1
|
Shi W, Li Y, Zhang W. Screening and functional characterization of isocitrate lyase AceA in the biofilm formation of Vibrio alginolyticus. Appl Environ Microbiol 2024:e0069724. [PMID: 39377591 DOI: 10.1128/aem.00697-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2024] [Accepted: 07/25/2024] [Indexed: 10/09/2024] Open
Abstract
Biofilm is a well-known sessile lifestyle for bacterial pathogens, but a little is known about the mechanism on biofilm formation in Vibrio alginolyticus. In this study, we screened V. alginolyticus strains with strong biofilm formation ability from coastal seawater. The antibiotic resistance of the biofilm cells (BFs) was higher than that of the planktonic cells (PTs). To study the genes and pathways involved in biofilm formation, we performed transcriptome analysis of the BFs and PTs of V. alginolyticus R9. A total of 685 differentially expressed genes (DEGs) were upregulated, and 517 DEGs were downregulated in the BFs. The upregulated DEGs were significantly enriched in several pathways including glyoxylate and dicarboxylate metabolism, while the downregulated genes were significantly enriched in the flagellar assembly pathways. The key gene involved in glyoxylate shunt, aceA, was cloned, and ΔaceA mutant was constructed to determine the function of AceA in carbon source utilization, biofilm formation, and virulence. Real-time reverse transcription PCR showed that the expression of aceA was higher at the mature stage but lower at the disperse stage of biofilm formation, and the expression of the flagellar related genes was upregulated in ΔaceA. This is the first study to illustrate the global gene expression profile during the biofilm formation of V. alginolyticus, and isocitrate lyase AceA, the key enzyme involved in glyoxylate shunt, was shown to maintain biofilms accompanied by downregulation of flagellation but promoted dispersal of BFs at the late stage.IMPORTANCEBiofilms pose serious public problems, not only protecting the cells in it from environmental hazard but also affecting the composition and abundance of bacteria, algae, fungi, and protozoa. The important opportunistic pathogen Vibrio alginolyticus is extremely ubiquitously present in seawater, and it also exhibited a strong ability to form biofilm; thus, investigation on the biofilm formation of V. alginolyticus at molecular level is fundamental for the deeper exploration of the environmental concerns arose by biofilm. In this study, transcriptome analysis of biofilm cells (BFs) and planktonic cells (PTs) from V. alginolyticus was performed and AceA was screened to play an important role in biofilm formation. AceA was shown to maintain biofilms accompanied by downregulation of flagellation but promoted dispersal of BFs at the disperse stage. This method was helpful to further understand the ability and mechanism of V. alginolyticus biofilm formation and provide clues for prevention of V. alginolyticus infection.
Collapse
Affiliation(s)
- Weibo Shi
- School of Marine Sciences, Ningbo University, Ningbo, P. R. China
| | - Ya Li
- School of Marine Sciences, Ningbo University, Ningbo, P. R. China
| | - Weiwei Zhang
- School of Marine Sciences, Ningbo University, Ningbo, P. R. China
| |
Collapse
|
2
|
Yi X, Xu X, Xu G, Zhang Y, Chen Y, Zhu Z, Guo M. The Sec pathway gene yidC regulates the virulence of mesophilic Aeromonassalmonicida. FISH & SHELLFISH IMMUNOLOGY 2024; 153:109863. [PMID: 39209005 DOI: 10.1016/j.fsi.2024.109863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2024] [Revised: 08/25/2024] [Accepted: 08/26/2024] [Indexed: 09/04/2024]
Abstract
Aeromonas salmonicida is a common pathogenic bacterial species found in both freshwater and marine fish, leading to significant economic losses in the aquaculture industry. YidC is an accessory to SecYEG and is essential for the SecYEG transporter to insert into the bacterial membrane. However, the roles of the yidC gene on the host immune response remain unclear. Here, we compared the pathogenicity of yidC gene-deleted (ΔyidC) strain and wild-type (SRW-OG1) strain of mesophilic A. salmonicida to Orange-spotted grouper (Epinephelus coioides), and explored the impacts of yidC gene on the immune response of E. coioides to mesophilic A. salmonicida infection by using Red/ET recombineering. In this study, the E. coioides in the Secondary infected group had a 53.9 % higher survival rate than those in the Primary infected group. In addition, the adhesion ability of ΔyidC strain decreased by about 83.36 % compared with that of the wild-type (SRW-OG1) strain. Further comparison of the biological phenotype of SRW-OG1 and ΔyidC revealed that this yidC gene could regulate the expression of genes related to iron metabolism and have no effect on bacterial growth under the limited iron concentration. In the low concentration of Fe3+ and Fe2+ environment, SRW-OG1 can obtain iron ions by regulating yidC. Based on the above results, yidC gene contributed to the pathogenicity of mesophilic A. salmonicida to E. coioides, deletion of yidC gene promoted the inflammation and immune response of E. coioides to mesophilic A. salmonicida infection.
Collapse
Affiliation(s)
- Xin Yi
- State Key Laboratory of Mariculture Breeding, Fisheries College, Jimei University, Xiamen, Fujian, 361021, China, Engineering Research Center of the Modern Technology for Eel Industry; Southern Marine Science and Engineering Guangdong Laboratory (Zhanjiang), Zhanjiang, 524000, China
| | - XiaoJin Xu
- State Key Laboratory of Mariculture Breeding, Fisheries College, Jimei University, Xiamen, Fujian, 361021, China, Engineering Research Center of the Modern Technology for Eel Industry.
| | - Genhuang Xu
- State Key Laboratory of Mariculture Breeding, Fisheries College, Jimei University, Xiamen, Fujian, 361021, China, Engineering Research Center of the Modern Technology for Eel Industry
| | - Youyu Zhang
- Institute of Electromagnetics and Acoustics, School of Electronic Science and Engineering, Xiamen University, Xiamen, Fujian, China.
| | - YuNong Chen
- State Key Laboratory of Mariculture Breeding, Fisheries College, Jimei University, Xiamen, Fujian, 361021, China, Engineering Research Center of the Modern Technology for Eel Industry
| | - ZhiQin Zhu
- State Key Laboratory of Mariculture Breeding, Fisheries College, Jimei University, Xiamen, Fujian, 361021, China, Engineering Research Center of the Modern Technology for Eel Industry
| | - Minglan Guo
- South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China
| |
Collapse
|
3
|
Wiegand T, Hoffmann FT, Walker MWG, Tang S, Richard E, Le HC, Meers C, Sternberg SH. TnpB homologues exapted from transposons are RNA-guided transcription factors. Nature 2024; 631:439-448. [PMID: 38926585 DOI: 10.1038/s41586-024-07598-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Accepted: 05/23/2024] [Indexed: 06/28/2024]
Abstract
Transposon-encoded tnpB and iscB genes encode RNA-guided DNA nucleases that promote their own selfish spread through targeted DNA cleavage and homologous recombination1-4. These widespread gene families were repeatedly domesticated over evolutionary timescales, leading to the emergence of diverse CRISPR-associated nucleases including Cas9 and Cas12 (refs. 5,6). We set out to test the hypothesis that TnpB nucleases may have also been repurposed for novel, unexpected functions other than CRISPR-Cas adaptive immunity. Here, using phylogenetics, structural predictions, comparative genomics and functional assays, we uncover multiple independent genesis events of programmable transcription factors, which we name TnpB-like nuclease-dead repressors (TldRs). These proteins use naturally occurring guide RNAs to specifically target conserved promoter regions of the genome, leading to potent gene repression in a mechanism akin to CRISPR interference technologies invented by humans7. Focusing on a TldR clade found broadly in Enterobacteriaceae, we discover that bacteriophages exploit the combined action of TldR and an adjacently encoded phage gene to alter the expression and composition of the host flagellar assembly, a transformation with the potential to impact motility8, phage susceptibility9, and host immunity10. Collectively, this work showcases the diverse molecular innovations that were enabled through repeated exaptation of transposon-encoded genes, and reveals the evolutionary trajectory of diverse RNA-guided transcription factors.
Collapse
Affiliation(s)
- Tanner Wiegand
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Florian T Hoffmann
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Matt W G Walker
- Department of Biological Sciences, Columbia University, New York, NY, USA
| | - Stephen Tang
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Egill Richard
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Hoang C Le
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Chance Meers
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Samuel H Sternberg
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA.
| |
Collapse
|
4
|
Wang L, Li H, Chen J, Wang Y, Gu Y, Jiu M. Antibacterial Mechanisms and Antivirulence Activities of Oridonin against Pathogenic Aeromonas hydrophila AS 1.1801. Microorganisms 2024; 12:415. [PMID: 38399819 PMCID: PMC10891661 DOI: 10.3390/microorganisms12020415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Revised: 02/08/2024] [Accepted: 02/15/2024] [Indexed: 02/25/2024] Open
Abstract
Aeromonas hydrophila, a Gram-negative bacterium widely found in freshwater environments, acts as a common conditional pathogen affecting humans, livestock, and aquatic animals. In this study, the impact of oridonin, an ent-kaurane diterpenoid compound derived from Rabdosia rubescens, on the virulence factors of A. hydrophila AS 1.1801 and its antibacterial mechanism was elucidated. The minimum inhibitory concentration (MIC) of oridonin against A. hydrophila AS 1.1801 was 100 μg/mL. Oridonin at inhibitory concentrations could significantly increase the electrical conductivity in the supernatant and escalate nucleic acid leakage (p < 0.01). This effect was concomitant with observed distortions in bacterial cells, the formation of cytoplasmic cavities, cellular damage, and pronounced inhibition of protein and nucleic acid synthesis. Additionally, oridonin at inhibitory levels exhibited a noteworthy suppressive impact on A. hydrophila AS 1.1801 across biofilm formation, motility, hemolytic activity, lipase activity, and protease activity (p < 0.05), demonstrating a dose-dependent enhancement. qRT-PCR analysis showed that the gene expression of luxR, qseB and omp were significantly downregulated after oridonin treatment in A. hydrophila AS 1.1801 (p < 0.05). Our results indicated that oridonin possessed significant antibacterial and anti-virulence effects on A. hydrophila AS 1.1801.
Collapse
Affiliation(s)
- Lunji Wang
- Key Laboratory of Microbial Resources Development and Utilization, Henan University of Science and Technology, Luoyang 471023, China; (L.W.); (J.C.)
- College of Food and Bioengineering, Henan University of Science and Technology, Luoyang 471023, China; (H.L.); (Y.W.); (Y.G.)
| | - Huijuan Li
- College of Food and Bioengineering, Henan University of Science and Technology, Luoyang 471023, China; (H.L.); (Y.W.); (Y.G.)
| | - Jinhao Chen
- Key Laboratory of Microbial Resources Development and Utilization, Henan University of Science and Technology, Luoyang 471023, China; (L.W.); (J.C.)
| | - Yi Wang
- College of Food and Bioengineering, Henan University of Science and Technology, Luoyang 471023, China; (H.L.); (Y.W.); (Y.G.)
| | - Yuqing Gu
- College of Food and Bioengineering, Henan University of Science and Technology, Luoyang 471023, China; (H.L.); (Y.W.); (Y.G.)
| | - Min Jiu
- Key Laboratory of Microbial Resources Development and Utilization, Henan University of Science and Technology, Luoyang 471023, China; (L.W.); (J.C.)
| |
Collapse
|
5
|
Mukherjee P, Agarwal S, Mallick SB, Dasgupta J. PAS domain of flagellar histidine kinase FlrB has a unique architecture and binds heme as a sensory ligand in an unconventional fashion. Structure 2024; 32:200-216.e5. [PMID: 38157857 DOI: 10.1016/j.str.2023.11.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 09/28/2023] [Accepted: 11/29/2023] [Indexed: 01/03/2024]
Abstract
Phosphorylation of the σ54-dependent transcription activator FlrC by the sensor histidine kinase FlrB is essential for flagellar synthesis of Vibrio cholerae. Despite that, the structure, sensory signal, and mechanistic basis of function of FlrB were elusive. Here, we report the crystal structure of the sensory PAS domain of FlrB in its functional dimeric state that exhibits a unique architecture. Series of biochemical/biophysical experiments on different constructs and mutants established that heme binds hydrophobically as sensory ligand in the shallow ligand-binding cleft of FlrB-PAS without axial coordination. Intriguingly, ATP binding to the C-terminal ATP-binding (CA) domain assists PAS domain to bind heme, vis-à-vis, heme binding to the PAS facilitates ATP binding to the CA domain. We hypothesize that synergistic binding of heme and ATP triggers conformational signaling in FlrB, leading to downstream flagellar gene transcription. Enhanced swimming motility of V. cholerae with increased heme uptake supports this proposition.
Collapse
Affiliation(s)
- Peeali Mukherjee
- Department of Biotechnology, St. Xavier's College (Autonomous), 30 Mother Teresa Sarani, Kolkata 700016, India
| | - Shubhangi Agarwal
- Department of Biotechnology, St. Xavier's College (Autonomous), 30 Mother Teresa Sarani, Kolkata 700016, India
| | - Sritapa Basu Mallick
- Department of Biotechnology, St. Xavier's College (Autonomous), 30 Mother Teresa Sarani, Kolkata 700016, India
| | - Jhimli Dasgupta
- Department of Biotechnology, St. Xavier's College (Autonomous), 30 Mother Teresa Sarani, Kolkata 700016, India.
| |
Collapse
|
6
|
Tian Z, Xiang F, Peng K, Qin Z, Feng Y, Huang B, Ouyang P, Huang X, Chen D, Lai W, Geng Y. The cAMP Receptor Protein (CRP) of Vibrio mimicus Regulates Its Bacterial Growth, Type II Secretion System, Flagellum Formation, Adhesion Genes, and Virulence. Animals (Basel) 2024; 14:437. [PMID: 38338079 PMCID: PMC10854923 DOI: 10.3390/ani14030437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 01/12/2024] [Accepted: 01/22/2024] [Indexed: 02/12/2024] Open
Abstract
Vibrio mimicus is a serious pathogen in aquatic animals, resulting in significant economic losses. The cAMP receptor protein (CRP) often acts as a central regulator in highly pathogenic pathogens. V. mimicus SCCF01 is a highly pathogenic strain isolated from yellow catfish; the crp gene deletion strain (Δcrp) was constructed by natural transformation to determine whether this deletion affects the virulence phenotypes. Their potential molecular connections were revealed by qRT-PCR analysis. Our results showed that the absence of the crp gene resulted in bacterial and colony morphological changes alongside decreases in bacterial growth, hemolytic activity, biofilm formation, enzymatic activity, motility, and cell adhesion. A cell cytotoxicity assay and animal experiments confirmed that crp contributes to V. mimicus pathogenicity, as the LD50 of the Δcrp strain was 73.1-fold lower compared to the WT strain. Moreover, qRT-PCR analysis revealed the inhibition of type II secretion system genes, flagellum genes, adhesion genes, and metalloproteinase genes in the deletion strain. This resulted in the virulence phenotype differences described above. Together, these data demonstrate that the crp gene plays a core regulatory role in V. mimicus virulence and pathogenicity.
Collapse
Affiliation(s)
- Ziqi Tian
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China; (Z.T.); (F.X.); (K.P.); (Z.Q.); (Y.F.); (B.H.); (P.O.); (W.L.)
| | - Fei Xiang
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China; (Z.T.); (F.X.); (K.P.); (Z.Q.); (Y.F.); (B.H.); (P.O.); (W.L.)
- Agricultural and Rural Bureau of Zhongjiang County, Deyang 618100, China
| | - Kun Peng
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China; (Z.T.); (F.X.); (K.P.); (Z.Q.); (Y.F.); (B.H.); (P.O.); (W.L.)
| | - Zhenyang Qin
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China; (Z.T.); (F.X.); (K.P.); (Z.Q.); (Y.F.); (B.H.); (P.O.); (W.L.)
| | - Yang Feng
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China; (Z.T.); (F.X.); (K.P.); (Z.Q.); (Y.F.); (B.H.); (P.O.); (W.L.)
| | - Bowen Huang
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China; (Z.T.); (F.X.); (K.P.); (Z.Q.); (Y.F.); (B.H.); (P.O.); (W.L.)
| | - Ping Ouyang
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China; (Z.T.); (F.X.); (K.P.); (Z.Q.); (Y.F.); (B.H.); (P.O.); (W.L.)
| | - Xiaoli Huang
- Department of Aquaculture, Sichuan Agricultural University, Chengdu 611130, China; (X.H.); (D.C.)
| | - Defang Chen
- Department of Aquaculture, Sichuan Agricultural University, Chengdu 611130, China; (X.H.); (D.C.)
| | - Weimin Lai
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China; (Z.T.); (F.X.); (K.P.); (Z.Q.); (Y.F.); (B.H.); (P.O.); (W.L.)
| | - Yi Geng
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China; (Z.T.); (F.X.); (K.P.); (Z.Q.); (Y.F.); (B.H.); (P.O.); (W.L.)
| |
Collapse
|
7
|
Morot A, Delavat F, Bazire A, Paillard C, Dufour A, Rodrigues S. Genetic Insights into Biofilm Formation by a Pathogenic Strain of Vibrio harveyi. Microorganisms 2024; 12:186. [PMID: 38258011 PMCID: PMC10820411 DOI: 10.3390/microorganisms12010186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Revised: 01/09/2024] [Accepted: 01/10/2024] [Indexed: 01/24/2024] Open
Abstract
The Vibrio genus includes bacteria widely distributed in aquatic habitats and the infections caused by these bacteria can affect a wide range of hosts. They are able to adhere to numerous surfaces, which can result in biofilm formation that helps maintain them in the environment. The involvement of the biofilm lifestyle in the virulence of Vibrio pathogens of aquatic organisms remains to be investigated. Vibrio harveyi ORM4 is a pathogen responsible for an outbreak in European abalone Haliotis tuberculata populations. In the present study, we used a dynamic biofilm culture technique coupled with laser scanning microscopy to characterize the biofilm formed by V. harveyi ORM4. We furthermore used RNA-seq analysis to examine the global changes in gene expression in biofilm cells compared to planktonic bacteria, and to identify biofilm- and virulence-related genes showing altered expression. A total of 1565 genes were differentially expressed, including genes associated with motility, polysaccharide synthesis, and quorum sensing. The up-regulation of 18 genes associated with the synthesis of the type III secretion system suggests that this virulence factor is induced in V. harveyi ORM4 biofilms, providing indirect evidence of a relationship between biofilm and virulence.
Collapse
Affiliation(s)
- Amandine Morot
- Laboratoire de Biotechnologie et Chimie Marines, Université Bretagne Sud, EMR CNRS 6076, IUEM, 56100 Lorient, France
- Univ Brest, CNRS, IRD, Ifremer, LEMAR, F-29280 Plouzané, France
| | | | - Alexis Bazire
- Laboratoire de Biotechnologie et Chimie Marines, Université Bretagne Sud, EMR CNRS 6076, IUEM, 56100 Lorient, France
| | | | - Alain Dufour
- Laboratoire de Biotechnologie et Chimie Marines, Université Bretagne Sud, EMR CNRS 6076, IUEM, 56100 Lorient, France
| | - Sophie Rodrigues
- Laboratoire de Biotechnologie et Chimie Marines, Université Bretagne Sud, EMR CNRS 6076, IUEM, 56100 Lorient, France
| |
Collapse
|
8
|
Wu S, Tang J, Wang B, Cai J, Jian J. Roles of Hcp2, a Hallmark of T6SS2 in Motility, Adhesive Capacity, and Pathogenicity of Vibrio alginolyticus. Microorganisms 2023; 11:2893. [PMID: 38138037 PMCID: PMC10745990 DOI: 10.3390/microorganisms11122893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 11/28/2023] [Accepted: 11/29/2023] [Indexed: 12/24/2023] Open
Abstract
The type VI secretion system (T6SS) is a large secretory device, widely found in Gram-negative bacteria, which plays important roles in virulence, bacterial competition, and environmental adaptation. Vibrio alginolyticus (V. alginolyticus) is an opportunistic pathogen that causes vibriosis in aquaculture animals. V. alginolyticus possesses two type VI secretion systems (named the T6SS1 and T6SS2), but their functions remain largely unclear. In this paper, the roles of the core component of the T6SS2 cluster of V. alginolyticus HY9901, hemolysin-coregulated protein2 coding gene hcp2, are reported. Deletion of hcp2 clearly impaired the swarming motility, adhesive capacity, and pathogenicity of V. alginolyticus against zebrafish. Furthermore, transmission electron microscopy (TEM) found that the abnormal morphology of flagellum filament in the hcp2 mutant strain could be partially restored by hcp2 complementarity. By proteomic and RT-qPCR analysis, we confirmed that the expression levels of flagellar flagellin and assembly-associated proteins were remarkably decreased in an hcp2 mutant strain, compared with the wild-type strain, and could be partially restored with a supply of hcp2. Accordingly, hcp2 had a positive influence on the transcription of flagellar regulons rpoN, rpoS, and fliA; this was verified by RT-qPCR. Taken together, these results suggested that hcp2 was involved in mediating the motility, adhesion, and pathogenicity of Vibrio alginolyticus through positively impacting its flagellar system.
Collapse
Affiliation(s)
- Shuilong Wu
- Guangdong Provincial Key Laboratory of Aquatic Animal Disease Control and Healthy Culture, College of Fishery, Guangdong Ocean University, Zhanjiang 524088, China
- Key Laboratory of Diseases Controlling for Aquatic Economic Animals of Guangdong Higher Education Institutions, College of Fishery, Guangdong Ocean University, Zhanjiang 524088, China
- Central People’s Hospital of Zhanjiang, Zhanjiang 524045, China
| | - Jufen Tang
- Guangdong Provincial Key Laboratory of Aquatic Animal Disease Control and Healthy Culture, College of Fishery, Guangdong Ocean University, Zhanjiang 524088, China
- Key Laboratory of Diseases Controlling for Aquatic Economic Animals of Guangdong Higher Education Institutions, College of Fishery, Guangdong Ocean University, Zhanjiang 524088, China
| | - Bei Wang
- Guangdong Provincial Key Laboratory of Aquatic Animal Disease Control and Healthy Culture, College of Fishery, Guangdong Ocean University, Zhanjiang 524088, China
- Key Laboratory of Diseases Controlling for Aquatic Economic Animals of Guangdong Higher Education Institutions, College of Fishery, Guangdong Ocean University, Zhanjiang 524088, China
| | - Jia Cai
- Guangdong Provincial Key Laboratory of Aquatic Animal Disease Control and Healthy Culture, College of Fishery, Guangdong Ocean University, Zhanjiang 524088, China
- Key Laboratory of Diseases Controlling for Aquatic Economic Animals of Guangdong Higher Education Institutions, College of Fishery, Guangdong Ocean University, Zhanjiang 524088, China
| | - Jichang Jian
- Guangdong Provincial Key Laboratory of Aquatic Animal Disease Control and Healthy Culture, College of Fishery, Guangdong Ocean University, Zhanjiang 524088, China
- Key Laboratory of Diseases Controlling for Aquatic Economic Animals of Guangdong Higher Education Institutions, College of Fishery, Guangdong Ocean University, Zhanjiang 524088, China
| |
Collapse
|
9
|
Gao ZM, Xu T, Chen HG, Lu R, Tao J, Wang HB, Qiu JW, Wang Y. Early genome erosion and internal phage-symbiont-host interaction in the endosymbionts of a cold-seep tubeworm. iScience 2023; 26:107033. [PMID: 37389180 PMCID: PMC10300362 DOI: 10.1016/j.isci.2023.107033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 03/11/2023] [Accepted: 05/31/2023] [Indexed: 07/01/2023] Open
Abstract
Endosymbiosis with chemosynthetic Gammaproteobacteria is widely recognized as an adaptive mechanism of siboglinid tubeworms, yet evolution of these endosymbionts and their driving forces remain elusive. Here, we report a finished endosymbiont genome (HMS1) of the cold-seep tubeworm Sclerolinum annulatum. The HMS1 genome is small in size, with abundant prophages and transposable elements but lacking gene sets coding for denitrification, hydrogen oxidization, oxidative phosphorylation, vitamin biosynthesis, cell pH and/or sodium homeostasis, environmental sensing, and motility, indicative of early genome erosion and adaptive evolution toward obligate endosymbiosis. Unexpectedly, a prophage embedded in the HMS1 genome undergoes lytic cycle. Highly expressed ROS scavenger and LexA repressor genes indicate that the tubeworm host likely activates the lysogenic phage into lytic cycle through the SOS response to regulate endosymbiont population and harvest nutrients. Our findings indicate progressive evolution of Sclerolinum endosymbionts toward obligate endosymbiosis and expand the knowledge about phage-symbiont-host interaction in deep-sea tubeworms.
Collapse
Affiliation(s)
- Zhao-Ming Gao
- Institute of Deep Sea Science and Engineering, Chinese Academy of Sciences, Sanya 572000, China
- HKUST-CAS Sanya Joint Laboratory of Marine Science Research, Chinese Academy of Sciences, Sanya 572000, China
| | - Ting Xu
- Department of Ocean Science, The Hong Kong University of Science and Technology, Hong Kong, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China
| | - Hua-Guan Chen
- Institute of Deep Sea Science and Engineering, Chinese Academy of Sciences, Sanya 572000, China
- University of Chinese Academy of Sciences, Beijing 101408, China
| | - Rui Lu
- Institute of Deep Sea Science and Engineering, Chinese Academy of Sciences, Sanya 572000, China
- University of Chinese Academy of Sciences, Beijing 101408, China
| | - Jun Tao
- MLR Key Laboratory of Marine Mineral Resources, Guangzhou Marine Geological Survey, China Geological Survey, Guangzhou 511458, China
| | - Hong-Bin Wang
- MLR Key Laboratory of Marine Mineral Resources, Guangzhou Marine Geological Survey, China Geological Survey, Guangzhou 511458, China
| | - Jian-Wen Qiu
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China
- Department of Biology, Hong Kong Baptist University, Hong Kong, China
| | - Yong Wang
- Institute of Deep Sea Science and Engineering, Chinese Academy of Sciences, Sanya 572000, China
- HKUST-CAS Sanya Joint Laboratory of Marine Science Research, Chinese Academy of Sciences, Sanya 572000, China
- Institute for Ocean Engineering, Shenzhen International Graduate School, Tsinghua University, Shenzhen 518000, China
| |
Collapse
|
10
|
Shi Y, Liao C, Dai F, Zhang Y, Li C, Liang W. Vibrio splendidus Fur regulates virulence gene expression, swarming motility, and biofilm formation, affecting its pathogenicity in Apostichopus japonicus. Front Vet Sci 2023; 10:1207831. [PMID: 37342622 PMCID: PMC10277475 DOI: 10.3389/fvets.2023.1207831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Accepted: 05/16/2023] [Indexed: 06/23/2023] Open
Abstract
Vibrio splendidus is an opportunistic pathogen that causes skin ulcer syndrome and results in huge losses to the Apostichopus japonicus breeding industry. Ferric uptake regulator (Fur) is a global transcription factor that affects varieties of virulence-related functions in pathogenic bacteria. However, the role of the V. splendidus fur (Vsfur) gene in the pathogenesis of V. splendidus remains unclear. Hence, we constructed a Vsfur knock-down mutant of the V. splendidus strain (MTVs) to investigate the role of the gene in the effect of biofilm, swarming motility, and virulence on A. japonicus. The result showed that the growth curves of the wild-type V. splendidus strain (WTVs) and MTVs were almost consistent. Compared with WTVs, the significant increases in the transcription of the virulence-related gene Vshppd mRNA were 3.54- and 7.33-fold in MTVs at the OD600 of 1.0 and 1.5, respectively. Similarly, compared with WTVs, the significant increases in the transcription of Vsm mRNA were 2.10- and 15.92-fold in MTVs at the OD600 of 1.0 and 1.5, respectively. On the contrary, the mRNA level of the flagellum assembly gene Vsflic was downregulated 0.56-fold in MTVs at the OD600 of 1.0 compared with the WTVs. MTVs caused delayed disease onset time and reduced A. japonicus mortality. The median lethal doses of WTVs and MTVs were 9.116 × 106 and 1.658 × 1011 CFU·ml-1, respectively. Compared with WTVs, the colonization abilities of MTVs to the muscle, intestine, tentacle, and coelomic fluid of A. japonicus were significantly reduced. Correspondingly, the swarming motility and biofilm formation in normal and iron-replete conditions were remarkably decreased compared with those of WTVs. Overall, these results demonstrate that Vsfur contributes to the pathogenesis of V. splendidus by regulating virulence-related gene expression and affecting its swarming and biofilm formation abilities.
Collapse
Affiliation(s)
- Yue Shi
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Ningbo University, Ningbo, Zhejiang, China
| | - Changyu Liao
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Ningbo University, Ningbo, Zhejiang, China
| | - Fa Dai
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Ningbo University, Ningbo, Zhejiang, China
| | - Yiwei Zhang
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Ningbo University, Ningbo, Zhejiang, China
| | - Chenghua Li
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Ningbo University, Ningbo, Zhejiang, China
- Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Weikang Liang
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Ningbo University, Ningbo, Zhejiang, China
| |
Collapse
|
11
|
Da F, Wan X, Lin G, Jian J, Cai S. Characterization of fliR-deletion mutant Δ fliR from Vibrio alginolyticus and the evaluation as a live attenuated vaccine. Front Cell Infect Microbiol 2023; 13:1162299. [PMID: 37180437 PMCID: PMC10166871 DOI: 10.3389/fcimb.2023.1162299] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Accepted: 04/05/2023] [Indexed: 05/16/2023] Open
Abstract
Vibrio alginolyticus is the common pathogen affecting various species of marine organisms. It has been demonstrated that fliR is a necessary virulence factor to adhere and infect their hosts for pathogenic bacteria. Frequent disease outbreaks in aquaculture have highlighted the necessity of developing effective vaccines. In the present study, in order to investigate the function of fliR in V.alginolyticus, the fliR deletion mutant ΔfliR was constructed and its biological properties were evaluated, additionally, the differences in gene expression levels between wild-type and ΔfliR were analyzed by transcriptomics. Finally, ΔfliR was used as a live attenuated vaccine to immunize grouper via the intraperitoneal route to evaluate its protective effect. Results show that fliR gene of V. alginolyticus was identified as being 783 bp in length, encoding 260 amino acids, and showing significant similarity to homologs of other Vibrio species. The fliR-deletion mutant ΔfliR of V. alginolyticus was successfully constructed, and its biological phenotype analysis showed no significant differences in growth capacity and extracellular enzyme activity compared to the wild-type. However, a substantial reduction of motility ability was detected in ΔfliR. Transcriptomic analysis revealed that the absence of fliR gene is responsible for a significantly decreased expression of flagellar genes, including flaA, flaB, fliS, flhB and fliM. The fliR-deletion mainly affects the related pathways involved in cell motility, membrane transport, signal transduction, carbohydrate metabolism, and amino acid metabolism in V. alginolyticus. The efficacy of ΔfliR as a candidate of live attenuated vaccine were evaluated by intraperitoneal injection in grouper. The ΔfliR provided the RPS (Relative protection rate) of 67.2% against V. alginolyticus in groupers. The ΔfliR efficiently stimulated antibody production with specific IgM still detected at 42 d post-vaccination, and significantly elevated the activity of antioxidant enzymes like Catalase (CAT), Superoxide dismutase (SOD), and lactate dehydrogenase (LDH) in the serum. The higher expression levels of immune-related genes were observed in the immune tissues of inoculated grouper compared to the control. In conclusion, ΔfliR effectively improved the immunity of inoculated fish. The results suggest that ΔfliR is an effective live attenuated vaccine against vibriosis in in grouper.
Collapse
Affiliation(s)
| | | | | | | | - Shuanghu Cai
- Guangdong Provincial Key Laboratory of Aquatic Animal Disease Control and Healthy Culture, Shenzhen Institute of Guangdong Ocean University, Fisheries College of Guangdong Ocean University, Guangdong, China
| |
Collapse
|
12
|
Yi X, Xu X, Chen Y, Xu G, Zhu Z, Li H, Shen H, Lin M, Zhao W, Zheng J, Jiang X. Genetic analysis of Vibrio alginolyticus challenged by Fructus schisandrae reveals the mechanism of virulence genes. Gene 2023; 870:147421. [PMID: 37031882 DOI: 10.1016/j.gene.2023.147421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 03/21/2023] [Accepted: 04/04/2023] [Indexed: 04/11/2023]
Abstract
Due to the abusive use of antibiotics, bacterial resistance has become a global problem and poses severe threats to aquaculture. The drug-resistant diseases caused by Vibrio alginolyticus have caused significant economic losses to cultured marine fish. Fructus schisandrae is used to treat inflammatory diseases in China and Japan. There have been no reports of bacterial molecular mechanisms associated with F. schisandrae stress. In this study, the inhibiting effect of F. schisandrae on the growth of V. alginolyticus was detected to understand response mechanisms at the molecular level. The antibacterial tests were analyzed via next-generation deep sequencing technology (RNA sequencing, RNA-seq). Wild V. alginolyticus (CK) was compared with V. alginolyticus, F. schisandrae incubated for 2 h, and V. alginolyticus, F. schisandrae incubated for 4 h. Our results revealed that there were 582 genes (236 upregulated and 346 downregulated) and 1068 genes (376 upregulated and 692 downregulated), respectively. Differentially expressed genes (DEGs) were involved in the following functional categories: metabolic process, single-organism process, catalytic activity, cellular process, binding, membrane, cell part, cell, and localization. FS_2 h was compared with FS_4 h, and 21 genes (14 upregulated and 7 downregulated) were obtained. The RNA-seq results were validated by detecting the expression levels of 13 genes using quantitative real-time polymerase chain reaction (qRT-PCR). The qRT-PCR results matched those of the sequencing, which reinforced the reliability of the RNA-seq. The results revealed the transcriptional response of V. alginolyticus to F. schisandrae, which will provide new ideas for studying V. alginolyticus' complex virulence molecular mechanism and the possibility of developing Schisandra to prevent and treat drug-resistant diseases.
Collapse
Affiliation(s)
- Xin Yi
- Fisheries College, Jimei University, Engineering Research Center of the Modern Technology for Eel Industry, Ministry of Education, Fujian Provincial Key Laboratory of Marine Fishery Resources and Eco-environment, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture and Rural Affairs, Fujian Province, Xiamen 361021, China
| | - XiaoJin Xu
- Fisheries College, Jimei University, Engineering Research Center of the Modern Technology for Eel Industry, Ministry of Education, Fujian Provincial Key Laboratory of Marine Fishery Resources and Eco-environment, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture and Rural Affairs, Fujian Province, Xiamen 361021, China; Fujian Province Key Laboratory of Special Aquatic Formula Feed(Fujian Tianma Science and Technology Group Co., Ltd.)
| | - YuNong Chen
- Fisheries College, Jimei University, Engineering Research Center of the Modern Technology for Eel Industry, Ministry of Education, Fujian Provincial Key Laboratory of Marine Fishery Resources and Eco-environment, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture and Rural Affairs, Fujian Province, Xiamen 361021, China; Fujian Province Key Laboratory of Special Aquatic Formula Feed(Fujian Tianma Science and Technology Group Co., Ltd.)
| | - Genhuang Xu
- Fisheries College, Jimei University, Engineering Research Center of the Modern Technology for Eel Industry, Ministry of Education, Fujian Provincial Key Laboratory of Marine Fishery Resources and Eco-environment, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture and Rural Affairs, Fujian Province, Xiamen 361021, China
| | - ZhiQin Zhu
- Fisheries College, Jimei University, Engineering Research Center of the Modern Technology for Eel Industry, Ministry of Education, Fujian Provincial Key Laboratory of Marine Fishery Resources and Eco-environment, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture and Rural Affairs, Fujian Province, Xiamen 361021, China
| | - Huiyao Li
- Fisheries Research Institute of Fujian, Xiamen 361013, China
| | - HaoYang Shen
- Fisheries College, Jimei University, Engineering Research Center of the Modern Technology for Eel Industry, Ministry of Education, Fujian Provincial Key Laboratory of Marine Fishery Resources and Eco-environment, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture and Rural Affairs, Fujian Province, Xiamen 361021, China
| | - Mao Lin
- Fisheries College, Jimei University, Engineering Research Center of the Modern Technology for Eel Industry, Ministry of Education, Fujian Provincial Key Laboratory of Marine Fishery Resources and Eco-environment, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture and Rural Affairs, Fujian Province, Xiamen 361021, China
| | - Wenyu Zhao
- Fisheries College, Jimei University, Engineering Research Center of the Modern Technology for Eel Industry, Ministry of Education, Fujian Provincial Key Laboratory of Marine Fishery Resources and Eco-environment, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture and Rural Affairs, Fujian Province, Xiamen 361021, China
| | - Jiang Zheng
- Fisheries College, Jimei University, Engineering Research Center of the Modern Technology for Eel Industry, Ministry of Education, Fujian Provincial Key Laboratory of Marine Fishery Resources and Eco-environment, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture and Rural Affairs, Fujian Province, Xiamen 361021, China
| | - XingLong Jiang
- Fisheries College, Jimei University, Engineering Research Center of the Modern Technology for Eel Industry, Ministry of Education, Fujian Provincial Key Laboratory of Marine Fishery Resources and Eco-environment, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture and Rural Affairs, Fujian Province, Xiamen 361021, China.
| |
Collapse
|
13
|
Xiao X, Li W, Pan Y, Wang J, Wei Z, Wang S, Wang N, Jian J, Pang H. Holistic analysis of lysine acetylation in aquaculture pathogenic bacteria Vibrio alginolyticus under bile salt stress. Front Vet Sci 2023; 10:1099255. [PMID: 37180076 PMCID: PMC10172577 DOI: 10.3389/fvets.2023.1099255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 04/11/2023] [Indexed: 05/15/2023] Open
Abstract
Lysine acetylation modification is a dynamic and reversible post-translational modification, which plays an important role in the metabolism and pathogenicity of pathogenic bacteria. Vibrio alginolyticus is a common pathogenic bacterium in aquaculture, and bile salt can trigger the expression of bacterial virulence. However, little is known about the function of lysine acetylation in V. alginolyticus under bile salt stress. In this study, 1,315 acetylated peptides on 689 proteins were identified in V. alginolyticus under bile salt stress by acetyl-lysine antibody enrichment and high-resolution mass spectrometry. Bioinformatics analysis found that the peptides motif ****A*Kac**** and *******Kac****A* were highly conserved, and protein lysine acetylation was involved in regulating various cellular biological processes and maintaining the normal life activities of bacteria, such as ribosome, aminoacyl-tRNA biosynthesis, fatty acid metabolism, two-component system, and bacterial secretion system. Further, 22 acetylated proteins were also found to be related to the virulence of V. alginolyticus under bile salt stress through secretion system, chemotaxis and motility, and adherence. Finally, comparing un-treated and treated with bile salt stress lysine acetylated proteins, it was found that there were 240 overlapping proteins, and found amino sugar and nucleotide sugar metabolism, beta-Lactam resistance, fatty acid degradation, carbon metabolism, and microbial metabolism in diverse environments pathways were significantly enriched in bile salt stress alone. In conclusion, this study is a holistic analysis of lysine acetylation in V. alginolyticus under bile salt stress, especially many virulence factors have also acetylated.
Collapse
Affiliation(s)
- Xing Xiao
- Fisheries College of Guangdong Ocean University & Southern Marine Science and Engineering Guangdong Laboratory (Zhanjiang), Zhanjiang, China
- Guangdong Provincial Key Laboratory of Aquatic Animal Disease Control and Healthy Culture, Key Laboratory of Control for Diseases of Aquatic Economic Animals of Guangdong Higher Education Institutes, Zhanjiang, China
| | - Wanxin Li
- School of Public Health, Fujian Medical University, Fujian, China
| | - Yanfang Pan
- Fisheries College of Guangdong Ocean University & Southern Marine Science and Engineering Guangdong Laboratory (Zhanjiang), Zhanjiang, China
- Guangdong Provincial Key Laboratory of Aquatic Animal Disease Control and Healthy Culture, Key Laboratory of Control for Diseases of Aquatic Economic Animals of Guangdong Higher Education Institutes, Zhanjiang, China
| | - Junlin Wang
- Fisheries College of Guangdong Ocean University & Southern Marine Science and Engineering Guangdong Laboratory (Zhanjiang), Zhanjiang, China
- Guangdong Provincial Key Laboratory of Aquatic Animal Disease Control and Healthy Culture, Key Laboratory of Control for Diseases of Aquatic Economic Animals of Guangdong Higher Education Institutes, Zhanjiang, China
| | - Zhiqing Wei
- Fisheries College of Guangdong Ocean University & Southern Marine Science and Engineering Guangdong Laboratory (Zhanjiang), Zhanjiang, China
- Guangdong Provincial Key Laboratory of Aquatic Animal Disease Control and Healthy Culture, Key Laboratory of Control for Diseases of Aquatic Economic Animals of Guangdong Higher Education Institutes, Zhanjiang, China
| | - Shi Wang
- Fisheries College of Guangdong Ocean University & Southern Marine Science and Engineering Guangdong Laboratory (Zhanjiang), Zhanjiang, China
- Guangdong Provincial Key Laboratory of Aquatic Animal Disease Control and Healthy Culture, Key Laboratory of Control for Diseases of Aquatic Economic Animals of Guangdong Higher Education Institutes, Zhanjiang, China
| | - Na Wang
- Chinese Academy of Inspection and Quarantine, Beijing, China
| | - Jichang Jian
- Fisheries College of Guangdong Ocean University & Southern Marine Science and Engineering Guangdong Laboratory (Zhanjiang), Zhanjiang, China
- Guangdong Provincial Key Laboratory of Aquatic Animal Disease Control and Healthy Culture, Key Laboratory of Control for Diseases of Aquatic Economic Animals of Guangdong Higher Education Institutes, Zhanjiang, China
| | - Huanying Pang
- Fisheries College of Guangdong Ocean University & Southern Marine Science and Engineering Guangdong Laboratory (Zhanjiang), Zhanjiang, China
- Guangdong Provincial Key Laboratory of Aquatic Animal Disease Control and Healthy Culture, Key Laboratory of Control for Diseases of Aquatic Economic Animals of Guangdong Higher Education Institutes, Zhanjiang, China
- *Correspondence: Huanying Pang
| |
Collapse
|
14
|
Yang D, Zhao L, Li Q, Huang L, Qin Y, Wang P, Zhu C, Yan Q. flgC gene is involved in the virulence regulation of Pseudomonas plecoglossicida and affects the immune response of Epinephelus coioides. FISH & SHELLFISH IMMUNOLOGY 2023; 132:108512. [PMID: 36587883 DOI: 10.1016/j.fsi.2022.108512] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Revised: 12/19/2022] [Accepted: 12/26/2022] [Indexed: 06/17/2023]
Abstract
As a pathogen of cultured teleosts, Pseudomonas plecoglossicida has caused significant economic losses. flgC plays an important role in encoding flagellar basal-body rod proteins. Our previous studies revealed the high expression of P. plecoglossicida flgC in infected Epinephelus coioides. To explore the role of flgC in the virulence of P. plecoglossicida and the immune response of E. coioides to the infection of P. plecoglossicida, flgC gene of P. plecoglossicida was knocked down by RNA interference (RNAi). The results showed that the flgC gene in all four mutants of P. plecoglossicida was significantly knocked down, and the mutant with the best knockdown efficiency of 94.3% was selected for subsequent studies. Compared with the NZBD9 strain of P. plecoglossicida, the flgC-RNAi strain showed a significantly decrease in chemotaxis, motility, adhesion, and biofilm formation. Furthermore, compared with the E. coioides infected with the NZBD9 strain, the infection of flgC-RNAi strain resulted in the infected E. coioides a 1.5-day delay in the time of first death and an 80% increase in survival rate, far fewer white nodules upon the spleen surfaces, and lower pathogen load in the spleens. RNAi of flgC significantly influenced the metabolome and transcriptome of the spleen in infected E. coioides. KEGG enrichment analysis exhibited that the Toll-like receptor signaling pathway was the most enriched immune pathway; the most significantly enriched metabolic pathways were associated with Linoleic acid metabolism, Choline metabolism in cancer, and Glycerophospholipid metabolism. Further combined analysis of transcriptome and metabolome indicated significant correlations among pantothenate and CoA biosynthesis, beta-alanine metabolism, lysosome metabolites, and related genes. These results suggested that flgC was a pathogenic gene of P. plecoglossicida; flgC was associated with the regulation of chemotaxis, motility, biofilm formation, and adhesion; flgC influenced the immune response of E. coioides to the infection of P. plecoglossicida.
Collapse
Affiliation(s)
- Dou Yang
- Fisheries College, Jimei University, Xiamen, Fujian, 361021, China
| | - Lingmin Zhao
- Fisheries College, Jimei University, Xiamen, Fujian, 361021, China
| | - Qi Li
- Fisheries College, Jimei University, Xiamen, Fujian, 361021, China
| | - Lixing Huang
- Fisheries College, Jimei University, Xiamen, Fujian, 361021, China
| | - Yingxue Qin
- Fisheries College, Jimei University, Xiamen, Fujian, 361021, China
| | - Pan Wang
- Key Laboratory of Aquatic Functional Feed and Environmental Regulation of Fujian Province, Fujian Dabeinong Aquatic Sci. & Tech. Co., Ltd., Zhangzhou, Fujian, 363503, China
| | - Chuanzhong Zhu
- Key Laboratory of Aquatic Functional Feed and Environmental Regulation of Fujian Province, Fujian Dabeinong Aquatic Sci. & Tech. Co., Ltd., Zhangzhou, Fujian, 363503, China
| | - Qingpi Yan
- Fisheries College, Jimei University, Xiamen, Fujian, 361021, China.
| |
Collapse
|
15
|
Nie W, Chen X, Tang Y, Xu N, Zhang H. Potential dsRNAs can be delivered to aquatic for defense pathogens. Front Bioeng Biotechnol 2022; 10:1066799. [PMID: 36466329 PMCID: PMC9712207 DOI: 10.3389/fbioe.2022.1066799] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Accepted: 11/03/2022] [Indexed: 10/29/2023] Open
Abstract
The use of antibiotics to facilitate resistance to pathogens in aquatic animals is a traditional method of pathogen control that is harmful to the environment and human health. RNAi is an emerging technology in which homologous small RNA molecules target specific genes for degradation, and it has already shown success in laboratory experiments. However, further research is needed before it can be applied in aquafarms. Many laboratories inject the dsRNA into aquatic animals for RNAi, which is obviously impractical and very time consuming in aquafarms. Therefore, to enable the use of RNAi on a large scale, the methods used to prepare dsRNA need to be continuously in order to be fast and efficient. At the same time, it is necessary to consider the issue of biological safety. This review summarizes the key harmful genes associated with aquatic pathogens (viruses, bacteria, and parasites) and provides potential targets for the preparation of dsRNA; it also lists some current examples where RNAi technology is used to control aquatic species, as well as how to deliver dsRNA to the target hydrobiont.
Collapse
Affiliation(s)
| | | | | | | | - Hao Zhang
- Key Laboratory of Marine Biotechnology of Zhejiang Province, School of Marine Sciences, Ningbo University, Ningbo, China
| |
Collapse
|
16
|
Yi X, Xu X, Qi X, Chen Y, Zhu Z, Xu G, Li H, Kraco EK, Shen H, Lin M, Zheng J, Qin Y, Jiang X. Mechanisms Underlying the Virulence Regulation of Vibrio alginolyticus ND-01 pstS and pstB with a Transcriptomic Analysis. Microorganisms 2022; 10:2093. [PMID: 36363689 PMCID: PMC9698627 DOI: 10.3390/microorganisms10112093] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 10/14/2022] [Accepted: 10/18/2022] [Indexed: 05/18/2024] Open
Abstract
Vibrio alginolyticus is a common opportunistic pathogen of fish, shrimp, and shellfish, and many diseases it causes can result in severe economic losses in the aquaculture industry. Causing host disease was confirmed by several virulence factors of V. alginolyticus. To date, there have been no reports on the effect of the pstS gene on its virulence regulation of V. alginolyticus. The virulence mechanism of target genes regulating V. alginolyticus is worthy of further study. Previous studies found that Fructus schisandrae (30 mg/mL) inhibited the growth of V. alginolyticus ND-01 (OD600 = 0.5) for 4 h, while the expressions of pstS and pstB were significantly affected by F. schisandrae stress. So, we speculated that pstS and pstB might be the virulence genes of V. alginolyticus, which were stably silenced by RNAi to construct the silencing strains pstS-RNAi and pstB-RNAi, respectively. After the expression of pstS or pstB gene was inhibited, the adhesion capacity and biofilm formation of V. alginolyticus were significantly down-regulated. The chemotaxis and biofilm formation ability of pstS-RNAi was reduced by 33.33% and 68.13% compared with the wild-type strain, respectively. Sequence alignment and homology analysis showed that pstS was highly conserved, which suggested that pstS played a vital role in the secretion system of V. alginolyticus. The pstS-RNAi with the highest silencing efficiency was selected for transcriptome sequencing. The Differentially Expressed Genes (DEGs) and GO terms were mapped to the reference genome of V. alginolyticus, including 1055 up-regulated genes and 1134 down-regulated genes. The functions of the DEGs were analyzed by GO and categorized into different enriched functional groups, such as ribosome synthesis, organelles, biosynthesis, pathogenesis, and secretion. These DEGs were then mapped to the reference KEGG pathways of V. alginolyticus and enriched in commonalities in the metabolic, ribosomal, and bacterial secretion pathways. Therefore, pstS and pstB could regulate the bacterial virulence of V. alginolyticus by affecting its adhesion, biofilm formation ability, and motility. Understanding the relationship between the expressions of pstS and pstB with bacterial virulence could provide new perspectives to prevent bacterial diseases.
Collapse
Affiliation(s)
- Xin Yi
- Key Laboratory of Healthy Mariculture for the East China Sea, Engineering Research Center of the Modern Technology for Eel Industry, Fisheries College, Jimei University, Xiamen 361021, China
| | - Xiaojin Xu
- Key Laboratory of Healthy Mariculture for the East China Sea, Engineering Research Center of the Modern Technology for Eel Industry, Fisheries College, Jimei University, Xiamen 361021, China
| | - Xin Qi
- Key Laboratory of Healthy Mariculture for the East China Sea, Engineering Research Center of the Modern Technology for Eel Industry, Fisheries College, Jimei University, Xiamen 361021, China
| | - Yunong Chen
- Key Laboratory of Healthy Mariculture for the East China Sea, Engineering Research Center of the Modern Technology for Eel Industry, Fisheries College, Jimei University, Xiamen 361021, China
| | - Zhiqin Zhu
- Key Laboratory of Healthy Mariculture for the East China Sea, Engineering Research Center of the Modern Technology for Eel Industry, Fisheries College, Jimei University, Xiamen 361021, China
| | - Genhuang Xu
- Key Laboratory of Healthy Mariculture for the East China Sea, Engineering Research Center of the Modern Technology for Eel Industry, Fisheries College, Jimei University, Xiamen 361021, China
| | - Huiyao Li
- Fisheries Research Institute of Fujian, Xiamen 361013, China
| | - Emma-Katharine Kraco
- School of Freshwater Sciences, University of Wisconsin-Milwaukee, 600 East Greenfield Avenue, Milwaukee, WI 53204, USA
| | - Haoyang Shen
- Key Laboratory of Healthy Mariculture for the East China Sea, Engineering Research Center of the Modern Technology for Eel Industry, Fisheries College, Jimei University, Xiamen 361021, China
| | - Mao Lin
- Key Laboratory of Healthy Mariculture for the East China Sea, Engineering Research Center of the Modern Technology for Eel Industry, Fisheries College, Jimei University, Xiamen 361021, China
| | - Jiang Zheng
- Key Laboratory of Healthy Mariculture for the East China Sea, Engineering Research Center of the Modern Technology for Eel Industry, Fisheries College, Jimei University, Xiamen 361021, China
| | - Yingxue Qin
- Key Laboratory of Healthy Mariculture for the East China Sea, Engineering Research Center of the Modern Technology for Eel Industry, Fisheries College, Jimei University, Xiamen 361021, China
| | - Xinglong Jiang
- Key Laboratory of Healthy Mariculture for the East China Sea, Engineering Research Center of the Modern Technology for Eel Industry, Fisheries College, Jimei University, Xiamen 361021, China
| |
Collapse
|
17
|
Xiao G, Zheng X, Li J, Yang Y, Yang J, Xiao N, Liu J, Sun Z. Contribution of the EnvZ/OmpR two-component system to growth, virulence and stress tolerance of colistin-resistant Aeromonas hydrophila. Front Microbiol 2022; 13:1032969. [PMID: 36312957 PMCID: PMC9597241 DOI: 10.3389/fmicb.2022.1032969] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 09/26/2022] [Indexed: 01/07/2024] Open
Abstract
Aeromonas hydrophila is an important zoonotic pathogen responsible for septicemia, diarrhea and gastroenteritis, and has attracted considerable attention. The EnvZ/OmpR two-component system (TCS) mediates environmental stress responses in gram-negative bacteria. We investigated the role of the TCS in A. hydrophila by comparing the characteristics of the parental (23-C-23), EnvZ/OmpR knockout (23-C-23:ΔEnvZ/OmpR), and complemented strains (23-C-23:CΔEnvZ/OmpR). Under non-stress conditions, the 23-C-23:ΔEnvZ/OmpR strain showed a significant decrease in growth rate compared to that of 23-C-23. Transcriptome and metabonomic analysis indicated that many metabolic pathways were remarkably affected in the ΔEnvZ/OmpR strain, including the TCA cycle and arginine biosynthesis. In addition, the virulence of the ΔEnvZ/OmpR strain was attenuated in a Kunming mouse model. The ΔEnvZ/OmpR strain exhibited notably reduced tolerance to environmental stresses, including high temperature, different pH conditions, oxidative stress, and high osmotic stress. The downregulated expression of genes related to cell metabolism, motility, and virulence in the ΔEnvZ/OmpR mutant strain was further validated by real-time quantitative PCR. Consequently, our data suggest that the EnvZ/OmpR TCS is required for growth, motility, virulence, and stress response in A. hydrophila, which has significant implications in the development of novel antibacterial and vaccine therapies targeting EnvZ/OmpR against A. hydrophila.
Collapse
Affiliation(s)
- Gang Xiao
- College of Veterinary Medicine, Hunan Agricultural University, Changsha, China
- Hunan Engineering Technology Research Center of Veterinary Drugs, Hunan Agricultural University, Changsha, China
| | - Xiaofeng Zheng
- College of Veterinary Medicine, Hunan Agricultural University, Changsha, China
- Hunan Engineering Technology Research Center of Veterinary Drugs, Hunan Agricultural University, Changsha, China
| | - Jiyun Li
- College of Veterinary Medicine, Hunan Agricultural University, Changsha, China
- Hunan Engineering Technology Research Center of Veterinary Drugs, Hunan Agricultural University, Changsha, China
| | - Yang Yang
- College of Veterinary Medicine, Hunan Agricultural University, Changsha, China
| | - Jie Yang
- College of Veterinary Medicine, Hunan Agricultural University, Changsha, China
- Hunan Engineering Technology Research Center of Veterinary Drugs, Hunan Agricultural University, Changsha, China
| | - Ning Xiao
- College of Veterinary Medicine, Hunan Agricultural University, Changsha, China
- Hunan Engineering Technology Research Center of Veterinary Drugs, Hunan Agricultural University, Changsha, China
| | - Junqi Liu
- Veterinary Drug Laboratory, Hunan Institute of Animal and Veterinary Science, Changsha, China
| | - Zhiliang Sun
- College of Veterinary Medicine, Hunan Agricultural University, Changsha, China
- Hunan Engineering Technology Research Center of Veterinary Drugs, Hunan Agricultural University, Changsha, China
- National Research Center of Engineering and Technology for Utilization of Botanical Functional Ingredients, Hunan Agricultural University, Changsha, China
| |
Collapse
|
18
|
Commercialized artemisinin derivatives combined with colistin protect against critical Gram-negative bacterial infection. Commun Biol 2022; 5:931. [PMID: 36076060 PMCID: PMC9458715 DOI: 10.1038/s42003-022-03898-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 08/25/2022] [Indexed: 11/25/2022] Open
Abstract
The emergence and spread of the mcr-1 gene and its mutants has immensely compromised the efficient usage of colistin for the treatment of drug-resistant Gram-negative bacterial infection in clinical settings. However, there are currently no clinically available colistin synergis. Here we identify artemisinin derivatives, such as dihydroartemisinin (DHA), that produces a synergistic antibacterial effect with colistin against the majority of Gram-negative bacteria (FIC < 0.5) without induced resistance, particularly those carrying the mcr-1 gene. Mechanism analysis reveals the direct engagement of DHA with the active center of MCR-1 to inhibit the activity of MCR-1. Meanwhile, the results from transcriptome and electron microscope analysis show that DHA could also simultaneously affect the flagellar assembly and the energy metabolism of bacteria. Moreover, in the mouse infection models of Gram-negative bacteria, combination therapy shows remarkable treatment benefits, as shown by an improved survival rate, reduced morbidity, alleviated pathological injury and decreased bacterial loading. Due to the generally safe profile of specialized malaria medication administration in humans, artemisinin derivatives are a promising class of multi-target inhibitors on bacterial resistance and virulence that can be used to extend the usage life of colistin and to tackle the inevitability of serious bacterial infection with colistin. The anti-malaria drugs artemisinin derivatives produce a synergistic antibacterial effect with colistin against Gram-negative bacteria by simultaneously inhibiting MCR-1 function and hindering flagella assembly and energy metabolism.
Collapse
|
19
|
Xin G, Zhao L, Zhuang Z, Wang X, Fu Q, Huang H, Huang L, Qin Y, Zhang J, Zhang J, Yan Q. Function of the rpoD gene in Pseudomonas plecoglossicida pathogenicity and Epinephelus coioides immune response. FISH & SHELLFISH IMMUNOLOGY 2022; 127:427-436. [PMID: 35779810 DOI: 10.1016/j.fsi.2022.06.045] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Revised: 06/24/2022] [Accepted: 06/24/2022] [Indexed: 06/15/2023]
Abstract
Pseudomonas plecoglossicida is a Gram-negative pathogenic bacterium that causes visceral white spot disease in several marine fish species, resulting in high mortality and financial loss. Based on previous RNA sequencing (RNA-seq) results, rpoD gene expression is significantly up-regulated in P. plecoglossicida during infection, indicating that rpoD may contribute to bacterial pathogenicity. To investigate the role of this gene, five specific short hairpin RNAs (shRNAs) were designed and synthesized based on the rpoD gene sequence, with all five mutants exhibiting a significant decrease in rpoD gene expression in P. plecoglossicida. The mutant with the highest silencing efficiency (89.2%) was chosen for further study. Compared with the wild-type (WT) P. plecoglossicida strain NZBD9, silencing rpoD in the rpoD-RNA interference (RNAi) strain resulted in a significant decrease in growth, motility, chemotaxis, adhesion, and biofilm formation in P. plecoglossicida. Silencing of rpoD also resulted in a 25% increase in the survival rate, a one-day delay in the onset of death, and a significant decrease in the number of white spots on the spleen surface of infected orange-spotted groupers (Epinephelus coioides). In addition, rpoD expression and pathogen load were significantly lower in the spleens of E. coioides infected with the rpoD-RNAi strain than with the WT strain of P. plecoglossicida. We performed RNA-seq of E. coioides spleens infected with different P. plecoglossicida strains. Results showed that rpoD silencing in P. plecoglossicida led to a significant change in the infected spleen transcriptomes. In addition, comparative transcriptome analysis showed that silencing rpoD caused significant changes in complement and coagulation cascades and the IL-17 signaling pathway. Thus, this study revealed the effects of the rpoD gene on P. plecoglossicida pathogenicity and identified the main pathway involved in the immune response of E. coioides.
Collapse
Affiliation(s)
- Ge Xin
- Fisheries College, Jimei University, Xiamen, Fujian, 361021, China
| | - Lingmin Zhao
- Fisheries College, Jimei University, Xiamen, Fujian, 361021, China
| | - Zhixia Zhuang
- College of Environment and Public Health, Xiamen Huaxia University, Xiamen, Fujian, 361024, China
| | - Xiaoru Wang
- College of Environment and Public Health, Xiamen Huaxia University, Xiamen, Fujian, 361024, China
| | - Qi Fu
- College of Environment and Public Health, Xiamen Huaxia University, Xiamen, Fujian, 361024, China
| | - Huabin Huang
- College of Environment and Public Health, Xiamen Huaxia University, Xiamen, Fujian, 361024, China
| | - Lixing Huang
- Fisheries College, Jimei University, Xiamen, Fujian, 361021, China
| | - Yingxue Qin
- Fisheries College, Jimei University, Xiamen, Fujian, 361021, China
| | - Jiaonan Zhang
- Key Laboratory of Special Aquatic Feed for Fujian, Fujian Tianma Technology Company Limited, Fuzhou, Fujian, 350308, China
| | - Jiaolin Zhang
- Key Laboratory of Special Aquatic Feed for Fujian, Fujian Tianma Technology Company Limited, Fuzhou, Fujian, 350308, China
| | - Qingpi Yan
- Fisheries College, Jimei University, Xiamen, Fujian, 361021, China.
| |
Collapse
|
20
|
Qi X, Xu X, Li H, Pan Y, Katharine Kraco E, Zheng J, Lin M, Jiang X. fliA, flrB, and fliR regulate adhesion by controlling the expression of critical virulence genes in Vibrio harveyi. Gene 2022; 839:146726. [PMID: 35835408 DOI: 10.1016/j.gene.2022.146726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 06/07/2022] [Accepted: 07/08/2022] [Indexed: 11/16/2022]
Abstract
Bacteria adhesion to fish mucus is a crucial virulence mechanism. As the initial step of bacterial infection, adhesion is impacted by bacterial motility and environmental conditions. However, its molecular mechanism is yet unclear. In this study, a significant decrease in gene expression of adhesion-deficient Vibrio harveyi was observed when the bacteria were subjected by Cu2+(50 mg/L), Pb2+(100 mg/L), Hg2+(25 mg/L), and Zn2+(50 mg/L). The genes fliA, fliR, and flrB were responsible for flagellation; being crucial for adhesion, these genes were identified and silenced via RNAi. After silencing of these genes by RNAi technology, the ability of adhesion, biofilm formation, motility, and flagella synthesis of V. harveyi were considerably reduced. Compared with the control group, it was observed that the expression levels of fliS, fliD, flgH, and flrC were significant down-regulated in fliR-RNAi, flrB-RNAi, and fliA-RNAi. This data indicates that the expression levels of most virulence genes are affected by fliA, fliR, and flrB. Also, the expression of fliA, fliR, and flrB can be influenced by the salinity, temperature, and pH. The results show that: (1) fliA, fliR, and flrB have important roles in the adhesion of V. harveyi; (2) fliA, fliR, and flrB can regulate bacterial adhesion by affecting its motility, and biofilm formation; (3) fliA, fliR, and flrB can regulate adhesion ability of V. harveyi in different environments.
Collapse
Affiliation(s)
- Xin Qi
- State Key Laboratory of Large Yellow Croaker Breeding, Fujian Fuding Seagull Fishing Food Co. Ltd., Ningde 352103, China; Fisheries College, Jimei University, Engineering Research Center of the Modern Technology for Eel Industry, Ministry of Education, Xiamen 361021, Fujian, China
| | - Xiaojin Xu
- State Key Laboratory of Large Yellow Croaker Breeding, Fujian Fuding Seagull Fishing Food Co. Ltd., Ningde 352103, China; Fisheries College, Jimei University, Engineering Research Center of the Modern Technology for Eel Industry, Ministry of Education, Xiamen 361021, Fujian, China; Fujian Province Key Laboratory of Special Aquatic Formula Feed (Fujian Tianma Science and Technology Group Co., Ltd., China; School of Freshwater Sciences, University of Wisconsin-Milwaukee, 600 East Greenfield Avenue, Milwaukee, WI 53204, USA.
| | - Huiyao Li
- State Key Laboratory of Large Yellow Croaker Breeding, Fujian Fuding Seagull Fishing Food Co. Ltd., Ningde 352103, China; Fisheries Research Institute of Fujian, Xiamen 361013, China
| | - Ying Pan
- State Key Laboratory of Large Yellow Croaker Breeding, Fujian Fuding Seagull Fishing Food Co. Ltd., Ningde 352103, China
| | | | - Jiang Zheng
- Fisheries College, Jimei University, Engineering Research Center of the Modern Technology for Eel Industry, Ministry of Education, Xiamen 361021, Fujian, China
| | - Mao Lin
- Fisheries College, Jimei University, Engineering Research Center of the Modern Technology for Eel Industry, Ministry of Education, Xiamen 361021, Fujian, China
| | - Xinglong Jiang
- State Key Laboratory of Large Yellow Croaker Breeding, Fujian Fuding Seagull Fishing Food Co. Ltd., Ningde 352103, China; Fisheries College, Jimei University, Engineering Research Center of the Modern Technology for Eel Industry, Ministry of Education, Xiamen 361021, Fujian, China.
| |
Collapse
|
21
|
Yan J, Yang Z, Xie J. Comparative Transcriptome Analysis of Shewanella putrefaciens WS13 Biofilms Under Cold Stress. Front Cell Infect Microbiol 2022; 12:851521. [PMID: 35811677 PMCID: PMC9257041 DOI: 10.3389/fcimb.2022.851521] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 05/18/2022] [Indexed: 01/08/2023] Open
Abstract
Shewanella putrefaciens is a Gram-negative bacterium that can cause seafood spoilage under low-temperature conditions. The bacterium easily forms biofilms to enhance its survival in challenging environments. Our previous research revealed that the biofilm formed by S. putrefaciens WS13 under the low temperature (4 °C) has larger biomass and tighter structure than at an optimum growth temperature (30 °C). In this study, comparative transcriptome analysis was further performed to get insights into the global-level of gene expression in the biofilm formed by S. putrefaciens WS13 under the refrigerating and optimal temperatures using Illumina RNA-Sequencing technique. The results revealed that a total of 761 genes were differentially expressed, of which 497 were significantly up-regulated and 264 were significantly down-regulated (p<0.05). The qRT-PCR results of randomly selected differentially expressed genes (DEGs) confirmed the RNA sequencing results. Comparison of transcriptome data revealed 28 significantly changed metabolic pathways under the cold stress, including the down-regulated chemotaxis, and motility, and up-regulated tryptophan metabolism, histidine biosynthesis, and quorum sensing, which benefited the biofilm formation of S. putrefaciens WS13 under the adverse circumstance. This study provided useful data for better understanding of the biofilm formation of S. putrefaciens, and also laid a theoretical foundation for novel vaccine and drug targets against the severe spoilage bacterium under the cold stress.
Collapse
Affiliation(s)
- Jun Yan
- College of Food Science & Technology, Shanghai Ocean University, Shanghai, China
- Laboratory for Quality and Safety Risk Assessment of Aquatic Products in Storage and Preservation of Ministry of Agriculture and Rural Affairs, Shanghai Ocean University, Shanghai, China
| | - Zhijun Yang
- College of Food Science & Technology, Shanghai Ocean University, Shanghai, China
| | - Jing Xie
- College of Food Science & Technology, Shanghai Ocean University, Shanghai, China
- Laboratory for Quality and Safety Risk Assessment of Aquatic Products in Storage and Preservation of Ministry of Agriculture and Rural Affairs, Shanghai Ocean University, Shanghai, China
- Shanghai Professional Technology Service Platform on Cold Chain Equipment Performance and Energy Saving Evaluation, Shanghai Ocean University, Shanghai, China
- National Experimental Teaching Demonstration Center for Food Science and Engineering, Shanghai Ocean University, Shanghai, China
- *Correspondence: Jing Xie,
| |
Collapse
|
22
|
Liang W, Zhang W, Li C. Vibrio splendidus virulence to Apostichopus japonicus is mediated by hppD through glutamate metabolism and flagellum assembly. Virulence 2022; 13:458-470. [PMID: 35259068 PMCID: PMC8920201 DOI: 10.1080/21505594.2022.2046949] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Vibrio splendidus is the main opportunistic pathogen that causes skin ulcer syndrome in Apostichopus japonicus. hppDIn the present study, mutant V. splendidus with an in-frame deletion of hppDV.s. (MTVs) was constructed. The median lethal doses of wild-type V. splendidus (WTVs) and MTVs were 5.129 × 106 and 2.606 × 1010 CFU mL−1, respectively. RNA-Seq was performed using WTVs and MTVs cells at different growth stages to explore the mechanisms of the pathogenesis mediated by hppDV.s. Gene Ontology analysis showed that the expression levels of 105 genes involved in amino acid metabolism and protein binding were remarkably different between MTVs and WTVs. Kyoto Encyclopedia of Genes and Genomes analysis showed that the pathways of glutamate metabolism and flagellum assembly involved in biofilm formation and swarming motility were suppressed in MTVs. Correspondingly, the swarming motility, biofilm formation and colonisation of MTVs were remarkably decreased compared with those of WTVs. The results showed that 4-hppD catalyses tyrosine into fumarate, which could enhance glutamate metabolism and ATP production; promote flagellum assembly through the TCA cycle and lead to higher swarming, biofilm formation and colonisation abilities, to contribute to the pathogenesis of V. splendidus.
Collapse
Affiliation(s)
- Weikang Liang
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Ningbo University, Ningbo, P. R. China
| | - Weiwei Zhang
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Ningbo University, Ningbo, P. R. China
| | - Chenghua Li
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Ningbo University, Ningbo, P. R. China.,Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, P. R. China
| |
Collapse
|
23
|
Zhang Y, Tan H, Yang S, Huang Y, Cai S, Jian J, Cai J, Qin Q. The role of dctP gene in regulating colonization, adhesion and pathogenicity of Vibrio alginolyticus strain HY9901. JOURNAL OF FISH DISEASES 2022; 45:421-434. [PMID: 34931326 DOI: 10.1111/jfd.13571] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 11/29/2021] [Accepted: 12/03/2021] [Indexed: 06/14/2023]
Abstract
Vibriosis caused by Vibrio alginolyticus has severely affected the development of mariculture industry in recent decades. DctP, a tripartite ATP-independent periplasmic transporter solute-binding subunit, is thought to be one of the virulence factors in Vibrio. In this study, the results displayed no difference in morphological characteristics and growth between ΔdctP (dctP mutant strain) and WT (wild-type strain). Nevertheless, the ability of swarming motility, biofilm formation, ECPase formation, cell adhesion and colonized ability of ΔdctP significantly decreased compared to those of WT. The LD50 of ΔdctP significantly increased by 40-fold compared to that of WT. The transcriptome analysis demonstrated the deletion mutation of dctP could regulate the expression levels of 22 genes related to colonization, adhesion and pathogenicity in V. alginolyticus. The analysis of qRT-PCR showed the transcriptome data were reliable. These results reveal the effect of attenuated function of DctP on colonization, adherence and pathogenicity by controlling the expression of related gene.
Collapse
Affiliation(s)
- Yilin Zhang
- Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animals & Key Laboratory of Control for Diseases of Aquatic Economic Animals of Guangdong Higher Education Institutes, Southern Marine Science and Engineering Guangdong Laboratory (Zhanjiang), Fisheries College of Guangdong Ocean University, Zhanjiang, China
| | - Huimin Tan
- Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animals & Key Laboratory of Control for Diseases of Aquatic Economic Animals of Guangdong Higher Education Institutes, Southern Marine Science and Engineering Guangdong Laboratory (Zhanjiang), Fisheries College of Guangdong Ocean University, Zhanjiang, China
| | - Shiping Yang
- Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animals & Key Laboratory of Control for Diseases of Aquatic Economic Animals of Guangdong Higher Education Institutes, Southern Marine Science and Engineering Guangdong Laboratory (Zhanjiang), Fisheries College of Guangdong Ocean University, Zhanjiang, China
| | - Yucong Huang
- Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animals & Key Laboratory of Control for Diseases of Aquatic Economic Animals of Guangdong Higher Education Institutes, Southern Marine Science and Engineering Guangdong Laboratory (Zhanjiang), Fisheries College of Guangdong Ocean University, Zhanjiang, China
| | - Shuanghu Cai
- Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animals & Key Laboratory of Control for Diseases of Aquatic Economic Animals of Guangdong Higher Education Institutes, Southern Marine Science and Engineering Guangdong Laboratory (Zhanjiang), Fisheries College of Guangdong Ocean University, Zhanjiang, China
- Guangdong Provincial Engineering Research Center for Aquatic Animal Health Assessment, Shenzhen Institute of Guangdong Ocean University, Shenzhen, China
| | - Jichang Jian
- Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animals & Key Laboratory of Control for Diseases of Aquatic Economic Animals of Guangdong Higher Education Institutes, Southern Marine Science and Engineering Guangdong Laboratory (Zhanjiang), Fisheries College of Guangdong Ocean University, Zhanjiang, China
- Guangdong Provincial Engineering Research Center for Aquatic Animal Health Assessment, Shenzhen Institute of Guangdong Ocean University, Shenzhen, China
| | - Jia Cai
- Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animals & Key Laboratory of Control for Diseases of Aquatic Economic Animals of Guangdong Higher Education Institutes, Southern Marine Science and Engineering Guangdong Laboratory (Zhanjiang), Fisheries College of Guangdong Ocean University, Zhanjiang, China
- Guangdong Provincial Engineering Research Center for Aquatic Animal Health Assessment, Shenzhen Institute of Guangdong Ocean University, Shenzhen, China
| | - Qiwei Qin
- College of Marine Sciences, South China Agricultural University, Guangzhou, China
| |
Collapse
|
24
|
Mekasha S, Linke D. Secretion Systems in Gram-Negative Bacterial Fish Pathogens. Front Microbiol 2022; 12:782673. [PMID: 34975803 PMCID: PMC8714846 DOI: 10.3389/fmicb.2021.782673] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 11/24/2021] [Indexed: 12/17/2022] Open
Abstract
Bacterial fish pathogens are one of the key challenges in the aquaculture industry, one of the fast-growing industries worldwide. These pathogens rely on arsenal of virulence factors such as toxins, adhesins, effectors and enzymes to promote colonization and infection. Translocation of virulence factors across the membrane to either the extracellular environment or directly into the host cells is performed by single or multiple dedicated secretion systems. These secretion systems are often key to the infection process. They can range from simple single-protein systems to complex injection needles made from dozens of subunits. Here, we review the different types of secretion systems in Gram-negative bacterial fish pathogens and describe their putative roles in pathogenicity. We find that the available information is fragmented and often descriptive, and hope that our overview will help researchers to more systematically learn from the similarities and differences between the virulence factors and secretion systems of the fish-pathogenic species described here.
Collapse
Affiliation(s)
- Sophanit Mekasha
- Section for Genetics and Evolutionary Biology, Department of Biosciences, University of Oslo, Oslo, Norway
| | - Dirk Linke
- Section for Genetics and Evolutionary Biology, Department of Biosciences, University of Oslo, Oslo, Norway
| |
Collapse
|
25
|
Jiao J, Zhao L, Huang L, Qin Y, Su Y, Zheng W, Zhang J, Yan Q. The contributions of fliG gene to the pathogenicity of Pseudomonas plecoglossicida and pathogen-host interactions with Epinephelus coioides. FISH & SHELLFISH IMMUNOLOGY 2021; 119:238-248. [PMID: 34634455 DOI: 10.1016/j.fsi.2021.09.032] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 09/23/2021] [Accepted: 09/25/2021] [Indexed: 06/13/2023]
Abstract
Pseudomonas plecoglossicida is a Gram-negative aerobic rod-shaped bacterium with polar flagella. It is the causative agent of visceral white spot disease in cultured fish, resulting in serious economic losses. In our previous study, RNA sequencing showed that the expression of the fliG gene in P. plecoglossicida is significantly up-regulated during infection of orange-spotted grouper (Epinephelus coioides). In this study, four P. plecoglossicida RNA interference (RNAi) mutants were successfully constructed by linking four short hairpin RNAs (shRNAs), which target different sites of the fliG gene, to pCM130/tac, respectively. The mRNA expression levels of the fliG gene in P. plecoglossicida were significantly decreased in four mutants. The shRNA-335 mutant (fliG-RNAi strain) showed the best silencing efficiency (88.2%) and was thus chosen for further analysis. Electron microscopy indicated that the flagella of the fliG-RNAi strain of P. plecoglossicida were shorter and finer than those of the wild type strain. The fliG-RNAi strain also showed significantly decreased mobility, chemotaxis, adhesion, and biofilm formation. Furthermore, compared with wild type strain infection, E. coioides infected with the fliG-RNAi strain exhibited a 0.5-d delay in the time of first death and 55% reduction in accumulated mortality, as well as milder splenic symptoms. RNAi of the fliG gene significantly affected the transcriptomes of both pathogen and host in the infected spleens of E. coioides. KEGG analysis revealed that the flagellar assembly pathway, bacterial chemotaxis pathway, and starch and sucrose metabolism pathway were significantly enriched in the pathogen at 3 days post infection (dpi). In contrast, the complement and coagulation cascade pathway and antigen processing and presentation pathway were significantly enriched in the host at 3 dpi. More immune-related pathways were enriched at 5 dpi and more differentially expressed genes were found in the complement and coagulation cascade and antigen processing and presentation pathways. Cytokine-cytokine receptor interaction, hematopoietic cell lineage, and IgA-producing intestinal immune network pathways were significantly enriched in the host at 5 dpi. These results indicate that fliG is an important virulence gene of P. plecoglossicida and contributes to the pathogenicity of P. plecoglossicida as well as pathogen-host interactions with E. coioides.
Collapse
Affiliation(s)
- Jiping Jiao
- Fisheries College, Jimei University, Xiamen, Fujian, 361021, China
| | - Lingmin Zhao
- Fisheries College, Jimei University, Xiamen, Fujian, 361021, China
| | - Lixing Huang
- Fisheries College, Jimei University, Xiamen, Fujian, 361021, China
| | - Yingxue Qin
- Fisheries College, Jimei University, Xiamen, Fujian, 361021, China
| | - Yongquan Su
- State Key Laboratory of Large Yellow Croaker Breeding, Ningde, Fujian, 352000, China
| | - Weiqiang Zheng
- State Key Laboratory of Large Yellow Croaker Breeding, Ningde, Fujian, 352000, China
| | - Jiaonan Zhang
- Key Laboratory of Special Aquatic Feed for Fujian, Fujian Tianma Technology Company Limited, Fuzhou, Fujian, 350308, China
| | - Qingpi Yan
- Fisheries College, Jimei University, Xiamen, Fujian, 361021, China; State Key Laboratory of Large Yellow Croaker Breeding, Ningde, Fujian, 352000, China.
| |
Collapse
|
26
|
Zhang Y, Deng Y, Feng J, Hu J, Chen H, Guo Z, Gao R, Su Y. ToxR modulates biofilm formation in fish pathogen Vibrio harveyi. Lett Appl Microbiol 2021; 74:288-299. [PMID: 34822732 DOI: 10.1111/lam.13606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 10/06/2021] [Accepted: 10/19/2021] [Indexed: 11/29/2022]
Abstract
Vibrio harveyi is a common aquaculture pathogen causing diseases in a variety of aquatic animals. toxR, a conserved virulence-associated gene in vibrios, is identified in V. harveyi 345, a pathogenic strain isolated from diseased fish. In this study, to gain insight into function of ToxR in V. harveyi, an in-frame deletion of the toxR gene was constructed to reveal the role of ToxR in the physiology and virulence of V. harveyi. The statistical analysis showed no significant differences in the growth ability, motility, extracellular protease secretion, antibiotic susceptibility, virulence by intraperitoneal injection and the ability of V. harveyi to colonize the spleen and liver tissues of the pearl gentian grouper between the wild-type (WT) and the toxR mutant. However, the deletion of toxR increased the biofilm formation. The structure of the V. harveyi biofilm was further analysed by using scanning electron microscopy (SEM) and confocal laser scanning microscopy, and the results showed that deletion of toxR increased the number and density of V. harveyi biofilm. Since biofilm production is flagella, exopolysaccharide (EPS) and lipopolysaccharide dependent, 16 of V. harveyi biofilm-related genes were selected for further analysis. Based on quantitative real-time reverse transcription-PCR, the expression levels of these genes, including genes flrB, motY and mshA, flaE, flrA and gmhD, were significantly up-regulated in the ΔtoxR+ strain as compared with the WT+ and C-ΔtoxR strains during the early and mid-exponential, while epsG, flaA, flaE, flgD, flgE, flrB, flrC, lpxB, motY, mshA and scrG genes were inhibited because of deletion of the toxR gene in the stationary growth phase. Our results indicate that ToxR plays an important role in controlling the biofilm in V. harveyi.
Collapse
Affiliation(s)
- Y Zhang
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China.,College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China
| | - Y Deng
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China
| | - J Feng
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China
| | - J Hu
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China.,College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China
| | - H Chen
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China.,College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China
| | - Z Guo
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China
| | - R Gao
- Zhaoqing Dahuanong Biology Medicine Co. Ltd, Guangdong, Zhaoqing, PR China
| | - Y Su
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China.,Innovative Institute of Animal Healthy Breeding, College of Animal Sciences and Technology, Zhongkai University of Agriculture and Engineering, Guangzhou, China
| |
Collapse
|
27
|
Hu L, Zhao L, Zhuang Z, Wang X, Fu Q, Huang H, Lin L, Huang L, Qin Y, Zhang J, Yan Q. The Effect of tonB Gene on the Virulence of Pseudomonas plecoglossicida and the Immune Response of Epinephelus coioides. Front Microbiol 2021; 12:720967. [PMID: 34484162 PMCID: PMC8415555 DOI: 10.3389/fmicb.2021.720967] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2021] [Accepted: 07/21/2021] [Indexed: 01/03/2023] Open
Abstract
Pseudomonas plecoglossicida is the causative agent of "visceral white spot disease" in cultured fish and has resulted in serious economic losses. tonB gene plays a crucial role in the uptake of nutrients from the outer membranes in Gram-negative bacteria. The previous results of our lab showed that the expression of tonB gene of P. plecoglossicida was significantly upregulated in the spleens of infected Epinephelus coioides. To explore the effect of tonB gene on the virulence of P. plecoglossicida and the immune response of E. coioides, tonB gene of P. plecoglossicida was knocked down by RNAi; and the differences between the wild-type strain and the tonB-RNAi strain of P. plecoglossicida were investigated. The results showed that all of the four mutants of P. plecoglossicida exhibited significant decreases in mRNA of tonB gene, and the best knockdown efficiency was 94.0%; the survival rate of E. coioides infected with the tonB-RNAi strain was 20% higher than of the counterpart infected with the wild strain of P. plecoglossicida. Meanwhile, the E. coioides infected with the tonB-RNAi strain of P. plecoglossicida carried less pathogens in the spleen and less white spots on the surface of the spleen; compared with the wild-type strain, the motility, chemotaxis, adhesion, and biofilm formation of the tonB-RNAi strain were significantly attenuated; the transcriptome data of E. coioides infected with the tonB-RNAi strain were different from the counterpart infected with the wild strain of P. plecoglossicida; the antigen processing and presentation pathway and the complement and coagulation cascade pathway were the most enriched immune pathways. The results indicated that tonB was a virulence gene of P. plecoglossicida; tonB gene was involved in the regulation of motility, chemotaxis, adhesion, and biofilm formation; tonB gene affected the immune response of E. coioides to P. plecoglossicida infection.
Collapse
Affiliation(s)
- Lingfei Hu
- Fisheries College, Jimei University, Xiamen, China
| | - Lingmin Zhao
- Fisheries College, Jimei University, Xiamen, China
| | - Zhixia Zhuang
- College of Environment and Public Health, Xiamen Huaxia University, Xiamen, China
| | - Xiaoru Wang
- College of Environment and Public Health, Xiamen Huaxia University, Xiamen, China
| | - Qi Fu
- College of Environment and Public Health, Xiamen Huaxia University, Xiamen, China
| | - Huabin Huang
- College of Environment and Public Health, Xiamen Huaxia University, Xiamen, China
| | - Lili Lin
- College of Environment and Public Health, Xiamen Huaxia University, Xiamen, China
| | - Lixing Huang
- Fisheries College, Jimei University, Xiamen, China
| | - Yingxue Qin
- Fisheries College, Jimei University, Xiamen, China
| | - Jiaonan Zhang
- Key Laboratory of Special Aquatic Feed for Fujian, Fujian Tianma Technology Company Limited, Fuzhou, China
| | - Qingpi Yan
- Fisheries College, Jimei University, Xiamen, China.,College of Environment and Public Health, Xiamen Huaxia University, Xiamen, China.,Key Laboratory of Special Aquatic Feed for Fujian, Fujian Tianma Technology Company Limited, Fuzhou, China
| |
Collapse
|
28
|
Disentangling the abundance and structure of Vibrio communities in a semi-enclosed Bay with mariculture (Dongshan Bay, Southern China). Comput Struct Biotechnol J 2021; 19:4381-4393. [PMID: 34429854 PMCID: PMC8365367 DOI: 10.1016/j.csbj.2021.07.040] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 07/26/2021] [Accepted: 07/29/2021] [Indexed: 11/23/2022] Open
Abstract
The genus Vibrio contains a diverse group of heterotrophic bacteria, which are members of ubiquitous and abundant microbial communities in coastal ecosystems. Vibrio has been frequently found in a wide range of marine environments either by employing Vibrio-specific 16S rRNA sequencing or culturing methods. A combination of molecular and cultivation-dependent methods was developed to more precisely discriminate between different members of the genus Vibrio in seawater. This newly developed assay was subsequently applied to characterize Vibrio community composition in surface water at 18 mariculture sites. It Substantially improved the taxonomic resolution of Vibrio species when compared to traditional 16S rRNA analysis. Our qPCR and cultivation analyses revealed that average Vibrio abundance (Vibrio 16S rRNA gene copy numbers: 3.46 × 106 to 6.70 × 106 copies L−1) and live cell numbers (5.65 × 104–5.75 × 105 cfu mL−1) are significantly related to pH. Total bacteria and Vibrio-specific 16S rRNA metabarcode sequenceing resulted in a total of 10 and 32 operational taxonomic units (OTUs), respectively, and 15 Vibrio species were identified by targeted cultivation of Vibrio strains, with Vibrio fortis and V. brasiliensis dominating in the mariculture areas. The purpose of this study was to combine several analytical methods to improve current sequence-based Vibrio community surveys, and to prove for the effectiveness of this methodological approach comprehensively testing for Vibrio dynamics in different coastal environments.
Collapse
|
29
|
Diffusible signal factor signaling controls bioleaching activity and niche protection in the acidophilic, mineral-oxidizing leptospirilli. Sci Rep 2021; 11:16275. [PMID: 34381075 PMCID: PMC8357829 DOI: 10.1038/s41598-021-95324-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 07/21/2021] [Indexed: 11/08/2022] Open
Abstract
Bioleaching of metal sulfide ores involves acidophilic microbes that catalyze the chemical dissolution of the metal sulfide bond that is enhanced by attached and planktonic cell mediated oxidation of iron(II)-ions and inorganic sulfur compounds. Leptospirillum spp. often predominate in sulfide mineral-containing environments, including bioheaps for copper recovery from chalcopyrite, as they are effective primary mineral colonizers and oxidize iron(II)-ions efficiently. In this study, we demonstrated a functional diffusible signal factor interspecies quorum sensing signaling mechanism in Leptospirillum ferriphilum and Leptospirillum ferrooxidans that produces (Z)-11-methyl-2-dodecenoic acid when grown with pyrite as energy source. In addition, pure diffusible signal factor and extracts from supernatants of pyrite grown Leptospirillum spp. inhibited biological iron oxidation in various species, and that pyrite grown Leptospirillum cells were less affected than iron grown cells to self inhibition. Finally, transcriptional analyses for the inhibition of iron-grown L. ferriphilum cells due to diffusible signal factor was compared with the response to exposure of cells to N- acyl-homoserine-lactone type quorum sensing signal compounds. The data suggested that Leptospirillum spp. diffusible signal factor production is a strategy for niche protection and defense against other microbes and it is proposed that this may be exploited to inhibit unwanted acidophile species.
Collapse
|
30
|
Xu X, Li H, Qi X, Chen Y, Qin Y, Zheng J, Jiang X. cheA, cheB, cheR, cheV, and cheY Are Involved in Regulating the Adhesion of Vibrio harveyi. Front Cell Infect Microbiol 2021; 10:591751. [PMID: 33614522 PMCID: PMC7887938 DOI: 10.3389/fcimb.2020.591751] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 12/01/2020] [Indexed: 11/13/2022] Open
Abstract
Diseases caused by Vibrio harveyi lead to severe economic losses in the aquaculture industry. Adhesion is an important disease-causing factor observed in bacteria with chemotactic activity. In our study, we measured the adhesion of V. harveyi by subjecting the bacteria to stress using Cu2+, Pb2+, Hg2+, and Zn2+. The genes responsible for chemotaxis (cheA, cheB, cheR, cheV, and cheY), which are also crucial for adhesion, were identified and silenced via RNAi. We observed that a decrease in chemotactic gene expression reduced the ability of the organism to demonstrate adhesion, motility, chemotaxis, and biofilm formation. Upon comparing the cheA-RNAi bacteria to the wild-type strain, we observed that the transcriptome of V. harveyi was significantly altered. Additionally, the expression of key genes and the adhesion ability were affected by the pH (pH of 5, 6, 7, 8, and 9), salinity (NaCl at concentrations of 0.8, 1.5, 2.5, 3.5, or 4.5%), and temperature (4, 15, 28, 37, and 44°C) of the medium. Based on these results, the following conclusions were made: (1) The chemotactic genes cheA, cheB, cheR, cheV, and cheY may regulate the adhesion ability of V. harveyi by affecting bacterial motility, and participate in the regulation of adhesion at different temperatures, salinities, and pH values; (2) stable silencing of cheA could alter the transcriptional landscape of V. harveyi and regulate the expression of genes associated with its adhesion mechanisms.
Collapse
Affiliation(s)
- Xiaojin Xu
- Fisheries College, Jimei University, Xiamen, China.,Engineering Research Centre of Eel Modern Industrial Technology, Ministry of Education, Xiamen, China.,Jimei University, Xiamen, China.,State Key Laboratory of Large Yellow Croaker Breeding, Ningde Fufa Fisheries Company Limited, Ningde, China.,Fujian Province Key Laboratory of Special Aquatic Formula Feed, Fujian Tianma Science and Technology Group Co., Ltd., Fuzhou, China
| | - Huiyao Li
- Fisheries College, Jimei University, Xiamen, China.,Engineering Research Centre of Eel Modern Industrial Technology, Ministry of Education, Xiamen, China.,Jimei University, Xiamen, China
| | - Xin Qi
- Fisheries College, Jimei University, Xiamen, China.,Engineering Research Centre of Eel Modern Industrial Technology, Ministry of Education, Xiamen, China.,Jimei University, Xiamen, China
| | - Yunong Chen
- Fisheries College, Jimei University, Xiamen, China.,Engineering Research Centre of Eel Modern Industrial Technology, Ministry of Education, Xiamen, China.,Jimei University, Xiamen, China
| | - Yingxue Qin
- Fisheries College, Jimei University, Xiamen, China.,Engineering Research Centre of Eel Modern Industrial Technology, Ministry of Education, Xiamen, China.,Jimei University, Xiamen, China
| | - Jiang Zheng
- Fisheries College, Jimei University, Xiamen, China.,Engineering Research Centre of Eel Modern Industrial Technology, Ministry of Education, Xiamen, China.,Jimei University, Xiamen, China.,State Key Laboratory of Large Yellow Croaker Breeding, Ningde Fufa Fisheries Company Limited, Ningde, China
| | - Xinglong Jiang
- Fisheries College, Jimei University, Xiamen, China.,Engineering Research Centre of Eel Modern Industrial Technology, Ministry of Education, Xiamen, China.,Jimei University, Xiamen, China
| |
Collapse
|
31
|
Setiaji J, Feliatra F, Teruna HY, Lukistyowati I, Suharman I, Muchlisin ZA, Johan TI. Antibacterial activity in secondary metabolite extracts of heterotrophic bacteria against Vibrio alginolyticus, Aeromonas hydrophila, and Pseudomonas aeruginosa. F1000Res 2020; 9:1491. [PMID: 33537126 PMCID: PMC7839275 DOI: 10.12688/f1000research.26215.1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/15/2020] [Indexed: 12/12/2022] Open
Abstract
Background: Disease causing bacteria such as Vibrio alginolyticus, Aeromonas hydrophila, and Pseudomonas aeruginosa present a problem for fish farming. Treatment to remove them are generally carried out using antibiotics which have side effects on fish, the environment and humans. However, the use of antibacterial compounds derived from heterotrophic bacteria serve as a good alternative for antibiotics. Therefore, this study aimed to explore antibacterial activity in the secondary metabolite extracts of heterotrophic bacteria against Vibrio alginolyticus, Aeromonas hydrophila, and Pseudomonas aeruginosa. Methods: Heterotrophic bacteria namely Bacillus sp. JS04 MT102913.1, Bacillus toyonensis JS08 MT102920.1, Bacillus cereus JS10 MT102922.1, Bacillus sp. JS11 MT102923.1, Pseudoalteromonas sp. JS19 MT102924.1, Bacillus cereus JS22 MT102926.1, and Bacillus sp. strain JS25 MT102927.1 were used in this study. The sequences of these bacteria have been deposited and are available from NCBI GenBank. Each heterotrophic bacterium was cultured on 6L nutrient broth for 8 days, and extracts produced using ethyl acetate to obtain their secondary metabolites. These extracts were tested for their phytochemical contents using FT-IR and also tested for their inhibitory property in pathogenic bacteria by agar diffusion method. Results: Phytochemical test results showed that the seven heterotrophic bacterial isolates produced terpenoid compounds. Based on the inhibitory test, the secondary metabolite extracts from Bacillus sp strain JS04 had the highest inhibitory effect on the growth of pathogenic bacteria namely, V. alginolyticus (17.5 mm), A. hydrophila (16.8 mm), and P. aeruginosa (17.3 mm). Conclusion: It was concluded that the secondary metabolite extracts of heterotrophic bacteria inhibit the growth of V. alginolyticus, A. hydrophila, and P. aeruginosa.
Collapse
Affiliation(s)
- Jarod Setiaji
- Faculty of Fisheries and Marine Science., Universitas Riau, Pekanbaru, Riau, Indonesia
- Faculty of Agriculture, Universitas Islam Riau, Pekanbaru, Riau, Indonesia
| | - Feli Feliatra
- Faculty of Fisheries and Marine Science., Universitas Riau, Pekanbaru, Riau, Indonesia
| | - Hilwan Yuda Teruna
- Faculty of Mathematics and Natural Science, Universitas Riau, Pekanbaru, Riau, Indonesia
| | - Iesje Lukistyowati
- Faculty of Fisheries and Marine Science., Universitas Riau, Pekanbaru, Riau, Indonesia
| | - Indra Suharman
- Faculty of Fisheries and Marine Science., Universitas Riau, Pekanbaru, Riau, Indonesia
| | - Zainal Abidin Muchlisin
- Faculty of Marine and Fisheries, Universitas Syiah Kuala, Banda Aceh, Aceh, 23111, Indonesia
| | | |
Collapse
|
32
|
Patterns and drivers of Vibrio isolates phylogenetic diversity in the Beibu Gulf, China. J Microbiol 2020; 58:998-1009. [PMID: 33095386 DOI: 10.1007/s12275-020-0293-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 08/04/2020] [Accepted: 08/31/2020] [Indexed: 12/12/2022]
Abstract
Members of the genus Vibrio are ubiquitous in aquatic environments and can be found either in a culturable or a viable but nonculturable (VBNC) state. Despite widespread concerns as to how to define the occurrence and dynamics of Vibrio populations by culture-independent approaches, further physiological research and relevant biotechnological developments will require the isolation and cultivation of the microbes from various environments. The present work provides data and perspectives on our understanding of culturable Vibrio community structure and diversity in the Beibu Gulf. Finally, we isolated 1,037 strains of Vibrio from 45 samples and identified 18 different species. Vibrio alginolyticus, V. cyclitrophicus, V. tasmaniensis, V. brasiliensis, and V. splendidus were the dominant species that had regional distribution characteristics. The correlation between the quantitative distribution and community structure of culturable Vibrio and environmental factors varied with the Vibrio species and geographical locations. Among them, salinity, nitrogen, and phosphorus were the main factors affecting the diversity of culturable Vibrio. These results help to fill a knowledge gap on Vibrio diversity and provide data for predicting and controlling pathogenic Vibrio outbreaks in the Beibu Gulf.
Collapse
|
33
|
Sun Y, Zhu Z, Weng S, He J, Dong C. Characterization of a highly lethal barramundi (Lates calcarifer) model of Pseudomonas plecoglossicida infection. Microb Pathog 2020; 149:104516. [PMID: 32971158 DOI: 10.1016/j.micpath.2020.104516] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 08/17/2020] [Accepted: 08/18/2020] [Indexed: 11/15/2022]
Abstract
Pseudomonas plecoglossicida is a highly lethal causative agent associated with severe economic losses in aquaculture industry. P. plecoglossicida has been documented as a highly alarming pathogen in a wide variety of freshwater cultured fish including ayu (Plecoglossus altivelis), rainbow trout (Oncorhynchus mykiss) and pejerrey (Odontesthes bonariensis), and marine cultured fish such as large yellow croaker (Larimichthys crocea) and orange-spotted grouper (Epinephelus coioides) etc. Fish infected with P. plecoglossicida usually exhibited various symptoms, including lethargy, inappetence, disorientation, abdominal swelling with severe ascites and numerous white spots covered on the surface of spleen tissue. In present study, barramundi, zebrafish, spotted seabass and mandarinfish were investigated as potential hosts of P. plecoglossicida. Among them, barramundi was confirmed the most sensitive host fish species for P. plecoglossicida infection. Dynamic histopathology revealed that P. plecoglossicida caused various histopathological effects to barramundi: a) spleen: granulomas appeared at 2 days post infection (dpi) and matured at 4 dpi; b) liver: steatosis at 1 dpi and fat necrosis over time, and damaged the most compared to spleens and metanephros; c) metanephros: Bowman capsule space became larger and glomerulus shrank were even collapsed at 1 dpi; d) ascites: either bacterium or melanin were wrapped in cells from ascites. All these results indicated that P. plecoglossicida could cause systemic diseases with typical clinical sighs to barramundi and would be an alarming pathogen to barramundi industry.
Collapse
Affiliation(s)
- Yujia Sun
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, Guangdong, PR China; Southern Marine Sciences and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, 519000, Guangdong, PR China; Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, Guangzhou, 510275, PR China
| | - Zhiming Zhu
- Southern Marine Sciences and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, 519000, Guangdong, PR China; Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, Guangzhou, 510275, PR China; School of Marine Sciences, Sun Yat-sen University, Zhuhai, 519000, Guangdong, PR China
| | - Shaoping Weng
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, Guangdong, PR China; Southern Marine Sciences and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, 519000, Guangdong, PR China; Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, Guangzhou, 510275, PR China
| | - Jianguo He
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, Guangdong, PR China; Southern Marine Sciences and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, 519000, Guangdong, PR China; Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, Guangzhou, 510275, PR China; School of Marine Sciences, Sun Yat-sen University, Zhuhai, 519000, Guangdong, PR China
| | - Chuanfu Dong
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, Guangdong, PR China; Southern Marine Sciences and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, 519000, Guangdong, PR China; Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, Guangzhou, 510275, PR China.
| |
Collapse
|
34
|
Dai F, Zhang W, Zhuang Q, Shao Y, Zhao X, Lv Z, Li C. Dihydrolipoamide dehydrogenase of Vibrio splendidus is involved in adhesion to Apostichopus japonicus. Virulence 2020; 10:839-848. [PMID: 31647357 PMCID: PMC6816312 DOI: 10.1080/21505594.2019.1682761] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Vibrio splendidus is one of the most opportunistic marine pathogens and infects many important marine animals, including the sea cucumber Apostichopus japonicus. In this study, two genes named DLD1 and DLD2, encoding dihydrolipoamide dehydrogenase (DLD) homologues in pathogenic V. splendidus, were cloned, and conditionally expressed in Escherichia coli BL21 (DE3). The enzymatic activities of DLD1 and DLD2 showed that they both belonged to the NADH oxidase family. Both DLD1 and DLD2 were located on the outer membrane of V. splendidus as detected by whole-cell ELISA. To study the adhesion function of DLD1 and DLD2, polyclonal antibodies were prepared, and antibody block assay was performed to detect the normal function of the two proteins. DLD1 and DLD2 were determined to play important roles in adhesion to different matrices and the adhesive ability of V. splendidus reduced more than 50% when DLD1 or DLD2 was defective.
Collapse
Affiliation(s)
- Fa Dai
- State Key Laboratory for Quality and Safety of Agro-products, Ningbo University , Ningbo , PR China
| | - Weiwei Zhang
- State Key Laboratory for Quality and Safety of Agro-products, Ningbo University , Ningbo , PR China
| | - Qiuting Zhuang
- State Key Laboratory for Quality and Safety of Agro-products, Ningbo University , Ningbo , PR China
| | - Yina Shao
- State Key Laboratory for Quality and Safety of Agro-products, Ningbo University , Ningbo , PR China
| | - Xuelin Zhao
- State Key Laboratory for Quality and Safety of Agro-products, Ningbo University , Ningbo , PR China
| | - Zhimeng Lv
- State Key Laboratory for Quality and Safety of Agro-products, Ningbo University , Ningbo , PR China
| | - Chenghua Li
- State Key Laboratory for Quality and Safety of Agro-products, Ningbo University , Ningbo , PR China.,Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology , Qingdao , PR China
| |
Collapse
|
35
|
Wu C, Zhao Z, Liu Y, Zhu X, Liu M, Luo P, Shi Y. Type III Secretion 1 Effector Gene Diversity Among Vibrio Isolates From Coastal Areas in China. Front Cell Infect Microbiol 2020; 10:301. [PMID: 32637366 PMCID: PMC7318850 DOI: 10.3389/fcimb.2020.00301] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2020] [Accepted: 05/20/2020] [Indexed: 01/22/2023] Open
Abstract
Vibrios, which include more than 120 valid species, are an abundant and diverse group of bacteria in marine and estuarine environments. Some of these bacteria have been recognized as pathogens of both marine animals and humans, and therefore, their virulence mechanisms have attracted increasing attention. The type III secretion system (T3SS) is an important virulence determinant in many gram-negative bacteria, in which this system directly translocates variable effectors into the host cytosol for the manipulation of the cellular responses. In this study, the distribution of the T3SS gene cluster was first examined in 110 Vibrio strains of 26 different species, including 98 strains isolated from coastal areas in China. Several T3SS1 genes, but not T3SS2 genes (T3SS2α and T3SS2β), were universally detected in all the strains of four species, Vibrio parahaemolyticus, Vibrio alginolyticus, Vibrio harveyi, and Vibrio campbellii. The effector coding regions within the T3SS1 gene clusters from the T3SS1-positive strains were further analyzed, revealing that variations in the effectors of Vibrio T3SS1 were observed among the four Vibrio species, even between different strains in V. harveyi, according to their genetic organization. Importantly, Afp17, a potential novel effector that may exert a similar function as the known effector VopS in T3SS1-induced cell death, based on cytotoxicity assay results, was found in the effector coding region of the T3SS1 in some V. harveyi and V. campbellii strains. Finally, it was revealed that differences in T3SS1-mediated cytotoxicity were dependent not only on the variations in the effectors of Vibrio T3SS1 but also on the initial adhesion ability to host cells, which is another prerequisite condition. Altogether, our results contribute to the clarification of the diversity of T3SS1 effectors and a better understanding of the differences in cytotoxicity among Vibrio species.
Collapse
Affiliation(s)
- Chao Wu
- Department of Marine Biology, College of Oceanography, Hohai University, Nanjing, China
| | - Zhe Zhao
- Department of Marine Biology, College of Oceanography, Hohai University, Nanjing, China
| | - Yupeng Liu
- Department of Marine Biology, College of Oceanography, Hohai University, Nanjing, China
| | - Xinyuan Zhu
- Department of Marine Biology, College of Oceanography, Hohai University, Nanjing, China
| | - Min Liu
- Department of Marine Biology, College of Oceanography, Hohai University, Nanjing, China
| | - Peng Luo
- Key Laboratory of Marine Bio-Resources Sustainable Utilization, Key Laboratory of Applied Marine Biology of Guangdong Province, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
| | - Yan Shi
- Department of Marine Biology, College of Oceanography, Hohai University, Nanjing, China
| |
Collapse
|
36
|
Zhang M, Kang J, Wu B, Qin Y, Huang L, Zhao L, Mao L, Wang S, Yan Q. Comparative transcriptome and phenotype analysis revealed the role and mechanism of ompR in the virulence of fish pathogenic Aeromonas hydrophila. Microbiologyopen 2020; 9:e1041. [PMID: 32282134 PMCID: PMC7349151 DOI: 10.1002/mbo3.1041] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 03/18/2020] [Accepted: 03/18/2020] [Indexed: 12/16/2022] Open
Abstract
Aeromonas hydrophila B11 strain was isolated from diseased Anguilla japonica, which had caused severe gill ulcers in farmed eel, causing huge economic losses. EnvZ‐OmpR is a model two‐component system in the bacteria and is widely used in the research of signal transduction and gene transcription regulation. In this study, the ompR of A. hydrophila B11 strain was first silenced by RNAi technology. The role of ompR in the pathogenicity of A. hydrophila B11 was investigated by analyzing both the bacterial comparative transcriptome and phenotype. The qRT‐PCR results showed that the expression of ompR in the ompR‐RNAi strain decreased by 97% compared with the wild‐type strain. The virulence test showed that after inhibition of the ompR expression, the LD50 of A. hydrophila B11 decreased by an order of magnitude, suggesting that ompR is involved in the regulation of bacterial virulence. Comparative transcriptome analysis showed that the expression of ompR can directly regulate the expression of several important virulence‐related genes, such as the bacterial type II secretion system; moreover, ompR expression also regulates the expression of multiple genes related to bacterial chemotaxis, motility, adhesion, and biofilm formation. Further studies on the phenotype of A. hydrophila B11 and ompR‐RNAi also confirmed that the downregulation of ompR expression can decrease bacterial chemotaxis, adhesion, and biofilm formation.
Collapse
Affiliation(s)
- Mengmeng Zhang
- Fisheries College, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Jimei University, Xiamen, China
| | - Jianping Kang
- Fujian Fisheries Technology Extension Center, Fuzhou, China
| | - Bin Wu
- Fujian Fisheries Technology Extension Center, Fuzhou, China
| | - Yingxue Qin
- Fisheries College, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Jimei University, Xiamen, China.,Fujian Province Key Laboratory of Special Aquatic Formula Feed, Fujian Tianma Science and Technology Group Co., Ltd., Fuqing, China
| | - Lixing Huang
- Fisheries College, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Jimei University, Xiamen, China
| | - Lingmin Zhao
- Fisheries College, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Jimei University, Xiamen, China
| | - Leilei Mao
- Fisheries College, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Jimei University, Xiamen, China
| | - Suyun Wang
- Fisheries College, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Jimei University, Xiamen, China
| | - Qingpi Yan
- Fisheries College, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Jimei University, Xiamen, China
| |
Collapse
|
37
|
He R, Zhao L, Xu X, Zheng W, Zhang J, Zhang J, Yan Q, Huang L. Aryl hydrocarbon receptor is required for immune response in Epinephelus coioides and Danio rerio infected by Pseudomonas plecoglossicida. FISH & SHELLFISH IMMUNOLOGY 2020; 97:564-570. [PMID: 31891808 DOI: 10.1016/j.fsi.2019.12.084] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 12/22/2019] [Accepted: 12/27/2019] [Indexed: 06/10/2023]
Abstract
Aryl hydrocarbon receptor (AhR), a ligand-dependent transcriptional factor that responds to environmental chemicals, has been recently found to be closely associated with immune response in mammals. Pseudomonas plecoglossicida (P. plecoglossicida) is a temperature-dependent bacterial pathogen of visceral white spot disease in fish. Using dual RNA-seq, we previously evaluated the expression levels of ahr1a, ahr1b, ahr2 and cyp1a in the spleen of Epinephelus coioides at different time points after infection with P. plecoglossicida. In the present study, the expression levels of ahr1a, ahr1b, ahr2 and cyp1a in different organs of E. coioides and Danio rerio showed similar trends after being infected by P. plecoglossicida. It also was noted that liver, intestine, spleen, and heart were the most obviously affected organs, and ahr2 particularly showed a dramatically increase in the spleen. Subsequently, macrophages of E. coioides were isolated, and then infected by P. plecoglossicida, followed by quantitative reverse transcription polymerase chain reaction (qRT-PCR) assay, which revealed that the expression level of ahr1a in macrophages was significantly down-regulated, while expression levels of ahr1b, ahr2 and cyp1a were noticeably up-regulated. Eventually, it was noted that ahr1b and ahr2 were knocked-down in macrophages, and intracellular survival rate and immune escape rate of P. plecoglossicida were markedly improved. Taken together, ahr1a, ahr1b, ahr2 and cyp1a participate in the immune response to P. plecoglossicida in different organs of fish, while ahr1b and ahr2 may play pivotal roles in the immune response of spleen and macrophages.
Collapse
Affiliation(s)
- Rongchao He
- Fisheries College, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Jimei University, Xiamen, Fujian, PR China
| | - Lingmin Zhao
- Fisheries College, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Jimei University, Xiamen, Fujian, PR China
| | - Xiaojin Xu
- Fisheries College, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Jimei University, Xiamen, Fujian, PR China
| | - Weiqiang Zheng
- State Key Laboratory of Large Yellow Croaker Breeding, Ningde, Fujian, 352000, PR China
| | - Jiaonan Zhang
- Key Laboratory of Special Aquatic Feed for Fujian, Fujian Tianma Technology Company Limited, Fuzhou, Fujian, 350308, China
| | - Jiaolin Zhang
- Key Laboratory of Special Aquatic Feed for Fujian, Fujian Tianma Technology Company Limited, Fuzhou, Fujian, 350308, China
| | - Qingpi Yan
- Fisheries College, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Jimei University, Xiamen, Fujian, PR China.
| | - Lixing Huang
- Fisheries College, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Jimei University, Xiamen, Fujian, PR China.
| |
Collapse
|
38
|
Luo G, Sun Y, Huang L, Su Y, Zhao L, Qin Y, Xu X, Yan Q. Time-resolved dual RNA-seq of tissue uncovers Pseudomonas plecoglossicida key virulence genes in host-pathogen interaction with Epinephelus coioides. Environ Microbiol 2019; 22:677-693. [PMID: 31797531 DOI: 10.1111/1462-2920.14884] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Accepted: 12/02/2019] [Indexed: 01/19/2023]
Abstract
Bacterial pathogen-host interactions are highly dynamic, regulated processes that have been primarily investigated using in vitro assays. The dynamics of bacterial pathogen-host interplay in vivo are poorly understood. Using time-resolved dual RNA-seq in a Pseudomonas plecoglossicida-Epinephelus coioides infection model, we observed that bacterial genes encoding classical virulence factors and host genes involved in immune regulation were dynamically expressed during infection. Using network inferencing, we were able to predict interspecies regulatory networks linking bacterial virulence genes to host immune genes. Together with gene co-expression network analysis of the pathogen, secY was predicted to be a key virulence gene for P. plecoglossicida pathogenicity in the host, fliN was predicted to be a less important virulence gene. The results of bioinformatics prediction were confirmed by animal infection experiments. Our work provides the first paradigm to study dynamic alterations of bacterial pathogen and host interactions based on the elucidation of time-resolved interactive transcriptomes in vivo, and may be developed into a novel and universal method for revealing the true complexity of the bacterial infection process.
Collapse
Affiliation(s)
- Gang Luo
- Fisheries College, Jimei University, Xiamen, Fujian, 361021, PR China
| | - Yujia Sun
- Fisheries College, Jimei University, Xiamen, Fujian, 361021, PR China
| | - Lixing Huang
- Fisheries College, Jimei University, Xiamen, Fujian, 361021, PR China
| | - Yongquan Su
- State Key Laboratory of Large Yellow Croaker Breeding, Ningde, Fujian, 352000, PR China
| | - Lingmin Zhao
- Fisheries College, Jimei University, Xiamen, Fujian, 361021, PR China
| | - Yingxue Qin
- Fisheries College, Jimei University, Xiamen, Fujian, 361021, PR China
| | - Xiaojin Xu
- Fisheries College, Jimei University, Xiamen, Fujian, 361021, PR China
| | - Qingpi Yan
- Fisheries College, Jimei University, Xiamen, Fujian, 361021, PR China.,State Key Laboratory of Large Yellow Croaker Breeding, Ningde, Fujian, 352000, PR China
| |
Collapse
|
39
|
Gao X, Miao Z, Li X, Chen N, Gu W, Liu X, Yang H, Wei W, Zhang X. Pathogenicity of non-O1/ O139 Vibrio cholerae and its induced immune response in Macrobrachium rosenbergii. FISH & SHELLFISH IMMUNOLOGY 2019; 92:300-307. [PMID: 31202968 DOI: 10.1016/j.fsi.2019.06.032] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 06/10/2019] [Accepted: 06/12/2019] [Indexed: 06/09/2023]
Abstract
Outbreaks of mass mortalities occurred in Macrobrachium rosenbergii farms in Gaoyou county, Jiangsu Province of China. The bacterial isolates from M. rosenbergii exhibited the same phenotypic traits and biochemical characteristics, and were identified as non-O1/O139 Vibrio cholerae according to biochemical characteristics and molecular identification. In challenge test, M. rosenbergii infected with non-O1/O139 V. cholerae GXFL1-4 developed similar pathological signs to the naturally diseased prawns, and LD50 of the strain to M. rosenbergii was 4.5 × 106 CFU/mL at 96 h post-infection. Histopathological analysis revealed that hepatopancreas and intestines of diseased M. rosenbergii exhibited obvious inflammatory responses to non-O1/O139 V. cholerae infection. Detection virulence factors of the strain GXFL1-4 showed that the bacteria produced caseinase, lipase, amylase, lecithinase and hemolysin, and carried toxR, hlyA, ompW, ompU, hap, rtxA and rtxC virulence related genes, supporting the strong virulence to M. rosenbergii. Additionally, the immune related gene expression in M. rosenbergii evaluated by qRT-PCR analysis showed that HSP70, Crustin, Lysozyme, TRL1, ALF1, Lectin, Peroxinectin, proPO and SOD immune related genes were significantly up-regulated at 6 and 12 h after infection with GXFL1-4. The results of our study suggested that non-O1/O139 V. cholerae was an etiological element in the mass mortalities of M. rosenbergii and this study provided preliminary insights into the diversity in the immune response of M. rosenbergii to the bacterial invasion.
Collapse
Affiliation(s)
- Xiaojian Gao
- College of Animal Science and Technology, Yangzhou University, Yangzhou, 225009, China
| | - Zhen Miao
- College of Animal Science and Technology, Yangzhou University, Yangzhou, 225009, China
| | - Xixi Li
- College of Animal Science and Technology, Yangzhou University, Yangzhou, 225009, China
| | - Nan Chen
- College of Animal Science and Technology, Yangzhou University, Yangzhou, 225009, China
| | - Wenwen Gu
- College of Animal Science and Technology, Yangzhou University, Yangzhou, 225009, China
| | - Xiaodan Liu
- College of Animal Science and Technology, Yangzhou University, Yangzhou, 225009, China
| | - Hui Yang
- College of Animal Science and Technology, Yangzhou University, Yangzhou, 225009, China
| | - Wanhong Wei
- College of Animal Science and Technology, Yangzhou University, Yangzhou, 225009, China
| | - Xiaojun Zhang
- College of Animal Science and Technology, Yangzhou University, Yangzhou, 225009, China.
| |
Collapse
|
40
|
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: 20] [Impact Index Per Article: 4.0] [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.
Collapse
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
| |
Collapse
|
41
|
Wang S, Yan Q, Zhang M, Huang L, Mao L, Zhang M, Xu X, Chen L, Qin Y. The role and mechanism of icmF in Aeromonas hydrophila survival in fish macrophages. JOURNAL OF FISH DISEASES 2019; 42:895-904. [PMID: 30919989 DOI: 10.1111/jfd.12991] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Revised: 02/22/2019] [Accepted: 02/24/2019] [Indexed: 06/09/2023]
Abstract
Survival in host macrophages is an effective strategy for pathogenic bacteria to spread. Aeromonas hydrophila has been found to survive in fish macrophages, but the mechanisms remain unknown. In this paper, the roles and possible mechanisms of IcmF in bacterial survival in fish macrophages were investigated. First, a stable silencing strain icmF-RNAi was constructed by shRNA and RT-qPCR confirmed the expression of icmF was down-regulated by 94.42%. The expression of Hcp, DotU and VgrG was also decreased in icmF-RNAi. The intracellular survival rate of the wild-type strain was 92.3%, while the survival rate of icmF-RNAi was only 20.58%. The escape rate of the wild-type strain was 20%, while that of the icmF-RNAi was only 7.5%. Further studies indicated that the expression of icmF can significantly affect the adhesion, biofilm formation, motility and acid resistance of A. hydrophila, but has no significant effect on the growth of A. hydrophila even under the stress of H2 O2 . The results indicated that IcmF of A. hydrophila not only acts as a structural protein which participates in virulence-related characteristics such as bacterial motility, adhesion and biofilm formation, but also acts as a key functional protein which participates in the interaction between bacteria and host macrophages.
Collapse
Affiliation(s)
- Suyun Wang
- Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Fisheries College, Jimei University, Xiamen, China
| | - Qingpi Yan
- Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Fisheries College, Jimei University, Xiamen, China
| | - Meimei Zhang
- Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Fisheries College, Jimei University, Xiamen, China
| | - Lixing Huang
- Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Fisheries College, Jimei University, Xiamen, China
| | - Leilei Mao
- Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Fisheries College, Jimei University, Xiamen, China
| | - Mengmeng Zhang
- Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Fisheries College, Jimei University, Xiamen, China
| | - Xiaojin Xu
- Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Fisheries College, Jimei University, Xiamen, China
| | - Liwei Chen
- Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Fisheries College, Jimei University, Xiamen, China
| | - Yingxue Qin
- Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Fisheries College, Jimei University, Xiamen, China
| |
Collapse
|
42
|
Yang CL, Chen XK, Wang R, Lin JQ, Liu XM, Pang X, Zhang CJ, Lin JQ, Chen LX. Essential Role of σ Factor RpoF in Flagellar Biosynthesis and Flagella-Mediated Motility of Acidithiobacillus caldus. Front Microbiol 2019; 10:1130. [PMID: 31178842 PMCID: PMC6543871 DOI: 10.3389/fmicb.2019.01130] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Accepted: 05/03/2019] [Indexed: 12/04/2022] Open
Abstract
Acidithiobacillaceae, an important family of acidophilic and chemoautotrophic sulfur or iron oxidizers, participate in geobiochemical circulation of the elements and drive the release of heavy metals in mining associated habitats. Because of their environmental adaptability and energy metabolic systems, Acidithiobacillus spp. have become the dominant bacteria used in bioleaching for heavy metal recovery. Flagella-driven motility is associated with bacterial chemotaxis and bacterial responses to environmental stimuli. However, little is known about how the flagellum of Acidithiobacillus spp. is regulated and how the flagellum affects the growth of these chemoautotrophic bacteria. In this study, we analyzed the flagellar gene clusters in Acidithiobacillus strains and uncovered the close relationship between flagella and the sulfur-oxidizing systems (Sox system). The σ28 gene (rpoF) knockout and overexpression strains of Acidithiobacillus caldus were constructed. Scanning electron microscopy shows that A. caldus ΔrpoF cells lacked flagella, indicating the essential role of RpoF in regulating flagella synthesis in these chemoautotrophic bacteria. Motility analysis suggests that the deletion of rpoF resulted in the reduction of swarming capability, while this capability was enhanced in the rpoF overexpression strain. Both static cultivation and low concentration of energy substrates (elemental sulfur or tetrathionate) led to weak growth of A. caldus ΔrpoF cells. The deletion of rpoF promoted bacterial attachment to the surface of elemental sulfur in static cultivation. The absence of RpoF caused an obvious change in transcription profile, including genes in flagellar cluster and those involved in biofilm formation. These results provide an understanding on the regulation of flagellar hierarchy and the flagellar function in these sulfur or iron oxidizers.
Collapse
Affiliation(s)
- Chun-Long Yang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Xian-Ke Chen
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Rui Wang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Jian-Qiang Lin
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Xiang-Mei Liu
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Xin Pang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Cheng-Jia Zhang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Jian-Qun Lin
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Lin-Xu Chen
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| |
Collapse
|
43
|
Huang L, Zhao L, Liu W, Xu X, Su Y, Qin Y, Yan Q. Dual RNA-Seq Unveils Pseudomonas plecoglossicida htpG Gene Functions During Host-Pathogen Interactions With Epinephelus coioides. Front Immunol 2019; 10:984. [PMID: 31130962 PMCID: PMC6509204 DOI: 10.3389/fimmu.2019.00984] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2019] [Accepted: 04/16/2019] [Indexed: 12/23/2022] Open
Abstract
Pseudomonas plecoglossicida is a temperature-dependent opportunistic pathogen which is associated with a variety of diseases in fish. During the development of "white nodules" disease, the expression of htpG in P. plecoglossicida was found to be significantly up-regulated at its virulent temperature of 18°C. The infection of htpG-RNAi strain resulted in the onset time delay, reduction in mortality and infection symptoms in spleen of Epinephelus coioides, and affected the bacterial tissue colonization. In order to reveal the effect of htpG silencing of P. plecoglossicida on the virulence regulation in P. plecoglossicida and immune response in E. coioides, dual RNA-seq was performed and a pathogen-host integration network was constructed. Our results showed that infection induced the expression of host genes related to immune response, but attenuated the expression of bacterial virulence genes. Novel integration was found between host immune genes and bacterial virulence genes, while IL6, IL1R2, IL1B, and TLR5 played key roles in the network. Further analysis with GeneMANIA indicated that flgD and rplF might play key roles during the htpG-dependent virulence regulation, which was in accordance with the reduced biofilm production, motility and virulence in htpG-RNAi strain. Meanwhile, IL6 and IL1B were found to play key roles during the defense against P. plecoglossicida, while CELA2, TRY, CPA1, CPA2, and CPB1 were important targets for P. plecoglossicida attacking to the host.
Collapse
Affiliation(s)
- Lixing Huang
- Key Laboratory of Healthy Mariculture for the East China Sea, Fisheries College, Jimei University, Ministry of Agriculture, Xiamen, China
| | - Lingmin Zhao
- Key Laboratory of Healthy Mariculture for the East China Sea, Fisheries College, Jimei University, Ministry of Agriculture, Xiamen, China
| | - Wenjia Liu
- Key Laboratory of Healthy Mariculture for the East China Sea, Fisheries College, Jimei University, Ministry of Agriculture, Xiamen, China
| | - Xiaojin Xu
- Key Laboratory of Healthy Mariculture for the East China Sea, Fisheries College, Jimei University, Ministry of Agriculture, Xiamen, China
| | - Yongquan Su
- State Key Laboratory of Large Yellow Croaker Breeding, Ningde, China
| | - Yingxue Qin
- Key Laboratory of Healthy Mariculture for the East China Sea, Fisheries College, Jimei University, Ministry of Agriculture, Xiamen, China
| | - Qingpi Yan
- Key Laboratory of Healthy Mariculture for the East China Sea, Fisheries College, Jimei University, Ministry of Agriculture, Xiamen, China
- State Key Laboratory of Large Yellow Croaker Breeding, Ningde, China
| |
Collapse
|
44
|
Huang L, Guo L, Xu X, Qin Y, Zhao L, Su Y, Yan Q. The role of rpoS in the regulation of Vibrio alginolyticus virulence and the response to diverse stresses. JOURNAL OF FISH DISEASES 2019; 42:703-712. [PMID: 30811044 DOI: 10.1111/jfd.12972] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 01/16/2019] [Accepted: 01/17/2019] [Indexed: 06/09/2023]
Abstract
Vibrio alginolyticus is a leading aquatic pathogen, causing huge losses to aquaculture. rpoS has been proven to play a variety of important roles in stress response and virulence in several bacteria. In our previous study, upon treatment with Cu2+ , Pb2+ , Hg2+ and low pH, the expression levels of rpoS were downregulated as assessed by RNA-seq, while impaired adhesion ability was observed, indicating that rpoS might play roles in the regulation of adhesion. In the present study, the RNAi technology was used to knockdown rpoS in V. alginolyticus. In comparison with wild-type V. alginolyticus, RNAi-treated bacteria showed significantly impaired abilities of adhesion, growth, haemolytic, biofilm production, movement and virulence. Meanwhile, alterations of temperature, salinity, pH and starvation starkly affected rpoS expression. The present data suggested that rpoS is a critical regulator of virulence in V. alginolyticus; in addition, rpoS regulates bacterial adhesion in response to temperature, pH and nutrient content changes. These are helpful to explore its pathogenic mechanism and provide reference for disease control.
Collapse
Affiliation(s)
- Lixing Huang
- Key Laboratory of Healthy Mariculture for the East China Sea, Fisheries College, Ministry of Agriculture, Jimei University, Xiamen, China
| | - Lina Guo
- Key Laboratory of Healthy Mariculture for the East China Sea, Fisheries College, Ministry of Agriculture, Jimei University, Xiamen, China
| | - Xiaojin Xu
- Key Laboratory of Healthy Mariculture for the East China Sea, Fisheries College, Ministry of Agriculture, Jimei University, Xiamen, China
| | - Yingxue Qin
- Key Laboratory of Healthy Mariculture for the East China Sea, Fisheries College, Ministry of Agriculture, Jimei University, Xiamen, China
| | - Lingmin Zhao
- Key Laboratory of Healthy Mariculture for the East China Sea, Fisheries College, Ministry of Agriculture, Jimei University, Xiamen, China
| | - Yongquan Su
- State Key Laboratory of Large Yellow Croaker Breeding, Ningde, China
| | - Qingpi Yan
- Key Laboratory of Healthy Mariculture for the East China Sea, Fisheries College, Ministry of Agriculture, Jimei University, Xiamen, China
- State Key Laboratory of Large Yellow Croaker Breeding, Ningde, China
| |
Collapse
|
45
|
Andrei AŞ, Salcher MM, Mehrshad M, Rychtecký P, Znachor P, Ghai R. Niche-directed evolution modulates genome architecture in freshwater Planctomycetes. THE ISME JOURNAL 2019; 13:1056-1071. [PMID: 30610231 PMCID: PMC6461901 DOI: 10.1038/s41396-018-0332-5] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 11/22/2018] [Accepted: 11/29/2018] [Indexed: 11/08/2022]
Abstract
Freshwater environments teem with microbes that do not have counterparts in culture collections or genetic data available in genomic repositories. Currently, our apprehension of evolutionary ecology of freshwater bacteria is hampered by the difficulty to establish organism models for the most representative clades. To circumvent the bottlenecks inherent to the cultivation-based techniques, we applied ecogenomics approaches in order to unravel the evolutionary history and the processes that drive genome architecture in hallmark freshwater lineages from the phylum Planctomycetes. The evolutionary history inferences showed that sediment/soil Planctomycetes transitioned to aquatic environments, where they gave rise to new freshwater-specific clades. The most abundant lineage was found to have the most specialised lifestyle (increased regulatory genetic circuits, metabolism tuned for mineralization of proteinaceous sinking aggregates, psychrotrophic behaviour) within the analysed clades and to harbour the smallest freshwater Planctomycetes genomes, highlighting a genomic architecture shaped by niche-directed evolution (through loss of functions and pathways not needed in the newly acquired freshwater niche).
Collapse
Affiliation(s)
- Adrian-Ştefan Andrei
- Department of Aquatic Microbial Ecology, Institute of Hydrobiology, Biology Centre CAS, Na Sádkách 702/7, 370 05 České Budějovice, Czech Republic.
| | - Michaela M Salcher
- Department of Aquatic Microbial Ecology, Institute of Hydrobiology, Biology Centre CAS, Na Sádkách 702/7, 370 05 České Budějovice, Czech Republic
- Limnological Station, Institute of Plant and Microbial Biology, University of Zurich, Seestrasse 187, 8802, Kilchberg, Switzerland
| | - Maliheh Mehrshad
- Department of Aquatic Microbial Ecology, Institute of Hydrobiology, Biology Centre CAS, Na Sádkách 702/7, 370 05 České Budějovice, Czech Republic
| | - Pavel Rychtecký
- Department of Aquatic Microbial Ecology, Institute of Hydrobiology, Biology Centre CAS, Na Sádkách 702/7, 370 05 České Budějovice, Czech Republic
| | - Petr Znachor
- Department of Aquatic Microbial Ecology, Institute of Hydrobiology, Biology Centre CAS, Na Sádkách 702/7, 370 05 České Budějovice, Czech Republic
| | - Rohit Ghai
- Department of Aquatic Microbial Ecology, Institute of Hydrobiology, Biology Centre CAS, Na Sádkách 702/7, 370 05 České Budějovice, Czech Republic.
| |
Collapse
|
46
|
Zhang B, Zhuang Z, Wang X, Huang H, Fu Q, Yan Q. Dual RNA-Seq reveals the role of a transcriptional regulator gene in pathogen-host interactions between Pseudomonas plecoglossicida and Epinephelus coioides. FISH & SHELLFISH IMMUNOLOGY 2019; 87:778-787. [PMID: 30776540 DOI: 10.1016/j.fsi.2019.02.025] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 01/26/2019] [Accepted: 02/15/2019] [Indexed: 06/09/2023]
Abstract
Pseudomonas plecoglossicida is a highly pathogenic bacterium for maricultured fish and causes serious losses. A transcriptional regulator gene RK21_RS10315 was found up-regulated during the whole infection process, which was confirmed by qRT-PCR. Five shRNA were designed to silence RK21_RS10315 gene, and the gene expression was reduced up to 96.1%. Compared with the counterpart infected with wild type strain, the infection of RK21_RS10315-RNAi strain resulted in the death time delay, and 90% reduction in mortality of Epinephelus coioides, as well as the alleviation in the symptoms of E. coioides spleen. Moreover, compared with the fish infected with wild type strain, the infection of RK21_RS10315-RNAi strain of P. plecoglossicida resulted in a significant change both in transcriptome of spleen of infected E. coioides and P. plecoglossicida. The KEGG analysis showed that genes of 16 immune pathways in E. coioides were affected by the silence of RK21_RS10315 of P. plecoglossicida. Among them, intestinal immune network for IgA production pathway and leukocyte transendothelial migration pathway were more prominent than other pathways. 19 euk-DEMs in these immune pathways had varying degrees of correlation with 19 pro-DEMs, and the expression of ipxA, grpE, yhbJ, truD and suhB from 19 pro-DEMs were predicted more related to RK21_RS10315 in P. plecoglossicida.
Collapse
Affiliation(s)
- Beibei Zhang
- College of Environment and Public Health, Xiamen Huaxia University, Xiamen, Fujian, 361024, China; Fisheries College, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Jimei University, Xiamen, Fujian, 361021, China
| | - Zhixia Zhuang
- College of Environment and Public Health, Xiamen Huaxia University, Xiamen, Fujian, 361024, China
| | - Xiaoru Wang
- College of Environment and Public Health, Xiamen Huaxia University, Xiamen, Fujian, 361024, China
| | - Huabin Huang
- College of Environment and Public Health, Xiamen Huaxia University, Xiamen, Fujian, 361024, China
| | - Qi Fu
- College of Environment and Public Health, Xiamen Huaxia University, Xiamen, Fujian, 361024, China
| | - Qingpi Yan
- Fisheries College, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Jimei University, Xiamen, Fujian, 361021, China.
| |
Collapse
|
47
|
SodA Contributes to the Virulence of Avian Pathogenic Escherichia coli O2 Strain E058 in Experimentally Infected Chickens. J Bacteriol 2019; 201:JB.00625-18. [PMID: 30602490 DOI: 10.1128/jb.00625-18] [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: 11/01/2018] [Accepted: 12/05/2018] [Indexed: 12/18/2022] Open
Abstract
Strains of avian pathogenic Escherichia coli (APEC), the common pathogen of avian colibacillosis, encounter reactive oxygen species (ROS) during the infection process. Superoxide dismutases (SODs), acting as antioxidant factors, can protect against ROS-mediated host defenses. Our previous reports showed that the sodA gene (encoding a Mn-cofactor-containing SOD [MnSOD]) is highly expressed during the septicemic infection process of APEC. sodA has been proven to be a virulence factor of certain pathogens, but its role in the pathogenicity of APEC has not been fully identified. In this study, we deleted the sodA gene from the virulent APEC O2 strain E058 and examined the in vitro and in vivo phenotypes of the mutant. The sodA mutant was more sensitive to hydrogen peroxide in terms of both its growth and viability than was the wild type. The ability to form a biofilm was weakened in the sodA mutant. The sodA mutant was significantly more easily phagocytosed by chicken macrophages than was the wild-type strain. Chicken infection assays revealed significantly attenuated virulence of the sodA mutant compared with the wild type at 24 h postinfection. The virulence phenotype was restored by complementation of the sodA gene. Quantitative real-time reverse transcription-PCR revealed that the inactivation of sodA reduced the expression of oxidative stress response genes katE, perR, and osmC but did not affect the expression of sodB and sodC Taken together, our studies indicate that SodA is important for oxidative resistance and virulence of APEC E058.IMPORTANCE Avian colibacillosis, caused by strains of avian pathogenic Escherichia coli, is a major bacterial disease of severe economic significance to the poultry industry worldwide. The virulence mechanisms of APEC are not completely understood. This study investigated the influence of an antioxidant protein, SodA, on the phenotype and pathogenicity of APEC O2 strain E058. This is the first report demonstrating that SodA plays an important role in protecting a specific APEC strain against hydrogen peroxide-induced oxidative stress and contributes to the virulence of this pathotype strain. Identification of this virulence factor will enhance our knowledge of APEC pathogenic mechanisms, which is crucial for designing successful strategies against associated infections and transmission.
Collapse
|
48
|
Huang L, Huang L, Zhao L, Qin Y, Su Y, Yan Q. The regulation of oxidative phosphorylation pathway on Vibrio alginolyticus adhesion under adversities. Microbiologyopen 2019; 8:e00805. [PMID: 30767412 PMCID: PMC6692554 DOI: 10.1002/mbo3.805] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 01/09/2019] [Accepted: 01/11/2019] [Indexed: 02/03/2023] Open
Abstract
Vibrio alginolyticus is one of the most important pathogens in mariculture and leading to heavy losses. After treatment with Cu2+, Pb2+, and low pH, the expression of oxidative phosphorylation pathway genes, including coxA, coxB, coxC, ccoN, ccoO, and ccoQ, was found commonly downregulated by RNA‐seq as well as quantitative real‐time PCR. RNAi significantly reduced the expression of coxA, coxB, coxC, ccoN, ccoO, and ccoQ in V. alginolyticus. Compared with the wild‐type strain, the adhesion abilities of RNAi strains of V. alginolyticus were significantly impaired, as well as their cytochrome C oxidase activity. ccoQ appeared to be more important in the regulation of bacterial adhesion in these target genes, while ccoO was relatively weak in the regulation of the adhesion. Meanwhile, the changes of temperature, salinity, pH, and starvation affected coxA, coxB, coxC, ccoN, ccoO, and ccoQ expression remarkably. These findings indicated that: the oxidative phosphorylation pathway is a critical regulator of adhesion in V. alginolyticus; coxA, coxB, coxC, ccoN, ccoO, and ccoQ regulate the bacterial adhesion in response to environmental changes such as temperature, salinity, pH, and starvation.
Collapse
Affiliation(s)
- Li Huang
- State Key Laboratory of Large Yellow Croaker Breeding, Ningde, Fujian, China.,Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Fisheries College, Jimei University, Xiamen, Fujian, China
| | - Lixing Huang
- Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Fisheries College, Jimei University, Xiamen, Fujian, China
| | - Lingmin Zhao
- Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Fisheries College, Jimei University, Xiamen, Fujian, China
| | - Yingxue Qin
- Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Fisheries College, Jimei University, Xiamen, Fujian, China
| | - Yongquan Su
- State Key Laboratory of Large Yellow Croaker Breeding, Ningde, Fujian, China
| | - Qingpi Yan
- State Key Laboratory of Large Yellow Croaker Breeding, Ningde, Fujian, China.,Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Fisheries College, Jimei University, Xiamen, Fujian, China
| |
Collapse
|
49
|
Zuo Y, Zhao L, Xu X, Zhang J, Zhang J, Yan Q, Huang L. Mechanisms underlying the virulence regulation of new Vibrio alginolyticus ncRNA Vvrr1 with a comparative proteomic analysis. Emerg Microbes Infect 2019; 8:1604-1618. [PMID: 31711375 PMCID: PMC6853220 DOI: 10.1080/22221751.2019.1687261] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 10/24/2019] [Indexed: 12/17/2022]
Abstract
The incidence of Vibrio alginolyticus infections has increased in recent years due to the influence of climate change and rising sea temperature. Vibrio virulence regulatory RNA 1 (Vvrr1) is a newly found noncoding RNA (ncRNA) predicted to be closely related to the adhesion ability of V. alginolyticus based on the previous RNA-seq. In this study, the target genes of Vvrr1 were fully screened and verified by constructing Vvrr1-overexpressing strains and using the proteome sequencing technology. Pyruvate kinase I (pykF) gene was predicted to be a chief target gene of Vvrr1 involved in virulence regulation. The adhesion ability, biofilm formation and virulence were significantly reduced in the Vvrr1-overexpressing and the pykF-silenced strain compared with the wild strains. Similar to the overexpression of Vvrr1, the silencing of pykF also reduced the expression level of virulence genes, such as ndk, eno, sdhB, glpF, and cysH. Meanwhile, by constructing the "pykF-GFP" fusion expression plasmid and using the GFP reporter gene analysis in Escherichia coli, the fluorescence intensity of the strain containing Vvrr1 whole ncRNA sequence vector was found to be significantly weakened. These indicated that Vvrr1 participated in the virulence regulation mechanism of V. alginolyticus by interacting with the virulence gene pykF.
Collapse
Affiliation(s)
- Yanfei Zuo
- Fisheries College, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Jimei University, Xiamen, PR People’s Republic of China
| | - Lingmin Zhao
- Fisheries College, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Jimei University, Xiamen, PR People’s Republic of China
| | - Xiaojin Xu
- Fisheries College, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Jimei University, Xiamen, PR People’s Republic of China
| | - Jiaonan Zhang
- Key Laboratory of Special Aquatic Feed for Fujian, Fujian Tianma Technology Company Limited, Fuzhou, People’s Republic of China
| | - Jiaolin Zhang
- Key Laboratory of Special Aquatic Feed for Fujian, Fujian Tianma Technology Company Limited, Fuzhou, People’s Republic of China
| | - Qingpi Yan
- Fisheries College, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Jimei University, Xiamen, PR People’s Republic of China
| | - Lixing Huang
- Fisheries College, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Jimei University, Xiamen, PR People’s Republic of China
| |
Collapse
|
50
|
Deng Y, Su Y, Liu S, Guo Z, Cheng C, Ma H, Wu J, Feng J, Chen C. Identification of a Novel Small RNA srvg23535 in Vibrio alginolyticus ZJ-T and Its Characterization With Phenotype MicroArray Technology. Front Microbiol 2018; 9:2394. [PMID: 30349521 PMCID: PMC6186989 DOI: 10.3389/fmicb.2018.02394] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2018] [Accepted: 09/18/2018] [Indexed: 01/28/2023] Open
Abstract
Small non-coding RNAs (sRNAs) are important modulators of gene expression and are involved in the pathogenesis and survival of prokaryotes. However, few studies have been conducted with Vibrio alginolyticus, which limits our ability to probe the regulation of virulence and environmental adaptation by sRNAs in this opportunistic pathogen. In this study, the sRNA candidate srvg23535 was identified in V. alginolyticus ZJ-T. The precise transcript end, secondary structure, and sequence conservation were determined. A srvg23535 null mutant was constructed and characterized by using Phenotype MicroArray (PM) technology. In silico target prediction was conducted by IntaRNA and TargetRNA2. Subsequently, a 107 nt transcript was validated with a sigma70 promoter at the 5' end and a Rho-independent terminator at the 3' end. The sRNA srvg23535 had four stem-loop structures and was conserved among Vibrio harveyi, Vibrio parahaemolyticus, and Vibrio splendidus. Deletion of srvg23535 in V. alginolyticus ZJ-T led to a weaker utilization of D-mannose, D-melibiose, lactulose, and inosine as carbon sources but stronger utilization of L-cysteine as nitrogen source. Moreover, the srvg2353 mutant showed stronger resistance to osmotic stress but weaker resistance to pH stress. Additionally, a total of 22 common targets were identified and several were related to the observed phenotype of the mutant. This study indicated that the novel sRNA, srvg23535, is conserved and restricted to Vibrio spp., affecting the utilization of several carbon and nitrogen sources and the response to osmotic and pH stress. These results extend our understanding of sRNA regulation in V. alginolyticus and provide a significant resource for the further study of the precise target mRNAs of srvg23535, which may provide targets for antibacterial therapeutic or attenuated vaccines against Vibrio spp.
Collapse
Affiliation(s)
- Yiqin Deng
- Key Laboratory of South China Sea Fishery Resources Exploitation and Utilization, Ministry of Agriculture, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China.,Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
| | - Youlu Su
- Key Laboratory of South China Sea Fishery Resources Exploitation and Utilization, Ministry of Agriculture, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China
| | - Songlin Liu
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
| | - Zhixun Guo
- Key Laboratory of South China Sea Fishery Resources Exploitation and Utilization, Ministry of Agriculture, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China
| | - Changhong Cheng
- Key Laboratory of South China Sea Fishery Resources Exploitation and Utilization, Ministry of Agriculture, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China
| | - Hongling Ma
- Key Laboratory of South China Sea Fishery Resources Exploitation and Utilization, Ministry of Agriculture, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China
| | - Jinjun Wu
- Key Laboratory of South China Sea Fishery Resources Exploitation and Utilization, Ministry of Agriculture, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China
| | - Juan Feng
- Key Laboratory of South China Sea Fishery Resources Exploitation and Utilization, Ministry of Agriculture, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China
| | - Chang Chen
- Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China.,Xisha/Nansha Ocean Observation and Research Station, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
| |
Collapse
|