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Gao Y, Wu J, Shen J, Xu Y, Li L, Wang W, Zhou N, Zhang M. Chitosan modified magnetic nanocomposite for biofilm destruction and precise photothermal/photodynamic therapy. Int J Biol Macromol 2024; 259:129402. [PMID: 38219940 DOI: 10.1016/j.ijbiomac.2024.129402] [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: 07/23/2023] [Revised: 12/28/2023] [Accepted: 01/09/2024] [Indexed: 01/16/2024]
Abstract
Getting rid of the biofilms is a major challenge when treating skin and soft tissue infections (SSTI), an inflammatory illness brought on by bacteria. Traditional magnetic materials have a limited dispersibility and a biofilm permeable property, making it challenging to remove biofilms and causing infection to linger. To solve these problems, we developed a kind of magnetic composite nanoplatform coated with indocyanine green carbon dots and modified with chitosan modification (Fe-ICGCDs@CS). Fe-ICGCDs@CS has high dispersibility and improves the conductivity of biofilms under magnetic action. Fe-ICGCDs@CS can adsorb bacteria via the positive charge and achieve precise photothermal sterilization and photodynamic therapy (PDT). Moreover, by catalyzing hydrogen peroxide (2 mM), Fe-ICGCDs@CS can produce oxygen to relieve the anoxic state in the deep layer of biofilms and activate dormant bacteria to make them sensitive to external stimuli. All in all, unlike the common "just kill" sterilization model, Fe-ICGCDs@CS can accurately kill bacteria and be recovered by an external magnetic field at the end of treatment, thus reducing the potential biological toxicity of nanomaterials. Therefore, the proposed Fe-ICGCDs@CS provides a new antibacterial method with low biotoxicity for clinical application in the treatment of biofilm infections.
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Affiliation(s)
- Yumeng Gao
- Jiangsu Key Laboratory of Oral Diseases, Jiangsu Province Engineering Research Center of Stomatological Translational Medicine, Nanjing Medical University, Nanjing 210029, PR China; Jiangsu Collaborative Innovation Center for Biomedical Functional Materials, School of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023, PR China
| | - Jing Wu
- Jiangsu Key Laboratory of Oral Diseases, Jiangsu Province Engineering Research Center of Stomatological Translational Medicine, Nanjing Medical University, Nanjing 210029, PR China; Jiangsu Collaborative Innovation Center for Biomedical Functional Materials, School of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023, PR China
| | - Jian Shen
- Jiangsu Collaborative Innovation Center for Biomedical Functional Materials, School of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023, PR China
| | - Yan Xu
- Jiangsu Key Laboratory of Oral Diseases, Jiangsu Province Engineering Research Center of Stomatological Translational Medicine, Nanjing Medical University, Nanjing 210029, PR China
| | - Lu Li
- Jiangsu Key Laboratory of Oral Diseases, Jiangsu Province Engineering Research Center of Stomatological Translational Medicine, Nanjing Medical University, Nanjing 210029, PR China
| | - Wentao Wang
- College of Science, Nanjing Forestry University, Nanjing 210037, PR China
| | - Ninglin Zhou
- Jiangsu Collaborative Innovation Center for Biomedical Functional Materials, School of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023, PR China
| | - Ming Zhang
- Jiangsu Key Laboratory of Oral Diseases, Jiangsu Province Engineering Research Center of Stomatological Translational Medicine, Nanjing Medical University, Nanjing 210029, PR China.
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He LL, Wang X, O'Neill Rothenberg D, Xu X, Wang HH, Deng X, Cui ZN. A novel strategy to control Pseudomonas syringae through inhibition of type III secretion system. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2023; 194:105471. [PMID: 37532345 DOI: 10.1016/j.pestbp.2023.105471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Revised: 05/10/2023] [Accepted: 05/15/2023] [Indexed: 08/04/2023]
Abstract
Pseudomonas syringae (P. syringae) is a highly prevalent Gram-negative pathogen with over 60 pathogenic variants that cause yield losses of up to 80% in various crops. Traditional control methods mainly involve the application of antibiotics to inactivate pathogenic bacteria, but large-scale application of antibiotics has led to the development of bacterial resistance. Gram-negative pathogens including P. syringae commonly use the type III secretion system (T3SS) as a transport channel to deliver effector proteins into host cells, disrupting host defences and facilitating virulence, providing a novel target for antibacterial drug development. In this study, we constructed a high-throughput screening reporter system based on our previous work to screen for imidazole, oxazole and thiazole compounds. The screening indicated that the three compounds (II-14, II-15 and II-24) significantly inhibited hrpW and hrpL gene promoter activity without influencing the growth of P. syringae, and the inhibitory activity was better than that of the positive control sulforaphane (4-methylsulfinylbutyl isothiocyanate, SFN) at 50 μM. Three compounds suppressed the transcript levels of representative T3SS genes to different degrees, suggesting that the compounds may suppress the expression of T3SS by modulating the HrpR/S-HrpL regulatory pathway. Inoculation experiments indicated that all three compounds suppressed the pathogenicity of Pseudomonas syringae pv. tomato DC3000 in tomato and Pseudomonas syringae pv. phaseolicola 1448A in bean to varying degrees. One representative compound, II-15, significantly inhibited the secretion of the Pst DC3000 AvrPto effector protein. These findings provide a theoretical basis for the development of novel P. syringae T3SS inhibitors for application in disease prevention and control.
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Affiliation(s)
- Lu-Lu He
- National Key Laboratory of Green Pesticide, Integrative Microbiology Research Centre, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, College of Plant Protection, South China Agricultural University, Guangzhou 510642, China
| | - Xin Wang
- National Key Laboratory of Green Pesticide, Integrative Microbiology Research Centre, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, College of Plant Protection, South China Agricultural University, Guangzhou 510642, China
| | | | - Xiaoli Xu
- Instrumental Analysis & Research Center, South China Agricultural University, Guangzhou 510642, China
| | - Hai-Hong Wang
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, Guangdong 510642, China
| | - Xin Deng
- Department of Biomedical Sciences, City University of Hong Kong, Kowloon Tong, Hong Kong SAR 999077, China; Shenzhen Research Institute, City University of Hong Kong, Shenzhen 518057, China
| | - Zi-Ning Cui
- National Key Laboratory of Green Pesticide, Integrative Microbiology Research Centre, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, College of Plant Protection, South China Agricultural University, Guangzhou 510642, China.
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Kim D, Park KW, Park JT, Choi I. Photoactive MOF-Derived Bimetallic Silver and Cobalt Nanocomposite with Enhanced Antibacterial Activity. ACS APPLIED MATERIALS & INTERFACES 2023; 15:22903-22914. [PMID: 36996415 DOI: 10.1021/acsami.3c01529] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Conventional antibiotic-based treatment of bacterial infections remains one of the most difficult challenges in medicine because of the threat of multidrug resistance caused by indiscriminate abuse. To solve these problems, it is essential to develop an effective antibacterial agent that can be used at a small dose while minimizing the occurrence of multiple resistance. Metal-organic frameworks (MOFs), which are hyper-porous hybrid materials containing metal ions linked by organic ligands, have recently attracted attention because of their strong antibacterial activity through metal-ion release, unlike conventional antibiotics. In this study, we developed a photoactive MOF-derived cobalt-silver bimetallic nanocomposite (Ag@CoMOF) by simply depositing silver nanoparticles on a cobalt-based MOF through nanoscale galvanic replacement. The nanocomposite structure continuously releases antibacterial metal ions (i.e., Ag and Co ions) in the aqueous phase and exhibits a strong photothermal conversion effect of Ag nanoparticles, accompanied by a rapid temperature increase of 25-80 °C under near-infrared (NIR) irradiation. Using this MOF-based bimetallic nanocomposite, superior antibacterial activities were achieved by 22.1-fold for Escherichia coli and 18.3-fold for Bacillus subtilis enhanced inhibition of bacterial growth in a liquid culture environment compared with the generally used chemical antibiotics. In addition, we confirmed the synergistic enhancement of the antibacterial ability of the bimetallic nanocomposite induced by NIR-triggered photothermal heating and bacterial membrane disruption even when using a small amount of the nanocomposites. We envision that this novel antibacterial agent using MOF-based nanostructures will replace traditional antibiotics to circumvent multidrug resistance and present a new approach to antibiotic development.
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Affiliation(s)
- Doyun Kim
- Department of Life Science, University of Seoul, 163, Seoulsiripdae-ro, Dongdaemun-gu, Seoul 02504, Republic of Korea
| | - Kun Woo Park
- Department of Chemical Engineering, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Jung Tae Park
- Department of Chemical Engineering, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Inhee Choi
- Department of Life Science, University of Seoul, 163, Seoulsiripdae-ro, Dongdaemun-gu, Seoul 02504, Republic of Korea
- Department of Applied Chemistry, University of Seoul, 163, Seoulsiripdae-ro, Dongdaemun-gu, Seoul 02504, Republic of Korea
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Costa-Júnior SD, Ferreira YLA, Agreles MAA, Alves ÁEF, Melo de Oliveira MB, Cavalcanti IMF. Gram-negative bacilli carrying mcr gene in Brazil: a pathogen on the rise. Braz J Microbiol 2023:10.1007/s42770-023-00948-w. [PMID: 36943639 PMCID: PMC10028778 DOI: 10.1007/s42770-023-00948-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Accepted: 03/04/2023] [Indexed: 03/23/2023] Open
Abstract
The incidence of infections caused by resistant Gram-negative pathogens has become a critical factor in public health due to the limitation of therapeutic options for the control of infections caused, especially, by Enterobacteriaceae (Escherichia coli and Klebsiella pneumoniae), Pseudomonas spp., and Acinetobacter spp. Thus, given the increase in resistant pathogens and the reduction of therapeutic options, polymyxins were reintroduced into the clinic. As the last treatment option, polymyxins were regarded as the therapeutic key, since they were one of the few classes of antimicrobials that had activity against multidrug-resistant Gram-negative bacilli. Nonetheless, over the years, the frequent use of this antimicrobial has led to reports of resistance cases. In 2015, mcr (mobile colistin resistance), a colistin resistance gene, was described in China. Due to its location on carrier plasmids, this gene is characterized by rapid spread through conjugation. It has thus been classified as a rising threat to public health worldwide. In conclusion, based on several reports that show the emergence of mcr in different regional and climatic contexts and species of isolates, this work aims to review the literature on the incidence of the mcr gene in Brazil in different regions, types of samples identified, species of isolates, and type of carrier plasmid.
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Affiliation(s)
- Sérgio Dias Costa-Júnior
- Department of Physiology and Pathology, Federal University of Paraíba (UFPB), 58.051-900, João Pessoa, Brazil
| | | | | | | | - Maria Betânia Melo de Oliveira
- Department of Bio of Biochemistry, Center for Biosciences, Federal University of Pernambuco (UFPE), Av. Moraes Rego S/N, Recife, PE, Brazil
| | - Isabella Macário Ferro Cavalcanti
- Keizo Asami Institute, Federal University of Pernambuco (iLIKA/UFPE), 50.670-901, Recife, Brazil.
- Microbiology and Immunology Laboratory, Academic Center of Vitória, Federal University of Pernambuco (CAV/UFPE), Centro Acadêmico de Vitória, Rua Do Alto Do Reservatório S/N, Bela Vista, Vitória de Santo Antão, PE, 55608-680, Brazil.
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Blasey N, Rehrmann D, Riebisch AK, Mühlen S. Targeting bacterial pathogenesis by inhibiting virulence-associated Type III and Type IV secretion systems. Front Cell Infect Microbiol 2023; 12:1065561. [PMID: 36704108 PMCID: PMC9872159 DOI: 10.3389/fcimb.2022.1065561] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2022] [Accepted: 12/19/2022] [Indexed: 01/12/2023] Open
Abstract
Infections caused by Gram-negative pathogens pose a major health burden. Both respiratory and gastrointestinal infections are commonly associated with these pathogens. With the increase in antimicrobial resistance (AMR) over the last decades, bacterial infections may soon become the threat they have been before the discovery of antibiotics. Many Gram-negative pathogens encode virulence-associated Type III and Type IV secretion systems, which they use to inject bacterial effector proteins across bacterial and host cell membranes into the host cell cytosol, where they subvert host cell functions in favor of bacterial replication and survival. These secretion systems are essential for the pathogens to cause disease, and secretion system mutants are commonly avirulent in infection models. Hence, these structures present attractive targets for anti-virulence therapies. Here, we review previously and recently identified inhibitors of virulence-associated bacterial secretions systems and discuss their potential as therapeutics.
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Gao ZY, Song YL, Li XT, Li TH, Lu CH, Shen YM. Effects of hydrolysable tannins from Terminalia citrina on type III secretion system (T3SS) and their intestinal metabolite urolithin B represses Salmonella T3SS through Hha–H-NS–HilD–HilC–RtsA–HilA regulatory pathway. Microb Pathog 2022; 173:105837. [DOI: 10.1016/j.micpath.2022.105837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2022] [Revised: 10/12/2022] [Accepted: 10/13/2022] [Indexed: 11/30/2022]
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Research Progress on Small Molecular Inhibitors of the Type 3 Secretion System. Molecules 2022; 27:molecules27238348. [PMID: 36500441 PMCID: PMC9740592 DOI: 10.3390/molecules27238348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 11/22/2022] [Accepted: 11/23/2022] [Indexed: 12/05/2022] Open
Abstract
The overuse of antibiotics has led to severe bacterial drug resistance. Blocking pathogen virulence devices is a highly effective approach to combating bacterial resistance worldwide. Type three secretion systems (T3SSs) are significant virulence factors in Gram-negative pathogens. Inhibition of these systems can effectively weaken infection whilst having no significant effect on bacterial growth. Therefore, T3SS inhibitors may be a powerful weapon against resistance in Gram-negative bacteria, and there has been increasing interest in the research and development of T3SS inhibitors. This review outlines several reported small-molecule inhibitors of the T3SS, covering those of synthetic and natural origin, including their sources, structures, and mechanisms of action.
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de Groot N, Meneguzzi M, de Souza B, de O Costa M. In Vitro Screening of Non-Antibiotic Components to Mitigate Intestinal Lesions Caused by Brachyspira hyodysenteriae, Lawsonia intracellularis and Salmonella enterica Serovar Typhimurium. Animals (Basel) 2022; 12:2356. [PMID: 36139216 PMCID: PMC9494979 DOI: 10.3390/ani12182356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 08/31/2022] [Accepted: 09/06/2022] [Indexed: 11/16/2022] Open
Abstract
Swine dysentery, ileitis, and porcine salmonellosis are production-limiting diseases of global importance for swine production. They are caused by infection with Brachyspira hyodysenteriae, Lawsonia intracellularis, and Salmonella enterica serovar Typhimurium, respectively. Currently, the prevention, treatment, and control of these diseases still relies on antimicrobials. The goal of this study was to evaluate the effectiveness of four commercially available non-antimicrobial compounds in preventing lesions caused by the bacteria cited above using an in vitro intestinal culture model. A total of five pigs per pathogen were used and multiple compounds were evaluated. For compound F (a fungal fermented rye), S (a blend of short and medium chain fatty acids), and P (a synergistic blend of short and medium chain fatty acids, including coated butyrates), a total of four explants/pig for each treatment were used, while for compound D (an extract of carob and thyme) only 12 explants/pig for each treatment were used. Explants were exposed to a combination of pathogen only (n = 4/compound/pig), compound only (n = 4/compound/pig), or pathogen and compound (n = 4/compound/pig) and sampled at two time-points. Histopathology and gene expression levels were evaluated to investigate the treatment effect on explants. Short and medium-chain fatty acids, and an extract of carob and thyme, was found to mitigate lesions due to B. hyodysenteriae exposure. A fungal fermented prebiotic increased healthy epithelial coverage when explants were exposed to L. intracellularis or S. Typhimurium. These findings represent a step towards finding alternatives to antimicrobials usage and control of swine dysentery, ileitis, and salmonellosis in pork production.
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Affiliation(s)
- Nienke de Groot
- Departamento de Producción Animal, Facultad de Veterinaria, Universidad de Murcia, 30100 Murcia, Spain
| | - Mariana Meneguzzi
- Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota, St. Paul, MN 55455, USA
| | - Barbara de Souza
- Departamento de Clínica and Cirurgia Veterinárias, Escola de Veterinária, Federal University of Minas Gerais, Belo Horizonte 31270-901, Brazil
| | - Matheus de O Costa
- Large Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK S7N 5B4, Canada
- Department of Population Health Sciences, Faculty of Veterinary Medicine, Utrecht University, 3584 CS Utrecht, The Netherlands
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Zambelloni R, Beckham KSH, Wu HJ, Elofsson M, Marquez R, Gabrielsen M, Roe AJ. Crystal structures of WrbA, a spurious target of the salicylidene acylhydrazide inhibitors of type III secretion in Gram-negative pathogens, and verification of improved specificity of next-generation compounds. MICROBIOLOGY (READING, ENGLAND) 2022; 168. [PMID: 35829699 DOI: 10.1099/mic.0.001211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The enterohemorrhagic Escherichia coli pathotype is responsible for severe and dangerous infections in humans. Establishment of the infection requires colonization of the gastro-intestinal tract, which is dependent on the Type III Secretion System. The Type III Secretion System (T3SS) allows attachment of the pathogen to the mammalian host cell and cytoskeletal rearrangements within the host cell. Blocking the functionality of the T3SS is likely to reduce colonization and therefore limit the disease. This route offers an alternative to antibiotics, and problems with the development of antibiotics resistance. Salicylidene acylhydrazides have been shown to have an inhibitory effect on the T3SS in several pathogens. However, the main target of these compounds is still unclear. Past work has identified a number of putative protein targets of these compounds, one of which being WrbA. Whilst WrbA is considered an off-target interaction, this study presents the effect of the salicylidne acylhydrazide compounds on the activity of WrbA, along with crystal structures of WrbA from Yersinia pseudotuberculosis and Salmonella serovar Typhimurium; the latter also containing parts of the compound in the structure. We also present data showing that the original compounds were unstable in acidic conditions, and that later compounds showed improved stability.
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Affiliation(s)
- Riccardo Zambelloni
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, Glasgow, G12 8TA, UK
- School of Chemistry, University of Glasgow, Glasgow G12 8QQ, UK
- Sygnature Discovery Ltd, Biocity, Discovery Building, Nottingham, NG1 1GR, UK
| | - Katherine S H Beckham
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, Glasgow, G12 8TA, UK
- EMBL Hamburg c/o DESY, Notkestraße 85, 22603 Hamburg, Germany
| | - Hong-Jin Wu
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, Glasgow, G12 8TA, UK
| | - Mikael Elofsson
- Umeå Centre for Microbial Research, Department of Chemistry, Umeå University, Umeå, Sweden
| | - Rudi Marquez
- School of Chemistry, University of Glasgow, Glasgow G12 8QQ, UK
- School of Physical and Chemical Sciences, Te Kura Matū, University of Canterbury, Christchurch, New Zealand
| | - Mads Gabrielsen
- MVLS Structural Biology and Biophysical Characterisation Facility, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Andrew J Roe
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, Glasgow, G12 8TA, UK
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A small molecule, C24H17ClN4O2S, inhibits the function of the type III secretion system in Salmonella Typhimurium. J Genet Eng Biotechnol 2022; 20:54. [PMID: 35380331 PMCID: PMC8982747 DOI: 10.1186/s43141-022-00336-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Accepted: 03/22/2022] [Indexed: 11/17/2022]
Abstract
Background Salmonella enterica serovar Typhimurium (S. Typhimurium) causes gastroenteritis and diarrhea in humans and food-producing animals. The type III secretion system (T3SS) has been known to be a potent virulence mechanism by injecting effector proteins into the cytosol of host cells. S. Typhimurium encodes two T3SSs by Salmonella pathogenicity islands 1 and 2. Previous studies showed that T3SS shared a potent virulence mechanism and molecular structure among several gram-negative bacteria. Therefore, T3SS has been identified as an attractive target in the development of novel therapeutics for the treatment of bacterial infections. Several studies reported that small-molecule compounds are able to inhibit functions of bacterial T3SSs. A small molecule, C24H17ClN4O2S, has been shown the ability to inhibit the activity of Yersinia pestis T3SS ATPase, YscN, resulting to block the secretion of effector proteins. In this study, we studied the effects and mechanism for SPI-1 T3SS inhibition of this compound in S. Typhimurium. Results We demonstrated that this compound prohibited the secretion of effector proteins from Salmonella via SPI-1 T3SS at 100 μM. As the result, bacterial invasion ability into epithelial cell cultures was reduced. In contrast with previous study, the C24H17ClN4O2S molecule did not inactivate the activity of SPI-1 T3SS ATPase, InvC, in Salmonella. However, we studied the global cellular effects of S. Typhimurium after being treated with this compound using a quantitative proteomic technique. These proteomic results showed that the main SPI-1 transcription regulator, InvF, and two effector proteins, SipA and SipC, were reduced in bacterial cells treated with the compound. Conclusions It may explain that action of the small-molecule compound, C24H17ClN4O2S, for blocking the secretion of SPI-1 T3SS in Salmonella is through inhibition of SPI-1 regulator, InvF, expression. Further studies are necessary to identify specific mechanisms for inhibition between this small-compound and InvF SPI-1 regulator protein.
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Hu A, Hu M, Chen S, Xue Y, Tan X, Zhou J. Five Plant Natural Products Are Potential Type III Secretion System Inhibitors to Effectively Control Soft-Rot Disease Caused by Dickeya. Front Microbiol 2022; 13:839025. [PMID: 35273588 PMCID: PMC8901885 DOI: 10.3389/fmicb.2022.839025] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Accepted: 02/01/2022] [Indexed: 11/23/2022] Open
Abstract
Dickeya zeae, a plant soft-rot pathogen, possesses a type III secretion system (T3SS) as one of the major virulence factors, infecting a wide variety of monocotyledonous and dicotyledonous plants and causing serious losses to the production of economic crops. In order to alleviate the problem of pesticide resistance during bacterial disease treatment, compounds targeting at T3SS have been screened using a hrpA-gfp bioreporter. After screening by Multifunctional Microplate Reader and determining by flow cytometer, five compounds including salicylic acid (SA), p-hydroxybenzoic acid (PHBA), cinnamyl alcohol (CA), p-coumaric acid (PCA), and hydrocinnamic acid (HA) significantly inhibiting hrpA promoter activity without affecting bacterial growth have been screened out. All the five compounds reduced hypersensitive response (HR) on non-host tobacco leaves and downregulated the expression of T3SS, especially the master regulator encoding gene hrpL. Inhibition efficacy of the five compounds against soft rot were also evaluated and results confirmed that the above compounds significantly lessened the soft-rot symptoms caused by Dickeya dadantii 3937 on potato, Dickeya fangzhongdai CL3 on taro, Dickeya oryzae EC1 on rice, and D. zeae MS2 on banana seedlings. Findings in this study provide potential biocontrol agents for prevention of soft-rot disease caused by Dickeya spp.
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Affiliation(s)
| | | | | | | | | | - Jianuan Zhou
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Center, South China Agricultural University, Guangzhou, China
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Kröger P, Shanmugaratnam S, Scheib U, Höcker B. Fine-tuning spermidine binding modes in the putrescine binding protein PotF. J Biol Chem 2021; 297:101419. [PMID: 34801550 PMCID: PMC8666671 DOI: 10.1016/j.jbc.2021.101419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 11/10/2021] [Accepted: 11/12/2021] [Indexed: 11/09/2022] Open
Abstract
A profound understanding of the molecular interactions between receptors and ligands is important throughout diverse research, such as protein design, drug discovery, or neuroscience. What determines specificity and how do proteins discriminate against similar ligands? In this study, we analyzed factors that determine binding in two homologs belonging to the well-known superfamily of periplasmic binding proteins, PotF and PotD. Building on a previously designed construct, modes of polyamine binding were swapped. This change of specificity was approached by analyzing local differences in the binding pocket as well as overall conformational changes in the protein. Throughout the study, protein variants were generated and characterized structurally and thermodynamically, leading to a specificity swap and improvement in affinity. This dataset not only enriches our knowledge applicable to rational protein design but also our results can further lay groundwork for engineering of specific biosensors as well as help to explain the adaptability of pathogenic bacteria.
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Affiliation(s)
- Pascal Kröger
- Department for Biochemistry, University of Bayreuth, Bayreuth, Germany
| | - Sooruban Shanmugaratnam
- Department for Biochemistry, University of Bayreuth, Bayreuth, Germany; Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Ulrike Scheib
- Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Birte Höcker
- Department for Biochemistry, University of Bayreuth, Bayreuth, Germany; Max Planck Institute for Developmental Biology, Tübingen, Germany.
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Swietnicki W. Secretory System Components as Potential Prophylactic Targets for Bacterial Pathogens. Biomolecules 2021; 11:892. [PMID: 34203937 PMCID: PMC8232601 DOI: 10.3390/biom11060892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 06/13/2021] [Accepted: 06/14/2021] [Indexed: 01/18/2023] Open
Abstract
Bacterial secretory systems are essential for virulence in human pathogens. The systems have become a target of alternative antibacterial strategies based on small molecules and antibodies. Strategies to use components of the systems to design prophylactics have been less publicized despite vaccines being the preferred solution to dealing with bacterial infections. In the current review, strategies to design vaccines against selected pathogens are presented and connected to the biology of the system. The examples are given for Y. pestis, S. enterica, B. anthracis, S. flexneri, and other human pathogens, and discussed in terms of effectiveness and long-term protection.
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Affiliation(s)
- Wieslaw Swietnicki
- Department of Immunology of Infectious Diseases, Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, ul. R. Weigla 12, 53-114 Wroclaw, Poland
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Hotinger JA, Pendergrass HA, May AE. Molecular Targets and Strategies for Inhibition of the Bacterial Type III Secretion System (T3SS); Inhibitors Directly Binding to T3SS Components. Biomolecules 2021; 11:biom11020316. [PMID: 33669653 PMCID: PMC7922566 DOI: 10.3390/biom11020316] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 02/16/2021] [Accepted: 02/17/2021] [Indexed: 01/01/2023] Open
Abstract
The type III secretion system (T3SS) is a virulence apparatus used by many Gram-negative pathogenic bacteria to cause infections. Pathogens utilizing a T3SS are responsible for millions of infections yearly. Since many T3SS knockout strains are incapable of causing systemic infection, the T3SS has emerged as an attractive anti-virulence target for therapeutic design. The T3SS is a multiprotein molecular syringe that enables pathogens to inject effector proteins into host cells. These effectors modify host cell mechanisms in a variety of ways beneficial to the pathogen. Due to the T3SS’s complex nature, there are numerous ways in which it can be targeted. This review will be focused on the direct targeting of components of the T3SS, including the needle, translocon, basal body, sorting platform, and effector proteins. Inhibitors will be considered a direct inhibitor if they have a binding partner that is a T3SS component, regardless of the inhibitory effect being structural or functional.
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Lunar Silva I, Cascales E. Molecular Strategies Underlying Porphyromonas gingivalis Virulence. J Mol Biol 2021; 433:166836. [PMID: 33539891 DOI: 10.1016/j.jmb.2021.166836] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 01/15/2021] [Accepted: 01/15/2021] [Indexed: 02/07/2023]
Abstract
The anaerobic Gram-negative bacterium Porphyromonas gingivalis is considered the keystone of periodontitis diseases, a set of inflammatory conditions that affects the tissues surrounding the teeth. In the recent years, the major virulence factors exploited by P. gingivalis have been identified and characterized, including a cocktail of toxins, mainly proteases called gingipains, which promote gingival tissue invasion. These effectors use the Sec pathway to cross the inner membrane and are then recruited and transported across the outer membrane by the type IX secretion system (T9SS). In P. gingivalis, most secreted effectors are attached to anionic lipopolysaccharides (A-LPS), and hence form a virulence coat at the cell surface. P. gingivalis produces additional virulence factors to evade host immune responses, such as capsular polysaccharide, fimbriae and outer membrane vesicles. In addition to periodontitis, it is proposed that this broad repertoire of virulence factors enable P. gingivalis to be involved in diverse human diseases such as rheumatoid arthritis, and neurodegenerative, Alzheimer, and cardiovascular disorders. Here, we review the major virulence determinants of P. gingivalis and discuss future directions to better understand their mechanisms of action.
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Affiliation(s)
- Ignacio Lunar Silva
- Laboratoire d'Ingénierie des Syst èmes Macromol éculaires (LISM), Institut de Microbiologie, Bioénergies and Biotechnologie (IM2B), Aix-Marseille Université, Centre National de la Recherche Scientifique (CNRS), UMR7255, 31 Chemin Joseph Aiguier CS7071, 13009 Marseille Cedex 20, France.
| | - Eric Cascales
- Laboratoire d'Ingénierie des Syst èmes Macromol éculaires (LISM), Institut de Microbiologie, Bioénergies and Biotechnologie (IM2B), Aix-Marseille Université, Centre National de la Recherche Scientifique (CNRS), UMR7255, 31 Chemin Joseph Aiguier CS7071, 13009 Marseille Cedex 20, France.
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Pendergrass HA, Johnson AL, Hotinger JA, May AE. Fluorescence Detection of Type III Secretion Using a Glu-CyFur Reporter System in Citrobacter rodentium. Microorganisms 2020; 8:microorganisms8121953. [PMID: 33316970 PMCID: PMC7764322 DOI: 10.3390/microorganisms8121953] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 12/02/2020] [Accepted: 12/06/2020] [Indexed: 12/21/2022] Open
Abstract
Enteropathogenic Escherichia coli (EPEC) is a major cause of infantile diarrhea worldwide. EPEC and the closely related murine model of EPEC infection, Citrobacter rodentium, utilize a type III secretion system (T3SS) to propagate the infection. Since the T3SS is not essential for the bacteria to survive or propagate, inhibiting the virulence factor with a therapeutic would treat the infection without causing harm to commensal bacteria. Studying inhibitors of the T3SS usually requires a BSL-2 laboratory designation and eukaryotic host cells while not indicating the mechanism of inhibition. We have designed a BSL-1 assay using the murine model C. rodentium that does not require mammalian cell culture. This CPG2-reporter assay allows for more rapid analysis of secretion efficiency than Western blotting and is sensitive enough to differentiate between partial and total inhibition of the T3SS. Here we present our method and the results of a small collection of compounds we have screened, including known T3SS inhibitors EGCG, regacin, and aurodox and related quorum sensing inhibitors tannic acid and ellagic acid. We have further characterized EGCG as a T3SS inhibitor and established its IC50 of 1.8 ± 0.4 μM. We also establish tannic acid as a potent inhibitor of the T3SS with an IC50 of 0.65 ± 0.09 μM.
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Huemer M, Mairpady Shambat S, Brugger SD, Zinkernagel AS. Antibiotic resistance and persistence-Implications for human health and treatment perspectives. EMBO Rep 2020; 21:e51034. [PMID: 33400359 PMCID: PMC7726816 DOI: 10.15252/embr.202051034] [Citation(s) in RCA: 226] [Impact Index Per Article: 56.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 08/13/2020] [Accepted: 11/02/2020] [Indexed: 12/24/2022] Open
Abstract
Antimicrobial resistance (AMR) and persistence are associated with an elevated risk of treatment failure and relapsing infections. They are thus important drivers of increased morbidity and mortality rates resulting in growing healthcare costs. Antibiotic resistance is readily identifiable with standard microbiological assays, and the threat imposed by antibiotic resistance has been well recognized. Measures aiming to reduce resistance development and spreading of resistant bacteria are being enforced. However, the phenomenon of bacteria surviving antibiotic exposure despite being fully susceptible, so-called antibiotic persistence, is still largely underestimated. In contrast to antibiotic resistance, antibiotic persistence is difficult to measure and therefore often missed, potentially leading to treatment failures. In this review, we focus on bacterial mechanisms allowing evasion of antibiotic killing and discuss their implications on human health. We describe the relationship between antibiotic persistence and bacterial heterogeneity and discuss recent studies that link bacterial persistence and tolerance with the evolution of antibiotic resistance. Finally, we review persister detection methods, novel strategies aiming at eradicating bacterial persisters and the latest advances in the development of new antibiotics.
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Affiliation(s)
- Markus Huemer
- Department of Infectious Diseases and Hospital EpidemiologyUniversity Hospital ZurichUniversity of ZurichZurichSwitzerland
| | - Srikanth Mairpady Shambat
- Department of Infectious Diseases and Hospital EpidemiologyUniversity Hospital ZurichUniversity of ZurichZurichSwitzerland
| | - Silvio D Brugger
- Department of Infectious Diseases and Hospital EpidemiologyUniversity Hospital ZurichUniversity of ZurichZurichSwitzerland
| | - Annelies S Zinkernagel
- Department of Infectious Diseases and Hospital EpidemiologyUniversity Hospital ZurichUniversity of ZurichZurichSwitzerland
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Correlation between Exogenous Compounds and the Horizontal Transfer of Plasmid-Borne Antibiotic Resistance Genes. Microorganisms 2020; 8:microorganisms8081211. [PMID: 32784449 PMCID: PMC7463591 DOI: 10.3390/microorganisms8081211] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 08/03/2020] [Accepted: 08/07/2020] [Indexed: 12/31/2022] Open
Abstract
The global spread of antibiotic resistance has posed a serious threat to public healthcare and undermined decades of progress made in the fight against bacterial infections. It has been demonstrated that the lack of novel effective antibiotics and rapid spread of antibiotic resistance genes via horizontal transfer in the ecosystem are mainly responsible for this crisis. Notably, plasmid-mediated horizontal transfer of antibiotic resistance genes (ARGs) is recognized as the most dominant dissemination pathway of ARGs in humans, animals and environmental settings. Antibiotic selective pressure has always been regarded as one of the crucial contributors to promoting the dissemination of antibiotic resistance through horizontal gene transfer (HGT). However, the roles of exogenous compounds and particularly non-antibiotic drugs in the spread of ARGs are still underappreciated. In this review, we first summarize the major pathways of HGT in bacteria, including conjugation, transformation, transduction and vesiduction. Subsequently, an overview of these compounds capable of promoting the HGT is presented, which guides to the formulation of more reasonable dosing regimens and drug residue standards in clinical practice. By contrast, these compounds that display an inhibition effect on HGT are also highlighted, which provides a unique strategy to minimize the spread of ARGs. Lastly, we discuss the implementations and challenges in bringing these HGT inhibitors into clinical trials.
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Chatterjee P, Sass G, Swietnicki W, Stevens DA. Review of Potential Pseudomonas Weaponry, Relevant to the Pseudomonas-Aspergillus Interplay, for the Mycology Community. J Fungi (Basel) 2020; 6:jof6020081. [PMID: 32517271 PMCID: PMC7345761 DOI: 10.3390/jof6020081] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 06/03/2020] [Accepted: 06/03/2020] [Indexed: 12/15/2022] Open
Abstract
Pseudomonas aeruginosa is one of the most prominent opportunistic bacteria in airways of cystic fibrosis patients and in immunocompromised patients. These bacteria share the same polymicrobial niche with other microbes, such as the opportunistic fungus Aspergillus fumigatus. Their inter-kingdom interactions and diverse exchange of secreted metabolites are responsible for how they both fare in competition for ecological niches. The outcomes of their contests likely determine persistent damage and degeneration of lung function. With a myriad of virulence factors and metabolites of promising antifungal activity, P. aeruginosa products or their derivatives may prove useful in prophylaxis and therapy against A. fumigatus. Quorum sensing underlies the primary virulence strategy of P. aeruginosa, which serves as cell–cell communication and ultimately leads to the production of multiple virulence factors. Understanding the quorum-sensing-related pathogenic mechanisms of P. aeruginosa is a first step for understanding intermicrobial competition. In this review, we provide a basic overview of some of the central virulence factors of P. aeruginosa that are regulated by quorum-sensing response pathways and briefly discuss the hitherto known antifungal properties of these virulence factors. This review also addresses the role of the bacterial secretion machinery regarding virulence factor secretion and maintenance of cell–cell communication.
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Affiliation(s)
- Paulami Chatterjee
- California Institute for Medical Research, San Jose, CA 95128, USA; (P.C.); (G.S.)
| | - Gabriele Sass
- California Institute for Medical Research, San Jose, CA 95128, USA; (P.C.); (G.S.)
| | - Wieslaw Swietnicki
- Department of Immunology of Infectious Diseases, Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, 50-114 Wroclaw, Poland;
| | - David A. Stevens
- California Institute for Medical Research, San Jose, CA 95128, USA; (P.C.); (G.S.)
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
- Correspondence: ; Tel.: +1-408-998-4554
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Delivery of Heterologous Proteins, Enzymes, and Antigens via the Bacterial Type III Secretion System. Microorganisms 2020; 8:microorganisms8050777. [PMID: 32455678 PMCID: PMC7285344 DOI: 10.3390/microorganisms8050777] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 05/14/2020] [Accepted: 05/19/2020] [Indexed: 12/27/2022] Open
Abstract
The Type III Secretion System (T3SS) is a multimeric protein complex composed of over 20 different proteins, utilized by Gram-negative bacteria to infect eukaryotic host cells. The T3SS has been implicated as a virulence factor by which pathogens cause infection and has recently been characterized as a communication tool between bacteria and plant cells in the rhizosphere. The T3SS has been repurposed to be used as a tool for the delivery of non-native or heterologous proteins to eukaryotic cells or the extracellular space for a variety of purposes, including drug discovery and drug delivery. This review covers the methodology of heterologous protein secretion as well as multiple cases of utilizing the T3SS to deliver heterologous proteins or artificial materials. The research covered in this review will serve to outline the scope and limitations of utilizing the T3SS as a tool for protein delivery.
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A predation assay using amoebae to screen for virulence factors unearthed the first W. chondrophila inclusion membrane protein. Sci Rep 2019; 9:19485. [PMID: 31862969 PMCID: PMC6925127 DOI: 10.1038/s41598-019-55511-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 11/11/2019] [Indexed: 01/21/2023] Open
Abstract
Waddlia chondrophila is an intracellular bacterium phylogenetically related to the well-studied human and animal pathogens of the Chlamydiaceae family. In the last decade, W. chondrophila was convincingly demonstrated to be associated with adverse pregnancy outcomes in humans and abortions in animals. All members of the phylum Chlamydiae possess a Type Three Secretion System that they use for delivering virulence proteins into the host cell cytosol to modulate their environment and create optimal conditions to complete their life cycle. To identify W. chondrophila virulence proteins, we used an original screening approach that combines a cosmid library with an assay monitoring resistance to predation by phagocytic amoebae. This technique combined with bioinformatic data allowed the identification of 28 candidate virulence proteins, including Wimp1, the first identified inclusion membrane protein of W. chondrophila.
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22
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A Potent Anti-SpuE Antibody Allosterically Inhibits Type III Secretion System and Attenuates Virulence of Pseudomonas Aeruginosa. J Mol Biol 2019; 431:4882-4896. [DOI: 10.1016/j.jmb.2019.10.026] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2019] [Revised: 10/12/2019] [Accepted: 10/20/2019] [Indexed: 01/12/2023]
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Hotinger JA, May AE. Animal Models of Type III Secretion System-Mediated Pathogenesis. Pathogens 2019; 8:pathogens8040257. [PMID: 31766664 PMCID: PMC6963218 DOI: 10.3390/pathogens8040257] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 11/18/2019] [Accepted: 11/20/2019] [Indexed: 01/22/2023] Open
Abstract
The type III secretion system (T3SS) is a conserved virulence factor used by many Gram-negative pathogenic bacteria and has become an important target for anti-virulence drugs. Most T3SS inhibitors to date have been discovered using in vitro screening assays. Pharmacokinetics and other important characteristics of pharmaceuticals cannot be determined with in vitro assays alone. In vivo assays are required to study pathogens in their natural environment and are an important step in the development of new drugs and vaccines. Animal models are also required to understand whether T3SS inhibition will enable the host to clear the infection. This review covers selected animal models (mouse, rat, guinea pig, rabbit, cat, dog, pig, cattle, primates, chicken, zebrafish, nematode, wax moth, flea, fly, and amoeba), where T3SS activity and infectivity have been studied in relation to specific pathogens (Escherichia coli, Salmonella spp., Pseudomonas spp., Shigella spp., Bordetella spp., Vibrio spp., Chlamydia spp., and Yersinia spp.). These assays may be appropriate for those researching T3SS inhibition.
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Ma YN, Chen L, Si NG, Jiang WJ, Zhou ZG, Liu JL, Zhang LQ. Identification of Benzyloxy Carbonimidoyl Dicyanide Derivatives as Novel Type III Secretion System Inhibitors via High-Throughput Screening. FRONTIERS IN PLANT SCIENCE 2019; 10:1059. [PMID: 31543889 PMCID: PMC6739442 DOI: 10.3389/fpls.2019.01059] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 08/05/2019] [Indexed: 06/10/2023]
Abstract
The type III secretion system (T3SS) in many Gram-negative bacterial pathogens is regarded as the most critical virulence determinant and an attractive target for novel anti-virulence drugs. In this study, we constructed a T3SS secretion reporter containing the β-lactamase gene fused with a signal peptide sequence of the T3SS effector gene, and established a high-throughput screening system for T3SS inhibitors in the plant pathogenic bacterium Acidovorax citrulli. From a library of 12,000 chemical compounds, we identified a series of benzyloxy carbonimidoyl dicyanide (BCD) derivatives that effectively blocked T3SS-dependent β-lactamase secretion. Substitution of halogens or nitro groups at the para-position on the benzene ring contributed to an increased inhibitory activity. One representative compound, BCD03 (3,4-dichloro-benzyloxy carbonimidoyl dicyanide), dramatically reduced pathogenicity of A. citrulli on melon seedlings, and attenuated hypersensitive responses in the non-host Nicotiana tabacum caused by pathogenic bacteria A. citrulli, Xanthomonas oryzae pv. oryzae and Pseudomonas syringae pv. tomato at sub-MIC concentrations. Western blotting assay further confirmed that BCD03 inhibited effector secretion from the above bacteria via T3SS in the liquid medium. Taken together, our data suggest that BCD derivatives act as novel inhibitors of T3SS in multiple plant bacterial pathogens.
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Affiliation(s)
- Yi-Nan Ma
- Department of Plant Pathology and MOA Key Laboratory of Pest Monitoring and Green Management, China Agricultural University, Beijing, China
| | - Liang Chen
- Department of Plant Pathology and MOA Key Laboratory of Pest Monitoring and Green Management, China Agricultural University, Beijing, China
- State Key Laboratory of the Discovery and Development of Novel Pesticide, Shenyang Sinochem Agrochemicals R&D Co., Ltd, Shenyang, China
| | - Nai-Guo Si
- State Key Laboratory of the Discovery and Development of Novel Pesticide, Shenyang Sinochem Agrochemicals R&D Co., Ltd, Shenyang, China
| | - Wen-Jun Jiang
- Department of Plant Pathology and MOA Key Laboratory of Pest Monitoring and Green Management, China Agricultural University, Beijing, China
| | - Zhi-Gang Zhou
- China-Norway Joint Lab on Fish Gut Microbiota, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Jun-Li Liu
- State Key Laboratory of the Discovery and Development of Novel Pesticide, Shenyang Sinochem Agrochemicals R&D Co., Ltd, Shenyang, China
| | - Li-Qun Zhang
- Department of Plant Pathology and MOA Key Laboratory of Pest Monitoring and Green Management, China Agricultural University, Beijing, China
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Soni N, Swain SK, Kant R, Singh A, Ravichandran R, Verma SK, Panda PK, Suar M. Landscape of ROD9 Island: Functional annotations and biological network of hypothetical proteins in Salmonella enterica. Comput Biol Chem 2019; 83:107110. [PMID: 31445418 DOI: 10.1016/j.compbiolchem.2019.107110] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2018] [Revised: 07/16/2019] [Accepted: 08/13/2019] [Indexed: 01/01/2023]
Abstract
Salmonella, an Enterobacteria is a therapeutically important pathogen for the host. The advancement of genome sequencing of S. enterica serovar Enteritidis have identified a distinct ROD9 pathogenic island, imparting virulence. The occurrence of 17 ROD9 hypothetical proteins, necessitates subsequent bioinformatics approach for structural and functional aspects of protein-protein relations or networks in different pathogenic phenotypes express. A collective analysis using predictive bioinformatics tools that includes NCBI-BLASTp and BLAST2GO annotated the motif patterns and functional significance. The VFDB identified 10 virulence proteins at both genomic and metagenomic level. Phylogenetic analysis revealed a divergent and convergent relationship between 17 ROD9 and 41 SP-1 proteins. Here, combining a comprehensive approach from sequence based, motif recognitions, domain identification, virulence ability to structural modelling provides a precise function to ROD9 proteins biological network, for which no experimental information is available.
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Affiliation(s)
- Nikita Soni
- School of Biotechnology and Bioinformatics, D. Y. Patil (Deemed to be University), Navi Mumbai, India
| | | | - Ravi Kant
- University of Delhi, New Delhi, India
| | - Aditya Singh
- School of Biotechnology and Bioinformatics, D. Y. Patil (Deemed to be University), Navi Mumbai, India
| | - Rahul Ravichandran
- School of Chemical and Biotechnology, SASTRA University, Tamil Nadu, India
| | - Suresh K Verma
- Institute of Environmental Medicine (IMM), C6, Molecular Toxicology, Karolinska Institutet, Sweden
| | - Pritam Kumar Panda
- Division of Pediatric Hematology and Oncology, University Medical Center, University of Freiburg, Germany.
| | - Mrutyunjay Suar
- School of Biotechnology, KIIT University, Bhubaneswar, India.
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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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Fan S, Tian F, Fang L, Yang CH, He C. Transcriptional responses of Xanthomonas oryzae pv. oryzae to type III secretion system inhibitor ortho-coumaric acid. BMC Microbiol 2019; 19:163. [PMID: 31307395 PMCID: PMC6631524 DOI: 10.1186/s12866-019-1532-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Accepted: 06/26/2019] [Indexed: 11/23/2022] Open
Abstract
Background We previously identified a plant-derived phenolic compound ortho-coumaric acid (OCA) as an inhibitor of type III secretion system (T3SS) of Xanthomonas oryzae pv. oryzae (Xoo), the pathogen causing bacterial leaf blight of rice, one of the most devastating bacterial diseases of this staple crop worldwide. However, the molecular mechanisms by which OCA suppresses T3SS and the transcriptional responses to the OCA treatments in Xoo remains unclear. Results The present study conducted the RNA-seq-based transcriptomic analysis to reveal changes in gene expression in Xoo in response to 30 min, 1 h, 3 h, and 6 h of OCA treatment. Results showed that OCA significantly inhibited the expression of T3SS genes after 30 min, and the inhibition also existed after 1 h, 3 h, and 6 h. After treatment for 30 min, membrane proteins in the functional category of cellular process was the predominant group affected, indicating that Xoo was in the early stress stage. Over time, more differentially-expressed genes (DEGs) gathered in the functional category of biological process. Analysis of common DEGs at all four of time points revealed the core elements of Xoo during the response to OCA treatment. Notable, a multidrug transporter cluster that consisted of a MarR-family protein (PXO_RS13760), a multidrug RND transporter (PXO_RS13755), a multidrug transporter (PXO_RS13750), and an MFS transporter (PXO_RS13745) were significantly up-regulated at all four of the time points. Although these three transporter genes were not upregulated by OCA in the PXO_RS13760 deletion mutant, the deficiency of PXO_RS13760 in Xoo did not affect T3SS transcript, and OCA still had the ability to inhibit the expression of T3SS in the mutant, suggesting that the MarR-family protein was involved in bacterial responses to OCA, but not direct OCA inhibition of T3SS in Xoo. Conclusions We analyzed the transcriptome of Xoo during OCA treatment at both early and late stages, which revealed the landscape of Xoo responses to OCA at the whole-genome transcription level. A multidrug transporter cluster was identified to be involved in the response process, but had no direct relation to T3SS in Xoo. Electronic supplementary material The online version of this article (10.1186/s12866-019-1532-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Susu Fan
- State Key Laboratory for Biology of Plant Diseases and Insect Pests Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.,Shandong Provincial Key Laboratory of Applied Microbiology, Ecology Institute, Shandong Academy of Sciences, Jinan, 250014, Shandong Province, China
| | - Fang Tian
- State Key Laboratory for Biology of Plant Diseases and Insect Pests Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.
| | - Liwei Fang
- Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, WI, 53211, USA
| | - Ching-Hong Yang
- Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, WI, 53211, USA
| | - Chenyang He
- State Key Laboratory for Biology of Plant Diseases and Insect Pests Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.
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Santos FF, Yamamoto D, Abe CM, Bryant JA, Hernandes RT, Kitamura FC, Castro FS, Valiatti TB, Piazza RMF, Elias WP, Henderson IR, Gomes TAT. The Type III Secretion System (T3SS)-Translocon of Atypical Enteropathogenic Escherichia coli (aEPEC) Can Mediate Adherence. Front Microbiol 2019; 10:1527. [PMID: 31338081 PMCID: PMC6629874 DOI: 10.3389/fmicb.2019.01527] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 06/18/2019] [Indexed: 12/18/2022] Open
Abstract
The intimin protein is the major adhesin involved in the intimate adherence of atypical enteropathogenic Escherichia coli (aEPEC) strains to epithelial cells, but little is known about the structures involved in their early colonization process. A previous study demonstrated that the type III secretion system (T3SS) plays an additional role in the adherence of an Escherichia albertii strain. Therefore, we assumed that the T3SS could be related to the adherence efficiency of aEPEC during the first stages of contact with epithelial cells. To test this hypothesis, we examined the adherence of seven aEPEC strains and their eae (intimin) isogenic mutants in the standard HeLa adherence assay and observed that all wild-type strains were adherent while five isogenic eae mutants were not. The two eae mutant strains that remained adherent were then used to generate the eae/escN double mutants (encoding intimin and the T3SS ATPase, respectively) and after the adherence assay, we observed that one strain lost its adherence capacity. This suggested a role for the T3SS in the initial adherence steps of this strain. In addition, we demonstrated that this strain expressed the T3SS at significantly higher levels when compared to the other wild-type strains and that it produced longer translocon-filaments. Our findings reveal that the T3SS-translocon can play an additional role as an adhesin at the beginning of the colonization process of aEPEC.
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Affiliation(s)
- Fernanda F Santos
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Denise Yamamoto
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Cecilia M Abe
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, Brazil
| | - Jack A Bryant
- Institute of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Rodrigo T Hernandes
- Departamento de Microbiologia e Imunologia, Instituto de Biociências, Universidade Estadual Paulista, Botucatu, Brazil
| | - Felipe C Kitamura
- Departamento de Diagnóstico por Imagem, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Felipe S Castro
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Tiago B Valiatti
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | | | - Waldir P Elias
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, Brazil
| | - Ian R Henderson
- Institute of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Tânia A T Gomes
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
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Francis MS, Auerbuch V. Editorial: The Pathogenic Yersiniae-Advances in the Understanding of Physiology and Virulence, Second Edition. Front Cell Infect Microbiol 2019; 9:119. [PMID: 31058103 PMCID: PMC6482262 DOI: 10.3389/fcimb.2019.00119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Accepted: 04/03/2019] [Indexed: 11/13/2022] Open
Affiliation(s)
- Matthew S Francis
- Department of Molecular Biology, Umeå Centre for Microbial Research, Umeå University, Umeå, Sweden
| | - Victoria Auerbuch
- Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, Santa Cruz, CA, United States
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Swietnicki W, Czarny A, Antkowiak L, Zaczynska E, Kolodziejczak M, Sycz J, Stachowicz L, Alicka M, Marycz K. Identification of a potent inhibitor of type II secretion system from Pseudomonas aeruginosa. Biochem Biophys Res Commun 2019; 513:688-693. [PMID: 30987825 DOI: 10.1016/j.bbrc.2019.04.055] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Accepted: 04/07/2019] [Indexed: 12/27/2022]
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen infecting human population. The pathogen is becoming a serious health problem due to its ability to evade normal immune response of the host and multiple drug resistance to many antibiotics. The pathogen has 2 major virulence systems of which the type III secretion system (T3SS) is of major concern to humans. A third system, type 2 secretion system (T2SS), is common to bacteria and used to secrete exotoxin A (ExoA) responsible for human cell destruction. To help bypass the drug resistance, a strategy to block the T2SS based on a low similarity between human ATPases and the essential ATPases of the T3SS and T2SS of P. aeruginosa, was used. An in silico-optimized inhibitor of T3SS, made directly from the computer-optimized of previously published compounds and their combinatorial libraries, showed IC50 = 1.3 ± 0.2 μM in the T2SS ExoA secretion blocking test. The compound was non-toxic to human lung epithelial cell line A549 and could block cellular destruction of those cells in a cell infection model at 200 μM for at least 24 h. The compound could be a lead candidate for the development of T2SS virulence blockers of Pseudomonas aeruginosa.
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Affiliation(s)
- Wieslaw Swietnicki
- Department of Immunology of Infectious Diseases, Laboratory of Medical Microbiology, USA.
| | - Anna Czarny
- Department of Immunology of Infectious Diseases, Laboratory of Medical Microbiology, USA
| | - Lukasz Antkowiak
- Faculty of Chemistry, Department of Biochemistry, Technical University of Wroclaw, Ul. C. K. Norwida 4/6, 50-373, Wroclaw, Poland
| | - Ewa Zaczynska
- Department of Experimental Therapy, Laboratory of Immunobiology, Institute of Immunology and Experimental Therapy PAS, 53-114, Wroclaw, Ul. R. Weigla 12, Poland
| | - Monika Kolodziejczak
- Faculty of Chemistry, Department of Biochemistry, Technical University of Wroclaw, Ul. C. K. Norwida 4/6, 50-373, Wroclaw, Poland
| | - Jordan Sycz
- Department of Chemistry, Wroclaw University of Environmental and Life Sciences, Ul. C. K. Norwida 25, 50-375, Wroclaw, Poland
| | - Lukasz Stachowicz
- Department of Pharmacology, Silesian Medical University, Ul. Jednosci 8, 41-200, Sosnowiec, Poland
| | - Michalina Alicka
- Department of Experimental Biology, Wroclaw University of Environmental and Life Sciences, Ul. C. K. Norwida 27B, 50-375, Wroclaw, Poland
| | - Krzysztof Marycz
- Department of Experimental Biology, Wroclaw University of Environmental and Life Sciences, Ul. C. K. Norwida 27B, 50-375, Wroclaw, Poland; Faculty of Veterinary Medicine, Equine Clinic - Equine Surgery, Justus-Liebig-University, 35392, Giessen, Germany
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Case HB, Mattock DS, Dickenson NE. Shutting Down Shigella Secretion: Characterizing Small Molecule Type Three Secretion System ATPase Inhibitors. Biochemistry 2018; 57:6906-6916. [PMID: 30460850 DOI: 10.1021/acs.biochem.8b01077] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Many important human pathogens rely on one or more type three secretion systems (T3SSs) to inject bacterial effector proteins directly into the host cell cytoplasm. Secretion of protein through the needlelike type three secretion apparatus (T3SA) is essential for pathogen virulence and relies on a highly conserved ATPase at the base of the apparatus, making it an attractive target for anti-infective therapeutics. Here, we leveraged the ability to purify an active oligomeric Shigella T3SS ATPase to provide kinetic analyses of three T3SS ATPase inhibitors of Spa47. In agreement with in silico docking simulations, the inhibitors displayed noncompetitive inhibition profiles and efficiently reduced Spa47 ATPase activity with IC50s as low as 52 ± 3 μM. Two of the inhibitors functioned well in vivo, nearly abolishing effector protein secretion without significantly affecting the Shigella growth phenotype or HeLa cell viability. Furthermore, characterization of Spa47 complexes in vitro and Shigella T3SA formation in vivo showed that the inhibitors do not function through disruption of Spa47 oligomers or by preventing T3SA formation. Together, these findings suggest that inhibitors targeting Spa47 may be an effective means of combating Shigella infection by shutting down type three secretion without preventing presentation of the highly antigenic T3SA tip proteins that aid in clearing the infection and developing pan- Shigella immunological memory. In summary, this is the first report of Shigella T3SS ATPase inhibitors and one of only a small number of studies characterizing T3SS ATPase inhibition in general. The work presented here provides much-needed insight into T3SS ATPase inhibition mechanisms and provides a strong platform for developing and evaluating non-antibiotic therapeutics targeting Spa47 and other T3SS ATPases.
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Affiliation(s)
- Heather B Case
- Department of Chemistry and Biochemistry , Utah State University , Logan , Utah 84322 , United States
| | - Dominic S Mattock
- Department of Chemistry and Biochemistry , Utah State University , Logan , Utah 84322 , United States
| | - Nicholas E Dickenson
- Department of Chemistry and Biochemistry , Utah State University , Logan , Utah 84322 , United States
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Li T, Zhang D, Oo TN, San MM, Mon AM, Hein PP, Wang Y, Lu C, Yang X. Investigation on the Antibacterial and Anti-T3SS Activity of Traditional Myanmar Medicinal Plants. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE : ECAM 2018; 2018:2812908. [PMID: 30402120 PMCID: PMC6198585 DOI: 10.1155/2018/2812908] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 09/27/2018] [Indexed: 01/18/2023]
Abstract
Myanmar has a rich pool of, but less known, medicinal plants with traditional knowledge. In this study, we aimed to investigate the inhibitory activity of traditional Myanmar medicinal plants against the type III secretion system (T3SS) of Salmonella enterica serovar Typhimurium UK-1 χ8956 and the intestinal disease-caused by microbes including S. enterica serovar Typhimurium UK-1 χ8956, Proteusbacillus vulgaris CPCC 160013, Escherichia coli CICC 10003, and Staphylococcus aureus ATCC 25923. The EtOH extracts of 93 samples were used to screen the inhibitory activities against the secretion of T3SS effector proteins SipA/B/C/D of S. enterica and the antibacterial activity against S. enterica, P. vulgaris, E. coli, and S. aureus. Out of 71 crude drugs traditionally used, 18 were proofed to be effective either on the growth inhibition of tested bacteria and/or as inhibitors for the T3SS. The EtOH extracts of five plants, Luvunga scandens (Roxb.) Buch.-Ham. ex Wight & Arn. (My7), Myrica nagi Thunb. (My11), Terminalia citrina Roxb. ex Fleming (My21), Thymus vulgaris L. (My49), and Cinnamomum bejolghota (Buch.-Ham.) Sweet (My104), showed potent inhibitory activities against the secretion of T3SS proteins SipA/B/C/D of S. enterica serovar Typhimurium UK-1 χ 8956. Mansonia gagei J.R.Drumm (My3) and Mesua ferrea (Roxb.) L. (My10) showed strong antibacterial activities against P. vulgaris and S. aureus. This study provided the first scientific evidence of T3SS prohibiting and antibacterial properties for the traditional knowledge in Myanmar of using plants as medicines for treating infections and gastrointestinal disease. Further researches are proposed to discover the active chemical compounds and mechanism of L. scandens (Roxb.) Buch.-Ham. ex Wight & Arn, M. nagi Thunb., T. citrina Roxb. ex Fleming, T. vulgaris L., and C. bejolghota (Buch.-Ham.) Sweet as antivirulence drugs and the potential of M. gagei J.R.Drumm and M. ferrea L. as new broad spectrum plant antibiotics.
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Affiliation(s)
- Tianhong Li
- Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences, Shandong University, Jinan 250012, China
| | - Dongdong Zhang
- Key Laboratory of Economic Plants and Biotechnology, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China
- Southeast Asia Biodiversity Research Institute, Chinese Academy of Sciences, Yezin, Nay Pyi Taw 05282, Myanmar
| | - Thaung Naing Oo
- Forest Research Institute, Yezin, Nay Pyi Taw 05282, Myanmar
| | - Myint Myint San
- Forest Research Institute, Yezin, Nay Pyi Taw 05282, Myanmar
| | - Aye Mya Mon
- Key Laboratory of Economic Plants and Biotechnology, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China
- Southeast Asia Biodiversity Research Institute, Chinese Academy of Sciences, Yezin, Nay Pyi Taw 05282, Myanmar
| | - Pyae Phyo Hein
- Key Laboratory of Economic Plants and Biotechnology, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China
- Southeast Asia Biodiversity Research Institute, Chinese Academy of Sciences, Yezin, Nay Pyi Taw 05282, Myanmar
| | - Yuehu Wang
- Key Laboratory of Economic Plants and Biotechnology, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China
| | - Chunhua Lu
- Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences, Shandong University, Jinan 250012, China
| | - Xuefei Yang
- Key Laboratory of Economic Plants and Biotechnology, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China
- Southeast Asia Biodiversity Research Institute, Chinese Academy of Sciences, Yezin, Nay Pyi Taw 05282, Myanmar
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Arifuzzaman M, Mitra S, Jahan SI, Jakaria M, Abeda T, Absar N, Dash R. A Computational workflow for the identification of the potent inhibitor of type II secretion system traffic ATPase of Pseudomonas aeruginosa. Comput Biol Chem 2018; 76:191-201. [DOI: 10.1016/j.compbiolchem.2018.07.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 06/30/2018] [Accepted: 07/10/2018] [Indexed: 01/04/2023]
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McCauley EP, Lam H, Lorig-Roach N, Luu J, Lloyd C, Tenney K, Pietraszkiewicz H, Diaz C, Valeriote FA, Auerbuch V, Crews P. Investigation of the Physical and Bioactive Properties of Bromo- and Iodo-Containing Sponge-Derived Compounds Possessing an Oxyphenylethanamine Core. JOURNAL OF NATURAL PRODUCTS 2017; 80:3255-3266. [PMID: 29144750 DOI: 10.1021/acs.jnatprod.7b00694] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
This research set out to identify compounds from marine sponges that can act as bacterial virulence blockers. Extracts from a total of 80 sponges collected from throughout Indonesia were screened in a high-throughput NF-κB-based screen that identifies compounds capable of inhibiting the bacterial type III secretion system (T3SS) in Yersinia pseudotuberculosis. An extract that was shown to inhibit T3SS-driven NF-κB expression was obtained from an Iotrochota cf. iota sponge and was the source of seven new bromo- and iodo-containing compounds, all of which contain a 2-(4-oxyphenyl)ethan-1-amine core. Five were determined to be new compounds and named enisorines A-E (1-5). The remaining two were determined to be new hemibastadinol analogues named (+)-1-O-methylhemibastadinol 2 (6) and (+)-1-O-methylhemibastadinol 4 (7). All seven compounds inhibited T3SS-dependent YopE secretion and did not affect the growth or metabolic activity of Y. pseudotuberculosis. The most potent inhibitors of T3SS activity were enisorine C (3), enisorine E (5), and (+)-1-O-methylhemibastadinol 2 (6), all of which inhibited YopE secretion by >50% at 30 μM.
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Affiliation(s)
- Erin P McCauley
- Department of Chemistry and Biochemistry, University of California , Santa Cruz, California 95064, United States
| | - Hanh Lam
- Department of Microbiology and Environmental Toxicology, University of California , Santa Cruz, California 95064, United States
| | - Nicholas Lorig-Roach
- Department of Chemistry and Biochemistry, University of California , Santa Cruz, California 95064, United States
| | - Justin Luu
- Department of Microbiology and Environmental Toxicology, University of California , Santa Cruz, California 95064, United States
| | - Cameron Lloyd
- Department of Microbiology and Environmental Toxicology, University of California , Santa Cruz, California 95064, United States
| | - Karen Tenney
- Department of Chemistry and Biochemistry, University of California , Santa Cruz, California 95064, United States
| | - Halina Pietraszkiewicz
- Department of Internal Medicine, Division of Hematology and Oncology, Henry Ford Hospital , Detroit, Michigan 48202, United States
| | - Cristina Diaz
- Harbor Branch Oceanographic Institute, Florida Atlantic University , Fort Pierce, Florida 34946, United States
| | - Frederick A Valeriote
- Department of Internal Medicine, Division of Hematology and Oncology, Henry Ford Hospital , Detroit, Michigan 48202, United States
| | - Victoria Auerbuch
- Department of Microbiology and Environmental Toxicology, University of California , Santa Cruz, California 95064, United States
| | - Phillip Crews
- Department of Chemistry and Biochemistry, University of California , Santa Cruz, California 95064, United States
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Cabezón E, de la Cruz F, Arechaga I. Conjugation Inhibitors and Their Potential Use to Prevent Dissemination of Antibiotic Resistance Genes in Bacteria. Front Microbiol 2017; 8:2329. [PMID: 29255449 PMCID: PMC5723004 DOI: 10.3389/fmicb.2017.02329] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Accepted: 11/13/2017] [Indexed: 11/17/2022] Open
Abstract
Antibiotic resistance has become one of the most challenging problems in health care. Bacteria conjugation is one of the main mechanisms whereby bacteria become resistant to antibiotics. Therefore, the search for specific conjugation inhibitors (COINs) is of interest in the fight against the spread of antibiotic resistances in a variety of laboratory and natural environments. Several compounds, discovered as COINs, are promising candidates in the fight against plasmid dissemination. In this review, we survey the effectiveness and toxicity of the most relevant compounds. Particular emphasis has been placed on unsaturated fatty acid derivatives, as they have been shown to be efficient in preventing plasmid invasiveness in bacterial populations. Biochemical and structural studies have provided insights concerning their potential molecular targets and inhibitory mechanisms. These findings open a new avenue in the search of new and more effective synthetic inhibitors. In this pursuit, the use of structure-based drug design methods will be of great importance for the screening of ligands and binding sites of putative targets.
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Affiliation(s)
- Elena Cabezón
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), CSIC-Universidad de Cantabria and Departamento de Biología Molecular, Universidad de Cantabria, Santander, Spain
| | - Fernando de la Cruz
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), CSIC-Universidad de Cantabria and Departamento de Biología Molecular, Universidad de Cantabria, Santander, Spain
| | - Ignacio Arechaga
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), CSIC-Universidad de Cantabria and Departamento de Biología Molecular, Universidad de Cantabria, Santander, Spain
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36
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The role of EscD in supporting EscC polymerization in the type III secretion system of enteropathogenic Escherichia coli. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1860:384-395. [PMID: 28988128 DOI: 10.1016/j.bbamem.2017.10.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2017] [Revised: 10/01/2017] [Accepted: 10/02/2017] [Indexed: 11/23/2022]
Abstract
The type III secretion system (T3SS) is a multi-protein complex that plays a central role in the virulence of many Gram-negative bacterial pathogens. In enteropathogenic Escherichia coli, a prevalent cause of diarrheal diseases, the needle complex base of the T3SS is formed by multi-rings: two concentric inner-membrane rings made by the two oligomerizing proteins (EscD and EscJ), and an outer ring made of a single oligomerizing protein (EscC). Although the oligomerization activity of these proteins is critical for their function and can, therefore, affect the virulence of the pathogen, the mechanisms underlying the oligomerization of these proteins have yet to be identified. In this study, we report that the proteins forming the inner-membrane T3SS rings, EscJ and EscD proteins, are crucial for the oligomerization of EscC. Moreover, we elucidate the oligomerization process of EscD and determine the contribution of individual regions of the protein to its self-oligomerization activity. We show that the oligomerization motif of EscD is located at its N-terminal portion and that its transmembrane domain can self-oligomerize, thus contributing to the self-oligomerization of the full-length EscD.
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37
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Development of a 3D printed device to support long term intestinal culture as an alternative to hyperoxic chamber methods. 3D Print Med 2017; 3:9. [PMID: 29782611 PMCID: PMC5954799 DOI: 10.1186/s41205-017-0018-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Accepted: 09/06/2017] [Indexed: 12/04/2022] Open
Abstract
Background Most interactions between pathogenic microorganisms and their target host occur on mucosal surfaces of internal organs such as the intestine. In vitro organ culture (IVOC) provides an unique tool for studying host-pathogen interactions in a controlled environment. However, this technique requires a complex laboratory setup and specialized apparatus. In addition, issues arise when anaerobic pathogens are exposed to the hyperoxic environment required for intestinal culture. The objective of this study was to develop an accessible 3D–printed device that would allow manipulation of the gas mixture used to supply the tissue culture media separately from the gas mixture exposed to the mucosal side of explants. Results Porcine colon explants from 2 pigs were prepared (n = 20) and cultured for 0h, 8h, 18h and 24h using the device. After the culture period, explants were fixed in formalin and H&E stained sections were evaluated for histological defects of the mucosa. At 8h, 66% of samples displayed no histological abnormalities, whereas samples collected at 18h and 24h displayed progressively increasing rates of superficial epithelial erosion and epithelial metaplasia. Conclusions The 3D–design reported here allows investigators to setup intestinal culture explants while manipulating the gas media explants are exposed to, to support tissue viability for a minimal of 8h. The amount of media necessary and tissue contamination are potential issues associated with this apparatus. Electronic supplementary material The online version of this article (10.1186/s41205-017-0018-z) contains supplementary material, which is available to authorized users.
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38
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Zambelloni R, Connolly JPR, Huerta Uribe A, Burgess K, Marquez R, Roe AJ. Novel compounds targeting the enterohemorrhagic Escherichia coli type three secretion system reveal insights into mechanisms of secretion inhibition. Mol Microbiol 2017; 105:606-619. [PMID: 28557017 PMCID: PMC5575525 DOI: 10.1111/mmi.13719] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Anti‐virulence (AV) compounds are a promising alternative to traditional antibiotics for fighting bacterial infections. The Type Three Secretion System (T3SS) is a well‐studied and attractive AV target, given that it is widespread in more than 25 species of Gram‐negative bacteria, including enterohemorrhagic E. coli (EHEC), and as it is essential for host colonization by many pathogens. In this work, we designed, synthesized and tested a new series of compounds that block the functionality of the T3SS of EHEC. Affinity chromatography experiments identified the primary target of the compounds as the T3SS needle pore protein EspD, which is essential for effector protein translocation into host cells. These data were supported by mechanistic studies that determined the coiled‐coil domain 1 of EspD as a key compound‐binding site, thereby preventing correct assembly of the T3SS complex on the cell surface. However, binding of inhibitors to EspD or deletion of EspD itself did not result in transcriptional down‐regulation of effector proteins. Instead, we found the compounds to exhibit dual‐functionality by also down‐regulating transcription of the entire chromosomal locus encoding the T3SS, further demonstrating their desirability and effectiveness.
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Affiliation(s)
- Riccardo Zambelloni
- Institute of Infection, Immunity & Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK
| | - James P R Connolly
- Institute of Infection, Immunity & Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Alejandro Huerta Uribe
- Institute of Infection, Immunity & Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Karl Burgess
- Institute of Infection, Immunity & Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Rodolfo Marquez
- Department of Chemistry, Xi'an Jiaotong-Liverpool University, SIP Suzhou, 215123, China
| | - Andrew J Roe
- Institute of Infection, Immunity & Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK
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The salicylidene acylhydrazide INP0341 attenuates Pseudomonas aeruginosa virulence in vitro and in vivo. J Antibiot (Tokyo) 2017; 70:937-943. [PMID: 28588224 DOI: 10.1038/ja.2017.64] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2017] [Revised: 04/19/2017] [Accepted: 04/23/2017] [Indexed: 11/08/2022]
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen that can be very hard to treat because of high resistance to different antibiotics and alternative treatment regimens are greatly needed. An alternative or a complement to traditional antibiotic is to inhibit virulence of the bacteria. The salicylidene acylhydrazide, INP0341, belongs to a class of compounds that has previously been shown to inhibit virulence in a number of Gram-negative bacteria. In this study, the virulence blocking effect of INP0341 on P. aeruginosa was studied in vitro and in vivo. Two important and closely related virulence system were examined, the type III secretion system (T3SS) that translocates virulence effectors into the cytosol of the host cell to evade immune defense and facilitate colonization and the flagella system, needed for motility and biofilm formation. INP0341 was shown to inhibit expression and secretion of the T3SS toxin exoenzyme S (ExoS) and to prevent bacterial motility on agar plates and biofilm formation. In addition, INP0341 showed an increased survival of P. aeruginosa-infected mice. In conclusion, INP0341 attenuates P. aeruginosa virulence.
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40
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Yulistiani R, Praseptiangga D, Supyani, Sudibya, Raharjo D, Shirakawa T. Prevalence of Antibiotic-resistance Enterobacteriaceae strains Isolated from Chicken Meat at Traditional Markets in Surabaya, Indonesia. ACTA ACUST UNITED AC 2017. [DOI: 10.1088/1757-899x/193/1/012007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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41
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Small Molecules That Sabotage Bacterial Virulence. Trends Pharmacol Sci 2017; 38:339-362. [PMID: 28209403 DOI: 10.1016/j.tips.2017.01.004] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Revised: 01/01/2017] [Accepted: 01/06/2017] [Indexed: 02/08/2023]
Abstract
The continued rise of antibiotic-resistant bacterial infections has motivated alternative strategies for target discovery and treatment of infections. Antivirulence therapies function through inhibition of in vivo required virulence factors to disarm the pathogen instead of directly targeting viability or growth. This approach to treating bacteria-mediated diseases may have advantages over traditional antibiotics because it targets factors specific for pathogenesis, potentially reducing selection for resistance and limiting collateral damage to the resident microbiota. This review examines vulnerable molecular mechanisms used by bacteria to cause disease and the antivirulence compounds that sabotage these virulence pathways. By expanding the study of antimicrobial targets beyond those that are essential for growth, antivirulence strategies offer new and innovative opportunities to combat infectious diseases.
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42
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Condry DLJ, Nilles ML. Identification of the Targets of Type III Secretion System Inhibitors. Methods Mol Biol 2017; 1531:203-211. [PMID: 27837494 DOI: 10.1007/978-1-4939-6649-3_18] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
A type III secretion system (T3SS) Inhibitor can be utilized for study in the research lab but also progressed into drug development. Since many pathogenic Gram-negative bacteria utilize this highly conserved system as a virulence factor, the prospect of the T3SS as a drug target is promising. To effectively move a T3SS inhibitor into the route of either research or pharmaceuticals an understanding of the target and mechanism of the inhibitor is required. Several methods can be utilized to identify the target. Included here is the use of knockout mutations, tagged inhibitor pull-down assays, and targeted identification methods.
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Affiliation(s)
- Danielle L Jessen Condry
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND, USA.
| | - Matthew L Nilles
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND, USA
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43
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Global Analysis of Type Three Secretion System and Quorum Sensing Inhibition of Pseudomonas savastanoi by Polyphenols Extracts from Vegetable Residues. PLoS One 2016; 11:e0163357. [PMID: 27668874 PMCID: PMC5036890 DOI: 10.1371/journal.pone.0163357] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Accepted: 09/06/2016] [Indexed: 11/30/2022] Open
Abstract
Protection of plants against bacterial diseases still mainly relies on the use of chemical pesticides, which in Europe correspond essentially to copper-based compounds. However, recently plant diseases control is oriented towards a rational use of molecules and extracts, generally with natural origin, with lower intrinsic toxicity and a reduced negative environmental impact. In this work, polyphenolic extracts from vegetable no food/feed residues of typical Mediterranean crops, as Olea europaea, Cynara scolymus, and Vitis vinifera were obtained and their inhibitory activity on the Type Three Secretion System (TTSS) and the Quorum Sensing (QS) of the Gram-negative phytopathogenic bacterium Pseudomonas savastanoi pv. nerii strain Psn23 was assessed. Extract from green tea (Camellia sinensis) was used as a positive control. Collectively, the data obtained through gfp-promoter fusion system and real-time PCR show that all the polyphenolic extracts here studied have a high inhibitory activity on both the TTSS and QS of Psn23, without any depressing effect on bacterial viability. Extracts from green tea and grape seeds were shown to be the most active. Such activity was confirmed in planta by a strong reduction in the ability of Psn23 to develop hyperplastic galls on explants from adult oleander plants, as well as to elicit hypersensitive response on tobacco. By using a newly developed Congo red assay and an ELISA test, we demonstrated that the TTSS-targeted activity of these polyphenolic extracts also affects the TTSS pilus assembly. In consideration of the potential application of polyphenolic extracts in plant protection, the absence of any toxicity of these polyphenolic compounds was also assessed. A widely and evolutionary conserved molecular target such as Ca2+-ATPase, essential for the survival of any living organism, was used for the toxicity assessment.
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Wang C, Liu X, Wang J, Zhou J, Cui Z, Zhang LH. Design and characterization of a polyamine derivative inhibiting the expression of type III secretion system in Pseudomonas aeruginosa. Sci Rep 2016; 6:30949. [PMID: 27484745 PMCID: PMC4971474 DOI: 10.1038/srep30949] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Accepted: 07/12/2016] [Indexed: 12/24/2022] Open
Abstract
The type III secretion system (TTSS) of Pseudomonas aeruginosa is a key virulence determinant for infection of eukaryotic hosts. Based on the findings that spermidine-mediated host-pathogen signalling is important for activation of type III secretion systems (TTSS), in this study, we designed, synthesized and evaluated a series of polyamine derivatives for their potentials in inhibiting the expression TTSS in P. aeruginosa. In vitro assay of 15 compounds synthesized in this study unveiled stringent structural requirements for TTSS-inhibitory activity. Among them, R101SPM, a conjugate between rhodamine 101 and spermine, showed a potent activity in inhibition of the TTSS gene expression and in attenuation of the TTSS-mediated cytotoxicity on human cells. In vivo analysis demonstrated that R101SPM could rescue mice from the lethal infection by P. aeruginosa. Moreover, genetic analysis showed that the full TTSS-inhibitory activity of R101SPM required a functional spermidine transporter. Taken together, our results present a new class of lead molecules for developing anti-virulence drugs and demonstrate that the spermidine transporter SpuDEGHF of P. aeruginosa is a promising drug target.
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Affiliation(s)
- Chao Wang
- Institute of Molecular and Cell Biology, 61 Biopolis Drive, 138673, Singapore.,National Cancer Centre Singapore, 11 Hospital Drive, 169610, Singapore
| | - Xiaoling Liu
- Institute of Molecular and Cell Biology, 61 Biopolis Drive, 138673, Singapore.,Chongqing Academy of Chinese Materia Medica, 400065, China
| | - Jing Wang
- Institute of Molecular and Cell Biology, 61 Biopolis Drive, 138673, Singapore
| | - Jianuan Zhou
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, 510642, China
| | - Zining Cui
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, 510642, China
| | - Lian-Hui Zhang
- Institute of Molecular and Cell Biology, 61 Biopolis Drive, 138673, Singapore.,Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, 510642, China
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Spadaro F, Scoffone VC, Chiarelli LR, Fumagalli M, Buroni S, Riccardi G, Forneris F. The Crystal Structure of Burkholderia cenocepacia DfsA Provides Insights into Substrate Recognition and Quorum Sensing Fatty Acid Biosynthesis. Biochemistry 2016; 55:3241-50. [PMID: 27198181 DOI: 10.1021/acs.biochem.6b00178] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Burkholderia cenocepacia is a major concern among respiratory tract infections in cystic fibrosis patients. This pathogen is particularly difficult to treat because of its high level of resistance to the clinically relevant antimicrobial agents. In B. cenocepacia, the quorum sensing cell-cell communication system is involved in different processes that are important for bacterial virulence, such as biofilm formation and protease and siderophore production. Targeting the enzymes involved in this process represents a promising therapeutic approach. With the aim of finding effective quorum sensing inhibitors, we have determined the three-dimensional structure of B. cenocepacia diffusible factor synthase A, DfsA. This bifunctional crotonase (dehydratase/thioesterase) produces the characteristic quorum sensing molecule of B. cenocepacia, cis-2-dodecenoic acid or BDSF, starting from 3-hydroxydodecanoyl-acyl carrier protein. Unexpectedly, the crystal structure revealed the presence of a lipid molecule in the catalytic site of the enzyme, which was identified as dodecanoic acid. Our biochemical characterization shows that DfsA is able to use dodecanoyl-acyl carrier protein as a substrate, demonstrating that dodecanoic acid, the product of this reaction, is released very slowly from the DfsA active site, therefore acting as a DfsA inhibitor. This molecule shows an unprecedented conformational arrangement inside the DfsA active site. In contrast with previous hypotheses, our data illustrate how DfsA and closely related homologous enzymes can recognize long hydrophobic substrates without large conformational changes or assistance by additional regulator molecules. The elucidation of the substrate binding mode in DfsA provides the starting point for structure-based drug discovery studies targeting B. cenocepacia quorum sensing-assisted virulence.
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Affiliation(s)
- Francesca Spadaro
- Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia , Via Ferrata 9/A, 27100 Pavia, Italy
| | - Viola C Scoffone
- Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia , Via Ferrata 9/A, 27100 Pavia, Italy
| | - Laurent R Chiarelli
- Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia , Via Ferrata 9/A, 27100 Pavia, Italy
| | - Marco Fumagalli
- Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia , Via Ferrata 9/A, 27100 Pavia, Italy
| | - Silvia Buroni
- Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia , Via Ferrata 9/A, 27100 Pavia, Italy
| | - Giovanna Riccardi
- Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia , Via Ferrata 9/A, 27100 Pavia, Italy
| | - Federico Forneris
- Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia , Via Ferrata 9/A, 27100 Pavia, Italy
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Reck M, Wagner-Döbler I. Carolacton Treatment Causes Delocalization of the Cell Division Proteins PknB and DivIVa in Streptococcus mutans in vivo. Front Microbiol 2016; 7:684. [PMID: 27242711 PMCID: PMC4862990 DOI: 10.3389/fmicb.2016.00684] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 04/26/2016] [Indexed: 12/20/2022] Open
Abstract
The small inhibitory molecule Carolacton has been shown to cause chain formation and bulging in Streptococci, suggesting a defect in cell division, but it is not known how cell division is impaired on a molecular level. Fluorescent fusion proteins have successfully been applied to visualize protein localization and dynamics in vivo and have revolutionized our understanding of cell wall growth, cell division, chromosome replication and segregation. However, in Streptococci the required vectors are largely lacking. We constructed vectors for chromosomal integration and inducible expression of fluorescent fusion proteins based on GFP+ in S. mutans. Their applicability was verified using four proteins with known localization in the cell. We then determined the effect of Carolacton on the subcellular localization of GFP+ fusions of the cell division protein DivIVa and the serine-threonine protein kinase PknB. Carolacton caused a significant delocalization of these proteins from midcell, in accordance with a previous study demonstrating the Carolacton insensitive phenotype of a pknB deletion strain. Carolacton treated cells displayed an elongated phenotype, increased septum formation and a severe defect in daughter cell separation. GFP+ fusions of two hypothetical proteins (SMU_503 and SMU_609), that had previously been shown to be the most strongly upregulated genes after Carolacton treatment, were found to be localized at the septum in midcell, indicating their role in cell division. These findings highlight the importance of PknB as a key regulator of cell division in streptococci and indicate a profound impact of Carolacton on the coordination between peripheral and septal cell wall growth. The established vector system represents a novel tool to study essential steps of cellular metabolism.
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Affiliation(s)
- Michael Reck
- Department of Microbiology, Microbial Communication, Helmholtz Centre for Infection Research Braunschweig, Germany
| | - Irene Wagner-Döbler
- Department of Microbiology, Microbial Communication, Helmholtz Centre for Infection Research Braunschweig, Germany
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Nesterenko LN, Zigangirova NA, Zayakin ES, Luyksaar SI, Kobets NV, Balunets DV, Shabalina LA, Bolshakova TN, Dobrynina OY, Gintsburg AL. A small-molecule compound belonging to a class of 2,4-disubstituted 1,3,4-thiadiazine-5-ones suppresses Salmonella infection in vivo. J Antibiot (Tokyo) 2016; 69:422-7. [PMID: 26732253 DOI: 10.1038/ja.2015.131] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Revised: 10/28/2015] [Accepted: 11/17/2015] [Indexed: 11/09/2022]
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. A novel compound with a predicted T3SS inhibitory activity named CL-55 (N-(2,4-difluorophenyl)-4-(3-ethoxy-4-hydroxybenzyl)-5-oxo-5,6-dihydro-4H-[1,3,4]-thiadiazine-2-carboxamide) was previously characterized by low toxicity, high levels of solubility, stability and specific efficiency toward Chlamydia trachomatis in vitro and in vivo. In this study, we describe the action of CL-55 on Salmonella enterica serovar Typhimurium. We found that CL-55 does not affect Salmonella growth in vitro but suppresses Salmonella infection in vivo. The i.p. injection of CL-55 at a dose of 10 mg kg(-1) for 4 days significantly (500-fold) decreased the numbers of Salmonella in the spleen and peritoneal lavages and increased the survival rates in susceptible (BALB/c, I/St) and resistant (A/Sn) mice. Twelve days of therapy led to complete eradication of Salmonella in mice. Moreover, no pathogen was found 4-6 weeks post treatment. CL-55 was not carcinogenic or mutagenic, did not increase the level of chromosomal aberrations in bone marrow cells and had low toxicity in mice, rats and rabbits. Pharmacokinetic studies have shown that CL-55 rapidly disappears from systemic blood circulation and is distributed in the organs. Our data demonstrates that CL-55 affects S. enterica serovar Typhimurium in vivo and could be used as a substance in the design of antibacterial inhibitors for pharmaceutical intervention of bacterial virulence for infection.
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Affiliation(s)
| | | | - Egor S Zayakin
- Gamaleya Research Center for Epidemiology and Microbiology, Moscow, Russia
| | - Sergey I Luyksaar
- Gamaleya Research Center for Epidemiology and Microbiology, Moscow, Russia
| | - Natalie V Kobets
- Gamaleya Research Center for Epidemiology and Microbiology, Moscow, Russia
| | - Denis V Balunets
- Gamaleya Research Center for Epidemiology and Microbiology, Moscow, Russia
| | | | | | - Olga Y Dobrynina
- Gamaleya Research Center for Epidemiology and Microbiology, Moscow, Russia
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Targeting of host organelles by pathogenic bacteria: a sophisticated subversion strategy. Nat Rev Microbiol 2015; 14:5-19. [PMID: 26594043 DOI: 10.1038/nrmicro.2015.1] [Citation(s) in RCA: 114] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Many bacterial pathogens have evolved the ability to subvert and exploit host functions in order to enter and replicate in eukaryotic cells. For example, bacteria have developed specific mechanisms to target eukaryotic organelles such as the nucleus, the mitochondria, the endoplasmic reticulum and the Golgi apparatus. In this Review, we highlight the most recent advances in our understanding of the mechanisms that bacterial pathogens use to target these organelles. We also discuss how these strategies allow bacteria to manipulate host functions and to ultimately enable bacterial infection.
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Type III Secretion-Dependent Sensitivity of Escherichia coli O157 to Specific Ketolides. Antimicrob Agents Chemother 2015; 60:459-70. [PMID: 26525795 PMCID: PMC4704242 DOI: 10.1128/aac.02085-15] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Accepted: 10/27/2015] [Indexed: 01/06/2023] Open
Abstract
A subset of Gram-negative bacterial pathogens uses a type III secretion system (T3SS) to open up a conduit into eukaryotic cells in order to inject effector proteins. These modulate pathways to enhance bacterial colonization. In this study, we screened established bioactive compounds for any that could repress T3SS expression in enterohemorrhagic Escherichia coli (EHEC) O157. The ketolides telithromycin and, subsequently, solithromycin both demonstrated repressive effects on expression of the bacterial T3SS at sub-MICs, leading to significant reductions in bacterial binding and actin-rich pedestal formation on epithelial cells. Preincubation of epithelial cells with solithromycin resulted in significantly less attachment of E. coli O157. Moreover, bacteria expressing the T3SS were more susceptible to solithromycin, and there was significant preferential killing of E. coli O157 bacteria when they were added to epithelial cells that had been preexposed to the ketolide. This killing was dependent on expression of the T3SS. Taken together, this research indicates that the ketolide that has accumulated in epithelial cells may traffic back into the bacteria via the T3SS. Considering that neither ketolide induces the SOS response, nontoxic members of this class of antibiotics, such as solithromycin, should be considered for future testing and trials evaluating their use for treatment of EHEC infections. These antibiotics may also have broader significance for treating infections caused by other pathogenic bacteria, including intracellular bacteria, that express a T3SS.
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50
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Gu L, Zhou S, Zhu L, Liang C, Chen X. Small-Molecule Inhibitors of the Type III Secretion System. Molecules 2015; 20:17659-74. [PMID: 26404233 PMCID: PMC6332019 DOI: 10.3390/molecules200917659] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Revised: 09/17/2015] [Accepted: 09/18/2015] [Indexed: 01/02/2023] Open
Abstract
Drug-resistant pathogens have presented increasing challenges to the discovery and development of new antibacterial agents. The type III secretion system (T3SS), existing in bacterial chromosomes or plasmids, is one of the most complicated protein secretion systems. T3SSs of animal and plant pathogens possess many highly conserved main structural components comprised of about 20 proteins. Many Gram-negative bacteria carry T3SS as a major virulence determinant, and using the T3SS, the bacteria secrete and inject effector proteins into target host cells, triggering disease symptoms. Therefore, T3SS has emerged as an attractive target for antimicrobial therapeutics. In recent years, many T3SS-targeting small-molecule inhibitors have been discovered; these inhibitors prevent the bacteria from injecting effector proteins and from causing pathophysiology in host cells. Targeting the virulence of Gram-negative pathogens, rather than their survival, is an innovative and promising approach that may greatly reduce selection pressures on pathogens to develop drug-resistant mutations. This article summarizes recent progress in the search for promising small-molecule T3SS inhibitors that target the secretion and translocation of bacterial effector proteins.
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Affiliation(s)
- Lingling Gu
- School of Pharmaceutical Engineering and Life Science, Changzhou University, Changzhou 213164, China.
| | - Shanshan Zhou
- School of Pharmaceutical Engineering and Life Science, Changzhou University, Changzhou 213164, China.
| | - Lanping Zhu
- School of Pharmaceutical Engineering and Life Science, Changzhou University, Changzhou 213164, China.
| | - Cuirong Liang
- School of Pharmaceutical Engineering and Life Science, Changzhou University, Changzhou 213164, China.
| | - Xin Chen
- School of Pharmaceutical Engineering and Life Science, Changzhou University, Changzhou 213164, China.
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