Edwardsiella tarda mutant disrupted in type III secretion system and chorismic acid synthesis and cured of a plasmid as a live attenuated vaccine in turbot

2013 ◽  
Vol 35 (3) ◽  
pp. 632-641 ◽  
Author(s):  
Jingfan Xiao ◽  
Tao Chen ◽  
Bing Liu ◽  
Weizheng Yang ◽  
Qiyao Wang ◽  
...  
Keyword(s):  
Type Iii Secretion ◽  
Type Iii Secretion System ◽  
Acid Synthesis ◽  
Secretion System ◽  
Edwardsiella Tarda ◽  
Live Attenuated Vaccine ◽  
Type Iii ◽  
Attenuated Vaccine ◽  
Chorismic Acid

scholarly journals Type III Secretion System Translocon Component EseB Forms Filaments on and Mediates Autoaggregation of and Biofilm Formation by Edwardsiella tarda

2015 ◽  
Vol 81 (17) ◽  
pp. 6078-6087 ◽  
Author(s):  
Zhi Peng Gao ◽  
Pin Nie ◽  
Jin Fang Lu ◽  
Lu Yi Liu ◽  
Tiao Yi Xiao ◽  
...  
Keyword(s):  
Type Iii Secretion ◽  
Biofilm Formation ◽  
Type Iii Secretion System ◽  
Secretion System ◽  
Effector Proteins ◽  
Host Cells ◽  
Edwardsiella Tarda ◽  
Dependent Manner ◽  
Content Type ◽  
Type Iii

ABSTRACTThe type III secretion system (T3SS) ofEdwardsiella tardaplays an important role in infection by translocating effector proteins into host cells. EseB, a component required for effector translocation, is reported to mediate autoaggregation ofE. tarda. In this study, we demonstrate that EseB forms filamentous appendages on the surface ofE. tardaand is required for biofilm formation byE. tardain Dulbecco's modified Eagle's medium (DMEM). Biofilm formation byE. tardain DMEM does not require FlhB, an essential component for assembling flagella. Dynamic analysis of EseB filament formation, autoaggregation, and biofilm formation shows that the formation of EseB filaments occurs prior to autoaggregation and biofilm formation. The addition of an EseB antibody toE. tardacultures before bacterial autoaggregation prevents autoaggregation and biofilm formation in a dose-dependent manner, whereas the addition of the EseB antibody toE. tardacultures in which biofilm is already formed does not destroy the biofilm. Therefore, EseB filament-mediated bacterial cell-cell interaction is a prerequisite for autoaggregation and biofilm formation.

scholarly journals Edwardsiella tarda-Induced Cytotoxicity Depends on Its Type III Secretion System and Flagellin

2014 ◽  
Vol 82 (8) ◽  
pp. 3436-3445 ◽  
Author(s):  
Hai-Xia Xie ◽  
Jin-Fang Lu ◽  
Nathalie Rolhion ◽  
David W. Holden ◽  
Pin Nie ◽  
...  
Keyword(s):  
Type Iii Secretion ◽  
Type Iii Secretion System ◽  
Secretion System ◽  
Host Cells ◽  
Edwardsiella Tarda ◽  
Dependent Manner ◽  
Gram Negative ◽  
Content Type ◽  
Murine Bone Marrow ◽  
Type Iii

ABSTRACTMany Gram-negative bacteria utilize a type III secretion system (T3SS) to translocate virulence proteins into host cells to cause diseases. In responding to infection, macrophages detect some of the translocated proteins to activate caspase-1-mediated cell death, called pyroptosis, and secretion of proinflammatory cytokines to control the infection.Edwardsiella tardais a Gram-negative enteric pathogen that causes hemorrhagic septicemia in fish and both gastrointestinal and extraintestinal infections in humans. In this study, we report that the T3SS ofE. tardafacilitates its survival and replication in murine bone marrow-derived macrophages, andE. tardainfection triggers pyroptosis of infected macrophages from mice and fish and increased secretion of the cytokine interleukin 1β in a T3SS-dependent manner. Deletion of the flagellin genefliCofE. tardaresults in decreased cytotoxicity for infected macrophages and does not attenuate its virulence in a fish model of infection, whereas upregulated expression of FliC in thefliCmutant strain reduces its virulence. We propose that the host controlsE. tardainfection partially by detecting FliC translocated by the T3SS, whereas the bacteria downregulate the expression of FliC to evade innate immunity.

scholarly journals Edwardsiella tarda EscE (Orf13 Protein) Is a Type III Secretion System-Secreted Protein That Is Required for the Injection of Effectors, Secretion of Translocators, and Pathogenesis in Fish

2015 ◽  
Vol 84 (1) ◽  
pp. 2-10 ◽  
Author(s):  
Jin Fang Lu ◽  
Wei Na Wang ◽  
Gai Ling Wang ◽  
He Zhang ◽  
Ying Zhou ◽  
...  
Keyword(s):  
Type Iii Secretion ◽  
Bacterial Species ◽  
Lethal Dose ◽  
Type Iii Secretion System ◽  
Secretion System ◽  
Edwardsiella Tarda ◽  
Dependent Manner ◽  
Wild Type ◽  
Content Type ◽  
Type Iii

The type III secretion system (T3SS) ofEdwardsiella tardais crucial for its intracellular survival and pathogenesis in fish. Theorf13gene (escE) ofE. tardais located 84 nucleotides (nt) upstream ofesrCin the T3SS gene cluster. We found that EscE is secreted and translocated in a T3SS-dependent manner and that amino acids 2 to 15 in the N terminus were required for a completely functional T3SS inE. tarda. Deletion ofescEabolished the secretion of T3SS translocators, as well as the secretion and translocation of T3SS effectors, but did not influence their intracellular protein levels inE. tarda. Complementation of theescEmutant with a secretion-incompetent EscE derivative restored the secretion of translocators and effectors. Interestingly, the effectors that were secreted and translocated were positively correlated with the EscE protein level inE. tarda. TheescEmutant was attenuated in the blue gourami fish infection model, as its 50% lethal dose (LD50) increased to 4 times that of the wild type. The survival rate of theescEmutant-strain-infected fish was 69%, which was much higher than that of the fish infected with the wild-type bacteria (6%). Overall, EscE represents a secreted T3SS regulator that controls effector injection and translocator secretion, thus contributing toE. tardapathogenesis in fish. The homology of EscE within the T3SSs of other bacterial species suggests that the mechanism of secretion and translocation control used byE. tardamay be commonly used by other bacterial pathogens.

scholarly journals EscC is a chaperone for the Edwardsiella tarda type III secretion system putative translocon components EseB and EseD

Microbiology ◽  
2007 ◽  
Vol 153 (6) ◽  
pp. 1953-1962 ◽  
Author(s):  
Jun Zheng ◽  
Nan Li ◽  
Yuen Peng Tan ◽  
J Sivaraman ◽  
Yu-Keung Mok ◽  
...  
Keyword(s):  
Type Iii Secretion ◽  
Type Iii Secretion System ◽  
Secretion System ◽  
Edwardsiella Tarda ◽  
Type Iii

scholarly journals Investigation of EscA as a chaperone for the Edwardsiella tarda type III secretion system putative translocon component EseC

Microbiology ◽  
2009 ◽  
Vol 155 (4) ◽  
pp. 1260-1271 ◽  
Author(s):  
Bo Wang ◽  
Zhao Lan Mo ◽  
Yun Xiang Mao ◽  
Yu Xia Zou ◽  
Peng Xiao ◽  
...  
Keyword(s):  
Type Iii Secretion ◽  
Cytoplasmic Membrane ◽  
Specific Interaction ◽  
Type Iii Secretion System ◽  
Secretion System ◽  
Edwardsiella Tarda ◽  
Cell Fractionation ◽  
Wild Type ◽  
Gram Negative ◽  
Type Iii

Edwardsiella tarda is an important Gram-negative enteric pathogen affecting both animals and humans. It possesses a type III secretion system (T3SS) essential for pathogenesis. EseB, EseC and EseD have been shown to form a translocon complex after secretion, while EscC functions as a T3SS chaperone for EseB and EseD. In this paper we identify EscA, a protein required for accumulation and proper secretion of another translocon component, EseC. The escA gene is located upstream of eseC and the EscA protein has the characteristics of T3SS chaperones. Cell fractionation experiments indicated that EscA is located in the cytoplasm and on the cytoplasmic membrane. Mutation with in-frame deletion of escA greatly decreased the secretion of EseC, while complementation of escA restored the wild-type secretion phenotype. The stabilization and accumulation of EseC in the cytoplasm were also affected in the absence of EscA. Mutation of escA did not affect the transcription of eseC but reduced the accumulation level of EseC as measured by using an EseC-LacZ fusion protein in Ed. tarda. Co-purification and co-immunoprecipitation studies demonstrated a specific interaction between EscA and EseC. Further analysis showed that residues 31–137 of EseC are required for EseC-EscA interaction. Mutation of EseC residues 31–137 reduced the secretion and accumulation of EseC in Ed. tarda. Finally, infection experiments showed that mutations of EscA and residues 31–137 of EseC increased the LD50 by approximately 10-fold in blue gourami fish. These results indicated that EscA functions as a specific chaperone for EseC and contributes to the virulence of Ed. tarda.

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