101
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Gopinath Samykannu, Perumal P, Rahul R, Arulandu A, Narayanan S. Crystallization and X-Ray Diffraction Studies of Salmonella Invasion Protein D (SipD), Insight Tip Component of Salmonella typhi Type III Secretion System. CRYSTALLOGR REP+ 2020. [DOI: 10.1134/s1063774519070174] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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102
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Matsuda S, Hiyoshi H, Tandhavanant S, Kodama T. Advances on
Vibrio parahaemolyticus
research in the postgenomic era. Microbiol Immunol 2020; 64:167-181. [DOI: 10.1111/1348-0421.12767] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Accepted: 12/08/2019] [Indexed: 01/13/2023]
Affiliation(s)
- Shigeaki Matsuda
- Department of Bacterial Infections, Research Institute for Microbial DiseasesOsaka University Suita Osaka Japan
| | - Hirotaka Hiyoshi
- Department of Bacterial Infections, Research Institute for Microbial DiseasesOsaka University Suita Osaka Japan
- Department of Medical Microbiology and Immunology, School of MedicineUniversity of California Davis California, USA
| | - Sarunporn Tandhavanant
- Department of Bacterial Infections, Research Institute for Microbial DiseasesOsaka University Suita Osaka Japan
- Department of Microbiology and Immunology, Faculty of Tropical MedicineMahidol University Bangkok Thailand
| | - Toshio Kodama
- Department of Bacterial Infections, Research Institute for Microbial DiseasesOsaka University Suita Osaka Japan
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103
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Lampaki D, Diepold A, Glatter T. A Serial Sample Processing Strategy with Improved Performance for in-Depth Quantitative Analysis of Type III Secretion Events in Pseudomonas aeruginosa. J Proteome Res 2020; 19:543-553. [PMID: 31814412 DOI: 10.1021/acs.jproteome.9b00628] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The efficient analysis of secretomes is important to study the mechanisms of bacterial secretion. However, secretome analysis of bacteria that rely on rich media for optimal secretion via modern quantitative shotgun proteomics workflows is often hampered by the higher degree of sample impurities. This may be a reason for the low number of quantitative secretome investigations in such cases. We assessed the efficiency and amenability for rich media secretome analysis of different workflows including precipitation, SP3, and a combined, serial workflow. Using the model organism Pseudomonas aeruginosa, we found that the combined TCA-SP3 strategy outperformed the other tested methods on all monitored qualitative and quantitative levels. This method proved to be most efficient in the recovery of proteins secreted by the type III secretion system (T3SS), including all known effector proteins and secretion machinery components. We monitored the compositional changes of secretome samples over time, and observed a strong increase in the secreted protein fraction by the T3SS 2 to 3 h after T3SS induction. Our study conceptually illustrates how the combination of TCA precipitation and SP3 results in orthogonality in depleting sample impurities accompanied by improved chromatographic peptide separation, and more efficient MS detection with improved quantification parameters.
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Affiliation(s)
- Dimitrios Lampaki
- Core Facility for Mass Spectrometry and Proteomics , Max Planck Institute for Terrestrial Microbiology , Karl-von-Frisch-Str. 10 , D-35043 Marburg , Germany.,Department of Ecophysiology , Max Planck Institute for Terrestrial Microbiology , Karl-von-Frisch-Str. 10 , D-35043 Marburg , Germany
| | - Andreas Diepold
- Department of Ecophysiology , Max Planck Institute for Terrestrial Microbiology , Karl-von-Frisch-Str. 10 , D-35043 Marburg , Germany
| | - Timo Glatter
- Core Facility for Mass Spectrometry and Proteomics , Max Planck Institute for Terrestrial Microbiology , Karl-von-Frisch-Str. 10 , D-35043 Marburg , Germany
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104
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Fu X, Yang Y. WEDeepT3: predicting type III secreted effectors based on word embedding and deep learning. QUANTITATIVE BIOLOGY 2019. [DOI: 10.1007/s40484-019-0184-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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105
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Ferro P, Vaz-Moreira I, Manaia CM. Betaproteobacteria are predominant in drinking water: are there reasons for concern? Crit Rev Microbiol 2019; 45:649-667. [PMID: 31686572 DOI: 10.1080/1040841x.2019.1680602] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Betaproteobacteria include some of the most abundant and ubiquitous bacterial genera that can be found in drinking water, including mineral water. The combination of physiology and ecology traits place some Betaproteobacteria in the list of potential, yet sometimes neglected, opportunistic pathogens that can be transmitted by water or aqueous solutions. Indeed, some drinking water Betaproteobacteria with intrinsic and sometimes acquired antibiotic resistance, harbouring virulence factors and often found in biofilm structures, can persist after water disinfection and reach the consumer. This literature review summarises and discusses the current knowledge about the occurrence and implications of Betaproteobacteria in drinking water. Although the sparse knowledge on the ecology and physiology of Betaproteobacteria thriving in tap or bottled natural mineral/spring drinking water (DW) is an evidence of this review, it is demonstrated that DW holds a high diversity of Betaproteobacteria, whose presence may not be innocuous. Frequently belonging to genera also found in humans, DW Betaproteobacteria are ubiquitous in different habitats, have the potential to resist antibiotics either due to intrinsic or acquired mechanisms, and hold different virulence factors. The combination of these factors places DW Betaproteobacteria in the list of candidates of emerging opportunistic pathogens. Improved bacterial identification of clinical isolates associated with opportunistic infections and additional genomic and physiological studies may contribute to elucidate the potential impact of these bacteria.
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Affiliation(s)
- Pompeyo Ferro
- Universidade Católica Portuguesa, CBQF - Centro de Biotecnologia e Química Fina - Laboratório Associado, Escola Superior de Biotecnologia, Porto, Portugal
| | - Ivone Vaz-Moreira
- Universidade Católica Portuguesa, CBQF - Centro de Biotecnologia e Química Fina - Laboratório Associado, Escola Superior de Biotecnologia, Porto, Portugal
| | - Célia M Manaia
- Universidade Católica Portuguesa, CBQF - Centro de Biotecnologia e Química Fina - Laboratório Associado, Escola Superior de Biotecnologia, Porto, Portugal
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106
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Yin Z, Yuan C, Du Y, Yang P, Qian C, Wei Y, Zhang S, Huang D, Liu B. Comparative genomic analysis of the Hafnia genus reveals an explicit evolutionary relationship between the species alvei and paralvei and provides insights into pathogenicity. BMC Genomics 2019; 20:768. [PMID: 31646960 PMCID: PMC6806506 DOI: 10.1186/s12864-019-6123-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Accepted: 09/20/2019] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND The Hafnia genus is an opportunistic pathogen that has been implicated in both nosocomial and community-acquired infections. Although Hafnia is fairly often isolated from clinical material, its taxonomy has remained an unsolved riddle, and the involvement and importance of Hafnia in human disease is also uncertain. Here, we used comparative genomic analysis to define the taxonomy of Hafnia, identify species-specific genes that may be the result of ecological and pathogenic specialization, and reveal virulence-related genetic profiles that may contribute to pathogenesis. RESULTS One complete genome sequence and 19 draft genome sequences for Hafnia strains were generated and combined with 27 publicly available genomes. We provided high-resolution typing methods by constructing phylogeny and population structure based on single-copy core genes in combination with whole genome average nucleotide identity to identify two distant Hafnia species (alvei and paralvei) and one mislabeled strain. The open pan-genome and the presence of numerous mobile genetic elements reveal that Hafnia has undergone massive gene rearrangements. Presence of species-specific core genomes associated with metabolism and transport suggests the putative niche differentiation between alvei and paralvei. We also identified possession of diverse virulence-related profiles in both Hafnia species., including the macromolecular secretion system, virulence, and antimicrobial resistance. In the macromolecular system, T1SS, Flagellum 1, Tad pilus and T6SS-1 were conserved in Hafnia, whereas T4SS, T5SS, and other T6SSs exhibited the evolution of diversity. The virulence factors in Hafnia are related to adherence, toxin, iron uptake, stress adaptation, and efflux pump. The identified resistance genes are associated with aminoglycoside, beta-lactam, bacitracin, cationic antimicrobial peptide, fluoroquinolone, and rifampin. These virulence-related profiles identified at the genomic level provide insights into Hafnia pathogenesis and the differentiation between alvei and paralvei. CONCLUSIONS Our research using core genome phylogeny and comparative genomics analysis of a larger collection of strains provides a comprehensive view of the taxonomy and species-specific traits between Hafnia species. Deciphering the genome of Hafnia strains possessing a reservoir of macromolecular secretion systems, virulence factors, and resistance genes related to pathogenicity may provide insights into addressing its numerous infections and devising strategies to combat the pathogen.
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Affiliation(s)
- Zhiqiu Yin
- Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, TEDA College, Nankai University, Tianjin, People’s Republic of China
- TEDA institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, People’s Republic of China
- Tianjin Key Laboratory of Microbial Functional Genomeics, TEDA college, Nankai university, Tianjin, People’s Republic of China
| | - Chao Yuan
- Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, TEDA College, Nankai University, Tianjin, People’s Republic of China
- TEDA institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, People’s Republic of China
- Tianjin Key Laboratory of Microbial Functional Genomeics, TEDA college, Nankai university, Tianjin, People’s Republic of China
| | - Yuhui Du
- Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, TEDA College, Nankai University, Tianjin, People’s Republic of China
- TEDA institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, People’s Republic of China
- Tianjin Key Laboratory of Microbial Functional Genomeics, TEDA college, Nankai university, Tianjin, People’s Republic of China
| | - Pan Yang
- Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, TEDA College, Nankai University, Tianjin, People’s Republic of China
- TEDA institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, People’s Republic of China
- Tianjin Key Laboratory of Microbial Functional Genomeics, TEDA college, Nankai university, Tianjin, People’s Republic of China
| | - Chengqian Qian
- Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, TEDA College, Nankai University, Tianjin, People’s Republic of China
- TEDA institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, People’s Republic of China
- Tianjin Key Laboratory of Microbial Functional Genomeics, TEDA college, Nankai university, Tianjin, People’s Republic of China
| | - Yi Wei
- Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, TEDA College, Nankai University, Tianjin, People’s Republic of China
- TEDA institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, People’s Republic of China
- Tianjin Key Laboratory of Microbial Functional Genomeics, TEDA college, Nankai university, Tianjin, People’s Republic of China
| | - Si Zhang
- Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, TEDA College, Nankai University, Tianjin, People’s Republic of China
- TEDA institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, People’s Republic of China
- Tianjin Key Laboratory of Microbial Functional Genomeics, TEDA college, Nankai university, Tianjin, People’s Republic of China
| | - Di Huang
- Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, TEDA College, Nankai University, Tianjin, People’s Republic of China
- TEDA institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, People’s Republic of China
- Tianjin Key Laboratory of Microbial Functional Genomeics, TEDA college, Nankai university, Tianjin, People’s Republic of China
| | - Bin Liu
- Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, TEDA College, Nankai University, Tianjin, People’s Republic of China
- TEDA institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, People’s Republic of China
- Tianjin Key Laboratory of Microbial Functional Genomeics, TEDA college, Nankai university, Tianjin, People’s Republic of China
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107
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Singh AK, Curtiss R, Sun W. A Recombinant Attenuated Yersinia pseudotuberculosis Vaccine Delivering a Y. pestis YopE Nt138-LcrV Fusion Elicits Broad Protection against Plague and Yersiniosis in Mice. Infect Immun 2019; 87:e00296-19. [PMID: 31331960 PMCID: PMC6759313 DOI: 10.1128/iai.00296-19] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Accepted: 07/18/2019] [Indexed: 12/22/2022] Open
Abstract
In this study, a novel recombinant attenuated Yersinia pseudotuberculosis PB1+ strain (χ10069) engineered with ΔyopK ΔyopJ Δasd triple mutations was used to deliver a Y. pestis fusion protein, YopE amino acid 1 to 138-LcrV (YopENt138-LcrV), to Swiss Webster mice as a protective antigen against infections by yersiniae. χ10069 bacteria harboring the pYA5199 plasmid constitutively synthesized the YopENt138-LcrV fusion protein and secreted it via the type 3 secretion system (T3SS) at 37°C under calcium-deprived conditions. The attenuated strain χ10069(pYA5199) was manifested by the establishment of controlled infection in different tissues without developing conspicuous signs of disease in histopathological analysis of microtome sections. A single-dose oral immunization of χ10069(pYA5199) induced strong serum antibody titers (log10 mean value, 4.2), secretory IgA in bronchoalveolar lavage (BAL) fluid from immunized mice, and Yersinia-specific CD4+ and CD8+ T cells producing high levels of tumor necrosis factor alpha (TNF-α), gamma interferon (IFN-γ), and interleukin 2 (IL-2), as well as IL-17, in both lungs and spleens of immunized mice, conferring comprehensive Th1- and Th2-mediated immune responses and protection against bubonic and pneumonic plague challenges, with 80% and 90% survival, respectively. Mice immunized with χ10069(pYA5199) also exhibited complete protection against lethal oral infections by Yersinia enterocolitica WA and Y. pseudotuberculosis PB1+. These findings indicated that χ10069(pYA5199) as an oral vaccine induces protective immunity to prevent bubonic and pneumonic plague, as well as yersiniosis, in mice and would be a promising oral vaccine candidate for protection against plague and yersiniosis for human and veterinary applications.
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Affiliation(s)
- Amit K Singh
- Department of Immunology and Microbial Disease, Albany Medical College, Albany, New York, USA
| | - Roy Curtiss
- Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, Gainesville, Florida, USA
| | - Wei Sun
- Department of Immunology and Microbial Disease, Albany Medical College, Albany, New York, USA
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108
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Pendergrass HA, May AE. Natural Product Type III Secretion System Inhibitors. Antibiotics (Basel) 2019; 8:antibiotics8040162. [PMID: 31554164 PMCID: PMC6963908 DOI: 10.3390/antibiotics8040162] [Citation(s) in RCA: 15] [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: 09/10/2019] [Revised: 09/18/2019] [Accepted: 09/19/2019] [Indexed: 01/05/2023] Open
Abstract
Many known inhibitors of the bacterial type III secretion system (T3SS), a virulence factor used by pathogenic bacteria to infect host cells, are natural products. These compounds, produced by bacteria, fungi, and plants, may have developed as prophylactic treatments for potential attack by bacterial pathogens or as an attempt by symbiotic organisms to protect their hosts. Regardless, better understanding of the structures and mechanisms of action of these compounds may open opportunities for drug development against diseases caused by pathogens utilizing the T3SS. This review will cover selected known natural products of the T3SS and detail what is known of their origin and mechanism of action. These inhibitors highlight nature’s ability to modulate interactions between organisms at a cellular level.
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Affiliation(s)
- Heather A Pendergrass
- Department of Medicinal Chemistry, Virginia Commonwealth University, Richmond, VA 23284, USA.
| | - Aaron E May
- Department of Medicinal Chemistry, Virginia Commonwealth University, Richmond, VA 23284, USA.
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109
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Kadari M, Lakhloufi D, Delforge V, Imbault V, Communi D, Smeesters P, Botteaux A. Multiple proteins arising from a single gene: The role of the Spa33 variants in Shigella T3SS regulation. Microbiologyopen 2019; 8:e932. [PMID: 31517452 PMCID: PMC6925163 DOI: 10.1002/mbo3.932] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 08/14/2019] [Accepted: 08/16/2019] [Indexed: 12/12/2022] Open
Abstract
Shigella invasion and dissemination in intestinal epithelial cells relies on a type 3 secretion system (T3SS), which mediates translocation of virulence proteins into host cells. T3SSs are composed of three major parts: an extracellular needle, a basal body, and a cytoplasmic complex. Three categories of proteins are hierarchically secreted: (a) the needle components, (b) the translocator proteins which form a pore (translocon) inside the host cell membrane and (c) the effectors interfering with the host cell signaling pathways. In the absence of host cell contact, the T3SS is maintained in an “off” state by the presence of a tip complex. Secretion is activated by host cell contact which allows the release of a gatekeeper protein called MxiC. In this work, we have investigated the role of Spa33, a component of the cytoplasmic complex, in the regulation of secretion. The spa33 gene encodes a 33‐kDa protein and a smaller fragment of 12 kDa (Spa33C) which are both essential components of the cytoplasmic complex. We have shown that the spa33 gene gives rise to 5 fragments of various sizes. Among them, three are necessary for T3SS. Interestingly, we have shown that Spa33 is implicated in the regulation of secretion. Indeed, the mutation of a single residue in Spa33 induces an effector mutant phenotype, in which MxiC is sequestered. Moreover, we have shown a direct interaction between Spa33 and MxiC.
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Affiliation(s)
- Mahendar Kadari
- Laboratory of Molecular Bacteriology, Faculty of Medicine, Free University of Brussels, Brussels, Belgium
| | - Dalila Lakhloufi
- Laboratory of Molecular Bacteriology, Faculty of Medicine, Free University of Brussels, Brussels, Belgium
| | - Valérie Delforge
- Laboratory of Molecular Bacteriology, Faculty of Medicine, Free University of Brussels, Brussels, Belgium
| | - Virginie Imbault
- Mass Spectrometry and Proteomics Facility, IRIBHM, Faculty of Medicine, Free University of Brussels, Brussels, Belgium
| | - David Communi
- Mass Spectrometry and Proteomics Facility, IRIBHM, Faculty of Medicine, Free University of Brussels, Brussels, Belgium
| | - Pierre Smeesters
- Laboratory of Molecular Bacteriology, Faculty of Medicine, Free University of Brussels, Brussels, Belgium.,Department of Pediatrics, Academic Children Hospital Queen Fabiola, Université libre de Bruxelles, Brussels, Belgium.,Tropical disease Group, Murdoch Children's, Research Institute, Melbourne, Vic., Australia.,Center for International Child Health, University of Melbourne, Melbourne, Vic., Australia
| | - Anne Botteaux
- Laboratory of Molecular Bacteriology, Faculty of Medicine, Free University of Brussels, Brussels, Belgium
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110
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Milne-Davies B, Helbig C, Wimmi S, Cheng DWC, Paczia N, Diepold A. Life After Secretion- Yersinia enterocolitica Rapidly Toggles Effector Secretion and Can Resume Cell Division in Response to Changing External Conditions. Front Microbiol 2019; 10:2128. [PMID: 31572334 PMCID: PMC6753693 DOI: 10.3389/fmicb.2019.02128] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Accepted: 08/29/2019] [Indexed: 12/12/2022] Open
Abstract
Many pathogenic bacteria use the type III secretion system (T3SS) injectisome to manipulate host cells by injecting virulence-promoting effector proteins into the host cytosol. The T3SS is activated upon host cell contact, and its activation is accompanied by an arrest of cell division; hence, many species maintain a T3SS-inactive sibling population to propagate efficiently within the host. The enteric pathogen Yersinia enterocolitica utilizes the T3SS to prevent phagocytosis and inhibit inflammatory responses. Unlike other species, almost all Y. enterocolitica are T3SS-positive at 37°C, which raises the question, how these bacteria are able to propagate within the host, that is, when and how they stop secretion and restart cell division after a burst of secretion. Using a fast and quantitative in vitro secretion assay, we have examined the initiation and termination of type III secretion. We found that effector secretion begins immediately once the activating signal is present, and instantly stops when this signal is removed. Following effector secretion, the bacteria resume division within minutes after being introduced to a non-secreting environment, and the same bacteria are able to re-initiate effector secretion at later time points. Our results indicate that Y. enterocolitica use their type III secretion system to promote their individual survival when necessary, and are able to quickly switch their behavior toward replication afterwards, possibly gaining an advantage during infection.
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Affiliation(s)
| | | | | | | | | | - Andreas Diepold
- Department of Ecophysiology, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
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111
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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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112
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Peter MF, Tuukkanen AT, Heubach CA, Selsam A, Duthie FG, Svergun DI, Schiemann O, Hagelueken G. Studying Conformational Changes of the Yersinia Type-III-Secretion Effector YopO in Solution by Integrative Structural Biology. Structure 2019; 27:1416-1426.e3. [DOI: 10.1016/j.str.2019.06.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 05/08/2019] [Accepted: 06/18/2019] [Indexed: 10/26/2022]
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113
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Bergeau D, Mazurier S, Barbey C, Merieau A, Chane A, Goux D, Bernard S, Driouich A, Lemanceau P, Vicré M, Latour X. Unusual extracellular appendages deployed by the model strain Pseudomonas fluorescens C7R12. PLoS One 2019; 14:e0221025. [PMID: 31461454 PMCID: PMC6713353 DOI: 10.1371/journal.pone.0221025] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 07/30/2019] [Indexed: 01/22/2023] Open
Abstract
Pseudomonas fluorescens is considered to be a typical plant-associated saprophytic bacterium with no pathogenic potential. Indeed, some P. fluorescens strains are well-known rhizobacteria that promote plant growth by direct stimulation, by preventing the deleterious effects of pathogens, or both. Pseudomonas fluorescens C7R12 is a rhizosphere-competent strain that is effective as a biocontrol agent and promotes plant growth and arbuscular mycorrhization. This strain has been studied in detail, but no visual evidence has ever been obtained for extracellular structures potentially involved in its remarkable fitness and biocontrol performances. On transmission electron microscopy of negatively stained C7R12 cells, we observed the following appendages: multiple polar flagella, an inducible putative type three secretion system typical of phytopathogenic Pseudomonas syringae strains and densely bundled fimbria-like appendages forming a broad fractal-like dendritic network around single cells and microcolonies. The deployment of one or other of these elements on the bacterial surface depends on the composition and affinity for the water of the microenvironment. The existence, within this single strain, of machineries known to be involved in motility, chemotaxis, hypersensitive response, cellular adhesion and biofilm formation, may partly explain the strong interactions of strain C7R12 with plants and associated microflora in addition to the type three secretion system previously shown to be implied in mycorrhizae promotion.
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Affiliation(s)
- Dorian Bergeau
- Laboratoire de Microbiologie Signaux et Microenvironnement (LMSM EA 4312)—Normandie Université - LMSM, Evreux, France
| | - Sylvie Mazurier
- Agroécologie, AgroSup Dijon, INRA, Univ. Bourgogne, Univ. Bourgogne Franche-Comté, Dijon, France
| | - Corinne Barbey
- Laboratoire de Microbiologie Signaux et Microenvironnement (LMSM EA 4312)—Normandie Université - LMSM, Evreux, France
- Structure Fédérative de Recherche Normandie Végétale 4277 (NORVEGE), Normandie, France
| | - Annabelle Merieau
- Laboratoire de Microbiologie Signaux et Microenvironnement (LMSM EA 4312)—Normandie Université - LMSM, Evreux, France
- Structure Fédérative de Recherche Normandie Végétale 4277 (NORVEGE), Normandie, France
| | - Andrea Chane
- Laboratoire de Microbiologie Signaux et Microenvironnement (LMSM EA 4312)—Normandie Université - LMSM, Evreux, France
| | - Didier Goux
- Centre de Microscopie Appliquée à la biologie, SFR 4206 ICORE Université de Caen Normandie (CMAbio3), Caen, France
| | - Sophie Bernard
- Structure Fédérative de Recherche Normandie Végétale 4277 (NORVEGE), Normandie, France
- Laboratoire de Glycobiologie et Matrice Extracellulaire Végétale—Normandie Université - EA 4358 Université de Rouen, Mont-Saint-Aignan, France
| | - Azeddine Driouich
- Structure Fédérative de Recherche Normandie Végétale 4277 (NORVEGE), Normandie, France
- Laboratoire de Glycobiologie et Matrice Extracellulaire Végétale—Normandie Université - EA 4358 Université de Rouen, Mont-Saint-Aignan, France
| | - Philippe Lemanceau
- Agroécologie, AgroSup Dijon, INRA, Univ. Bourgogne, Univ. Bourgogne Franche-Comté, Dijon, France
| | - Maïté Vicré
- Structure Fédérative de Recherche Normandie Végétale 4277 (NORVEGE), Normandie, France
- Laboratoire de Glycobiologie et Matrice Extracellulaire Végétale—Normandie Université - EA 4358 Université de Rouen, Mont-Saint-Aignan, France
| | - Xavier Latour
- Laboratoire de Microbiologie Signaux et Microenvironnement (LMSM EA 4312)—Normandie Université - LMSM, Evreux, France
- Structure Fédérative de Recherche Normandie Végétale 4277 (NORVEGE), Normandie, France
- * E-mail:
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Synthesis and bioactivity of 1,3-thiazolidine-2-thione derivatives against type III secretion system of Xanthomonas oryzae. Bioorg Med Chem 2019; 27:3364-3371. [PMID: 31204227 DOI: 10.1016/j.bmc.2019.06.019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Revised: 05/24/2019] [Accepted: 06/10/2019] [Indexed: 11/23/2022]
Abstract
Targeting virulence factors of bacterial without affecting their growth and survival, has been an initiative strategy for the development of novel anti-microbial agents. The type III secretion system (T3SS), one of essential and highly conserved virulence factors in most Gram-negative pathogenic bacteria, has been regarded as an effective target that developed new anti-microbial drugs. Xanthomonas oryzae pv. oryzae (Xoo) is one of the most important bacterial pathogens on rice, which causes leaf blight disease. To discover potential anti-virulence agents against the pathogens, a new series of 1,3-thiazolidine-2-thione derivatives containing 5-phenyl-2-furan were designed and synthesized. Their structures were characterized by 1H NMR, 13C NMR, MS, and elemental analysis. All the title compounds inhibited the promoter activity of a harpin gene hpa1, significantly, that were further checked for the impact on bacterial growth. The results indicated that treatment of Xoo with the title compound III-7 did not affect bacterial growth or survival. Moreover, quantitative reverse transcription-polymerase chain reaction (qRT-PCR) analysis showed that the expression of the Xoo T3SS was suppressed by treatment with the inhibitor. The mRNA levels of representative genes in the hrp (hypersensitive response and pathogenicity) cluster, as well as the regulatory genes hrpG and hrpX, were reduced. Finally, the in vivo test demonstrated that the compounds could reduce the disease symptoms of Xoo on the rice cultivar (Oryza sativa) IR24.
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Lou L, Zhang P, Piao R, Wang Y. Salmonella Pathogenicity Island 1 (SPI-1) and Its Complex Regulatory Network. Front Cell Infect Microbiol 2019; 9:270. [PMID: 31428589 PMCID: PMC6689963 DOI: 10.3389/fcimb.2019.00270] [Citation(s) in RCA: 153] [Impact Index Per Article: 30.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Accepted: 07/12/2019] [Indexed: 11/30/2022] Open
Abstract
Salmonella species can infect a diverse range of birds, reptiles, and mammals, including humans. The type III protein secretion system (T3SS) encoded by Salmonella pathogenicity island 1 (SPI-1) delivers effector proteins required for intestinal invasion and the production of enteritis. The T3SS is regarded as the most important virulence factor of Salmonella. SPI-1 encodes transcription factors that regulate the expression of some virulence factors of Salmonella, while other transcription factors encoded outside SPI-1 participate in the expression of SPI-1-encoded genes. SPI-1 genes are responsible for the invasion of host cells, regulation of the host immune response, e.g., the host inflammatory response, immune cell recruitment and apoptosis, and biofilm formation. The regulatory network of SPI-1 is very complex and crucial. Here, we review the function, effectors, and regulation of SPI-1 genes and their contribution to the pathogenicity of Salmonella.
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Affiliation(s)
- Lixin Lou
- Department of Infectious Diseases, First Hospital of Jilin University, Changchun, China
| | - Peng Zhang
- Department of Infectious Diseases, First Hospital of Jilin University, Changchun, China.,Department of Pediatrics, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
| | - Rongli Piao
- Department of Pediatrics, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States.,Department of Gastroenterology, First Hospital of Jilin University, Changchun, China
| | - Yang Wang
- Department of Infectious Diseases, First Hospital of Jilin University, Changchun, China.,Department of Pediatrics, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
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116
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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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118
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Luo G, Xu X, Zhao L, Qin Y, Huang L, Su Y, Yan Q. clpV is a key virulence gene during in vivo Pseudomonas plecoglossicida infection. JOURNAL OF FISH DISEASES 2019; 42:991-1000. [PMID: 30957245 DOI: 10.1111/jfd.13001] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 03/10/2019] [Accepted: 03/14/2019] [Indexed: 06/09/2023]
Abstract
Interaction between bacterial pathogen and aquatic animal host is exceedingly complex, which involves large dynamic changes in gene expression during different stages of the disease. However, research on identifying key virulence genes based on the dynamics of gene expression changes of a one-sided bacterial pathogen in tissue has not been reported so far across different stages of infectious disease. The clpV for the T6SS of Pseudomonas plecoglossicida was identified for a candidate for key virulence gene based on dynamic changes of gene expression. For the Epinephelus coioides infected using clpV-RNAi strain, no deaths were observed up to 20 dpi. The spleens, kidneys and livers of all the E. coioides that received clpV-RNAi strain failed to develop visible nodules at 5-8 dpi, with the swelling gradually disappearing. The burdens of clpV-RNAi strain in the spleen and blood were greatly reduced at most of the time points after injection, and the burdens of clpV-RNAi strain in the head kidneys and trunk kidneys also had a sharp reduction from 72 to 120 hpi. This paper provides a new insight into the discovery of key virulence genes of pathogens in infected tissue systems.
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Affiliation(s)
- Gang Luo
- Fisheries College, Jimei University, Xiamen, Fujian, China
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, Hubei, China
| | - Xiaojin Xu
- Fisheries College, Jimei University, Xiamen, Fujian, China
| | - Lingmin Zhao
- Fisheries College, Jimei University, Xiamen, Fujian, China
| | - Yingxue Qin
- Fisheries College, Jimei University, Xiamen, Fujian, China
| | - Lixing Huang
- Fisheries College, Jimei University, Xiamen, Fujian, China
| | - Yongquan Su
- State Key Laboratory of Large Yellow Croaker Breeding, Ningde, Fujian, China
| | - Qingpi Yan
- Fisheries College, Jimei University, Xiamen, Fujian, China
- State Key Laboratory of Large Yellow Croaker Breeding, Ningde, Fujian, China
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119
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Work TM, Dagenais J, Stacy BA, Ladner JT, Lorch JM, Balazs GH, Barquero-Calvo E, Berlowski-Zier BM, Breeden R, Corrales-Gómez N, Gonzalez-Barrientos R, Harris HS, Hernández-Mora G, Herrera-Ulloa Á, Hesami S, Jones TT, Morales JA, Norton TM, Rameyer RA, Taylor DR, Waltzek TB. A novel host-adapted strain of Salmonella Typhimurium causes renal disease in olive ridley turtles (Lepidochelys olivacea) in the Pacific. Sci Rep 2019; 9:9313. [PMID: 31249336 PMCID: PMC6597722 DOI: 10.1038/s41598-019-45752-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 06/14/2019] [Indexed: 01/01/2023] Open
Abstract
Salmonella spp. are frequently shed by wildlife including turtles, but S. enterica subsp. enterica serovar Typhimurium or lesions associated with Salmonella are rare in turtles. Between 1996 and 2016, we necropsied 127 apparently healthy pelagic olive ridley turtles (Lepidochelys olivacea) that died from drowning bycatch in fisheries and 44 live or freshly dead stranded turtles from the west coast of North and Central America and Hawaii. Seven percent (9/127) of pelagic and 47% (21/44) of stranded turtles had renal granulomas associated with S. Typhimurium. Stranded animals were 12 times more likely than pelagic animals to have Salmonella-induced nephritis suggesting that Salmonella may have been a contributing cause of stranding. S. Typhimurium was the only Salmonella serovar detected in L. olivacea, and phylogenetic analysis from whole genome sequencing showed that the isolates from L. olivacea formed a single clade distinct from other S. Typhimurium. Molecular clock analysis revealed that this novel clade may have originated as recently as a few decades ago. The phylogenetic lineage leading to this group is enriched for non-synonymous changes within the genomic area of Salmonella pathogenicity island 1 suggesting that these genes are important for host adaptation.
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Affiliation(s)
- Thierry M Work
- US Geological Survey, National Wildlife Health Center, Honolulu Field Station, Honolulu, Hawaii, 96850, United States of America.
| | - Julie Dagenais
- US Geological Survey, National Wildlife Health Center, Honolulu Field Station, Honolulu, Hawaii, 96850, United States of America
| | - Brian A Stacy
- NOAA Fisheries, Office of Protected Resources, University of Florida, Gainesville, Florida, 32603, United States of America
| | - Jason T Ladner
- The Pathogen and Microbiome Institute, Northern Arizona University, Flagstaff, Arizona, 86011, United States of America
| | - Jeffrey M Lorch
- US Geological Survey, National Wildlife Health Center, Madison, Wisconsin, 53711, United States of America
| | - George H Balazs
- Golden Honu Services of Oceania, Honolulu, Hawaii, 96825, United States of America
| | - Elías Barquero-Calvo
- Escuela de Medicina Veterinaria (EMV), Universidad Nacional Costa Rica, Heredia, 3000, Costa Rica
| | - Brenda M Berlowski-Zier
- US Geological Survey, National Wildlife Health Center, Madison, Wisconsin, 53711, United States of America
| | - Renee Breeden
- US Geological Survey, National Wildlife Health Center, Honolulu Field Station, Honolulu, Hawaii, 96850, United States of America
| | | | - Rocio Gonzalez-Barrientos
- Pathology Area National Service of Animal Health (SENASA), Ministry of Agriculture and Livestock, Heredia, 3000, Costa Rica
| | - Heather S Harris
- NOAA Fisheries West Coast Region, Morro Bay, California, United States of America
| | - Gabriela Hernández-Mora
- Pathology Area National Service of Animal Health (SENASA), Ministry of Agriculture and Livestock, Heredia, 3000, Costa Rica
| | - Ángel Herrera-Ulloa
- Bacteriology Area, National Service of Animal Health (SENASA), Ministry of Agriculture and Livestock, Heredia, 3000, Costa Rica
| | - Shoreh Hesami
- Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, Gainesville, Florida, 32603, United States of America
| | - T Todd Jones
- NOAA Fisheries, Pacific Islands Fisheries Science Center, Honolulu, Hawaii, 96818, United States of America
| | - Juan Alberto Morales
- Escuela de Medicina Veterinaria (EMV), Universidad Nacional Costa Rica, Heredia, 3000, Costa Rica
| | - Terry M Norton
- Georgia Sea Turtle Center/Jekyll Island Authority, Jekyll Island, Georgia, 31527, United States of America
| | - Robert A Rameyer
- US Geological Survey, National Wildlife Health Center, Honolulu Field Station, Honolulu, Hawaii, 96850, United States of America
| | - Daniel R Taylor
- US Geological Survey, National Wildlife Health Center, Madison, Wisconsin, 53711, United States of America
| | - Thomas B Waltzek
- Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, Gainesville, Florida, 32603, United States of America
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Pena RT, Blasco L, Ambroa A, González-Pedrajo B, Fernández-García L, López M, Bleriot I, Bou G, García-Contreras R, Wood TK, Tomás M. Relationship Between Quorum Sensing and Secretion Systems. Front Microbiol 2019; 10:1100. [PMID: 31231316 PMCID: PMC6567927 DOI: 10.3389/fmicb.2019.01100] [Citation(s) in RCA: 137] [Impact Index Per Article: 27.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 04/30/2019] [Indexed: 01/15/2023] Open
Abstract
Quorum sensing (QS) is a communication mechanism between bacteria that allows specific processes to be controlled, such as biofilm formation, virulence factor expression, production of secondary metabolites and stress adaptation mechanisms such as bacterial competition systems including secretion systems (SS). These SS have an important role in bacterial communication. SS are ubiquitous; they are present in both Gram-negative and Gram-positive bacteria and in Mycobacterium sp. To date, 8 types of SS have been described (T1SS, T2SS, T3SS, T4SS, T5SS, T6SS, T7SS, and T9SS). They have global functions such as the transport of proteases, lipases, adhesins, heme-binding proteins, and amidases, and specific functions such as the synthesis of proteins in host cells, adaptation to the environment, the secretion of effectors to establish an infectious niche, transfer, absorption and release of DNA, translocation of effector proteins or DNA and autotransporter secretion. All of these functions can contribute to virulence and pathogenesis. In this review, we describe the known types of SS and discuss the ones that have been shown to be regulated by QS. Due to the large amount of information about this topic in some pathogens, we focus mainly on Pseudomonas aeruginosa and Vibrio spp.
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Affiliation(s)
- Rocio Trastoy Pena
- Deapartamento de Microbiología y Parasitología, Complejo Hospitalario Universitario A Coruña (CHUAC), Instituto de Investigación Biomédica (INIBIC), Universidad de A Coruña (UDC), A Coruña, Spain
| | - Lucia Blasco
- Deapartamento de Microbiología y Parasitología, Complejo Hospitalario Universitario A Coruña (CHUAC), Instituto de Investigación Biomédica (INIBIC), Universidad de A Coruña (UDC), A Coruña, Spain
| | - Antón Ambroa
- Deapartamento de Microbiología y Parasitología, Complejo Hospitalario Universitario A Coruña (CHUAC), Instituto de Investigación Biomédica (INIBIC), Universidad de A Coruña (UDC), A Coruña, Spain
| | - Bertha González-Pedrajo
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Laura Fernández-García
- Deapartamento de Microbiología y Parasitología, Complejo Hospitalario Universitario A Coruña (CHUAC), Instituto de Investigación Biomédica (INIBIC), Universidad de A Coruña (UDC), A Coruña, Spain
| | - Maria López
- Deapartamento de Microbiología y Parasitología, Complejo Hospitalario Universitario A Coruña (CHUAC), Instituto de Investigación Biomédica (INIBIC), Universidad de A Coruña (UDC), A Coruña, Spain
| | - Ines Bleriot
- Deapartamento de Microbiología y Parasitología, Complejo Hospitalario Universitario A Coruña (CHUAC), Instituto de Investigación Biomédica (INIBIC), Universidad de A Coruña (UDC), A Coruña, Spain
| | - German Bou
- Deapartamento de Microbiología y Parasitología, Complejo Hospitalario Universitario A Coruña (CHUAC), Instituto de Investigación Biomédica (INIBIC), Universidad de A Coruña (UDC), A Coruña, Spain
| | - Rodolfo García-Contreras
- Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Thomas Keith Wood
- Department of Chemical Engineering, Pennsylvania State University, University Park, PA, United States
| | - Maria Tomás
- Deapartamento de Microbiología y Parasitología, Complejo Hospitalario Universitario A Coruña (CHUAC), Instituto de Investigación Biomédica (INIBIC), Universidad de A Coruña (UDC), A Coruña, Spain
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Kusmierek M, Hoßmann J, Witte R, Opitz W, Vollmer I, Volk M, Heroven AK, Wolf-Watz H, Dersch P. A bacterial secreted translocator hijacks riboregulators to control type III secretion in response to host cell contact. PLoS Pathog 2019; 15:e1007813. [PMID: 31173606 PMCID: PMC6583979 DOI: 10.1371/journal.ppat.1007813] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 06/19/2019] [Accepted: 05/02/2019] [Indexed: 02/05/2023] Open
Abstract
Numerous Gram-negative pathogens use a Type III Secretion System (T3SS) to promote virulence by injecting effector proteins into targeted host cells, which subvert host cell processes. Expression of T3SS and the effectors is triggered upon host cell contact, but the underlying mechanism is poorly understood. Here, we report a novel strategy of Yersinia pseudotuberculosis in which this pathogen uses a secreted T3SS translocator protein (YopD) to control global RNA regulators. Secretion of the YopD translocator upon host cell contact increases the ratio of post-transcriptional regulator CsrA to its antagonistic small RNAs CsrB and CsrC and reduces the degradosome components PNPase and RNase E levels. This substantially elevates the amount of the common transcriptional activator (LcrF) of T3SS/Yop effector genes and triggers the synthesis of associated virulence-relevant traits. The observed hijacking of global riboregulators allows the pathogen to coordinate virulence factor expression and also readjusts its physiological response upon host cell contact.
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Affiliation(s)
- Maria Kusmierek
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Jörn Hoßmann
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Rebekka Witte
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Wiebke Opitz
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Ines Vollmer
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
- Institute for Infectiology, University of Münster, Germany
| | - Marcel Volk
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
- Institute for Infectiology, University of Münster, Germany
| | - Ann Kathrin Heroven
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Hans Wolf-Watz
- Department of Molecular Biology, Umea University, Sweden
| | - Petra Dersch
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
- Institute for Infectiology, University of Münster, Germany
- * E-mail:
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Rifflet A, Filali S, Chenau J, Simon S, Fenaille F, Junot C, Carniel E, Becher F. Quantification of low abundance Yersinia pestis markers in dried blood spots by immuno-capture and quantitative high-resolution targeted mass spectrometry. EUROPEAN JOURNAL OF MASS SPECTROMETRY (CHICHESTER, ENGLAND) 2019; 25:268-277. [PMID: 31096787 DOI: 10.1177/1469066718795978] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Plague, caused by the bacterium Yersinia pestis, is still present in several countries worldwide. Besides, Y. pestis has been designated as Tier 1 agent, the highest rank of bioterrorism agents. In this context, reliable diagnostic methods are of great importance. Here, we have developed an original workflow based upon dried blood spot for simplified sampling of clinical specimens, and specific immuno-mass spectrometry monitoring of Y. pestis biomarkers. Targeted proteins were selectively enriched from dried blood spot extracts by multiplex immunocapture using antibody-coated magnetic beads. After accelerated on-beads digestion, proteotypic peptides were monitored by multiplex LC-MS/MS through the parallel reaction monitoring mode. The DBS-IC-MS assay was designed to quantify both F1 and LcrV antigens, although 10-fold lower sensitivity was observed with LcrV. The assay was successfully validated for F1 with a lower limit of quantification at 5 ng·mL-1 in spiked blood, corresponding to only 0.1 ng on spots. In vivo quantification of F1 in blood and organ samples was demonstrated in the mouse model of pneumonic plague. The new assay could help to simplify the laboratory confirmation of positive point of care F1 dipstick.
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Affiliation(s)
- Aline Rifflet
- 1 Service de Pharmacologie et d'Immunoanalyse (SPI), CEA, INRA, Université Paris-Saclay, Gif sur Yvette, France
| | - Sofia Filali
- 2 Yersinia Research Unit, Institut Pasteur, Paris, France
| | - Jérôme Chenau
- 1 Service de Pharmacologie et d'Immunoanalyse (SPI), CEA, INRA, Université Paris-Saclay, Gif sur Yvette, France
| | - Stéphanie Simon
- 1 Service de Pharmacologie et d'Immunoanalyse (SPI), CEA, INRA, Université Paris-Saclay, Gif sur Yvette, France
| | - François Fenaille
- 1 Service de Pharmacologie et d'Immunoanalyse (SPI), CEA, INRA, Université Paris-Saclay, Gif sur Yvette, France
| | - Christophe Junot
- 1 Service de Pharmacologie et d'Immunoanalyse (SPI), CEA, INRA, Université Paris-Saclay, Gif sur Yvette, France
| | | | - François Becher
- 1 Service de Pharmacologie et d'Immunoanalyse (SPI), CEA, INRA, Université Paris-Saclay, Gif sur Yvette, France
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Ohgita T, Saito H. Biophysical Mechanism of Protein Export by Bacterial Type III Secretion System. Chem Pharm Bull (Tokyo) 2019; 67:341-344. [PMID: 30930438 DOI: 10.1248/cpb.c18-00947] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Type III secretion system (T3SS) is a protein injection nano-machine consisting of syringe and needle-like structure spanning bacterial inner and outer membranes. Bacteria insert the tip of T3SS needle to host cell membranes, and deliver effector proteins directly into host cells via T3SS to prime the host cell environment for infection. Thus inhibition of T3SS would be a potent strategy for suppressing bacterial infection. We previously demonstrated that T3SS needle rotates by proton-motive force (PMF) with the same mechanism as two evolutionally related rotary protein motors, flagellum and ATP synthase (FASEB J., 27, 2013, Ohgita et al.). Inhibition of needle rotation resulted in suppression of effector secretion, indicating the requirement of needle rotation for effector export. Simulation analysis of protein export by the T3SS needle suggests the importance of a hydrophobic helical groove formed by the conserved aromatic residue in the needle components. Based on these results, we have proposed a novel model of protein export by the T3SS needle, in which effector proteins are exported by PMF-dependent needle rotation oppositely to the hydrophobic helical groove in the needle. Quantitative examinations of the correlation between the speeds of T3SS rotation and the amount of effector export support this model. In this review, we summarize our current understanding of T3SS, and discuss our novel model of the protein export mechanism of T3SS based on the needle rotation.
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Affiliation(s)
- Takashi Ohgita
- Department of Biophysical Chemistry, Kyoto Pharmaceutical University
| | - Hiroyuki Saito
- Department of Biophysical Chemistry, Kyoto Pharmaceutical University
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Strayer-Scherer A, Jones JB, Paret ML. Recombinase Polymerase Amplification Assay for Field Detection of Tomato Bacterial Spot Pathogens. PHYTOPATHOLOGY 2019; 109:690-700. [PMID: 30211633 DOI: 10.1094/phyto-03-18-0101-r] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Bacterial spot of tomato is caused by Xanthomonas gardneri, X. euvesicatoria, X. perforans, and X. vesicatoria. Current diagnostic methods for the pathogens are not in-field assays. Recombinase polymerase amplification (RPA) is ideal for in-field detection assays, because it is an isothermal technique that is rapid and more tolerant to inhibitors compared with polymerase chain reaction. Hence, novel RPA probes and primers were designed to amplify regions of the hrcN gene of X. gardneri, X. euvesicatoria, and X. perforans. The X. gardneri RPA is specific to X. gardneri with a detection limit of 106 CFU/ml and detected X. gardneri in lesions from naturally (n = 6) or artificially (n = 18) infected plants. The X. euvesicatoria RPA detects both X. euvesicatoria and X. perforans with a detection limit of 106 CFU/ml and detected both pathogens in plants artificially infected (n = 36) or naturally infected (n = 85) with either X. euvesicatoria or X. perforans. The X. perforans RPA is specific to X. perforans with a detection limit of 107 CFU/ml. Although the X. perforans RPA assay was unable to detect X. perforans from lesions, the X. euvesicatoria RPA was successfully used in field to detect X. perforans from symptomatic field samples (n = 31). The X. perforans RPA was then used to confirm the pathogen in the laboratory. The X. euvesicatoria and X. gardneri RPA is promising for rapid, real-time in-field detection of bacterial spot and one of the first developed among plant pathogenic bacteria.
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Affiliation(s)
- A Strayer-Scherer
- 1 Department of Plant Pathology, University of Florida, Gainesville 32611; and
| | - J B Jones
- 1 Department of Plant Pathology, University of Florida, Gainesville 32611; and
| | - M L Paret
- 2 Department of Plant Pathology, North Florida Research and Education Center, University of Florida, Quincy 32351
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125
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Lombardi C, Tolchard J, Bouillot S, Signor L, Gebus C, Liebl D, Fenel D, Teulon JM, Brock J, Habenstein B, Pellequer JL, Faudry E, Loquet A, Attrée I, Dessen A, Job V. Structural and Functional Characterization of the Type Three Secretion System (T3SS) Needle of Pseudomonas aeruginosa. Front Microbiol 2019; 10:573. [PMID: 31001211 PMCID: PMC6455054 DOI: 10.3389/fmicb.2019.00573] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Accepted: 03/05/2019] [Indexed: 01/23/2023] Open
Abstract
The type three secretion system (T3SS) is a macromolecular protein nano-syringe used by different bacterial pathogens to inject effectors into host cells. The extracellular part of the syringe is a needle-like filament formed by the polymerization of a 9-kDa protein whose structure and proper localization on the bacterial surface are key determinants for efficient toxin injection. Here, we combined in vivo, in vitro, and in silico approaches to characterize the Pseudomonas aeruginosa T3SS needle and its major component PscF. Using a combination of mutagenesis, phenotypic analyses, immunofluorescence, proteolysis, mass spectrometry, atomic force microscopy, electron microscopy, and molecular modeling, we propose a model of the P. aeruginosa needle that exposes the N-terminal region of each PscF monomer toward the outside of the filament, while the core of the fiber is formed by the C-terminal helix. Among mutations introduced into the needle protein PscF, D76A, and P47A/Q54A caused a defect in the assembly of the needle on the bacterial surface, although the double mutant was still cytotoxic on macrophages in a T3SS-dependent manner and formed filamentous structures in vitro. These results suggest that the T3SS needle of P. aeruginosa displays an architecture that is similar to that of other bacterial needles studied to date and highlight the fact that small, targeted perturbations in needle assembly can inhibit T3SS function. Therefore, the T3SS needle represents an excellent drug target for small molecules acting as virulence blockers that could disrupt pathogenesis of a broad range of bacteria.
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Affiliation(s)
- Charlotte Lombardi
- Univ. Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale (IBS), Grenoble, France
| | - James Tolchard
- Institute of Chemistry and Biology of Membranes and Nanoobjects, Institut Européen de Chimie et Biologie (CBMN), UMR5248 CNRS, University of Bordeaux, Pessac, France
| | - Stephanie Bouillot
- Univ. Grenoble Alpes, Bacterial Pathogenesis and Cellular Responses Group, U1036 INSERM, ERL5261 CNRS, CEA, Grenoble, France
| | - Luca Signor
- Univ. Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale (IBS), Grenoble, France
| | - Caroline Gebus
- Univ. Grenoble Alpes, Bacterial Pathogenesis and Cellular Responses Group, U1036 INSERM, ERL5261 CNRS, CEA, Grenoble, France
| | - David Liebl
- Univ. Grenoble Alpes, Bacterial Pathogenesis and Cellular Responses Group, U1036 INSERM, ERL5261 CNRS, CEA, Grenoble, France
| | - Daphna Fenel
- Univ. Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale (IBS), Grenoble, France
| | - Jean-Marie Teulon
- Univ. Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale (IBS), Grenoble, France
| | - Juliane Brock
- Univ. Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale (IBS), Grenoble, France
| | - Birgit Habenstein
- Institute of Chemistry and Biology of Membranes and Nanoobjects, Institut Européen de Chimie et Biologie (CBMN), UMR5248 CNRS, University of Bordeaux, Pessac, France
| | - Jean-Luc Pellequer
- Univ. Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale (IBS), Grenoble, France
| | - Eric Faudry
- Univ. Grenoble Alpes, Bacterial Pathogenesis and Cellular Responses Group, U1036 INSERM, ERL5261 CNRS, CEA, Grenoble, France
| | - Antoine Loquet
- Institute of Chemistry and Biology of Membranes and Nanoobjects, Institut Européen de Chimie et Biologie (CBMN), UMR5248 CNRS, University of Bordeaux, Pessac, France
| | - Ina Attrée
- Univ. Grenoble Alpes, Bacterial Pathogenesis and Cellular Responses Group, U1036 INSERM, ERL5261 CNRS, CEA, Grenoble, France
| | - Andréa Dessen
- Univ. Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale (IBS), Grenoble, France.,Brazilian Biosciences National Laboratory (LNBio), Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Campinas, Brazil
| | - Viviana Job
- Univ. Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale (IBS), Grenoble, France.,Univ. Grenoble Alpes, Bacterial Pathogenesis and Cellular Responses Group, U1036 INSERM, ERL5261 CNRS, CEA, Grenoble, France
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126
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Mir DA, Balamurugan K. A proteomic analysis of Caenorhabditis elegans mitochondria during bacterial infection. Mitochondrion 2019; 48:37-50. [PMID: 30926536 DOI: 10.1016/j.mito.2019.03.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 01/13/2019] [Accepted: 03/12/2019] [Indexed: 12/11/2022]
Abstract
Mitochondria are involved in a variety of cellular metabolic processes and their functions are regulated by intrinsic and extrinsic stimuli. Recent studies have revealed functional diversity and importance of mitochondria in many cellular processes, including the innate immune response. This study evaluated the specific response and proteomic changes in host Caenorhabditis elegans mitochondria during Pseudomonas aeruginosa PAO1 infection. We performed an inclusive approach to determine the C. elegans mitochondria proteome. The protein fractions of mitochondria were analysed by tandem LC-MS/MS, 129 differentially regulated proteins were identified, indicating an involvement of various mitochondrial processes. The several known components of the oxidative phosphorylation (OXPHOS) machinery, the tricarboxylic acid (TCA) cycle, mitochondrial unfolded protein response (UPRmt) and stable mitochondria-encoded proteins were found to be differentially expressed. Our results in-depth provide new horizons for mitochondria-associated protein functions and the classification of mitochondrial diseases during host-pathogen interaction.
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Affiliation(s)
- Dilawar Ahmad Mir
- Department of Biotechnology, Alagappa University, Karaikudi, Tamil Nadu 630003, India
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127
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Gorelik O, Levy N, Shaulov L, Yegodayev K, Meijler MM, Sal-Man N. Vibrio cholerae autoinducer-1 enhances the virulence of enteropathogenic Escherichia coli. Sci Rep 2019; 9:4122. [PMID: 30858454 PMCID: PMC6411865 DOI: 10.1038/s41598-019-40859-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 02/25/2019] [Indexed: 12/19/2022] Open
Abstract
Diarrhoea is the second leading cause of death in children under the age of five. The bacterial species, Vibrio cholerae and enteropathogenic Escherichia coli (EPEC), are among the main pathogens that cause diarrhoeal diseases, which are associated with high mortality rates. These two pathogens have a common infection site-the small intestine. While it is known that both pathogens utilize quorum sensing (QS) to determine their population size, it is not yet clear whether potential bacterial competitors can also use this information. In this study, we examined the ability of EPEC to determine V. cholerae population sizes and to modulate its own virulence mechanisms accordingly. We found that EPEC virulence is enhanced in response to elevated concentrations of cholera autoinducer-1 (CAI-1), even though neither a CAI-1 synthase nor CAI-1 receptors have been reported in E. coli. This CAI-1 sensing and virulence upregulation response may facilitate the ability of EPEC to coordinate successful colonization of a host co-infected with V. cholerae. To the best of our knowledge, this is the first observed example of 'eavesdropping' between two bacterial pathogens that is based on interspecies sensing of a QS molecule.
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Affiliation(s)
- Orna Gorelik
- The Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Niva Levy
- The Department of Chemistry and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Lihi Shaulov
- The Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Ksenia Yegodayev
- The Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Michael M Meijler
- The Department of Chemistry and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Neta Sal-Man
- The Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel.
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128
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Tao H, Fan SS, Jiang S, Xiang X, Yan X, Zhang LH, Cui ZN. Small Molecule Inhibitors Specifically Targeting the Type III Secretion System of Xanthomonas oryzae on Rice. Int J Mol Sci 2019; 20:E971. [PMID: 30813400 PMCID: PMC6412923 DOI: 10.3390/ijms20040971] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 01/27/2019] [Accepted: 02/03/2019] [Indexed: 11/24/2022] Open
Abstract
The initiative strategy for the development of novel anti-microbial agents usually uses the virulence factors of bacteria as a target, without affecting their growth and survival. The type III secretion system (T3SS), one of the essential virulence factors in most Gram-negative pathogenic bacteria because of its highly conserved construct, has been regarded as an effective target that developed new anti-microbial drugs. Xanthomonas oryzae pv. oryzae (Xoo) causes leaf blight diseases and is one of the most important pathogens on rice. To find potential anti-virulence agents against this pathogen, a number of natural compounds were screened for their effects on the T3SS of Xoo. Three of 34 compounds significantly inhibited the promoter activity of the harpin gene, hpa1, and were further checked for their impact on bacterial growth and on the hypersensitive response (HR) caused by Xoo on non-host tobacco plants. The results indicated that treatment of Xoo with CZ-1, CZ-4 and CZ-9 resulted in an obviously attenuated HR without affecting bacterial growth and survival. Moreover, quantitative reverse transcription-polymerase chain reaction (qRT-PCR) analysis showed that the expression of the Xoo T3SS was suppressed by treatment with the three inhibitors. The mRNA levels of representative genes in the hypersensitive response and pathogenicity (hrp) cluster, as well as the regulatory genes hrpG and hrpX, were reduced. Finally, the in vivo test demonstrated that the compounds could reduce the disease symptoms of Xoo on the rice cultivar (Oryza sativa) IR24.
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Affiliation(s)
- Hui Tao
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Integrative Microbiology Research Centre, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou 510642, China.
| | - Su-Su Fan
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
| | - Shan Jiang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Integrative Microbiology Research Centre, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou 510642, China.
| | - Xuwen Xiang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Integrative Microbiology Research Centre, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou 510642, China.
| | - Xiaojing Yan
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
| | - Lian-Hui Zhang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Integrative Microbiology Research Centre, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou 510642, China.
| | - Zi-Ning Cui
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Integrative Microbiology Research Centre, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou 510642, China.
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129
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Characterization of Pyrin Dephosphorylation and Inflammasome Activation in Macrophages as Triggered by the Yersinia Effectors YopE and YopT. Infect Immun 2019; 87:IAI.00822-18. [PMID: 30602502 DOI: 10.1128/iai.00822-18] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 12/14/2018] [Indexed: 01/24/2023] Open
Abstract
Pathogenic Yersinia species deliver Yop effector proteins through a type III secretion system into host cells. Among these effectors, YopE and YopT are Rho-modifying toxins, which function to modulate host cell physiology and evade immune responses. YopE is a GTPase-activating protein (GAP) while YopT is a protease, and they inhibit RhoA by different modes of action. Modifications to RhoA are sensed by pyrin, which, once activated, assembles a caspase-1 inflammasome, which generates cytokines such as interleukin-1β (IL-1β) and cell death by pyroptosis. In Yersinia-infected macrophages, YopE or YopT triggers inflammasome assembly only in the absence of another effector, YopM, which counteracts pyrin by keeping it inactive. The glucosyltransferase TcdB from Clostridium difficile, a well-studied RhoA-inactivating toxin, triggers activation of murine pyrin by dephosphorylation of Ser205 and Ser241. To determine if YopE or YopT triggers pyrin dephosphorylation, we infected lipopolysaccharide (LPS)-primed murine macrophages with ΔyopM Yersinia pseudotuberculosis strains expressing wild-type (wt) or YopE mutant variants or YopT. By immunoblotting pyrin after infection, we observed that wt YopE triggered dephosphorylation of Ser205 and inflammasome activation. Pyrin dephosphorylation was reduced if a YopE variant had a defect in stability or RhoA specificity but not membrane localization. We also observed that wt YopT triggered pyrin dephosphorylation but more slowly than YopE, suggesting that YopE is dominant in this process. Our findings provide evidence that RhoA-modifying toxins trigger activation of pyrin by a conserved dephosphorylation mechanism. In addition, by characterization of YopE and YopT, we show that different features of effectors, such as RhoA specificity, affect the efficiency of pyrin dephosphorylation.
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130
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Song J, Hou HM, Wu HY, Li KX, Wang Y, Zhou QQ, Zhang GL. Transcriptomic Analysis of Vibrio parahaemolyticus Reveals Different Virulence Gene Expression in Response to Benzyl Isothiocyanate. Molecules 2019; 24:molecules24040761. [PMID: 30791538 PMCID: PMC6412943 DOI: 10.3390/molecules24040761] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 02/13/2019] [Accepted: 02/19/2019] [Indexed: 01/01/2023] Open
Abstract
Vibrio parahaemolyticus isolated from seafood is a pathogenic microorganism that leads to several acute diseases that are harmful to our health and is frequently transmitted by food. Therefore, there is an urgent need for the control and suppression of this pathogen. In this paper, transcriptional analysis was used to determine the effect of treatment with benzyl isothiocyanate (BITC) extracted from cruciferous vegetables on V. parahaemolyticus and to elucidate the molecular mechanisms underlying the response to BITC. Treatment with BITC resulted in 332 differentially expressed genes, among which 137 genes were downregulated, while 195 genes were upregulated. Moreover, six differentially expressed genes (DEGs) in RNA sequencing studies were further verified by quantitative real-time polymerase chain reaction (qRT-PCR). Genes found to regulate virulence encoded an l-threonine 3-dehydrogenase, a GGDEF family protein, the outer membrane protein OmpV, a flagellum-specific adenosine triphosphate synthase, TolQ protein and VirK protein. Hence, the results allow us to speculate that BITC may be an effective control strategy for inhibiting microorganisms growing in foods.
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Affiliation(s)
- Jie Song
- School of Food Science and Technology, Dalian Polytechnic University, Dalian 116034, China.
| | - Hong-Man Hou
- School of Food Science and Technology, Dalian Polytechnic University, Dalian 116034, China.
| | - Hong-Yan Wu
- Graduate School of Environmental and Life Science, Okayama University, Okayama 700-8530, Japan.
| | - Ke-Xin Li
- School of Food Science and Technology, Dalian Polytechnic University, Dalian 116034, China.
| | - Yan Wang
- School of Food Science and Technology, Dalian Polytechnic University, Dalian 116034, China.
| | - Qian-Qian Zhou
- School of Food Science and Technology, Dalian Polytechnic University, Dalian 116034, China.
| | - Gong-Liang Zhang
- School of Food Science and Technology, Dalian Polytechnic University, Dalian 116034, China.
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131
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Identifying Pseudomonas syringae Type III Secreted Effector Function via a Yeast Genomic Screen. G3-GENES GENOMES GENETICS 2019; 9:535-547. [PMID: 30573466 PMCID: PMC6385969 DOI: 10.1534/g3.118.200877] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Gram-negative bacterial pathogens inject type III secreted effectors (T3SEs) directly into host cells to promote pathogen fitness by manipulating host cellular processes. Despite their crucial role in promoting virulence, relatively few T3SEs have well-characterized enzymatic activities or host targets. This is in part due to functional redundancy within pathogen T3SE repertoires as well as the promiscuity of individual T3SEs that can have multiple host targets. To overcome these challenges, we generated and characterized a collection of yeast strains stably expressing 75 T3SE constructs from the plant pathogen Pseudomonas syringae. This collection is devised to facilitate heterologous genetic screens in yeast, a non-host organism, to identify T3SEs that target conserved eukaryotic processes. Among 75 T3SEs tested, we identified 16 that inhibited yeast growth on rich media and eight that inhibited growth on stress-inducing media. We utilized Pathogenic Genetic Array (PGA) screens to identify potential host targets of P. syringae T3SEs. We focused on the acetyltransferase, HopZ1a, which interacts with plant tubulin and alters microtubule networks. To uncover putative HopZ1a host targets, we identified yeast genes with genetic interaction profiles most similar (i.e., congruent) to the PGA profile of HopZ1a and performed a functional enrichment analysis of these HopZ1a-congruent genes. We compared the congruence analyses above to previously described HopZ physical interaction datasets and identified kinesins as potential HopZ1a targets. Finally, we demonstrated that HopZ1a can target kinesins by acetylating the plant kinesins HINKEL and MKRP1, illustrating the utility of our T3SE-expressing yeast library to characterize T3SE functions.
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132
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Sood U, Hira P, Kumar R, Bajaj A, Rao DLN, Lal R, Shakarad M. Comparative Genomic Analyses Reveal Core-Genome-Wide Genes Under Positive Selection and Major Regulatory Hubs in Outlier Strains of Pseudomonas aeruginosa. Front Microbiol 2019; 10:53. [PMID: 30787911 PMCID: PMC6372532 DOI: 10.3389/fmicb.2019.00053] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Accepted: 01/14/2019] [Indexed: 12/11/2022] Open
Abstract
Genomic information for outlier strains of Pseudomonas aeruginosa is exiguous when compared with classical strains. We sequenced and constructed the complete genome of an environmental strain CR1 of P. aeruginosa and performed the comparative genomic analysis. It clustered with the outlier group, hence we scaled up the analyses to understand the differences in environmental and clinical outlier strains. We identified eight new regions of genomic plasticity and a plasmid pCR1 with a VirB/D4 complex followed by trimeric auto-transporter that can induce virulence phenotype in the genome of strain CR1. Virulence genotype analysis revealed that strain CR1 lacked hemolytic phospholipase C and D, three genes for LPS biosynthesis and had reduced antibiotic resistance genes when compared with clinical strains. Genes belonging to proteases, bacterial exporters and DNA stabilization were found to be under strong positive selection, thus facilitating pathogenicity and survival of the outliers. The outliers had the complete operon for the production of vibrioferrin, a siderophore present in plant growth promoting bacteria. The competence to acquire multidrug resistance and new virulence factors makes these strains a potential threat. However, we identified major regulatory hubs that can be used as drug targets against both the classical and outlier groups.
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Affiliation(s)
- Utkarsh Sood
- Department of Zoology, University of Delhi, New Delhi, India
- PhiXGen Private Limited, Gurugram, India
| | - Princy Hira
- Department of Zoology, University of Delhi, New Delhi, India
| | - Roshan Kumar
- Department of Zoology, University of Delhi, New Delhi, India
- PhiXGen Private Limited, Gurugram, India
- Department of Veterinary & Biomedical Sciences, South Dakota State University, Brookings, SD, United States
| | - Abhay Bajaj
- Department of Zoology, University of Delhi, New Delhi, India
- National Centre for Microbial Resource, National Centre for Cell Science, Pune, India
| | | | - Rup Lal
- Department of Zoology, University of Delhi, New Delhi, India
- PhiXGen Private Limited, Gurugram, India
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133
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Diepold A. Assembly and Post-assembly Turnover and Dynamics in the Type III Secretion System. Curr Top Microbiol Immunol 2019; 427:35-66. [PMID: 31218503 DOI: 10.1007/82_2019_164] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The type III secretion system (T3SS) is one of the largest transmembrane complexes in bacteria, comprising several intricately linked and embedded substructures. The assembly of this nanomachine is a hierarchical process which is regulated and controlled by internal and external cues at several critical points. Recently, it has become obvious that the assembly of the T3SS is not a unidirectional and deterministic process, but that parts of the T3SS constantly exchange or rearrange. This article aims to give an overview on the assembly and post-assembly dynamics of the T3SS, with a focus on emerging general concepts and adaptations of the general assembly pathway.
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Affiliation(s)
- Andreas Diepold
- Department of Ecophysiology, Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Straße 10, 35043, Marburg, Germany.
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134
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Export Mechanisms and Energy Transduction in Type-III Secretion Machines. Curr Top Microbiol Immunol 2019; 427:143-159. [PMID: 31218506 DOI: 10.1007/82_2019_166] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The remarkably complex architecture and organization of bacterial nanomachines originally raised the enigma to how they are assembled in a coordinated manner. Over the years, the assembly processes of the flagellum and evolutionary-related injectisome complexes have been deciphered and were shown to rely on a conserved protein secretion machine: the type-III secretion system. In this book chapter, we demonstrate how individually evolved mechanisms cooperate in highly versatile and robust secretion machinery to export and assemble the building blocks of those nanomachines.
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135
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Halder PK, Roy C, Datta S. Structural and functional characterization of type three secretion system ATPase PscN and its regulator PscL from Pseudomonas aeruginosa. Proteins 2018; 87:276-288. [PMID: 30561072 DOI: 10.1002/prot.25648] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 10/29/2018] [Accepted: 12/12/2018] [Indexed: 12/16/2022]
Affiliation(s)
- Pranab Kumar Halder
- Structural Biology and Bioinformatics Division; Council of Scientific and Industrial Research-Indian Institute of Chemical Biology; Kolkata West Bengal India
| | - Chittran Roy
- Structural Biology and Bioinformatics Division; Council of Scientific and Industrial Research-Indian Institute of Chemical Biology; Kolkata West Bengal India
| | - Saumen Datta
- Structural Biology and Bioinformatics Division; Council of Scientific and Industrial Research-Indian Institute of Chemical Biology; Kolkata West Bengal India
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136
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Nauth T, Huschka F, Schweizer M, Bosse JB, Diepold A, Failla AV, Steffen A, Stradal TEB, Wolters M, Aepfelbacher M. Visualization of translocons in Yersinia type III protein secretion machines during host cell infection. PLoS Pathog 2018; 14:e1007527. [PMID: 30586431 PMCID: PMC6324820 DOI: 10.1371/journal.ppat.1007527] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 01/08/2019] [Accepted: 12/14/2018] [Indexed: 12/13/2022] Open
Abstract
Type III secretion systems (T3SSs) are essential virulence factors of numerous bacterial pathogens. Upon host cell contact the T3SS machinery—also named injectisome—assembles a pore complex/translocon within host cell membranes that serves as an entry gate for the bacterial effectors. Whether and how translocons are physically connected to injectisome needles, whether their phenotype is related to the level of effector translocation and which target cell factors trigger their formation have remained unclear. We employed the superresolution fluorescence microscopy techniques Stimulated Emission Depletion (STED) and Structured Illumination Microscopy (SIM) as well as immunogold electron microscopy to visualize Y. enterocolitica translocons during infection of different target cell types. Thereby we were able to resolve translocon and needle complex proteins within the same injectisomes and demonstrate that these fully assembled injectisomes are generated in a prevacuole, a PI(4,5)P2 enriched host cell compartment inaccessible to large extracellular proteins like antibodies. Furthermore, the operable translocons were produced by the yersiniae to a much larger degree in macrophages (up to 25% of bacteria) than in HeLa cells (2% of bacteria). However, when the Rho GTPase Rac1 was activated in the HeLa cells, uptake of the yersiniae into the prevacuole, translocon formation and effector translocation were strongly enhanced reaching the same levels as in macrophages. Our findings indicate that operable T3SS translocons can be visualized as part of fully assembled injectisomes with superresolution fluorescence microscopy techniques. By using this technology, we provide novel information about the spatiotemporal organization of T3SS translocons and their regulation by host cell factors. Many human, animal and plant pathogenic bacteria employ a molecular machine termed injectisome to inject their toxins into host cells. Because injectisomes are crucial for these bacteria’s infectious potential they have been considered as targets for antiinfective drugs. Injectisomes are highly similar between the different bacterial pathogens and most of their overall structure is well established at the molecular level. However, only little information is available for a central part of the injectisome named the translocon. This pore-like assembly integrates into host cell membranes and thereby serves as an entry gate for the bacterial toxins. We used state of the art fluorescence microscopy to watch translocons of the diarrheagenic pathogen Yersinia enterocolitica during infection of human host cells. Thereby we could for the first time—with fluorescence microscopy—visualize translocons connected to other parts of the injectisome. Furthermore, because translocons mark functional injectisomes we could obtain evidence that injectisomes only become active for secretion of translocators when the bacteria are almost completely enclosed by host cells. These findings provide a novel view on the organization and regulation of bacterial translocons and may thus open up new strategies to block the function of infectious bacteria.
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Affiliation(s)
- Theresa Nauth
- Institute of Medical Microbiology, Virology and Hygiene, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
| | - Franziska Huschka
- Institute of Medical Microbiology, Virology and Hygiene, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
| | - Michaela Schweizer
- Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
| | - Jens B. Bosse
- Heinrich-Pette-Institute (HPI), Leibniz-Institute for Experimental Virology, Hamburg, Germany
| | - Andreas Diepold
- Department of Ecophysiology, Max-Planck-Institute for Terrestrial Microbiology, Marburg, Germany
| | - Antonio Virgilio Failla
- UKE Microscopy Imaging Facility, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
| | - Anika Steffen
- Department of Cell Biology, Helmholtz Centre for Infection Research (HZI), Braunschweig, Germany
| | - Theresia E. B. Stradal
- Department of Cell Biology, Helmholtz Centre for Infection Research (HZI), Braunschweig, Germany
| | - Manuel Wolters
- Institute of Medical Microbiology, Virology and Hygiene, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
| | - Martin Aepfelbacher
- Institute of Medical Microbiology, Virology and Hygiene, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
- * E-mail:
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137
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Bao X, Yu X, Xia C, Yang N, Yang S, Zhao Y. Synthesis and Antichlamydial Activity of Novel Phenazines. LETT DRUG DES DISCOV 2018. [DOI: 10.2174/1570180815666180518112952] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Abstract: Background: Chlamydiae are widespread Gram-negative bacteria that cause a number of human diseases. Chlamydia trachomatis is the most prevalent sexually transmitted bacterial pathogen. </P><P> Methods: Fourteen novel phenazine derivatives were efficiently synthesized via Buchwald-Hartwig cross coupling reaction and Suzuki reaction from 4-bromo-1-methoxyphenazine. All the derivatives displayed antichlamydial activity with IC50 values from 1.01-19.77 µM against Chlamydia trachomatis D and L2 for inhibiting progeny formation.Results:C-4 morpholinyl 8a and C-4 phenyl phenazine 9c exhibited stronger antichlamydial activity with no apparent cytotoxicity. Both phenazine derivatives inhibited chlamydial inclusions formation and growth in a dose-dependent manner. They inhibited Chlamydia infection by reducing elementary body infectivity and disturbing Chlamydia growth at the mid-stage of the chlamydial developmental cycle.Conclusion:Our findings suggest C-4 aryl and C-4 amino phenazine derivatives as promising lead molecules for antichlamydials development.
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Affiliation(s)
- Xiaofeng Bao
- School of Pharmacy, Nantong University, Nantong 226001, China
| | - Xiaowei Yu
- School of Pharmacy, Nantong University, Nantong 226001, China
| | - Chao Xia
- School of Pharmacy, Nantong University, Nantong 226001, China
| | - Ningjing Yang
- School of Pharmacy, Nantong University, Nantong 226001, China
| | - Shengju Yang
- Department of Dermatology and Venereology, Affiliated Hospital of Nantong University, Nantong, China
| | - Yu Zhao
- School of Pharmacy, Nantong University, Nantong 226001, China
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138
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Li P, Xin W, Xia S, Luo Y, Chen Z, Jin D, Gao S, Yang H, Ji B, Wang H, Yan Y, Kang L, Wang J. MALDI-TOF mass spectrometry-based serotyping of V. parahaemolyticus isolated from the Zhejiang province of China. BMC Microbiol 2018; 18:185. [PMID: 30424744 PMCID: PMC6234682 DOI: 10.1186/s12866-018-1328-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Accepted: 10/29/2018] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND Vibrio parahaemolyticus is as an important food-borne pathogen circulating in China. Since 1996, the core serotype has become O3:K6, which has specific genetic markers. This serotype causes the majority of outbreaks worldwide. Until now, nearly 21 serotypes were considered as serovariants of O3:K6. Among these, O4:K68, O1:K25 and O1:KUT have caused pandemic outbreaks. O4:K8, a serovariant of O3:K6, has become the second most dominant serotype circulating in China after O3:K6. In this study, we report the use of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) to analyze and characterize 146 V. parahaemolyticus isolates belonging to 23 serotypes. RESULTS Upon mass spectral analysis, isolates belonging to O4:K8 formed a distinct group among the five main pandemic groups (O3:K6, O4:K8, O4:K68, O1:K25 and O1:KUT). Two major protein peaks (m/z 4383 and 4397) were significantly different between serotype O4:K8 and the four other pandemic strains. Both of these peaks were present in 32 out of 36 O4:K8 isolates, but were absent in 105 out of 110 non-O4:K8 isolates. These peaks were also absent in all 74 pandemic serotypes (O3:K6, O4:K68, O1:K25 and O1:KUT). CONCLUSION Our results highlight the threat of O4:K8 forming a distinct group, which differs significantly from pandemic serotypes on the proteomic level. The use of MALDI-TOF MS has not been reported before in a study of this nature. Mass spectrum peaks at m/z 4383 and 4397 may be specific for O4:K8. However, we cannot conclude that MALDI-TOF MS can be used to serotype V. parahaemolyticus.
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Affiliation(s)
- Ping Li
- Graduate College, Anhui Medical University, No.81 Meishan Road, Hefei, 230032, Anhui, China.,Jiaxing Key Laboratory of Pathogenic Microbiology, Jiaxing Center for Disease Control and Prevention, No.486 Wenqiao Road, Nanhu district, Jiaxing, 314050, China.,State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, No.20 Dongdajie, Fengtai, Beijing, 100071, China
| | - Wenwen Xin
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, No.20 Dongdajie, Fengtai, Beijing, 100071, China
| | - Susu Xia
- Graduate College, Anhui Medical University, No.81 Meishan Road, Hefei, 230032, Anhui, China.,State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, No.20 Dongdajie, Fengtai, Beijing, 100071, China
| | - Yun Luo
- Department of Microbiology, Zhejiang Province Center for Disease Control and Prevention, No.3399 Binsheng Road, Hangzhou, 310000, China
| | - Zhongwen Chen
- Jiaxing Key Laboratory of Pathogenic Microbiology, Jiaxing Center for Disease Control and Prevention, No.486 Wenqiao Road, Nanhu district, Jiaxing, 314050, China
| | - Dazhi Jin
- Department of Microbiology, Zhejiang Province Center for Disease Control and Prevention, No.3399 Binsheng Road, Hangzhou, 310000, China
| | - Shan Gao
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, No.20 Dongdajie, Fengtai, Beijing, 100071, China
| | - Hao Yang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, No.20 Dongdajie, Fengtai, Beijing, 100071, China
| | - Bin Ji
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, No.20 Dongdajie, Fengtai, Beijing, 100071, China
| | - Henghui Wang
- Jiaxing Key Laboratory of Pathogenic Microbiology, Jiaxing Center for Disease Control and Prevention, No.486 Wenqiao Road, Nanhu district, Jiaxing, 314050, China
| | - Yong Yan
- Jiaxing Key Laboratory of Pathogenic Microbiology, Jiaxing Center for Disease Control and Prevention, No.486 Wenqiao Road, Nanhu district, Jiaxing, 314050, China
| | - Lin Kang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, No.20 Dongdajie, Fengtai, Beijing, 100071, China.
| | - Jinglin Wang
- Graduate College, Anhui Medical University, No.81 Meishan Road, Hefei, 230032, Anhui, China. .,State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, No.20 Dongdajie, Fengtai, Beijing, 100071, China.
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139
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Xue L, Tang B, Chen W, Luo J. DeepT3: deep convolutional neural networks accurately identify Gram-negative bacterial type III secreted effectors using the N-terminal sequence. Bioinformatics 2018; 35:2051-2057. [DOI: 10.1093/bioinformatics/bty931] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Revised: 10/22/2018] [Accepted: 11/07/2018] [Indexed: 11/12/2022] Open
Affiliation(s)
- Li Xue
- School of Public Health, Southwest Medical University, Luzhou, Sichuan, PR, China
| | - Bin Tang
- Basic Medical College of Southwest Medical University, Luzhou, Sichuan, PR, China
| | - Wei Chen
- Integrative Genomics Core, City of Hope National Medical Center, Duarte, CA, USA
| | - Jiesi Luo
- Key Laboratory for Aging and Regenerative Medicine, Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, Sichuan, China
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Boulant T, Boudehen YM, Filloux A, Plesiat P, Naas T, Dortet L. Higher Prevalence of PldA, a Pseudomonas aeruginosa Trans-Kingdom H2-Type VI Secretion System Effector, in Clinical Isolates Responsible for Acute Infections and in Multidrug Resistant Strains. Front Microbiol 2018; 9:2578. [PMID: 30420847 PMCID: PMC6215852 DOI: 10.3389/fmicb.2018.02578] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Accepted: 10/09/2018] [Indexed: 12/17/2022] Open
Abstract
Pseudomonas aeruginosa can manipulate eukaryotic host cells using secreted effectors delivered by the type III or the type VI Secretion Systems (T3SS and T6SS). The T3SS allows the injection of bacterial effectors (Exo toxins) into eukaryotic cell. P. aeruginosa, encodes three T6SSs, H1-, H2- and H3-T6SS. The H1-T6SS is mainly involved in delivering toxins to kill bacterial competitors. Recently, two T6SS-secreted phospholipases D, PldA (H2-T6SS) and PldB (H3-T6SS), were identified as trans-kingdom virulence effectors, triggering both killing of bacterial competitors and internalization into non-phagocytic cells. We deciphered the prevalence of T3SS and T6SS effectors encoding genes in 185 clinical isolates responsible for infections (septicaemia, pulmonary infections, urinary tract infections, and chronic infections in CF patients), 47 environmental strains, and on 33 carbapenemase-producers. We included 107 complete genomes of P. aeruginosa available in public databases. The prevalence of pldA is increased in clinical isolates responsible for severe acute infection and particularly in multi-drug resistant strains. In contrast, the pldB prevalence was high (96.8%) in all isolates. Regarding T3SS effectors, exoT and exoY are present in nearly all isolates while exoS and exoU were found to be exclusive with a higher prevalence of exoU+ strains in severe acute infections. The hypervirulent exoU+ isolates are more prone to be pldA+, suggesting a role of PldA in virulence. Finally, we observed that extremely drug resistant isolates producing an IMP-type carbapenemase were all pldA+. Our results suggest that PldA might have a role during pulmonary infections and have been co-selected in multidrug resistant strains particularly IMP-producers.
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Affiliation(s)
- Thibaud Boulant
- EA7361 Structure, Dynamic, Function and Expression of Broad Spectrum β-Lactamases, LabEx Lermit, Faculty of Medicine, Université Paris Sud - Université Paris Saclay, Le Kremlin-Bicêtre, France
| | - Yves-Marie Boudehen
- EA7361 Structure, Dynamic, Function and Expression of Broad Spectrum β-Lactamases, LabEx Lermit, Faculty of Medicine, Université Paris Sud - Université Paris Saclay, Le Kremlin-Bicêtre, France
| | - Alain Filloux
- MRC Centre for Molecular Microbiology and Infection, Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Patrick Plesiat
- Bacteriology Unit, University Hospital of Besançon, Besançon, France
| | - Thierry Naas
- EA7361 Structure, Dynamic, Function and Expression of Broad Spectrum β-Lactamases, LabEx Lermit, Faculty of Medicine, Université Paris Sud - Université Paris Saclay, Le Kremlin-Bicêtre, France.,Bacteriology-Hygiene Unit, Assistance Publique/Hôpitaux de Paris, Bicêtre Hospital, Le Kremlin-Bicêtre, France.,Associated French National Reference Center for Antibiotic Resistance: Carbapenemase-producing Enterobacteriaceae, Le Kremlin-Bicêtre, France
| | - Laurent Dortet
- EA7361 Structure, Dynamic, Function and Expression of Broad Spectrum β-Lactamases, LabEx Lermit, Faculty of Medicine, Université Paris Sud - Université Paris Saclay, Le Kremlin-Bicêtre, France.,MRC Centre for Molecular Microbiology and Infection, Department of Life Sciences, Imperial College London, London, United Kingdom.,Bacteriology-Hygiene Unit, Assistance Publique/Hôpitaux de Paris, Bicêtre Hospital, Le Kremlin-Bicêtre, France.,Associated French National Reference Center for Antibiotic Resistance: Carbapenemase-producing Enterobacteriaceae, Le Kremlin-Bicêtre, France
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141
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Versluis D, Nijsse B, Naim MA, Koehorst JJ, Wiese J, Imhoff JF, Schaap PJ, van Passel MWJ, Smidt H, Sipkema D. Comparative Genomics Highlights Symbiotic Capacities and High Metabolic Flexibility of the Marine Genus Pseudovibrio. Genome Biol Evol 2018; 10:125-142. [PMID: 29319806 PMCID: PMC5765558 DOI: 10.1093/gbe/evx271] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/18/2017] [Indexed: 12/19/2022] Open
Abstract
Pseudovibrio is a marine bacterial genus members of which are predominantly isolated from sessile marine animals, and particularly sponges. It has been hypothesized that Pseudovibrio spp. form mutualistic relationships with their hosts. Here, we studied Pseudovibrio phylogeny and genetic adaptations that may play a role in host colonization by comparative genomics of 31 Pseudovibrio strains, including 25 sponge isolates. All genomes were highly similar in terms of encoded core metabolic pathways, albeit with substantial differences in overall gene content. Based on gene composition, Pseudovibrio spp. clustered by geographic region, indicating geographic speciation. Furthermore, the fact that isolates from the Mediterranean Sea clustered by sponge species suggested host-specific adaptation or colonization. Genome analyses suggest that Pseudovibrio hongkongensis UST20140214-015BT is only distantly related to other Pseudovibrio spp., thereby challenging its status as typical Pseudovibrio member. All Pseudovibrio genomes were found to encode numerous proteins with SEL1 and tetratricopeptide repeats, which have been suggested to play a role in host colonization. For evasion of the host immune system, Pseudovibrio spp. may depend on type III, IV, and VI secretion systems that can inject effector molecules into eukaryotic cells. Furthermore, Pseudovibrio genomes carry on average seven secondary metabolite biosynthesis clusters, reinforcing the role of Pseudovibrio spp. as potential producers of novel bioactive compounds. Tropodithietic acid, bacteriocin, and terpene biosynthesis clusters were highly conserved within the genus, suggesting an essential role in survival, for example through growth inhibition of bacterial competitors. Taken together, these results support the hypothesis that Pseudovibrio spp. have mutualistic relations with sponges.
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Affiliation(s)
- Dennis Versluis
- Laboratory of Microbiology, Wageningen University & Research, The Netherlands
| | - Bart Nijsse
- Laboratory of Microbiology, Wageningen University & Research, The Netherlands.,Laboratory of Systems and Synthetic Biology, Wageningen University & Research, The Netherlands
| | - Mohd Azrul Naim
- Laboratory of Microbiology, Wageningen University & Research, The Netherlands
| | - Jasper J Koehorst
- Laboratory of Systems and Synthetic Biology, Wageningen University & Research, The Netherlands
| | - Jutta Wiese
- Marine Microbiology, GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
| | - Johannes F Imhoff
- Marine Microbiology, GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
| | - Peter J Schaap
- Laboratory of Systems and Synthetic Biology, Wageningen University & Research, The Netherlands
| | - Mark W J van Passel
- Laboratory of Microbiology, Wageningen University & Research, The Netherlands.,National Institute for Public Health and the Environment, Bilthoven, The Netherlands
| | - Hauke Smidt
- Laboratory of Microbiology, Wageningen University & Research, The Netherlands
| | - Detmer Sipkema
- Laboratory of Microbiology, Wageningen University & Research, The Netherlands
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142
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SsaV Interacts with SsaL to Control the Translocon-to-Effector Switch in the Salmonella SPI-2 Type Three Secretion System. mBio 2018; 9:mBio.01149-18. [PMID: 30279280 PMCID: PMC6168863 DOI: 10.1128/mbio.01149-18] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Salmonella Typhimurium is an intracellular pathogen that uses the SPI-2 type III secretion system to deliver virulence proteins across the vacuole membrane surrounding intracellular bacteria. This involves a tightly regulated hierarchy of protein secretion controlled by two molecular switches. We found that SPI-2-encoded proteins SsaP and SsaU are involved in the first but not the second secretion switch. We identify key amino acids of the inner membrane protein SsaV that are required to interact with the so-called gatekeeper protein SsaL and show that the dissociation of SsaV-SsaL causes the second switch, leading to delivery of effector proteins. Our results provide insights into the molecular events controlling virulence-associated type III secretion and suggest a broader model describing how the process is regulated. Nonflagellar type III secretion systems (nf T3SSs) form a cell surface needle-like structure and an associated translocon that deliver bacterial effector proteins into eukaryotic host cells. This involves a tightly regulated hierarchy of protein secretion. A switch involving SctP and SctU stops secretion of the needle protein. The gatekeeper protein SctW is required for secretion of translocon proteins and controls a second switch to start effector secretion. Salmonella enterica serovar Typhimurium encodes two T3SSs in Salmonella pathogenicity island 1 (SPI-1) and SPI-2. The acidic vacuole containing intracellular bacteria stimulates assembly of the SPI-2 T3SS and its translocon. Sensing the nearly neutral host cytosolic pH is required for effector translocation. Here, we investigated the involvement of SPI-2-encoded proteins SsaP (SctP), SsaU (SctU), SsaV (SctV), and SsaL (SctW) in regulation of secretion. We found that SsaP and SsaU are involved in the first but not the second secretion switch. A random-mutagenesis screen identified amino acids of SsaV that regulate translocon and effector secretion. Single substitutions in subdomain 4 of SsaV or InvA (SPI-1-encoded SctV) phenocopied mutations of their corresponding gatekeepers with respect to translocon and effector protein secretion and host cell interactions. SsaL interacted with SsaV in bacteria exposed to low ambient pH but not after the pH was raised to 7.2. We propose that SsaP and SsaU enable the apparatus to become competent for a secretion switch and facilitate the SsaL-SsaV interaction. This mediates secretion of translocon proteins until neutral pH is sensed, which causes their dissociation, resulting in arrest of translocon secretion and derepression of effector translocation.
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143
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Terashima H, Imada K. Novel insight into an energy transduction mechanism of the bacterial flagellar type III protein export. Biophys Physicobiol 2018; 15:173-178. [PMID: 30250776 PMCID: PMC6145943 DOI: 10.2142/biophysico.15.0_173] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Accepted: 07/20/2018] [Indexed: 01/05/2023] Open
Abstract
Type III secretion system (T3SS) is a protein translocator complex family including pathogenic injectisome or bacterial flagellum. The inejectisomal T3SS serves to deliver virulence proteins into host cell and the flagellar T3SS constructs the flagellar axial structure. Although earlier studies have provided many findings on the molecular mechanism of the Type III protein export, they were not sufficient to reveal energy transduction mechanism due to difficulties in controlling measurement conditions in vivo. Recently, we developed an in vitro flagellar Type III protein transport assay system using inverted membrane vesicles (IMVs), and analyzed protein export by using the in vitro method. We reproduced protein export of the flagellar T3SS, hook assembly and substrate specificity switch in IMV to a similar extent to what is seen in living cell. Furthermore, we demonstrated that ATP-hydrolysis energy can drive protein transport even in the absence of proton-motive force (PMF). In this mini-review, we will summarize our new in vitro Type III transport assay method and our findings on the molecular mechanism of Type III protein export.
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Affiliation(s)
- Hiroyuki Terashima
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Aichi 464-8602, Japan
| | - Katsumi Imada
- Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
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144
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Molecular basis for CesT recognition of type III secretion effectors in enteropathogenic Escherichia coli. PLoS Pathog 2018; 14:e1007224. [PMID: 30118511 PMCID: PMC6114900 DOI: 10.1371/journal.ppat.1007224] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 08/29/2018] [Accepted: 07/17/2018] [Indexed: 11/19/2022] Open
Abstract
Enteropathogenic Escherichia coli (EPEC) use a needle-like injection apparatus known as the type III secretion system (T3SS) to deliver protein effectors into host cells. Effector translocation is highly stratified in EPEC with the translocated intimin receptor (Tir) being the first effector delivered into the host. CesT is a multi-cargo chaperone that is required for the secretion of Tir and at least 9 other effectors. However, the structural and mechanistic basis for differential effector recognition by CesT remains unclear. Here, we delineated the minimal CesT-binding region on Tir to residues 35–77 and determined the 2.74 Å structure of CesT bound to an N-terminal fragment of Tir. Our structure revealed that the CesT-binding region in the N-terminus of Tir contains an additional conserved sequence, distinct from the known chaperone-binding β-motif, that we termed the CesT-extension motif because it extends the β-sheet core of CesT. This motif is also present in the C-terminus of Tir that we confirmed to be a unique second CesT-binding region. Point mutations that disrupt CesT-binding to the N- or C-terminus of Tir revealed that the newly identified carboxy-terminal CesT-binding region was required for efficient Tir translocation into HeLa cells and pedestal formation. Furthermore, the CesT-extension motif was identified in the N-terminal region of NleH1, NleH2, and EspZ, and mutations that disrupt this motif reduced translocation of these effectors, and in some cases, overall effector stability, thus validating the universality of this CesT-extension motif. The presence of two CesT-binding regions in Tir, along with the presence of the CesT-extension motif in other highly translocated effectors, may contribute to differential cargo recognition by CesT. Enteropathogenic Escherichia coli injects effector proteins into host cells using a type III secretion system (T3SS). The translocated intimin receptor (Tir) is the first effector delivered into host cells and imparts efficient secretion of other effectors. However, the mechanism for Tir-dependent modulation of the T3SS is poorly understood. We provide evidence that the multi-cargo chaperone CesT binds to two regions in Tir at the N- and C-terminus through a specific recognition motif, and show that CesT binding to the Tir C-terminus is important for host translocation. Furthermore we show that the CesT-specific motif is conserved in a subset of highly translocated effectors. This study highlights the multi-faceted role that T3SS chaperones play in effector secretion dynamics.
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145
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Ray S, Das S, Panda PK, Suar M. Identification of a new alanine racemase in Salmonella Enteritidis and its contribution to pathogenesis. Gut Pathog 2018; 10:30. [PMID: 30008809 PMCID: PMC6040060 DOI: 10.1186/s13099-018-0257-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Accepted: 07/03/2018] [Indexed: 01/28/2023] Open
Abstract
BACKGROUND Non-typhoidal Salmonella (NTS) infections caused primarily by S. Enteritidis and S. Typhimurium particularly in immunocompromised hosts have accounted for a large percentage of fatalities in developed nations. Antibiotics have revolutionized the cure of enteric infections but have also led to the rapid emergence of pathogen resistance. New powerful therapeutics involving metabolic enzymes are expected to be potential targets for combating microbial infections and ensuring effective health management. Therefore, the need for new antimicrobials to fight such health emergencies is paramount. Enteric bacteria successfully evade the gut and colonize their hosts through specialized virulence strategies. An important player, alanine racemase is a key enzyme facilitating bacterial survival. RESULTS This study aims at understanding the contribution of alanine racemase genes alr, dadX and SEN3897 to Salmonella survival in vitro and in vivo. We have shown SEN3897 to function as a unique alanine racemase in S. Enteritidis which displayed essential alanine racemase activity. Interestingly, the sole presence of this gene in alr dadX double mutant showed a strict dependence on d-alanine supplementation both in vitro and in vivo. However, Alr complementation in d-alanine auxotrophic strain restored the alanine racemase deficiency. The Km and Vmax of SEN3897 was 89.15 ± 10.2 mM, 400 ± 25.6 µmol/(min mg) for l-alanine and 35 ± 6 mM, 132.5 ± 11.3 µmol/(min mg) for d-alanine, respectively. In vitro assays for invasion and survival as well as in vivo virulence assays involving SEN3897 mutant showed attenuated phenotypes. Further, this study also showed attenuation of d-alanine auxotrophic strain in vivo for the development of potential targets against Salmonella that can be investigated further. CONCLUSION This study identified a third alanine racemase gene unique in S. Enteritidis which had a potential effect on survival and pathogenesis in vitro and in vivo. Our results also confirmed that SEN3897 by itself wasn't able to rescue d-alanine auxotrophy in S. Enteritidis which further contributed to its virulence properties.
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Affiliation(s)
- Shilpa Ray
- School of Biotechnology, KIIT University, Bhubaneswar, Odisha India
| | - Susmita Das
- School of Biotechnology, KIIT University, Bhubaneswar, Odisha India
| | | | - Mrutyunjay Suar
- School of Biotechnology, KIIT University, Bhubaneswar, Odisha India
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146
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In Vitro
Reconstitution of Functional Type III Protein Export and Insights into Flagellar Assembly. mBio 2018; 9:mBio.00988-18. [PMID: 29946050 PMCID: PMC6020293 DOI: 10.1128/mbio.00988-18] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
ABSTRACT
The type III secretion system (T3SS) forms the functional core of injectisomes, protein transporters that allow bacteria to deliver virulence factors into their hosts for infection, and flagella, which are critical for many pathogens to reach the site of infection. In spite of intensive genetic and biochemical studies, the T3SS protein export mechanism remains unclear due to the difficulty of accurate measurement of protein export
in vivo
. Here, we developed an
in vitro
flagellar T3S protein transport assay system using an inverted cytoplasmic membrane vesicle (IMV) for accurate and controlled measurements of flagellar protein export. We show that the flagellar T3SS in the IMV fully retains export activity. The flagellar hook was constructed inside the lumen of the IMV by adding purified component proteins externally to the IMV solution. We reproduced the hook length control and export specificity switch in the IMV consistent with that seen in the native cell. Previous
in vivo
analyses showed that flagellar protein export is driven by proton motive force (PMF) and facilitated by ATP hydrolysis by FliI, a T3SS-specific ATPase. Our
in vitro
assay recapitulated these previous
in vivo
observations but furthermore clearly demonstrated that even ATP hydrolysis by FliI alone can drive flagellar protein export. Moreover, this assay showed that addition of the FliH
2
/FliI complex to the assay solution at a concentration similar to that in the cell dramatically enhanced protein export, confirming that the FliH
2
/FliI complex in the cytoplasm is important for effective protein transport.
IMPORTANCE
The type III secretion system (T3SS) is the functional core of the injectisome, a bacterial protein transporter used to deliver virulence proteins into host cells, and bacterial flagella, critical for many pathogens. The molecular mechanism of protein transport is still unclear due to difficulties in accurate measurements of protein transport under well-controlled conditions
in vivo
. We succeeded in developing an
in vitro
transport assay system of the flagellar T3SS using inverted membrane vesicles (IMVs). Flagellar hook formation was reproduced in the IMV, suggesting that the export apparatus in the IMV retains a protein transport activity similar to that in the cell. Using this system, we revealed that ATP hydrolysis by the T3SS ATPase can drive protein export without PMF.
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147
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Gao X, Mu Z, Yu X, Qin B, Wojdyla J, Wang M, Cui S. Structural Insight Into Conformational Changes Induced by ATP Binding in a Type III Secretion-Associated ATPase From Shigella flexneri. Front Microbiol 2018; 9:1468. [PMID: 30013545 PMCID: PMC6036117 DOI: 10.3389/fmicb.2018.01468] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Accepted: 06/12/2018] [Indexed: 11/13/2022] Open
Abstract
Gram-negative bacteria utilize the type III secretion system (T3SS) to inject effector proteins into the host cell cytoplasm, where they subvert cellular functions and assist pathogen invasion. The conserved type III-associated ATPase is critical for the separation of chaperones from effector proteins, the unfolding of effector proteins and translocating them through the narrow channel of the secretion apparatus. However, how ATP hydrolysis is coupled to the mechanical work of the enzyme remains elusive. Herein, we present a complete description of nucleoside triphosphate binding by surface presentation antigens 47 (Spa47) from Shigella flexneri, based on crystal structures containing ATPγS, a catalytic magnesium ion and an ordered water molecule. Combining the crystal structures of Spa47-ATPγS and unliganded Spa47, we propose conformational changes in Spa47 associated with ATP binding, the binding of ATP induces a conformational change of a highly conserved luminal loop, facilitating ATP hydrolysis by the Spa47 ATPase. Additionally, we identified a specific hydrogen bond critical for ATP recognition and demonstrated that, while ATPγS is an ideal analog for probing ATP binding, AMPPNP is a poor ATP mimic. Our findings provide structural insight pertinent for inhibitor design.
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Affiliation(s)
- Xiaopan Gao
- MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Zhixia Mu
- MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Xia Yu
- MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Bo Qin
- MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Justyna Wojdyla
- Swiss Light Source, Paul Scherrer Institute, Villigen, Switzerland
| | - Meitian Wang
- Swiss Light Source, Paul Scherrer Institute, Villigen, Switzerland
| | - Sheng Cui
- MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
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148
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Nadler H, Shaulov L, Blitsman Y, Mordechai M, Jopp J, Sal-Man N, Berkovich R. Deciphering the Mechanical Properties of Type III Secretion System EspA Protein by Single Molecule Force Spectroscopy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:6261-6270. [PMID: 29726683 DOI: 10.1021/acs.langmuir.8b01198] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Bacterial pathogens inject virulence factors into host cells during bacterial infections using type III secretion systems. In enteropathogenic Escherichia coli, this system contains an external filament, formed by a self-oligomerizing protein called E. coli secreted protein A (EspA). The EspA filament penetrates the thick viscous mucus layer to facilitate the attachment of the bacteria to the gut-epithelium. To do that, the EspA filament requires noteworthy mechanical endurance considering the mechanical shear stresses found within the intestinal tract. To date, the mechanical properties of the EspA filament and the structural and biophysical knowledge of monomeric EspA are very limited, mostly due to the strong tendency of the protein to self-oligomerize. To overcome this limitation, we employed a single molecule force spectroscopy (SMFS) technique and studied the mechanical properties of EspA. Force extension dynamic of (I91)4-EspA-(I91)4 chimera revealed two structural unfolding events occurring at low forces during EspA unfolding, thus indicating no unique mechanical stability of the monomeric protein. SMFS examination of purified monomeric EspA protein, treated by a gradually refolding protocol, exhibited similar mechanical properties as the EspA protein within the (I91)4-EspA-(I91)4 chimera. Overall, our results suggest that the mechanical integrity of the EspA filament likely originates from the interactions between EspA monomers and not from the strength of an individual monomer.
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Affiliation(s)
- Hila Nadler
- Department of Chemical Engineering , Ben-Gurion University of the Negev , Beer Sheva 8410501 , Israel
| | - Lihi Shaulov
- Department of Microbiology, Immunology and Genetics , Ben-Gurion University of the Negev , Beer Sheva 8410501 , Israel
| | - Yossi Blitsman
- Department of Chemical Engineering , Ben-Gurion University of the Negev , Beer Sheva 8410501 , Israel
| | - Moran Mordechai
- Department of Chemical Engineering , Ben-Gurion University of the Negev , Beer Sheva 8410501 , Israel
| | - Jürgen Jopp
- The Ilse Katz Institute for Nanoscale Science and Technology , Ben-Gurion University of the Negev , Beer Sheva 8410501 , Israel
| | - Neta Sal-Man
- Department of Microbiology, Immunology and Genetics , Ben-Gurion University of the Negev , Beer Sheva 8410501 , Israel
| | - Ronen Berkovich
- Department of Chemical Engineering , Ben-Gurion University of the Negev , Beer Sheva 8410501 , Israel
- The Ilse Katz Institute for Nanoscale Science and Technology , Ben-Gurion University of the Negev , Beer Sheva 8410501 , Israel
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149
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García-Sánchez L, Melero B, Rovira J. Campylobacter in the Food Chain. ADVANCES IN FOOD AND NUTRITION RESEARCH 2018; 86:215-252. [PMID: 30077223 DOI: 10.1016/bs.afnr.2018.04.005] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Currently Campylobacter is the most commonly reported zoonosis in developed and developing countries. In the European Union, the number of reported confirmed cases of human campylobacteriosis was 246,307 in 2016, which represents 66.3 cases per 100,000 population. The genus Campylobacter includes 31 species with 10 subspecies. Within the genus Campylobacter, C. jejuni subsp. jejuni and C. coli are most frequently associated with human illness. Mainly, the infection is sporadic and self-limiting, although some cases of outbreaks have been also reported and some complications such as Guillain-Barré syndrome might appear sporadically. Although campylobacters are fastidious microaerophilic, unable to multiply outside the host and generally very sensitive, they can adapt and survive in the environment, exhibiting aerotolerance and resistance to starvation. Many mechanisms are involved in this, including pathogenicity, biofilm formation, and antibiotic resistant pathways. This chapter reviews the sources, transmission routes, the mechanisms, and strategies used by Campylobacter to persist in the whole food chain, from farm to fork. Additionally, different strategies are recommended for application along the poultry food chain to avoid the public health risk associated with this pathogen.
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Affiliation(s)
| | - Beatriz Melero
- Biotechnology and Food Science Department, University of Burgos, Burgos, Spain
| | - Jordi Rovira
- Biotechnology and Food Science Department, University of Burgos, Burgos, Spain.
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150
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Tchagang CF, Xu R, Doumbou CL, Tambong JT. Genome analysis of two novel Pseudomonas strains exhibiting differential hypersensitivity reactions on tobacco seedlings reveals differences in nonflagellar T3SS organization and predicted effector proteins. Microbiologyopen 2018; 7:e00553. [PMID: 29464939 PMCID: PMC5911992 DOI: 10.1002/mbo3.553] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Revised: 07/17/2017] [Accepted: 07/18/2017] [Indexed: 11/06/2022] Open
Abstract
Multilocus sequence analysis (MLSA) of two new biological control strains (S1E40 and S3E12) of Pseudomonas was performed to assess their taxonomic position relative to close lineages, and comparative genomics employed to investigate whether these strains differ in key genetic features involved in hypersensitivity responses (HRs). Strain S3E12, at high concentration, incites HRs on tobacco and corn plantlets while S1E40 does not. Phylogenies based on individual genes and 16S rRNA-gyrB-rpoB-rpoD concatenated sequence data show strains S1E40 and S3E12 clustering in distinct groups. Strain S3E12 consistently clustered with Pseudomonas marginalis, a bacterium causing soft rots on plant tissues. MLSA data suggest that strains S1E40 and S3E12 are novel genotypes. This is consistent with the data of genome-based DNA-DNA homology values that are below the proposed cutoff species boundary. Comparative genomics analysis of the two strains revealed major differences in the type III secretion systems (T3SS) as well as the predicted T3SS secreted effector proteins (T3Es). One nonflagellar (NF-T3SS) and two flagellar T3SSs (F-T3SS) clusters were identified in both strains. While F-T3SS clusters in both strains were relatively conserved, the NF-T3SS clusters differed in the number of core components present. The predicted T3Es also differed in the type and number of CDSs with both strains having unique predicted protease-related effectors. In addition, the T1SS organization of the S3E12 genome has protein-coding sequences (CDSs) encoding for key factors such as T1SS secreted agglutinin repeats-toxins (a group of cytolysins and cytotoxins), a membrane fusion protein (LapC), a T1SS ATPase of LssB family (LapB), and T1SS-associated transglutaminase-like cysteine proteinase (LapP). In contrast, strain S1E40 has all CDSs for the seven-gene operon (pelA-pelG) required for Pel biosynthesis but not S3E12, suggesting that biofilm formation in these strains is modulated differently. The data presented here provide an insight of the genome organization of these two phytobacterial strains.
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Affiliation(s)
- Caetanie F. Tchagang
- Ottawa Research and Development CentreOttawaONCanada
- Institut des sciences de santé et de la vie Collège La CitéOttawaONCanada
| | - Renlin Xu
- Ottawa Research and Development CentreOttawaONCanada
| | - Cyr Lézin Doumbou
- Institut des sciences de santé et de la vie Collège La CitéOttawaONCanada
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