Interfaculty Institute of Microbiology and Infection Medicine (IMIT), Elfriede-Aulhorn-Str. 6, 72076 Tübingen, Germany
| | - Nidhi Singh
- University of Tübingen, Interfaculty Institute of Microbiology and Infection Medicine (IMIT), Elfriede-Aulhorn-Str. 6, 72076 Tübingen, Germany
| | - Claudia E Torres-Vargas
- University of Tübingen, Interfaculty Institute of Microbiology and Infection Medicine (IMIT), Elfriede-Aulhorn-Str. 6, 72076 Tübingen, Germany
| | - Sibel Westerhausen
- University of Tübingen, Interfaculty Institute of Microbiology and Infection Medicine (IMIT), Elfriede-Aulhorn-Str. 6, 72076 Tübingen, Germany
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Abstract
Antibiotics have saved millions of lives over the past decades. However, the accumulation of so many antibiotic resistance genes by some clinically relevant pathogens has begun to lead to untreatable infections worldwide. The current antibiotic resistance crisis will require greater efforts by governments and the scientific community to increase the research and development of new antibacterial drugs with new mechanisms of action. A major challenge is the identification of novel microbial targets, essential for in vivo growth or pathogenicity, whose inhibitors can overcome the currently circulating resistome of human pathogens. In this article, we focus on the potential high value of bacterial transcriptional regulators as targets for the development of new antibiotics, discussing in depth the molecular role of these regulatory proteins in bacterial physiology and pathogenesis. Recent advances in the search for novel compounds that inhibit the biological activity of relevant transcriptional regulators in pathogenic bacteria are reviewed.
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Dey S, Anbanandam A, Mumford BE, De Guzman RN. Characterization of Small-Molecule Scaffolds That Bind to the Shigella Type III Secretion System Protein IpaD. ChemMedChem 2017; 12:1534-1541. [PMID: 28750143 DOI: 10.1002/cmdc.201700348] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2017] [Revised: 07/26/2017] [Indexed: 11/08/2022]
Abstract
Many pathogens such as Shigella and other bacteria assemble the type III secretion system (T3SS) nanoinjector to inject virulence proteins into their target cells to cause infectious diseases in humans. The rise of drug resistance among pathogens that rely on the T3SS for infectivity, plus the dearth of new antibiotics require alternative strategies in developing new antibiotics. The Shigella T3SS tip protein IpaD is an attractive target for developing anti-infectives because of its essential role in virulence and its exposure on the bacterial surface. Currently, the only known small molecules that bind to IpaD are bile salt sterols. In this study we identified four new small-molecule scaffolds that bind to IpaD, based on the methylquinoline, pyrrolidine-aniline, hydroxyindole, and morpholinoaniline scaffolds. NMR mapping revealed potential hotspots in IpaD for binding small molecules. These scaffolds can be used as building blocks in developing small-molecule inhibitors of IpaD that could lead to new anti-infectives.
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Affiliation(s)
- Supratim Dey
- Department of Molecular Biosciences, University of Kansas, 1200 Sunnyside Avenue, Lawrence, KS, 66045, USA
| | - Asokan Anbanandam
- Current address: Center for Drug Discovery and Innovation, University of South Florida, 3720 Spectrum Blvd., Suite #303, Tampa, FL, 33612, USA
| | - Ben E Mumford
- Department of Molecular Biosciences, University of Kansas, 1200 Sunnyside Avenue, Lawrence, KS, 66045, USA
| | - Roberto N De Guzman
- Department of Molecular Biosciences, University of Kansas, 1200 Sunnyside Avenue, Lawrence, KS, 66045, USA
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van Teeseling MCF, de Pedro MA, Cava F. Determinants of Bacterial Morphology: From Fundamentals to Possibilities for Antimicrobial Targeting. Front Microbiol 2017; 8:1264. [PMID: 28740487 PMCID: PMC5502672 DOI: 10.3389/fmicb.2017.01264] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Accepted: 06/23/2017] [Indexed: 12/11/2022] Open
Abstract
Bacterial morphology is extremely diverse. Specific shapes are the consequence of adaptive pressures optimizing bacterial fitness. Shape affects critical biological functions, including nutrient acquisition, motility, dispersion, stress resistance and interactions with other organisms. Although the characteristic shape of a bacterial species remains unchanged for vast numbers of generations, periodical variations occur throughout the cell (division) and life cycles, and these variations can be influenced by environmental conditions. Bacterial morphology is ultimately dictated by the net-like peptidoglycan (PG) sacculus. The species-specific shape of the PG sacculus at any time in the cell cycle is the product of multiple determinants. Some morphological determinants act as a cytoskeleton to guide biosynthetic complexes spatiotemporally, whereas others modify the PG sacculus after biosynthesis. Accumulating evidence supports critical roles of morphogenetic processes in bacteria-host interactions, including pathogenesis. Here, we review the molecular determinants underlying morphology, discuss the evidence linking bacterial morphology to niche adaptation and pathogenesis, and examine the potential of morphological determinants as antimicrobial targets.
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Affiliation(s)
- Muriel C F van Teeseling
- Laboratory for Molecular Infection Medicine Sweden, Department of Molecular Biology, Umeå Centre for Microbial Research, Umeå UniversityUmeå, Sweden
| | - Miguel A de Pedro
- Centro de Biología Molecular "Severo Ochoa" - Consejo Superior de Investigaciones Científicas, Universidad Autónoma de MadridMadrid, Spain
| | - Felipe Cava
- Laboratory for Molecular Infection Medicine Sweden, Department of Molecular Biology, Umeå Centre for Microbial Research, Umeå UniversityUmeå, Sweden
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Salicylidene Acylhydrazides and Hydroxyquinolines Act as Inhibitors of Type Three Secretion Systems in Pseudomonas aeruginosa by Distinct Mechanisms. Antimicrob Agents Chemother 2017; 61:AAC.02566-16. [PMID: 28396545 DOI: 10.1128/aac.02566-16] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2016] [Accepted: 03/23/2017] [Indexed: 12/27/2022] Open
Abstract
Type 3 secretion systems (T3SSs) are major virulence factors in Gram-negative bacteria. Pseudomonas aeruginosa expresses two T3SSs, namely, an injectisome (iT3SS) translocating effector proteins in the host cell cytosol and a flagellum (fT3SS) ensuring bacterial motility. Inhibiting these systems is an appealing therapeutic strategy for acute infections. This study examines the protective effects of the salicylidene acylhydrazide INP0341 and of the hydroxyquinoline INP1750 (previously described as T3SS inhibitors in other species) toward cytotoxic effects of P. aeruginosain vitro Both compounds reduced cell necrosis and inflammasome activation induced by reference strains or clinical isolates expressing T3SS toxins or only the translocation apparatus. INP0341 inhibited iT3SS transcriptional activation, including in strains with constitutive iT3SS expression, and reduced the total expression of toxins, suggesting it targets iT3SS gene transcription. INP1750 inhibited toxin secretion and flagellar motility and impaired the activity of the YscN ATPase from Yersinia pseudotuberculosis (homologous to the ATPase present in the basal body of P. aeruginosa iT3SS and fT3SS), suggesting that it rather targets a T3SS core constituent with high homology among iT3SS and fT3SS. This mode of action is similar to that previously described for INP1855, another hydroxyquinoline, against P. aeruginosa Thus, although acting by different mechanisms, INP0341 and INP1750 appear as useful inhibitors of the virulence of P. aeruginosa Hydroxyquinolines may have a broader spectrum of activity by the fact they act upon two virulence factors (iT3SS and fT3SS).
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Elhosseiny NM, El-Tayeb OM, Yassin AS, Lory S, Attia AS. The secretome of Acinetobacter baumannii ATCC 17978 type II secretion system reveals a novel plasmid encoded phospholipase that could be implicated in lung colonization. Int J Med Microbiol 2016; 306:633-641. [PMID: 27713027 DOI: 10.1016/j.ijmm.2016.09.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Revised: 09/24/2016] [Accepted: 09/30/2016] [Indexed: 02/01/2023] Open
Abstract
Acinetobacter baumannii infections are compounded with a striking lack of treatment options. In many Gram-negative bacteria, secreted proteins play an important early role in avoiding host defences. Typically, these proteins are targeted to the external environment or into host cells using dedicated transport systems. Despite the fact that medically relevant species of Acinetobacter possess a type II secretion system (T2SS), only recently, its significance as an important pathway for delivering virulence factors has gained attention. Using in silico analysis to characterize the genetic determinants of the T2SS, which are found clustered in other organisms, in Acinetobacter species, they appear to have a unique genetic organization and are distributed throughout the genome. When compared to other T2SS orthologs, individual components of the T2SS apparatus showed the highest similarity to those of Pseudomonas aeruginosa. A mutant of Acinetobacter baumannii strain ATCC 17978 lacking the secretin component of the T2SS (ΔgspD), together with a trans-complemented mutant, were tested in a series of in vitro and in vivo assays to determine the role of T2SS in pathogenicity. The ΔgspD mutant displayed decreased lipolytic activity, associated with attenuated colonization ability in a murine pneumonia model. These phenotypes are linked to LipAN, a novel plasmid-encoded phospholipase, identified through mass spectroscopy as a T2SS substrate. Recombinant LipAN showed specific phospholipase activity in vitro. Proteomics on the T2-dependent secretome of ATCC 17978 strain revealed its potential dedication to the secretion of a number of lipolytic enzymes, among others which could contribute to its virulence. This study highlights the role of T2SS as an active contributor to the virulence of A. baumannii potentially through secretion of a newly identified phospholipase.
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Affiliation(s)
- Noha M Elhosseiny
- Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University, Cairo, 11562, Egypt; Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Ossama M El-Tayeb
- Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University, Cairo, 11562, Egypt
| | - Aymen S Yassin
- Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University, Cairo, 11562, Egypt
| | - Stephen Lory
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Ahmed S Attia
- Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University, Cairo, 11562, Egypt.
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Meriläinen G, Koski MK, Wierenga RK. The extended structure of the periplasmic region of CdsD, a structural protein of the type III secretion system of Chlamydia trachomatis. Protein Sci 2016; 25:987-98. [PMID: 26914207 PMCID: PMC4838655 DOI: 10.1002/pro.2906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Accepted: 02/19/2016] [Indexed: 11/10/2022]
Abstract
The type III secretion system (T3SS) is required for the virulence of many gram-negative bacterial human pathogens. It is composed of several structural proteins, forming the secretion needle and its basis, the basal body. In Chlamydia spp., the T3SS inner membrane ring (IM-ring) of the basal body is formed by the periplasmic part of CdsD (outer ring) and CdsJ (inner ring). Here we describe the crystal structure of the C-terminal, periplasmic part of CdsD, not including the last 60 residues. Two crystal forms were obtained, grown in three different crystallization conditions. In both crystal forms there is one molecule per asymmetric unit adopting a similar extended structure. The structures consist of three periplasmic domains (PDs) of similar αββαβ topology as seen also in the structures of the homologous PrgH (Salmonella typhimurium) and YscD (Yersinia enterocolitica). Only in the C2 crystal form, there is a C-terminal additional helix after the PD3 domain. The relative orientation of the three subsequent CdsD PD domains with respect to each other is more extended than in PrgH but less extended than in YscD. Small-angle X-ray scattering data show that also in solution this CdsD construct adopts the same elongated shape. In both crystal forms the CdsD molecules are packed in a parallel fashion, using translational crystallographic symmetry. The most extensive crystal contacts are preserved in both crystal forms, suggesting a possible mode of assembly of the CdsD periplasmic part into a 24-mer complex forming the outer ring of the IM-ring of the T3SS.
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Affiliation(s)
- Gitte Meriläinen
- Biocenter Oulu and Faculty of Biochemistry and Molecular Medicine, 90014 University of OuluOuluFinland
| | - M. Kristian Koski
- Biocenter Oulu and Faculty of Biochemistry and Molecular Medicine, 90014 University of OuluOuluFinland
| | - Rik K. Wierenga
- Biocenter Oulu and Faculty of Biochemistry and Molecular Medicine, 90014 University of OuluOuluFinland
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33
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Nariya MK, Israeli J, Shi JJ, Deeds EJ. Mathematical Model for Length Control by the Timing of Substrate Switching in the Type III Secretion System. PLoS Comput Biol 2016; 12:e1004851. [PMID: 27078235 PMCID: PMC4831731 DOI: 10.1371/journal.pcbi.1004851] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 03/06/2016] [Indexed: 12/28/2022] Open
Abstract
Type III Secretion Systems (T3SS) are complex bacterial structures that provide gram-negative pathogens with a unique virulence mechanism whereby they grow a needle-like structure in order to inject bacterial effector proteins into the cytoplasm of a host cell. Numerous experiments have been performed to understand the structural details of this nanomachine during the past decade. Despite the concerted efforts of molecular and structural biologists, several crucial aspects of the assembly of this structure, such as the regulation of the length of the needle itself, remain unclear. In this work, we used a combination of mathematical and computational techniques to better understand length control based on the timing of substrate switching, which is a possible mechanism for how bacteria ensure that the T3SS needles are neither too short nor too long. In particular, we predicted the form of the needle length distribution based on this mechanism, and found excellent agreement with available experimental data from Salmonella typhimurium with only a single free parameter. Although our findings provide preliminary evidence in support of the substrate switching model, they also make a set of quantitative predictions that, if tested experimentally, would assist in efforts to unambiguously characterize the regulatory mechanisms that control the growth of this crucial virulence factor.
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Affiliation(s)
- Maulik K. Nariya
- Department of Physics and Astronomy, University of Kansas, Lawrence, Kansas, United States of America
| | - Johnny Israeli
- Department of Physics and Astronomy, University of Kansas, Lawrence, Kansas, United States of America
| | - Jack J. Shi
- Department of Physics and Astronomy, University of Kansas, Lawrence, Kansas, United States of America
| | - Eric J. Deeds
- Center for Computational Biology, University of Kansas, Lawrence, Kansas, United States of America
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas, United States of America
- Sante Fe Institute, Santa Fe, New Mexico, United States of America
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McShan AC, Anbanandam A, Patnaik S, De Guzman RN. Characterization of the Binding of Hydroxyindole, Indoleacetic acid, and Morpholinoaniline to the Salmonella Type III Secretion System Proteins SipD and SipB. ChemMedChem 2016; 11:963-71. [PMID: 26990667 DOI: 10.1002/cmdc.201600065] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2016] [Revised: 03/05/2016] [Indexed: 01/01/2023]
Abstract
Many Gram-negative bacteria require the type III secretion system (T3SS) to cause infectious diseases in humans. A looming public health problem is that all bacterial pathogens that require the T3SS to cause infectious diseases in humans have developed multidrug resistance to current antibiotics. The T3SS is an attractive target for the development of new antibiotics because of its critical role in virulence. An initial step in developing anti-T3SS-based therapeutics is the identification of small molecules that can bind to T3SS proteins. Currently, the only small molecules that are known to bind to the Salmonella T3SS proteins SipD and SipB are bile salts (to SipD) and sphingolipids and cholesterol (to SipB). Herein we report the results of a surface plasmon resonance screen of 288 compounds wherein the binding of 4-morpholinoaniline to SipD, 3-indoleacetic acid to SipB, and 5-hydroxyindole to both SipD and SipB were identified. We also identified by NMR the SipD surfaces involved in binding. These three compounds represent a new class of molecules that can bind to T3SS tip (SipD) and translocon (SipB) proteins that could find use in future drug design.
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Affiliation(s)
- Andrew C McShan
- Department of Molecular Biosciences, University of Kansas, 1200 Sunnyside Ave., Lawrence, KS, 66045, USA
| | - Asokan Anbanandam
- Biomolecular NMR Core Facility, University of Kansas, Lawrence, KS, 66045, USA
| | - Sikta Patnaik
- Department of Molecular Biosciences, University of Kansas, 1200 Sunnyside Ave., Lawrence, KS, 66045, USA
| | - Roberto N De Guzman
- Department of Molecular Biosciences, University of Kansas, 1200 Sunnyside Ave., Lawrence, KS, 66045, USA.
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35
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Abstract
Governments, academics and industry are beginning to listen to the medical communities call for new anti-bacterials. This special issue brings together diverse review articles on topics from economics and pricing to new discovery methods.
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Affiliation(s)
- Roberta J Melander
- Department of Chemistry, North Carolina State University, Raleigh, NC, 27695, USA
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Craney A, Romesberg FE. The inhibition of type I bacterial signal peptidase: Biological consequences and therapeutic potential. Bioorg Med Chem Lett 2015; 25:4761-4766. [PMID: 26276537 DOI: 10.1016/j.bmcl.2015.07.072] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Revised: 07/16/2015] [Accepted: 07/21/2015] [Indexed: 01/05/2023]
Abstract
The general secretory pathway has long been regarded as a potential antibiotic drug target. In particular, bacterial type I signal peptidase (SPase) is emerging as a strong candidate for therapeutic use. In this review, we focus on the information gained from the use of SPase inhibitors as probes of prokaryote biology. A thorough understanding of the consequences of SPase inhibition and the mechanisms of resistance that arise are essential to the success of SPase as an antibiotic target. In addition to the role of SPase in processing secreted proteins, the use of SPase inhibitors has elucidated a previously unknown function for SPase in regulating cleavage events of membrane proteins.
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Affiliation(s)
- Arryn Craney
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Floyd E Romesberg
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
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37
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Charro N, Mota LJ. Approaches targeting the type III secretion system to treat or prevent bacterial infections. Expert Opin Drug Discov 2015; 10:373-87. [DOI: 10.1517/17460441.2015.1019860] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Nuno Charro
- 1UCIBIO, REQUIMTE, Departmento de Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica 2829-516, Portugal
| | - Luís Jaime Mota
- 2UCIBIO, REQUIMTE, Departmento de Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica 2829-516, Portugal ;
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38
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Abstract
Resistance of important bacterial pathogens to common antimicrobial therapies and the emergence of multidrug-resistant bacteria are increasing at an alarming rate and constitute one of our greatest challenges in the combat of bacterial infection and accompanied diseases. The current shortage of effective drugs, lack of successful prevention measures and only a few new antibiotics in the clinical pipeline demand the development of novel treatment options and alternative antimicrobial therapies. Our increasing understanding of bacterial virulence strategies and the induced molecular pathways of the infectious disease provides novel opportunities to target and interfere with crucial pathogenicity factors or virulence-associated traits of the bacteria while bypassing the evolutionary pressure on the bacterium to develop resistance. In the past decade, numerous new bacterial targets for anti-virulence therapies have been identified, and structure-based tailoring of intervention strategies and screening assays for small-molecule inhibitors of such pathways were successfully established. In this chapter, we will take a closer look at the bacterial virulence-related factors and processes that present promising targets for anti-virulence therapies, recently discovered inhibitory substances and their promises and discuss the challenges, and problems that have to be faced.
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