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Ma Z, Xu W, Li S, Chen S, Yang Y, Li Z, Xing T, Zhao Z, Hou D, Li Q, Lu Z, Zhang H. Effect of RpoS on the survival, induction, resuscitation, morphology, and gene expression of viable but non-culturable Salmonella Enteritidis in powdered infant formula. Int J Food Microbiol 2024; 410:110463. [PMID: 38039925 DOI: 10.1016/j.ijfoodmicro.2023.110463] [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: 06/09/2023] [Revised: 10/19/2023] [Accepted: 10/27/2023] [Indexed: 12/03/2023]
Abstract
Involvement of the transcriptional regulator RpoS in the persistence of viable but non-culturable (VBNC) state has been demonstrated in several species of bacteria. This study investigated the role of the RpoS in the formation and resuscitation of VBNC state in Salmonella enterica serovar Enteritidis CICC 21482 by measuring bacterial survival, morphology, physiological characteristics, and gene expression in wild-type (WT) and rpoS-deletion (ΔrpoS) strains during long-term storage in powdered infant formula (PIF). The ΔrpoS strain was produced by allelic exchange using a suicide plasmid. Bacteria were inoculated into PIF for 635-day storage. Survival, morphology, intracellular reactive oxygen species (ROS) levels and intercellular quorum sensing autoinducer-2 (AI-2) contents were regularly measured. Resuscitation assays were conducted after obtaining VBNC cells. Gene expression was measured using real-time quantitative polymerase chain reaction (qPCR). The results showed that RpoS and low temperature conditions were associated with enhanced culturability and recoverability of Salmonella Enteritidis after desiccation storage in low water activity (aw) PIF. In addition, the synthesis of intracellular ROS and intercellular quorum sensing AI-2 was regulated by RpoS, inducing the formation and resuscitation of VBNC cells. Gene expression of soxS, katG and relA was found strongly associated with RpoS. Due to the lack of RpoS factor, the ΔrpoS strain could not normally synthesize SoxS, catalase and (p)ppGpp, resulting in its early shift to the VBNC state. This study elucidates the role of rpoS in desiccation stress and the formation and resuscitation mechanism of VBNC cells under desiccation stress. It serves as the basis for preventing and controlling the recovery of pathogenic bacteria in VBNC state in low aw foods.
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Affiliation(s)
- Zhuolin Ma
- College of Biological and Pharmaceutical Science, Guangdong University of Technology, No. 100 Waihuan Xi Road, Panyu District, Guangzhou 510006, China
| | - Weiying Xu
- College of Biological and Pharmaceutical Science, Guangdong University of Technology, No. 100 Waihuan Xi Road, Panyu District, Guangzhou 510006, China
| | - Shaoting Li
- College of Biological and Pharmaceutical Science, Guangdong University of Technology, No. 100 Waihuan Xi Road, Panyu District, Guangzhou 510006, China
| | - Siyi Chen
- College of Biological and Pharmaceutical Science, Guangdong University of Technology, No. 100 Waihuan Xi Road, Panyu District, Guangzhou 510006, China
| | - Yuheng Yang
- College of Biological and Pharmaceutical Science, Guangdong University of Technology, No. 100 Waihuan Xi Road, Panyu District, Guangzhou 510006, China
| | - Zefeng Li
- College of Biological and Pharmaceutical Science, Guangdong University of Technology, No. 100 Waihuan Xi Road, Panyu District, Guangzhou 510006, China
| | - Tong Xing
- College of Biological and Pharmaceutical Science, Guangdong University of Technology, No. 100 Waihuan Xi Road, Panyu District, Guangzhou 510006, China
| | - Zepeng Zhao
- College of Biological and Pharmaceutical Science, Guangdong University of Technology, No. 100 Waihuan Xi Road, Panyu District, Guangzhou 510006, China
| | - Dongping Hou
- College of Biological and Pharmaceutical Science, Guangdong University of Technology, No. 100 Waihuan Xi Road, Panyu District, Guangzhou 510006, China
| | - Qingqing Li
- College of Biological and Pharmaceutical Science, Guangdong University of Technology, No. 100 Waihuan Xi Road, Panyu District, Guangzhou 510006, China
| | - Ziying Lu
- College of Biological and Pharmaceutical Science, Guangdong University of Technology, No. 100 Waihuan Xi Road, Panyu District, Guangzhou 510006, China
| | - Hongmei Zhang
- College of Biological and Pharmaceutical Science, Guangdong University of Technology, No. 100 Waihuan Xi Road, Panyu District, Guangzhou 510006, China.
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Jeong GJ, Khan F, Tabassum N, Kim YM. Cellular and physiological roles of sigma factors in Vibrio spp.: A comprehensive review. Int J Biol Macromol 2024; 254:127833. [PMID: 37918595 DOI: 10.1016/j.ijbiomac.2023.127833] [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: 08/23/2023] [Revised: 10/30/2023] [Accepted: 10/30/2023] [Indexed: 11/04/2023]
Abstract
Vibrio species are motile gram-negative bacteria commonly found in aquatic environments. Vibrio species include pathogenic as well as non-pathogenic strains. Pathogenic Vibrio species have been reported in invertebrates and humans, whereas non-pathogenic strains are involved in symbiotic relationships with their eukaryotic hosts. These bacteria are also able to adapt to fluctuations in temperature, salinity, and pH, in addition to oxidative stress, and osmotic pressure in aquatic ecosystems. Moreover, they have also developed protective mechanisms against the immune systems of their hosts. Vibrio species accomplish adaptation to changing environments outside or inside the host by altering their gene expression profiles. To this end, several sigma factors specifically regulate gene expression, particularly under stressful environmental conditions. Moreover, other sigma factors are associated with biofilm formation and virulence as well. This review discusses different types of sigma and anti-sigma factors of Vibrio species involved in virulence and regulation of gene expression upon changes in environmental conditions. The evolutionary relationships between sigma factors with various physiological roles in Vibrio species are also discussed extensively.
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Affiliation(s)
- Geum-Jae Jeong
- Department of Food Science and Technology, Pukyong National University, Busan 48513, Republic of Korea
| | - Fazlurrahman Khan
- Institute of Fisheries Sciences, Pukyong National University, Busan 48513, Republic of Korea; Marine Integrated Biomedical Technology Center, The National Key Research Institutes in Universities, Pukyong National University, Busan 48513, Republic of Korea; Research Center for Marine Integrated Bionics Technology, Pukyong National University, Busan 48513, Republic of Korea.
| | - Nazia Tabassum
- Marine Integrated Biomedical Technology Center, The National Key Research Institutes in Universities, Pukyong National University, Busan 48513, Republic of Korea; Research Center for Marine Integrated Bionics Technology, Pukyong National University, Busan 48513, Republic of Korea
| | - Young-Mog Kim
- Department of Food Science and Technology, Pukyong National University, Busan 48513, Republic of Korea; Marine Integrated Biomedical Technology Center, The National Key Research Institutes in Universities, Pukyong National University, Busan 48513, Republic of Korea; Research Center for Marine Integrated Bionics Technology, Pukyong National University, Busan 48513, Republic of Korea.
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Comprehensive insights into the metabolism characteristics of small RNA Qrr4 in Vibrio alginolyticus. Appl Microbiol Biotechnol 2023; 107:1887-1902. [PMID: 36795140 DOI: 10.1007/s00253-023-12435-1] [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: 11/23/2022] [Revised: 01/30/2023] [Accepted: 01/31/2023] [Indexed: 02/17/2023]
Abstract
Vibrio alginolyticus is an important foodborne pathogen that can infect both humans and marine animals and cause massive economic losses in aquaculture. Small noncoding RNAs (sRNAs) are emerging posttranscriptional regulators that affect bacterial physiology and pathological processes. In the present work, a new cell density-dependent sRNA, Qrr4, was characterized in V. alginolyticus based on a previously reported RNA-seq analysis and bioinformatics approach. The effects of Qrr4 actions on the physiology, virulence, and metabolism of V. alginolyticus were comprehensively investigated based on molecular biology and metabolomics approaches. The results showed that qrr4 deletion markedly inhibited growth, motility and extracellular protease activities. Additionally, nontargeted metabolism and lipidomics analyses revealed that qrr4 deletion induced significant disturbance of multiple metabolic pathways. The key metabolic remodelling that occurred in response to qrr4 deletion was found to involve phospholipid, nucleotide, carbohydrate and amino acid metabolic pathways, providing novel clues about a potential mechanism via which mutation of qrr4 could interfere with cellular energy homeostasis, modulate membrane phospholipid composition and inhibit nucleic acid and protein syntheses to regulate the motility, growth and virulence characteristics of V. alginolyticus. Overall, this study provides a comprehensive understanding of the regulatory roles of the new cell density-dependent sRNA Qrr4 in V. alginolyticus. KEY POINTS: • A novel cell density-dependent sRNA, Qrr4, was cloned in V. alginolyticus. •Qrr4 regulated growth and virulence factors of V. alginolyticus. • Phospholipid, nucleotide and energy metabolisms were modulated obviously by Qrr4.
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Host-specific signal perception by PsaR2 LuxR solo induces Pseudomonas syringae pv. actinidiae virulence traits. Microbiol Res 2022; 260:127048. [DOI: 10.1016/j.micres.2022.127048] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 03/23/2022] [Accepted: 04/19/2022] [Indexed: 11/19/2022]
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Sami Z, Kaouthar M, Nadia C, Hedi BM. Effect of sunlight and salinity on the survival of pathogenic and non-pathogenic strains of Vibrio parahaemolyticus in water microcosms. WATER ENVIRONMENT RESEARCH : A RESEARCH PUBLICATION OF THE WATER ENVIRONMENT FEDERATION 2022; 94:e10689. [PMID: 35112431 DOI: 10.1002/wer.10689] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 12/23/2021] [Accepted: 01/07/2022] [Indexed: 06/14/2023]
Abstract
The effect of sunlight and salinities (10, 20, 39, and 60 psu) on the survival of Vibrio parahaemolyticus strains carrying either (thermostable direct hemolysin) tdh, the (thermostable related hemolysin) trh, and both or none of them were studied in water microcosms stabilized at 20°C using plate count agar and acridine orange direct viable count. All V. parahaemolyticus strains exposed to sunlight rapidly lose their culturability and evolve into a viable but non-culturable state (VBNC). However, the tdh positive strains remain more culturable than the non-virulent or trh positive strain but statically insignificant. At tested salinities, the survival time was higher at 10, 20, and 60 psu compared with that observed in seawater (39 psu). In seawater under dark condition, Vibrio strains remain culturable for up to 200 days with a significant difference between strains (p < 0.05). Furthermore, the non-pathogenic strain survives longer than the virulent ones. At different salinities, a better adaptation is observed at 10 and 20 psu compared with 39 and 60 psu. Resuscitations essays performed on VBNC bacteria in a nutrient broth at 20°C and 37°C does not show any revivification. PRACTITIONER POINTS: Effect of sunlight and salinities on the survival of V. parahaemolyticus in the marine environment. Resuscitation essay performed on viable but no cultivable bacteria. Microscope motility examines show that all strains exposed to sunlight remain motile after the loss of cultivability.
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Affiliation(s)
- Zaafrane Sami
- National Institute of Sciences and Seawater Technologies Salammbô, Salammbo, Tunisia
| | - Maatouk Kaouthar
- National Institute of Sciences and Seawater Technologies Salammbô, Salammbo, Tunisia
| | - Cherif Nadia
- National Institute of Sciences and Seawater Technologies Salammbô, Salammbo, Tunisia
| | - Ben Mansour Hedi
- Unité de Recherche Analyses et Procédés Appliqués à l'Environnement-ISSAT, Mahdia, Tunisia
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Glutaredoxin Interacts with GR and AhpC to Enhance Low-Temperature Tolerance of Antarctic Psychrophile Psychrobacter sp. ANT206. Int J Mol Sci 2022; 23:ijms23031313. [PMID: 35163237 PMCID: PMC8836231 DOI: 10.3390/ijms23031313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 01/22/2022] [Accepted: 01/22/2022] [Indexed: 02/05/2023] Open
Abstract
Glutaredoxin (Grx) is an important oxidoreductase to maintain the redox homoeostasis of cells. In our previous study, cold-adapted Grx from Psychrobacter sp. ANT206 (PsGrx) has been characterized. Here, we constructed an in-frame deletion mutant of psgrx (Δpsgrx). Mutant Δpsgrx was more sensitive to low temperature, demonstrating that psgrx was conducive to the growth of ANT206. Mutant Δpsgrx also had more malondialdehyde (MDA) and protein carbonylation content, suggesting that PsGrx could play a part in the regulation of tolerance against low temperature. A yeast two-hybrid system was adopted to screen interacting proteins of 26 components. Furthermore, two target proteins, glutathione reductase (GR) and alkyl hydroperoxide reductase subunit C (AhpC), were regulated by PsGrx under low temperature, and the interactions were confirmed via bimolecular fluorescence complementation (BiFC) and co-immunoprecipitation (Co-IP). Moreover, PsGrx could enhance GR activity. trxR expression in Δpsgrx, Δahpc, and ANT206 were illustrated 3.7, 2.4, and 10-fold more than mutant Δpsgrx Δahpc, indicating that PsGrx might increase the expression of trxR by interacting with AhpC. In conclusion, PsGrx may participate in glutathione metabolism and ROS-scavenging by regulating GR and AhpC to protect the growth of ANT206. These findings preliminarily suggest the role of PsGrx in the regulation of oxidative stress, which could improve the low-temperature tolerance of ANT206.
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Wang Y, Hou Y, Wang Q, Wang Y. The elucidation of the biodegradation of nitrobenzene and p-nitrophenol of nitroreductase from Antarctic psychrophile Psychrobacter sp. ANT206 under low temperature. JOURNAL OF HAZARDOUS MATERIALS 2021; 413:125377. [PMID: 33609870 DOI: 10.1016/j.jhazmat.2021.125377] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Revised: 02/06/2021] [Accepted: 02/06/2021] [Indexed: 06/12/2023]
Abstract
Psychrobacter is one important typical strain in the Antarctic environment. In our previous study, Psychrobacter sp. ANT206 from Antarctica with novel cold-adapted nitroreductase (PsNTR) could biodegrade nitrobenzene and p-nitrophenol in low temperature environment. In this study, the in-frame deletion mutant of psntr (Δpsntr-ANT206) that displayed well genetic stability and kanamycin resistance stability was constructed using allelic replacement method. Additionally, Δpsntr-ANT206 was more sensitive to nitrobenzene and p-nitrophenol in the comparison of heat and hyperosmolarity, suggesting that psntr gene participated in the regulation of the tolerance against nitro-aromatic compounds (NACs). Further analysis was conducted by integrated gas chromatography-mass spectrometry (GC-MS), and several metabolites were identified. Among them, ethylbenzene, L-Alanine, citric acid, aniline, 4-aminophenol and other metabolites were different between the wild-type strain and Δpsntr-ANT206 under nitrobenzene and p-nitrophenol stress at different time periods under low temperature, respectively. These data could increase the knowledge of the construction of deletion mutant strains and biodegradation mechanism of NACs of typical strains Psychrobacter from Antarctica, which would also provide the basis of the molecular technique on the regulation of bioremediation of the contaminants under low temperature in the future.
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Affiliation(s)
- Yifan Wang
- School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Yanhua Hou
- School of Marine Science and Technology, Harbin Institute of Technology, Weihai 264209, China.
| | - Quanfu Wang
- School of Environment, Harbin Institute of Technology, Harbin 150090, China; School of Marine Science and Technology, Harbin Institute of Technology, Weihai 264209, China.
| | - Yatong Wang
- School of Environment, Harbin Institute of Technology, Harbin 150090, China
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Fish borne Edwardsiella tarda eha involved in the bacterial biofilm formation, hemolytic activity, adhesion capability and pathogenicity. Arch Microbiol 2019; 202:835-842. [PMID: 31865430 DOI: 10.1007/s00203-019-01794-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 11/29/2019] [Accepted: 12/06/2019] [Indexed: 10/25/2022]
Abstract
Edwardsiella tarda (E. tarda) is distributed widely in a variety of hosts including humans, other mammals and fish, and it is worthwhile to notice that E. tarda -caused fish infections lead to the most important bacterial disease in fish. Considering Eha acting as a transcriptional regulator in E. tarda strain ET13 have been reported previously, to better understand its pathogenesis due to this, a type of cell of epithelial cell line (Caco-2) infection model for the pathogen was established in the laboratory. We focused on studying various parameters such as lactate dehydrogenase release (to measure cytotoxicity) and cell adhesions, both of which are related to the bacterial pathogenesis. Furthermore biofilm formation, hemolytic activity, and adhesion to Caco-2 cells were decreased in an E.tarda mutant strain with deletion in-frame isogenic gene eha (∆eha) compared to the wild-type and the complementary strain eha+ (an engineered construct of ∆eha expressing eha); Meanwhile, we found that hemolytic activity and biofilm formation were significantly enhanced in the strain eha+. Moreover, the ∆eha strain had attenuated pathogenicity in the zebrafish infection model. The data also demonstrated that the series of genes fimA, esrB, gadB, mukF, katB, and katG are regulated by eha based on a quantitative reverse transcription polymerase chain reaction tests and analysis. Thus our research data indicated that eha has an impact on hemolytic activity, biofilm formation, adhesion, and pathogenicity of pathogenic strain ET13 and plays an essential role in manifesting the virulence factors.
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Alternative Sigma Factor RpoX Is a Part of the RpoE Regulon and Plays Distinct Roles in Stress Responses, Motility, Biofilm Formation, and Hemolytic Activities in the Marine Pathogen Vibrio alginolyticus. Appl Environ Microbiol 2019; 85:AEM.00234-19. [PMID: 31053580 DOI: 10.1128/aem.00234-19] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 04/20/2019] [Indexed: 12/13/2022] Open
Abstract
Vibrio alginolyticus is one of the most abundant microorganisms in marine environments and is also an opportunistic pathogen mediating high-mortality vibriosis in marine animals. Alternative sigma factors play essential roles in bacterial pathogens in the adaptation to environmental changes during infection and the adaptation to various niches, but little is known about them for V. alginolyticus Our previous investigation indicated that the transcript level of the gene rpoX significantly decreased in an RpoE mutant. Here, we found that rpoX was highly expressed in response to high temperature and low osmotic stress and was under the direct control of the alternative sigma factor RpoE and its own product RpoX. Moreover, transcriptome sequencing (RNA-seq) results showed that RpoE and RpoX had different regulons, although they coregulated 105 genes at high temperature (42°C), including genes associated with biofilm formation, motility, virulence, regulatory factors, and the stress response. RNA-seq and chromatin immunoprecipitation sequencing (ChIP-seq) analyses as well as electrophoretic mobility shift assays (EMSAs) revealed the distinct binding motifs of RpoE and RpoX proteins. Furthermore, quantitative real-time reverse transcription-PCR (qRT-PCR) analysis also confirmed that RpoX can upregulate genes associated with flagella, biofilm formation, and hemolytic activities at higher temperatures. rpoX abrogation does not appear to attenuate virulence toward model fish at normal temperature. Collectively, data from this study demonstrated the regulatory cascades of RpoE and an alternative sigma factor, RpoX, in response to heat and osmotic stresses and their distinct and overlapping roles in pathogenesis and stress responses in the marine bacterium V. alginolyticus IMPORTANCE The alternative sigma factor RpoE is essential for the virulence of Vibrio alginolyticus toward marine fish, coral, and other animals in response to sea surface temperature increases. In this study, we characterized another alternative sigma factor, RpoX, which is induced at high temperatures and under low-osmotic-stress conditions. The expression of rpoX is under the tight control of RpoE and RpoX. Although RpoE and RpoX coregulate 105 genes, they are programming different regulatory functions in stress responses and virulence in V. alginolyticus These findings illuminated the RpoE-RpoX-centered regulatory cascades and their distinct and overlapping regulatory roles in V. alginolyticus, which facilitates unraveling of the mechanisms by which the bacterium causes diseases in various sea animals in response to temperature fluctuations as well as the development of appropriate strategies to tackle infections by this bacterium.
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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.
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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
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The alternative sigma factor RpoQ regulates colony morphology, biofilm formation and motility in the fish pathogen Aliivibrio salmonicida. BMC Microbiol 2018; 18:116. [PMID: 30208852 PMCID: PMC6134601 DOI: 10.1186/s12866-018-1258-9] [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: 04/16/2018] [Accepted: 09/04/2018] [Indexed: 02/04/2023] Open
Abstract
Background Quorum sensing (QS) is a cell-to cell communication system that bacteria use to synchronize activities as a group. LitR, the master regulator of QS in Aliivibrio salmonicida, was recently shown to regulate activities such as motility, rugosity and biofilm formation in a temperature dependent manner. LitR was also found to be a positive regulator of rpoQ. RpoQ is an alternative sigma factor belonging to the sigma −70 family. Alternative sigma factors direct gene transcription in response to environmental signals. In this work we have studied the role of RpoQ in biofilm formation, colony morphology and motility of A. salmonicida LFI1238. Results The rpoQ gene in A. salmonicida LFI1238 was deleted using allelic exchange. We found that RpoQ is a strong repressor of rugose colony morphology and biofilm formation, and that it controls motility of the bacteria. We also show that overexpression of rpoQ in a ΔlitR mutant of A. salmonicida disrupts the biofilm produced by the ΔlitR mutant and decreases its motility, whereas rpoQ overexpression in the wild-type completely eliminates the motility. Conclusion The present work demonstrates that the RpoQ sigma factor is a novel regulatory component involved in modulating motility, colony morphology and biofilm formation in the fish pathogen A. salmonicida. The findings also confirm that RpoQ functions downstream of the QS master regulator LitR. However further studies are needed to elucidate how LitR and RpoQ work together in controlling phenotypes related to QS in A. salmonicida. Electronic supplementary material The online version of this article (10.1186/s12866-018-1258-9) contains supplementary material, which is available to authorized users.
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Role of RpoS in stress resistance, quorum sensing and spoilage potential of Pseudomonas fluorescens. Int J Food Microbiol 2018; 270:31-38. [DOI: 10.1016/j.ijfoodmicro.2018.02.011] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 02/04/2018] [Accepted: 02/11/2018] [Indexed: 01/02/2023]
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Ma Y, Hao L, Ke H, Liang Z, Ma J, Liu Z, Li Y. LuxS/AI-2 in Streptococcus agalactiae reveals a key role in acid tolerance and virulence. Res Vet Sci 2017; 115:501-507. [PMID: 28858764 DOI: 10.1016/j.rvsc.2017.07.032] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Revised: 07/18/2017] [Accepted: 07/26/2017] [Indexed: 12/30/2022]
Abstract
LuxS-mediated autoinducer-2 (AI-2) directly or indirectly regulates important physiologic function in a variety of bacteria. We found a luxS homologue in the genome of Streptococcus agalactiae, an important pathogen of tilapia. To investigate the relationship between luxS/AI-2 and pathogenicity for tilapia, its bioluminescent activity, acid resistance, cell adherence, virulence, and regulation of virulence gene were evaluated. Compared with the wild-type strain, the bioluminescent activity lost in the luxS mutant, its resistance to acid (pH2.8) was significantly decreased 33.8 times, and furthermore, its adherence to the NGF-2 cell line was dramatically reduced 3 times in the mutant strain. The virulence of the mutant strain was decreased in the tilapia infection model, exogenous AI-2 molecule (7.4nM) and luxS gene complementation with plasmid could complement the deficiencies of function in the luxS mutant strain. These results showed that inactivation of luxS gene caused a significant decrease of bioluminance, acid resistance, cell adhesion, virulence to tilapia and transcription levels of many virulence genes in S. agalactiae. Expression of the known stress resistance factors DnaK and GroEL, relative regulator factors CovR/CovS and virulence factor cpsE verified above results. These findings suggest that luxS may be involved in the interruption of bacterial virulence and resistance to environmental factors.
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Affiliation(s)
- Yanping Ma
- Guangdong Provincial key Laboratory of Livestock Disease Prevention, Guangdong Open Laboratory of Veterinary Public Health, Institute of Animal Health, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, PR China
| | - Le Hao
- Guangdong Provincial key Laboratory of Livestock Disease Prevention, Guangdong Open Laboratory of Veterinary Public Health, Institute of Animal Health, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, PR China
| | - Hao Ke
- Guangdong Provincial key Laboratory of Livestock Disease Prevention, Guangdong Open Laboratory of Veterinary Public Health, Institute of Animal Health, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, PR China
| | - Zhiling Liang
- Guangdong Provincial key Laboratory of Livestock Disease Prevention, Guangdong Open Laboratory of Veterinary Public Health, Institute of Animal Health, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, PR China
| | - Jiangyao Ma
- Guangdong Provincial key Laboratory of Livestock Disease Prevention, Guangdong Open Laboratory of Veterinary Public Health, Institute of Animal Health, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, PR China
| | - Zhenxing Liu
- Guangdong Provincial key Laboratory of Livestock Disease Prevention, Guangdong Open Laboratory of Veterinary Public Health, Institute of Animal Health, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, PR China.
| | - Yugu Li
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China.
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Song S, Xue Y, Liu E, Wang K, Zhang Y, Wu H, Zhang H. Comparative analysis of sigma factors RpoS, FliA, and RpoN in Edwardsiella tarda. Can J Microbiol 2016; 62:861-869. [DOI: 10.1139/cjm-2016-0158] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Sigma factors are important regulators that bacteria employ to cope with environmental changes. Studies on the functions of sigma factors have uncovered their roles in many important cellular activities, such as growth, stress tolerance, motility, biofilm formation, and virulence. However, comparative analyses of sigma factors that examine their common and unique features or elucidate their cross-regulatory relationships have rarely been conducted for Edwardsiella tarda. Here, we characterized and compared motility and resistance to oxidative stress of E. tarda strains complemented with rpoS, fliA, and rpoN mutants. The results suggest that the sigma factors FliA and RpoN regulated motility, whereas RpoS exhibited no such function. RpoS and RpoN were essential for oxidative stress resistance, whereas FliA had no obvious impact under oxidative stress conditions. Furthermore, 2-dimensional gel electrophoresis based proteomics analysis combined with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry revealed 12 differentially expressed protein spots that represented 11 proteins between the mutant and wild-type strains. Quantification of the expression of target genes by quantitative reverse transcription PCR confirmed the results of our proteomics analysis. Collectively, these results suggest that these sigma factors are multifunctional mediators involved in controlling the expression of many metabolic pathway genes.
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Affiliation(s)
- ShanShan Song
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, People’s Republic of China
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, People’s Republic of China
| | - Yuanyuan Xue
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, People’s Republic of China
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, People’s Republic of China
| | - Enfu Liu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, People’s Republic of China
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, People’s Republic of China
| | - Keping Wang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, People’s Republic of China
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, People’s Republic of China
| | - Yuanxing Zhang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, People’s Republic of China
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, People’s Republic of China
| | - Haizhen Wu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, People’s Republic of China
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, People’s Republic of China
| | - Huizhan Zhang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, People’s Republic of China
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, People’s Republic of China
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15
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Abstract
Similar to other genera and species of bacteria, whole genomic sequencing has revolutionized how we think about and address questions of basic Vibrio biology. In this review we examined 36 completely sequenced and annotated members of the Vibrionaceae family, encompassing 12 different species of the genera Vibrio, Aliivibrio, and Photobacterium. We reconstructed the phylogenetic relationships among representatives of this group of bacteria by using three housekeeping genes and 16S rRNA sequences. With an evolutionary framework in place, we describe the occurrence and distribution of primary and alternative sigma factors, global regulators present in all bacteria. Among Vibrio we show that the number and function of many of these sigma factors differs from species to species. We also describe the role of the Vibrio-specific regulator ToxRS in fitness and survival. Examination of the biochemical capabilities was and still is the foundation of classifying and identifying new Vibrio species. Using comparative genomics, we examine the distribution of carbon utilization patterns among Vibrio species as a possible marker for understanding bacteria-host interactions. Finally, we discuss the significant role that horizontal gene transfer, specifically, the distribution and structure of integrons, has played in Vibrio evolution.
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16
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Gu D, Guo M, Yang M, Zhang Y, Zhou X, Wang Q. A σE-Mediated Temperature Gauge Controls a Switch from LuxR-Mediated Virulence Gene Expression to Thermal Stress Adaptation in Vibrio alginolyticus. PLoS Pathog 2016; 12:e1005645. [PMID: 27253371 PMCID: PMC4890791 DOI: 10.1371/journal.ppat.1005645] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Accepted: 04/28/2016] [Indexed: 01/15/2023] Open
Abstract
In vibrios, the expression of virulence factors is often controlled by LuxR, the master quorum-sensing regulator. Here, we investigate the interplay between LuxR and σE, an alternative sigma factor, during the control of virulence-related gene expression and adaptations to temperature elevations in the zoonotic pathogen Vibrio alginolyticus. An rpoE null V. alginolyticus mutant was unable to adapt to various stresses and was survival-deficient in fish. In wild type V. alginolyticus, the expression of LuxR-regulated virulence factors increased as the temperature was increased from 22°C to 37°C, but mutants lacking σE did not respond to temperature, indicating that σE is critical for the temperature-dependent upregulation of virulence genes. Further analyses revealed that σE binds directly to -10 and -35 elements in the luxR promoter that drive its transcription. ChIP assays showed that σE binds to the promoter regions of luxR, rpoH and rpoE at high temperatures (e.g., 30°C and 37°C). However, at higher temperatures (42°C) that induce thermal stress, σE binding to the luxR promoter decreased, while its binding to the rpoH and rpoE promoters was unchanged. Thus, the temperature-dependent binding of σE to distinct promoters appears to underlie a σE-controlled switch between the expression of virulence genes and adaptation to thermal stress. This study illustrates how a conserved temperature response mechanism integrates into quorum-sensing circuits to regulate both virulence and stress adaptation. Zoonotic Vibrio outbreaks are believed to be closely associated with increases in environmental temperature. The mechanisms underlying this phenomenon have not been defined. Here, we show that the expression of the V. alginolyticus exotoxin Asp and other quorum-sensing (QS)-regulated virulence factors are induced by increasing temperatures, with the maximum expression observed at approximately 37°C. σE plays an essential role in regulating the QS master regulator LuxR in response to temperature shifts by binding directly to the -10 and -35 regions of the luxR promoter to drive its transcription. However, at higher thermal stress temperatures, σE binding to the luxR promoter decreased, resulting in a reduction in luxR transcription. This change underlies a binomial switch mechanism that regulates σE-controlled virulence gene expression patterns. Furthermore, we found that anti-σE signaling was involved in this stress and virulence reciprocal switch. This study suggests that a common temperature response mechanism is integrated into QS circuits to regulate both virulence and adaptation in related Vibrio taxa.
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Affiliation(s)
- Dan Gu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Min Guo
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Minjun Yang
- Shanghai—MOST Key Laboratory of Health and Disease Genomics, Chinese National Human Genome Center at Shanghai, Shanghai, China
| | - Yuanxing Zhang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
- Shanghai Collaborative Innovation Center for Biomanufacturing Technology, Shanghai, China
- Shanghai Engineering Research Center of Maricultured Animal Vaccines, Shanghai, China
| | - Xiaohui Zhou
- Department of Pathobiology and Veterinary Science, University of Connecticut, Storrs, Connecticut, United States of America
- * E-mail: (XZ); (QW)
| | - Qiyao Wang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
- Shanghai Collaborative Innovation Center for Biomanufacturing Technology, Shanghai, China
- Shanghai Engineering Research Center of Maricultured Animal Vaccines, Shanghai, China
- * E-mail: (XZ); (QW)
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17
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Roles of RpoS in Yersinia pseudotuberculosis stress survival, motility, biofilm formation and type VI secretion system expression. J Microbiol 2015; 53:633-42. [DOI: 10.1007/s12275-015-0099-6] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Revised: 07/16/2015] [Accepted: 07/22/2015] [Indexed: 12/27/2022]
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18
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Alternative sigma factor RpoE is important for Vibrio parahaemolyticus cell envelope stress response and intestinal colonization. Infect Immun 2014; 82:3667-77. [PMID: 24935982 DOI: 10.1128/iai.01854-14] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Vibrio parahaemolyticus is a halophile that inhabits brackish waters and a wide range of hosts, including crustaceans, fish, mollusks, and humans. In humans, it is the leading cause of bacterial seafood-borne gastroenteritis. The focus of this work was to determine the role of alternative sigma factors in the stress response of V. parahaemolyticus RIMD2210633, an O3:K6 pandemic isolate. Bioinformatics identified five putative extracytoplasmic function (ECF) family of alternative sigma factors: VP0055, VP2210, VP2358, VP2578, and VPA1690. ECF factors typically respond to cell wall/cell envelope stress, iron levels, and the oxidation state of the cell. We have demonstrated here that one such sigma factor, VP2578, a homologue of RpoE from Escherichia coli, is important for survival under a number of cell envelope stress conditions and in gastrointestinal colonization of a streptomycin-treated adult mouse. In this study, we determined that an rpoE deletion mutant strain BHM2578 compared to the wild type (WT) was significantly more sensitive to polymyxin B, ethanol, and high-temperature stresses. We demonstrated that in in vivo competition assays between the rpoE mutant and the WT marked with the β-galactosidase gene lacZ (WBWlacZ), the mutant strain was defective in colonization compared to the WT. In contrast, deletion of the rpoS stress response regulator did not affect in vivo survival. In addition, we examined the role of the outer membrane protein, OmpU, which in V. cholerae is proposed to be the sole activator of RpoE. We found that an ompU deletion mutant was sensitive to bile salt stress but resistant to polymyxin B stress, indicating OmpU is not essential for the cell envelope stress responses or RpoE function. Overall, these data demonstrate that RpoE is a key cell envelope stress response regulator and, similar to E. coli, RpoE may have several factors that stimulate its function.
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19
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Johnson CN. Fitness factors in vibrios: a mini-review. MICROBIAL ECOLOGY 2013; 65:826-851. [PMID: 23306394 DOI: 10.1007/s00248-012-0168-x] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Accepted: 12/13/2012] [Indexed: 06/01/2023]
Abstract
Vibrios are Gram-negative curved bacilli that occur naturally in marine, estuarine, and freshwater systems. Some species include human and animal pathogens, and some vibrios are necessary for natural systems, including the carbon cycle and osmoregulation. Countless in vivo and in vitro studies have examined the interactions between vibrios and their environment, including molecules, cells, whole animals, and abiotic substrates. Many studies have characterized virulence factors, attachment factors, regulatory factors, and antimicrobial resistance factors, and most of these factors impact the organism's fitness regardless of its external environment. This review aims to identify common attributes among factors that increase fitness in various environments, regardless of whether the environment is an oyster, a rabbit, a flask of immortalized mammalian cells, or a planktonic chitin particle. This review aims to summarize findings published thus far to encapsulate some of the basic similarities among the many vibrio fitness factors and how they frame our understanding of vibrio ecology. Factors representing these similarities include hemolysins, capsular polysaccharides, flagella, proteases, attachment factors, type III secretion systems, chitin binding proteins, iron acquisition systems, and colonization factors.
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Affiliation(s)
- Crystal N Johnson
- Department of Environmental Sciences, Louisiana State University, Baton Rouge, LA, USA.
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20
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Dong X, Fan X, Wang B, Shi X, Zhang XH. Invasin of Edwardsiella tarda
is essential for its haemolytic activity, biofilm formation and virulence towards fish. J Appl Microbiol 2013; 115:12-9. [DOI: 10.1111/jam.12198] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Revised: 03/13/2013] [Accepted: 03/14/2013] [Indexed: 12/01/2022]
Affiliation(s)
- X. Dong
- College of Marine Life Sciences; Ocean University of China; Qingdao China
| | - X. Fan
- College of Marine Life Sciences; Ocean University of China; Qingdao China
| | - B. Wang
- College of Marine Life Sciences; Ocean University of China; Qingdao China
| | - X. Shi
- College of Marine Life Sciences; Ocean University of China; Qingdao China
| | - X.-H. Zhang
- College of Marine Life Sciences; Ocean University of China; Qingdao China
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21
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Wahl M, Goecke F, Labes A, Dobretsov S, Weinberger F. The second skin: ecological role of epibiotic biofilms on marine organisms. Front Microbiol 2012; 3:292. [PMID: 22936927 PMCID: PMC3425911 DOI: 10.3389/fmicb.2012.00292] [Citation(s) in RCA: 222] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2012] [Accepted: 07/24/2012] [Indexed: 12/27/2022] Open
Abstract
In the aquatic environment, biofilms on solid surfaces are omnipresent. The outer body surface of marine organisms often represents a highly active interface between host and biofilm. Since biofilms on living surfaces have the capacity to affect the fluxes of information, energy, and matter across the host’s body surface, they have an important ecological potential to modulate the abiotic and biotic interactions of the host. Here we review existing evidence how marine epibiotic biofilms affect their hosts’ ecology by altering the properties of and processes across its outer surfaces. Biofilms have a huge potential to reduce its host’s access to light, gases, and/or nutrients and modulate the host’s interaction with further foulers, consumers, or pathogens. These effects of epibiotic biofilms may intensely interact with environmental conditions. The quality of a biofilm’s impact on the host may vary from detrimental to beneficial according to the identity of the epibiotic partners, the type of interaction considered, and prevailing environmental conditions. The review concludes with some unresolved but important questions and future perspectives.
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Affiliation(s)
- Martin Wahl
- Department Benthic Ecology, Helmholtz Centre for Ocean Research Kiel Kiel, Germany
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22
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Li P, Liu X, Li H, Peng XX. Downregulation of Na(+)–NQR complex is essential for Vibrio alginolyticus in resistance to balofloxacin. J Proteomics 2012; 75:2638-48. [DOI: 10.1016/j.jprot.2012.03.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2011] [Revised: 02/14/2012] [Accepted: 03/10/2012] [Indexed: 02/01/2023]
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23
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Liu W, Dong N, Zhang XH. Overexpression of mltA in Edwardsiella tarda reduces resistance to antibiotics and enhances lethality in zebra fish. J Appl Microbiol 2012; 112:1075-85. [PMID: 22443589 DOI: 10.1111/j.1365-2672.2012.05291.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
AIMS The aim of this study was to investigate the role of membrane-bound lytic murein transglycosylase A (MltA) in a bacterial fish pathogen Edwardsiella tarda. METHODS AND RESULTS An mltA in-frame deletion mutant (ΔmltA) and an mltA overexpression strain (mltA(+)) of Edw. tarda were constructed through double-crossover allelic exchange and by transformation of a low-copy plasmid carrying the intact mltA into the ΔmltA mutant, respectively. Either inactivation or overexpression of MltA in Edw. tarda resulted in elevated sensitivity to β-lactam antibiotics and lower viability in oligotrophic or high osmotic environment than wild-type strain. Autolysis induced by EDTA was reduced in ΔmltA strain, while mltA(+) strain was virtually flimsy, indicating that MltA is responsible for the lysis effect. Moreover, mltA(+) strain exhibited significant increases in lipopolysaccharide (LPS) biosynthesis and virulence to zebra fish compared with wild-type strain. CONCLUSIONS The results indicated that MltA plays essential roles in β-lactam antibiotics and environmental stresses resistance, autolysis, LPS biosynthesis and pathogenicity of Edw. tarda. This is the first report that MltA has a virulence-related function in Edw. tarda. SIGNIFICANCE AND IMPACT OF THE STUDY This study provided useful information for further studies on pathogenesis of Edw. tarda.
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Affiliation(s)
- W Liu
- College of Marine Life Sciences, Ocean University of China, Qingdao, China
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24
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Wang K, Liu E, Song S, Wang X, Zhu Y, Ye J, Zhang H. Characterization of Edwardsiella tarda rpoN: roles in σ70 family regulation, growth, stress adaption and virulence toward fish. Arch Microbiol 2012; 194:493-504. [DOI: 10.1007/s00203-011-0786-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2011] [Revised: 12/15/2011] [Accepted: 12/23/2011] [Indexed: 12/26/2022]
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25
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The novel sigma factor-like regulator RpoQ controls luminescence, chitinase activity, and motility in Vibrio fischeri. mBio 2012; 3:mBio.00285-11. [PMID: 22233679 PMCID: PMC3252764 DOI: 10.1128/mbio.00285-11] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Vibrio fischeri, the bacterial symbiont of the Hawaiian bobtail squid, Euprymna scolopes, uses quorum sensing to control genes involved in bioluminescence, host colonization, and other biological processes. Previous work has shown that AinS/R-directed quorum sensing also regulates the expression of rpoQ (VF_A1015), a gene annotated as an RpoS-like sigma factor. In this study, we demonstrate using phylogenetics that RpoQ is related to, but distinct from, the stationary-phase sigma factor RpoS. Overexpression of rpoQ results in elevated chitinase activity but decreased motility and luminescence, three activities associated with symbiosis. The reduction in bacterial luminescence associated with the overexpression of rpoQ occurs both in culture and within the light-emitting organ of the squid host. This suppression of bioluminescence is due to the repression of the luxICDABEG promoter. Our results highlight RpoQ as a novel regulatory component, embedded in the quorum-signaling network that controls several biological processes in V. fischeri. Quorum signaling is a widely occurring phenomenon that functions in diverse bacterial taxa. It is most often found associated with species that interact with animal or plant hosts, either as mutualists or pathogens, and controls the expression of genes critical to tissue colonization. We present the discovery of rpoQ, which encodes a new regulatory component in the quorum-signaling pathway of Vibrio fischeri. RpoQ is a novel protein in the RpoS family of stationary-phase sigma factors. Unlike many other regulatory proteins involved in the quorum-signaling pathways of the Vibrionaceae, the distribution of RpoQ appears to be restricted to only two closely related species. The role of this regulator is to enhance some quorum-signaling outputs (chitinase activity) while suppressing others (luminescence). We propose that RpoQ may be a recently evolved or acquired component in V. fischeri that provides this organism with an additional level of regulation to modulate its existing quorum-signaling pathway.
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26
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Liu H, Gu D, Cao X, Liu Q, Wang Q, Zhang Y. Characterization of a new quorum sensing regulator luxT and its roles in the extracellular protease production, motility, and virulence in fish pathogen Vibrio alginolyticus. Arch Microbiol 2011; 194:439-52. [PMID: 22130678 DOI: 10.1007/s00203-011-0774-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2011] [Revised: 09/28/2011] [Accepted: 11/07/2011] [Indexed: 11/28/2022]
Abstract
Vibrio alginolyticus, an opportunistic pathogen that causes vibriosis in miscellaneous fish species, has brought about serious economic damage to the mariculture industry in South China. The mechanism of virulence regulation in V. alginolyticus is yet not known except a Vibrio harveyi-like quorum sensing (QS) system that is established to manipulate the expression of diverse genes including those encoding virulence determinants. In this study, a new TetR family QS regulator, luxT, was identified and characterized in V. alginolyticus. The transcription of luxT gene was cell density dependent and was positively regulated by LuxU, an established QS component relaying the signal from three paralleled QS regulatory systems in V. harveyi. In addition, luxT positively regulated both luxO at transcriptional level and luxR at post-transcriptional level, which is thoroughly different from the established QS regulation mode in V. harveyi and Vibrio vulnificus. The mutant of luxT deletion produced markedly decreased total extracellular proteases and reduced motility ability compared to the wild type and the complemented strain luxT (+). The fish infection results indicated that mutation of luxT led to marginal attenuation in the virulence of V. alginolyticus, suggesting that LuxT might play a role in the fine-tuning of the virulence via QS in V. alginolyticus.
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Affiliation(s)
- Huan Liu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China
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27
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Roles of Hfq in the stress adaptation and virulence in fish pathogen Vibrio alginolyticus and its potential application as a target for live attenuated vaccine. Appl Microbiol Biotechnol 2011; 91:353-64. [DOI: 10.1007/s00253-011-3286-3] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2010] [Revised: 03/09/2011] [Accepted: 04/07/2011] [Indexed: 11/27/2022]
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28
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Genotype Analysis of Collagenase Gene by PCR-SSCP in Vibrio alginolyticus and its Association with Virulence to Marine Fish. Curr Microbiol 2011; 62:1697-703. [DOI: 10.1007/s00284-011-9916-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2011] [Accepted: 02/22/2011] [Indexed: 11/25/2022]
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29
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Kim CM, Shin SH. Change ofVibrio vulnificusMetalloprotease VvpE Production by Temperature and Salinity. ACTA ACUST UNITED AC 2011. [DOI: 10.4167/jbv.2011.41.3.147] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Choon-Mee Kim
- Research Center for Resistant Cells, Chosun University Medical School, Gwangju, Korea
| | - Sung-Heui Shin
- Research Center for Resistant Cells, Chosun University Medical School, Gwangju, Korea
- Department of Microbiology, Chosun University Medical School, Gwangju, Korea
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30
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Functional Characterization of Vibrio alginolyticus Twin-Arginine Translocation System: Its Roles in Biofilm Formation, Extracellular Protease Activity, and Virulence Towards Fish. Curr Microbiol 2010; 62:1193-9. [DOI: 10.1007/s00284-010-9844-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2010] [Accepted: 11/24/2010] [Indexed: 10/18/2022]
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31
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Zhao Z, Zhang L, Ren C, Zhao J, Chen C, Jiang X, Luo P, Hu CQ. Autophagy is induced by the type III secretion system of Vibrio alginolyticus in several mammalian cell lines. Arch Microbiol 2010; 193:53-61. [PMID: 21046072 DOI: 10.1007/s00203-010-0646-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2010] [Revised: 10/07/2010] [Accepted: 10/13/2010] [Indexed: 01/19/2023]
Abstract
Vibrio alginolyticus is a gram-negative bacterium and has been recognized as an opportunistic pathogen in marine animals as well as humans. Here, we further characterized a cell death mechanism caused by this bacterium in several mammalian cell lines. The T3SS of V. alginolyticus killed HeLa cells by a very similar cell cytolysis mechanism in fish cells, as evidenced by cell rounding and LDH release; however, DNA fragmentation was not observed. Further studies showed that caspase-1 and caspase-3 were not activated during the T3SS-mediated cell death, indicating that the death mechanism is completely independent of pyroptosis and apoptosis in HeLa cells. Conversely, autophagy was detected during the T3SS-mediated cell death by the appearance of MDC-labeled punctate fluorescence and accumulation of autophagic vesicles. Moreover, western blot analysis revealed increase in conversion of LC3-I to LC3-II in infected mammalian cell lines, confirming that autophagy occurs during the process. Together, these data demonstrate that the death process used by V. alginolyticus in mammalian cells is different from that in fish cells, including induction of autophagy, cell rounding and osmotic lysis. This study provides some evidences hinting that differences in death mechanism in responses to V. alginolyticus infection may be attributed to the species of infected cells from which it was derived.
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Affiliation(s)
- Zhe Zhao
- Key Laboratory of Applied Marine Biology of Guangdong Province and Key Laboratory of Marine Bio-Resources Sustainable Utilization, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, People's Republic of China
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32
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Xiong XP, Wang C, Ye MZ, Yang TC, Peng XX, Li H. Differentially expressed outer membrane proteins of Vibrio alginolyticus in response to six types of antibiotics. MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2010; 12:686-695. [PMID: 20217167 DOI: 10.1007/s10126-009-9256-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2009] [Accepted: 12/16/2009] [Indexed: 05/28/2023]
Abstract
Vibrio alginolyticus is an opportunistic pathogen that occasionally causes life-threatening infections in individuals and results in great losses in marine aquacultures of crustaceans and fish. Recently, antibiotic-resistant strains of the bacterium from clinical and environmental sources have been reported with increasing frequency. However, few reports were involved in the antibiotic resistance of this bacterium at molecular levels. In the present study, Western blotting was utilized to investigate altered OM proteins of V. alginolyticus in response to six types of antibiotics: erythromycin, kanamycin, tetracycline, streptomycin, nalidixic acid, and chloromycetin. Seventeen OM proteins have been reported here for the first time to be related to antibiotic resistance. They were porins OmpU, OmpN, putative OmpU and LamB; transport proteins VA0802, VA2212 (FadL) and VPA0860; TolC family TolC and VA1631; lipoprotein VA0449; OmpA family VPA1186 and VA0764; iron-regulated proteins OmpV, VPA1435, and VA2602; and receptor protein OmpK; hypothetical protein VA1475. Importantly, VA2212 was up-regulated in response to the five antibiotics except nalidixic acid, and VPA1186 was down-regulated in response to the six antibiotics in antibiotic-stressed bacteria. They might be potentially universal targets for designing the new drugs that inhibit multi-resistant bacteria. These findings suggested that parallel investigations into a bacterium responding to several types of antibiotics would be helpful not only for the further understanding of antibiotic-resistant mechanisms but also for the screening of valuable targets of new drugs controlling antibiotic-resistant bacteria.
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Affiliation(s)
- Xiao-Peng Xiong
- Center for Proteomics, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, People's Republic of China
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Cloning, identification, and characterization of the rpoS-like sigma factor rpoX from Vibrio alginolyticus. J Biomed Biotechnol 2009; 2009:126986. [PMID: 20069110 PMCID: PMC2804039 DOI: 10.1155/2009/126986] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2009] [Revised: 08/05/2009] [Accepted: 09/28/2009] [Indexed: 11/18/2022] Open
Abstract
Vibrio alginolyticus ZJ-51 displays phase variation between opaque/rugose colonies (Op) and translucent/smooth colonies (Tr). These colony variants show great differences in biofilm formation and motility. In this study, a gene encoding for an rpoS-like sigma factor, rpoX, has been cloned and characterized. The absence of rpoX did not affect colony switching rate but did decrease biofilm formation in both the Op and the Tr variants. When challenged with hydrogen peroxide, the DeltarpoX in the Op background showed a slightly higher survival rate compared with the wild type, whereas survival was decreased in the Tr background. Deletion of rpoX in the Tr background resulted in a higher ability to resist ethanol challenges and to survive hyperosmolarity challenges, and in the Op background the opposite phenotype was observed. This indicates that the rpoX gene is involved in biofilm formation and stress response but the effects are controlled by colony phase variation in V. alginolyticus.
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Ma L, Chen J, Liu R, Zhang XH, Jiang YA. Mutation ofrpoS gene decreased resistance to environmental stresses, synthesis of extracellular products and virulence ofVibrio anguillarum. FEMS Microbiol Ecol 2009; 70:130-6. [DOI: 10.1111/j.1574-6941.2009.00713.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Li H, Xiong XP, Peng B, Xu CX, Ye MZ, Yang TC, Wang SY, Peng XX. Identification of Broad Cross-Protective Immunogens Using Heterogeneous Antiserum-Based Immunoproteomic Approach. J Proteome Res 2009; 8:4342-9. [PMID: 19640004 DOI: 10.1021/pr900439j] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Hui Li
- Center for Proteomics, State Key Laboratory of Bio-Control, School of Life Sciences, Sun Yat-Sen University, University City, Guangzhou 510006, People’s Republic of China, School of Life Sciences, Xiamen University, Xiamen 361005, People’s Republic of China, and Center of Clinical Laboratory, Xiamen Zhongshan Hospital, Xiamen University, Xiamen 361004, Fujian, People’s Republic of China
| | - Xiao-Peng Xiong
- Center for Proteomics, State Key Laboratory of Bio-Control, School of Life Sciences, Sun Yat-Sen University, University City, Guangzhou 510006, People’s Republic of China, School of Life Sciences, Xiamen University, Xiamen 361005, People’s Republic of China, and Center of Clinical Laboratory, Xiamen Zhongshan Hospital, Xiamen University, Xiamen 361004, Fujian, People’s Republic of China
| | - Bo Peng
- Center for Proteomics, State Key Laboratory of Bio-Control, School of Life Sciences, Sun Yat-Sen University, University City, Guangzhou 510006, People’s Republic of China, School of Life Sciences, Xiamen University, Xiamen 361005, People’s Republic of China, and Center of Clinical Laboratory, Xiamen Zhongshan Hospital, Xiamen University, Xiamen 361004, Fujian, People’s Republic of China
| | - Chang-Xin Xu
- Center for Proteomics, State Key Laboratory of Bio-Control, School of Life Sciences, Sun Yat-Sen University, University City, Guangzhou 510006, People’s Republic of China, School of Life Sciences, Xiamen University, Xiamen 361005, People’s Republic of China, and Center of Clinical Laboratory, Xiamen Zhongshan Hospital, Xiamen University, Xiamen 361004, Fujian, People’s Republic of China
| | - Ming-Zhi Ye
- Center for Proteomics, State Key Laboratory of Bio-Control, School of Life Sciences, Sun Yat-Sen University, University City, Guangzhou 510006, People’s Republic of China, School of Life Sciences, Xiamen University, Xiamen 361005, People’s Republic of China, and Center of Clinical Laboratory, Xiamen Zhongshan Hospital, Xiamen University, Xiamen 361004, Fujian, People’s Republic of China
| | - Tian-Ci Yang
- Center for Proteomics, State Key Laboratory of Bio-Control, School of Life Sciences, Sun Yat-Sen University, University City, Guangzhou 510006, People’s Republic of China, School of Life Sciences, Xiamen University, Xiamen 361005, People’s Republic of China, and Center of Clinical Laboratory, Xiamen Zhongshan Hospital, Xiamen University, Xiamen 361004, Fujian, People’s Republic of China
| | - San-Ying Wang
- Center for Proteomics, State Key Laboratory of Bio-Control, School of Life Sciences, Sun Yat-Sen University, University City, Guangzhou 510006, People’s Republic of China, School of Life Sciences, Xiamen University, Xiamen 361005, People’s Republic of China, and Center of Clinical Laboratory, Xiamen Zhongshan Hospital, Xiamen University, Xiamen 361004, Fujian, People’s Republic of China
| | - Xuan-Xian Peng
- Center for Proteomics, State Key Laboratory of Bio-Control, School of Life Sciences, Sun Yat-Sen University, University City, Guangzhou 510006, People’s Republic of China, School of Life Sciences, Xiamen University, Xiamen 361005, People’s Republic of China, and Center of Clinical Laboratory, Xiamen Zhongshan Hospital, Xiamen University, Xiamen 361004, Fujian, People’s Republic of China
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Characterization of Edwardsiella tarda rpoS: effect on serum resistance, chondroitinase activity, biofilm formation, and autoinducer synthetases expression. Appl Microbiol Biotechnol 2009; 83:151-60. [DOI: 10.1007/s00253-009-1924-9] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2009] [Revised: 02/16/2009] [Accepted: 02/17/2009] [Indexed: 10/21/2022]
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