1
|
Li Y, Liang X, Chen N, Yuan X, Wang J, Wu Q, Ding Y. The promotion of biofilm dispersion: a new strategy for eliminating foodborne pathogens in the food industry. Crit Rev Food Sci Nutr 2024:1-25. [PMID: 39054781 DOI: 10.1080/10408398.2024.2354524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/27/2024]
Abstract
Food safety is a critical global concern due to its direct impact on human health and overall well-being. In the food processing environment, biofilm formation by foodborne pathogens poses a significant problem as it leads to persistent and high levels of food contamination, thereby compromising the quality and safety of food. Therefore, it is imperative to effectively remove biofilms from the food processing environment to ensure food safety. Unfortunately, conventional cleaning methods fall short of adequately removing biofilms, and they may even contribute to further contamination of both equipment and food. It is necessary to develop alternative approaches that can address this challenge in food industry. One promising strategy in tackling biofilm-related issues is biofilm dispersion, which represents the final step in biofilm development. Here, we discuss the biofilm dispersion mechanism of foodborne pathogens and elucidate how biofilm dispersion can be employed to control and mitigate biofilm-related problems. By shedding light on these aspects, we aim to provide valuable insights and solutions for effectively addressing biofilm contamination issues in food industry, thus enhancing food safety and ensuring the well-being of consumers.
Collapse
Affiliation(s)
- Yangfu Li
- State Key Laboratory of Applied Microbiology Southern China, National Health Commission Science and Technology Innovation Platform for Nutrition and Safety of Microbial Food, Guangdong Provincial Key Laboratory of Microbial Safety and Health, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Xinmin Liang
- State Key Laboratory of Applied Microbiology Southern China, National Health Commission Science and Technology Innovation Platform for Nutrition and Safety of Microbial Food, Guangdong Provincial Key Laboratory of Microbial Safety and Health, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
- Department of Food Science & Engineering, College of Life Science and Technology, Jinan University, Guangzhou, China
| | - Nuo Chen
- State Key Laboratory of Applied Microbiology Southern China, National Health Commission Science and Technology Innovation Platform for Nutrition and Safety of Microbial Food, Guangdong Provincial Key Laboratory of Microbial Safety and Health, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Xiaoming Yuan
- State Key Laboratory of Applied Microbiology Southern China, National Health Commission Science and Technology Innovation Platform for Nutrition and Safety of Microbial Food, Guangdong Provincial Key Laboratory of Microbial Safety and Health, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
- Department of Food Science & Engineering, College of Life Science and Technology, Jinan University, Guangzhou, China
| | - Juan Wang
- College of Food Science, South China Agricultural University, Guangzhou, China
| | - Qingping Wu
- State Key Laboratory of Applied Microbiology Southern China, National Health Commission Science and Technology Innovation Platform for Nutrition and Safety of Microbial Food, Guangdong Provincial Key Laboratory of Microbial Safety and Health, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Yu Ding
- Department of Food Science & Engineering, College of Life Science and Technology, Jinan University, Guangzhou, China
| |
Collapse
|
2
|
Rasal TA, Mallery CP, Brockley MW, Brown LC, Paczkowski JE, van Kessel JC. Ligand binding determines proteolytic stability of Vibrio LuxR/HapR quorum sensing transcription factors. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.15.580527. [PMID: 38405947 PMCID: PMC10888775 DOI: 10.1101/2024.02.15.580527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
In Vibrio species, quorum sensing signaling culminates in the production of a TetR-type master transcription factor collectively called the LuxR/HapR family, which regulates genes required for colonization and infection of host organisms. These proteins possess a solvent accessible putative ligand binding pocket. However, a native ligand has not been identified, and the role of ligand binding in LuxR/HapR function in Vibrionaceae is unknown. To probe the role of the ligand binding pocket, we utilize the small molecule thiophenesulfonamide inhibitor PTSP (3- p henyl-1-( t hiophen-2-yl s ulfonyl)-1 H - p yrazole) that we previously showed targets LuxR/HapR proteins. Amino acid conservation in the ligand binding pocket determines the specificity and efficacy of PTSP inhibition across Vibrio species. Here, we used structure-function analyses to identify PTSP-interacting residues in the ligand binding pocket of SmcR - the Vibrio vulnificus LuxR/HapR homolog - that are required for PTSP inhibition of SmcR activity in vivo . Forward genetic screening combined with X-ray crystallography structural determination of SmcR bound to PTSP identified substitutions at eight residues that were sufficient to reduce or eliminate PTSP-mediated SmcR inhibition. Small-angle X-ray scattering and computational modeling determined that PTSP drives allosteric unfolding at the N-terminal DNA binding domain. We discovered that SmcR is degraded by the ClpAP protease in the presence of PTSP in vivo ; substitution of key PTSP-interacting residues stabilized or increased SmcR levels in the cell. This mechanism of inhibition is observed for all thiophenesulfonamide compounds tested and against other Vibrio species. We conclude that thiophenesulfonamides specifically bind in the ligand binding pocket of LuxR/HapR proteins, promoting protein degradation and thereby suppressing downstream gene expression, implicating ligand binding as a mediator of LuxR/HapR protein stability and function to govern virulence gene expression in Vibrio pathogens. SIGNIFICANCE LuxR/HapR proteins were discovered in the 1990s as central regulators of quorum sensing gene expression and later discovered to be conserved in all studied Vibrio species. LuxR/HapR homologs regulate a wide range of genes involved in pathogenesis, including but not limited to genes involved in biofilm production and toxin secretion. As archetypal members of the broad class of TetR-type transcription factors, each LuxR/HapR protein has a predicted ligand binding pocket. However, no ligand has been identified for LuxR/HapR proteins that control their function as regulators. Here, we used LuxR/HapR-specific chemical inhibitors to determine that ligand binding drives proteolytic degradation in vivo , the first demonstration of LuxR/HapR function connected to ligand binding for this historical protein family.
Collapse
|
3
|
Xie H, Zhang R, Guo R, Zhang Y, Zhang J, Li H, Fu Q, Wang X. Characterization of AI-2/LuxS quorum sensing system in biofilm formation, pathogenesis of Streptococcus equi subsp. zooepidemicus. Front Cell Infect Microbiol 2024; 14:1339131. [PMID: 38379770 PMCID: PMC10876813 DOI: 10.3389/fcimb.2024.1339131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Accepted: 01/24/2024] [Indexed: 02/22/2024] Open
Abstract
Streptococcus equi subsp. zooepidemicus (SEZ) is an opportunistic pathogen of both humans and animals. Quorum sensing (QS) plays an important role in the regulation of bacterial group behaviors. The aim of this study was to characterize the LuxS in SEZ and evaluate its impact on biofilm formation, pathogenesis and gene expression. The wild-type SEZ and its LuxS mutant (ΔluxS) were examined for growth, biofilm formation, virulence factors, and transcriptomic profiles. Our results showed that LuxS deficiency did not affect SEZ hemolytic activity, adhesion or capsule production. For biofilm assay demonstrated that mutation in the luxS gene significantly enhances biofilm formation, produced a denser biofilm and attached to a glass surface. RAW264.7 cell infection indicated that ΔluxS promoted macrophage apoptosis and pro-inflammatory responses. In mice infection, there was no significant difference in mortality between SEZ and ΔluxS. However, the bacterial load in the spleen of mice infected with ΔluxS was significantly higher than in those infected with SEZ. And the pathological analysis further indicated that spleen damage was more severe in the ΔluxS group. Moreover, transcriptomics analysis revealed significant alterations in carbon metabolism, RNA binding and stress response genes in ΔluxS. In summary, this study provides the first evidence of AI-2/LuxS QS system in SEZ and reveals its regulatory effects on biofilm formation, pathogenicity and gene expression.
Collapse
Affiliation(s)
- Honglin Xie
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
| | - Riteng Zhang
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
| | - Ruhai Guo
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
| | - Yining Zhang
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
| | - Jingya Zhang
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
| | - Hui Li
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
| | - Qiang Fu
- School of Life Science and Engineering, Foshan University, Foshan, China
| | - Xinglong Wang
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
| |
Collapse
|
4
|
Huq M, Wahid SUH, Istivan T. Biofilm Formation in Campylobacter concisus: The Role of the luxS Gene. Microorganisms 2023; 12:46. [PMID: 38257873 PMCID: PMC10820981 DOI: 10.3390/microorganisms12010046] [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: 11/30/2023] [Revised: 12/19/2023] [Accepted: 12/22/2023] [Indexed: 01/24/2024] Open
Abstract
Campylobacter concisus is a bacterium that inhabits human oral cavities and is an emerging intestinal tract pathogen known to be a biofilm producer and one of the bacterial species found in dental plaque. In this study, biofilms of oral and intestinal C. concisus isolates were phenotypically characterized. The role of the luxS gene, which is linked to the regulation of biofilm formation in other pathogens, was assessed in relation to the pathogenic potential of this bacterium. Biofilm formation capacity was assessed using phenotypic assays. Oral strains were shown to be the highest producers. A luxS mutant was created by inserting a kanamycin cassette within the luxS gene of the highest biofilm-forming isolate. The loss of the polar flagellum was observed with scanning and transmission electron microscopy (SEM and TEM). Furthermore, the luxS mutant exhibited a significant reduction (p < 0.05) in biofilm formation, motility, and its expression of flaB, in addition to the capability to invade intestinal epithelial cells, compared to the parental strain. The study concluded that C. concisus oral isolates are significantly higher biofilm producers than the intestinal isolates and that LuxS plays a role in biofilm formation, invasion, and motility in this bacterium.
Collapse
Affiliation(s)
- Mohsina Huq
- School of Science, STEM College, RMIT University, Bundoora, Melbourne, VIC 3083, Australia
- Department of Medical Laboratories, College of Applied Medical Sciences, Qassim University, Buraydah 51452, Saudi Arabia
| | | | - Taghrid Istivan
- School of Science, STEM College, RMIT University, Bundoora, Melbourne, VIC 3083, Australia
| |
Collapse
|
5
|
Kragh KN, Tolker-Nielsen T, Lichtenberg M. The non-attached biofilm aggregate. Commun Biol 2023; 6:898. [PMID: 37658117 PMCID: PMC10474055 DOI: 10.1038/s42003-023-05281-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 08/24/2023] [Indexed: 09/03/2023] Open
Abstract
Biofilms have conventionally been perceived as dense bacterial masses on surfaces, following the five-step model of development. Initial biofilm research focused on surface-attached formations, but detached aggregates have received increasing attention in the past decade due to their pivotal role in chronic infections. Understanding their nature sparked fervent discussions in biofilm conferences and scientific literature. This review consolidates current insights on non-attached aggregates, offering examples of their occurrence in nature and diseases. We discuss their formation and dispersion mechanisms, resilience to antibiotics and immune-responses, drawing parallels to surface-attached biofilms. Moreover, we outline available in vitro models for studying non-attached aggregates.
Collapse
Affiliation(s)
- Kasper N Kragh
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Tim Tolker-Nielsen
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Mads Lichtenberg
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark.
| |
Collapse
|
6
|
Sen H, Choudhury GB, Pawar G, Sharma Y, Bhalerao SE, Chaudhari VD, Datta S, Raychaudhuri S. Diversity in the ligand binding pocket of HapR attributes to its uniqueness towards several inhibitors with respect to other homologues - A structural and molecular perspective. Int J Biol Macromol 2023; 233:123495. [PMID: 36739058 DOI: 10.1016/j.ijbiomac.2023.123495] [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: 11/24/2022] [Revised: 01/06/2023] [Accepted: 01/28/2023] [Indexed: 02/05/2023]
Abstract
Vibrio cholerae is a prolific bacterium. Cumulative studies clearly demonstrate the key role of quorum sensing on the lifecycle of this bacterium. Of the sensory network components, HapR is known as high cell density master regulator. Until now, no information is available on native HapR ligand despite the protein having a ligand binding pocket. Interestingly, function of SmcR, a HapR homologue of Vibrio vulnificus is inhibited by a small molecule Qstatin. Structural analysis of SmcR with Qstatin identifies key interacting residues in SmcR ligand binding domain. Despite bearing significant homology with SmcR, HapR function remained unabated by Qstatin. Sequence alignment indicates divergence in the key residues of ligand binding pocket between these two regulators. A series of ligand binding domain mutants of HapR was constructed where only HapR quadruple mutant responded to Qstatin and newly synthesized IMT-VC-212. Crystal structure analysis revealed four key residues are responsible for changes in the volume of ligand binding pocket of HapR quadruple mutant compared to the wild type counterpart, thereby increasing the accessibility of Qstatin and its derivative in case of the former. The mechanistic insights exuberating from this study will remain instrumental in designing inhibitors against wild type HapR.
Collapse
Affiliation(s)
- Himanshu Sen
- CSIR-Institute of Microbial Technology, Sector 39A, Chandigarh 160036, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Gourab Basu Choudhury
- CSIR-Indian Institute of Chemical Biology, Raja S C Mullick Road, Jadavpur, Kolkata 700032, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Ganesh Pawar
- CSIR-Institute of Microbial Technology, Sector 39A, Chandigarh 160036, India
| | - Yogesh Sharma
- CSIR-Institute of Microbial Technology, Sector 39A, Chandigarh 160036, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | | | - Vinod D Chaudhari
- CSIR-Institute of Microbial Technology, Sector 39A, Chandigarh 160036, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India..
| | - Saumen Datta
- CSIR-Indian Institute of Chemical Biology, Raja S C Mullick Road, Jadavpur, Kolkata 700032, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India..
| | - Saumya Raychaudhuri
- CSIR-Institute of Microbial Technology, Sector 39A, Chandigarh 160036, India.
| |
Collapse
|
7
|
Midgett CR, Kull FJ. Structural Insights into Regulation of Vibrio Virulence Gene Networks. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1404:269-294. [PMID: 36792881 DOI: 10.1007/978-3-031-22997-8_14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
One of the best studied aspects of pathogenic Vibrios are the virulence cascades that lead to the production of virulence factors and, ultimately, clinical outcomes. In this chapter, we will examine the regulation of Vibrio virulence gene networks from a structural and biochemical perspective. We will discuss the recent research into the numerous proteins that contribute to regulating virulence in Vibrio spp such as quorum sensing regulator HapR, the transcription factors AphA and AphB, or the virulence regulators ToxR and ToxT. We highlight how insights gained from these studies are already illuminating the basic molecular mechanisms by which the virulence cascade of pathogenic Vibrios unfold and contend that understanding how protein interactions contribute to the host-pathogen communications will enable the development of new antivirulence compounds that can effectively target these pathogens.
Collapse
Affiliation(s)
| | - F Jon Kull
- Chemistry Department, Dartmouth College, Hanover, NH, USA.
| |
Collapse
|
8
|
Lee H, Im H, Hwang SH, Ko D, Choi SH. Two novel genes identified by large-scale transcriptomic analysis are essential for biofilm and rugose colony development of Vibrio vulnificus. PLoS Pathog 2023; 19:e1011064. [PMID: 36656902 PMCID: PMC9888727 DOI: 10.1371/journal.ppat.1011064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 01/31/2023] [Accepted: 12/13/2022] [Indexed: 01/20/2023] Open
Abstract
Many pathogenic bacteria form biofilms to survive under environmental stresses and host immune defenses. Differential expression (DE) analysis of the genes in biofilm and planktonic cells under a single condition, however, has limitations to identify the genes essential for biofilm formation. Independent component analysis (ICA), a machine learning algorithm, was adopted to comprehensively identify the biofilm genes of Vibrio vulnificus, a fulminating human pathogen, in this study. ICA analyzed the large-scale transcriptome data of V. vulnificus cells under various biofilm and planktonic conditions and then identified a total of 72 sets of independently co-regulated genes, iModulons. Among the three iModulons specifically activated in biofilm cells, BrpT-iModulon mainly consisted of known genes of the regulon of BrpT, a transcriptional regulator controlling biofilm formation of V. vulnificus. Interestingly, the BrpT-iModulon additionally contained two novel genes, VV1_3061 and VV2_1694, designated as cabH and brpN, respectively. cabH and brpN were shared in other Vibrio species and not yet identified by DE analyses. Genetic and biochemical analyses revealed that cabH and brpN are directly up-regulated by BrpT. The deletion of cabH and brpN impaired the robust biofilm and rugose colony formation. CabH, structurally similar to the previously known calcium-binding matrix protein CabA, was essential for attachment to the surface. BrpN, carrying an acyltransferase-3 domain as observed in BrpL, played an important role in exopolysaccharide production. Altogether, ICA identified two novel genes, cabH and brpN, which are regulated by BrpT and essential for the development of robust biofilms and rugose colonies of V. vulnificus.
Collapse
Affiliation(s)
- Hojun Lee
- National Research Laboratory of Molecular Microbiology and Toxicology, Department of Agricultural Biotechnology, Seoul National University, Seoul, Republic of Korea
- Center for Food and Bioconvergence, and Research Institute of Agriculture and Life Science, Seoul National University, Seoul, Republic of Korea
| | - Hanhyeok Im
- National Research Laboratory of Molecular Microbiology and Toxicology, Department of Agricultural Biotechnology, Seoul National University, Seoul, Republic of Korea
- Center for Food and Bioconvergence, and Research Institute of Agriculture and Life Science, Seoul National University, Seoul, Republic of Korea
| | - Seung-Ho Hwang
- National Research Laboratory of Molecular Microbiology and Toxicology, Department of Agricultural Biotechnology, Seoul National University, Seoul, Republic of Korea
- Center for Food and Bioconvergence, and Research Institute of Agriculture and Life Science, Seoul National University, Seoul, Republic of Korea
| | - Duhyun Ko
- National Research Laboratory of Molecular Microbiology and Toxicology, Department of Agricultural Biotechnology, Seoul National University, Seoul, Republic of Korea
- Center for Food and Bioconvergence, and Research Institute of Agriculture and Life Science, Seoul National University, Seoul, Republic of Korea
| | - Sang Ho Choi
- National Research Laboratory of Molecular Microbiology and Toxicology, Department of Agricultural Biotechnology, Seoul National University, Seoul, Republic of Korea
- Center for Food and Bioconvergence, and Research Institute of Agriculture and Life Science, Seoul National University, Seoul, Republic of Korea
- * E-mail:
| |
Collapse
|
9
|
Choi G, Choi SH. Complex regulatory networks of virulence factors in Vibrio vulnificus. Trends Microbiol 2022; 30:1205-1216. [PMID: 35753865 DOI: 10.1016/j.tim.2022.05.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 05/13/2022] [Accepted: 05/18/2022] [Indexed: 01/13/2023]
Abstract
The fulminating zoonotic pathogen Vibrio vulnificus is the causative agent of fatal septicemia in humans and fish, raising tremendous economic burdens in healthcare and the aquaculture industry. V. vulnificus exploits various virulence factors, including biofilm-related factors and exotoxins, for its persistence in nature and pathogenesis during infection. Substantial studies have found that the expression of virulence factors is coordinately regulated by numerous transcription factors that recognize the changing environments. Here, we summarize and discuss the recent discoveries of the physiological roles of virulence factors in V. vulnificus and their regulation by transcription factors in response to various environmental signals. This expanded understanding of molecular pathogenesis would provide novel clues to develop an effective antivirulence therapy against V. vulnificus infection.
Collapse
Affiliation(s)
- Garam Choi
- National Research Laboratory of Molecular Microbiology and Toxicology, Department of Agricultural Biotechnology, Seoul National University, Seoul 08826, Republic of Korea; Center for Food and Bioconvergence, Seoul National University, Seoul 08826, Republic of Korea
| | - Sang Ho Choi
- National Research Laboratory of Molecular Microbiology and Toxicology, Department of Agricultural Biotechnology, Seoul National University, Seoul 08826, Republic of Korea; Center for Food and Bioconvergence, Seoul National University, Seoul 08826, Republic of Korea.
| |
Collapse
|
10
|
Effect of luxS encoding a synthase of quorum-sensing signal molecule AI-2 of Vibrio vulnificus on mouse gut microbiome. Appl Microbiol Biotechnol 2022; 106:3721-3734. [PMID: 35488933 DOI: 10.1007/s00253-022-11935-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 04/11/2022] [Accepted: 04/20/2022] [Indexed: 12/19/2022]
Abstract
Autoinducer-2 (AI-2), a quorum-sensing signal molecule from the human pathogen Vibrio vulnificus, was assessed for its effect on the gut microbiome of mice. For this, we employed 16S rRNA sequencing to compare the gut microbiome of mice infected with either wild-type V. vulnificus or with the isotype ΔluxS that has a deletion in luxS which encodes the biosynthetic function of AI-2. The relative ratio of wild-type Vibrio species in the jejunum and ileum of mice infected with the wild type was significantly higher than that in mice infected with ΔluxS, suggesting that AI-2 plays an important role in the colonization of V. vulnificus in the small intestine. The bacterial composition in the gut of mice infected with ΔluxS comprises a higher proportion of Firmicutes, composed mainly of Lactobacillus, compared to the mice infected with wild-type cells. In the large intestine, Vibrio species were barely detected regardless of genetic background. Three Lactobacillus spp. isolated from fecal samples from mice infected with ΔluxS manifested significant antibacterial activities against V. vulnificus. Culture supernatants from these three species were dissolved by HPLC, and a substance in fractions showing inhibitory activity against V. vulnificus was determined to be lactic acid. Our results suggest that luxS in V. vulnificus affects not only the ability of the species to colonize the host gut but also its susceptibility to the growth-inhibiting activity of commensal bacteria including Lactobacillus. KEY POINTS: • Gut microbiomes of ΔluxS-infected and WT Vibrio-infected mice differed greatly. • Difference was most prominent in the jejunum and ileum compared to the duodenum or large intestine. • In the small and large intestines of mice, the relative proportions of Vibrio and Lactobacillus species showed a negative relationship. • Effector molecules produced by Lactobacillus in mouse gut inhibit Vibrio growth.
Collapse
|
11
|
Regulator of ribonuclease activity modulates the pathogenicity of Vibrio vulnificus. J Microbiol 2021; 59:1133-1141. [PMID: 34751908 DOI: 10.1007/s12275-021-1518-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 10/19/2021] [Accepted: 10/20/2021] [Indexed: 12/19/2022]
Abstract
RraA, a protein regulator of RNase E activity, plays a unique role in modulating the mRNA abundance in Escherichia coli. The marine pathogenic bacterium Vibrio vulnificus also possesses homologs of RNase E (VvRNase E) and RraA (VvRraA1 and VvRraA2). However, their physiological roles have not yet been investigated. In this study, we demonstrated that VvRraA1 expression levels affect the pathogenicity of V. vulnificus. Compared to the wild-type strain, the VvrraA1-deleted strain (ΔVvrraA1) showed decreased motility, invasiveness, biofilm formation ability as well as virulence in mice; these phenotypic changes of ΔVvrraA1 were restored by the exogenous expression of VvrraA1. Transcriptomic analysis indicated that VvRraA1 expression levels affect the abundance of a large number of mRNA species. Among them, the half-lives of mRNA species encoding virulence factors (e.g., smcR and htpG) that have been previously shown to affect VvrraA1 expression-dependent phenotypes were positively correlated with VvrraA1 expression levels. These findings suggest that VvRraA1 modulates the pathogenicity of V. vulnificus by regulating the abundance of a subset of mRNA species.
Collapse
|
12
|
Newman JD, Chopra J, Shah P, Shi E, McFadden ME, Horness RE, Brown LC, van Kessel JC. Amino acid divergence in the ligand-binding pocket of Vibrio LuxR/HapR proteins determines the efficacy of thiophenesulfonamide inhibitors. Mol Microbiol 2021; 116:1173-1188. [PMID: 34468051 DOI: 10.1111/mmi.14804] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 08/09/2021] [Accepted: 08/26/2021] [Indexed: 12/12/2022]
Abstract
The quorum-sensing signaling systems in Vibrio bacteria converge to control levels of the master transcription factors LuxR/HapR, a family of highly conserved proteins that regulate gene expression for bacterial behaviors. A compound library screen identified 2-thiophenesulfonamide compounds that specifically inhibit Vibrio campbellii LuxR but do not affect cell growth. We synthesized a panel of 50 thiophenesulfonamide compounds to examine the structure-activity relationship effects on Vibrio quorum sensing. The most potent molecule identified, PTSP (3-phenyl-1-(thiophen-2-ylsulfonyl)-1H-pyrazole), inhibits quorum sensing in multiple strains of V. vulnificus, V. parahaemolyticus, and V. campbellii at nanomolar concentrations. However, thiophenesulfonamide inhibition efficacy varies significantly among Vibrio species: PTSP is most inhibitory against V. vulnificus SmcR, but V. cholerae HapR is completely resistant to all thiophenesulfonamides tested. Reverse genetics experiments show that PTSP efficacy is dictated by amino acid sequence in the putative ligand-binding pocket: F75Y and C170F SmcR substitutions are each sufficient to eliminate PTSP inhibition. Further, in silico modeling distinguished the most potent thiophenesulfonamides from less-effective derivatives. Our results revealed the previously unknown differences in LuxR/HapR proteins that control quorum sensing in Vibrio species and underscore the potential for developing thiophenesulfonamides as specific quorum sensing-directed treatments for Vibrio infections.
Collapse
Affiliation(s)
- Jane D Newman
- Department of Biology, Indiana University, Bloomington, Indiana, USA
| | - Jay Chopra
- Department of Chemistry, Indiana University, Bloomington, Indiana, USA
| | - Priyanka Shah
- Department of Chemistry, Indiana University, Bloomington, Indiana, USA
| | - Eda Shi
- Department of Chemistry, Indiana University, Bloomington, Indiana, USA
| | - Molly E McFadden
- Department of Chemistry, Indiana University, Bloomington, Indiana, USA
| | - Rachel E Horness
- Department of Chemistry, Indiana University, Bloomington, Indiana, USA
| | - Laura C Brown
- Department of Chemistry, Indiana University, Bloomington, Indiana, USA
| | | |
Collapse
|
13
|
Simpson CA, Petersen BD, Haas NW, Geyman LJ, Lee AH, Podicheti R, Pepin R, Brown LC, Rusch DB, Manzella MP, Papenfort K, van Kessel JC. The quorum-sensing systems of Vibrio campbellii DS40M4 and BB120 are genetically and functionally distinct. Environ Microbiol 2021; 23:5412-5432. [PMID: 33998118 PMCID: PMC8458232 DOI: 10.1111/1462-2920.15602] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 05/13/2021] [Indexed: 11/28/2022]
Abstract
Vibrio campbellii BB120 (previously classified as Vibrio harveyi) is a fundamental model strain for studying quorum sensing in vibrios. A phylogenetic evaluation of sequenced Vibrio strains in Genbank revealed that BB120 is closely related to the environmental isolate V. campbellii DS40M4. We exploited DS40M4's competence for exogenous DNA uptake to rapidly generate greater than 30 isogenic strains with deletions of genes encoding BB120 quorum-sensing system homologues. Our results show that the quorum-sensing circuit of DS40M4 is distinct from BB120 in three ways: (i) DS40M4 does not produce an acyl homoserine lactone autoinducer but encodes an active orphan LuxN receptor, (ii) the quorum regulatory small RNAs (Qrrs) are not solely regulated by autoinducer signalling through the response regulator LuxO and (iii) the DS40M4 quorum-sensing regulon is much smaller than BB120 (~100 genes vs. ~400 genes, respectively). Using comparative genomics to expand our understanding of quorum-sensing circuit diversity, we observe that conservation of LuxM/LuxN proteins differs widely both between and within Vibrio species. These strains are also phenotypically distinct: DS40M4 exhibits stronger interbacterial cell killing, whereas BB120 forms more robust biofilms and is bioluminescent. These results underscore the need to examine wild isolates for a broader view of bacterial diversity in the marine ecosystem.
Collapse
Affiliation(s)
| | | | - Nicholas W Haas
- Department of Biology, Indiana University, Bloomington, IN, USA
| | - Logan J Geyman
- Department of Biology, Indiana University, Bloomington, IN, USA
| | - Aimee H Lee
- Department of Biology, Indiana University, Bloomington, IN, USA
| | - Ram Podicheti
- Centre for Genomics and Bioinformatics, Indiana University, Bloomington, IN, USA
| | - Robert Pepin
- Mass Spectrometry Facility, Indiana University, Bloomington, IN, USA
- Department of Chemistry, Indiana University, Bloomington, IN, USA
| | - Laura C Brown
- Department of Chemistry, Indiana University, Bloomington, IN, USA
| | - Douglas B Rusch
- Centre for Genomics and Bioinformatics, Indiana University, Bloomington, IN, USA
| | | | - Kai Papenfort
- Friedrich Schiller University, Institute of Microbiology, Jena, Germany
- Microverse Cluster, Friedrich Schiller University Jena, Jena, Germany
| | | |
Collapse
|
14
|
Hammers D, Carothers K, Lee S. The Role of Bacterial Proteases in Microbe and Host-microbe Interactions. Curr Drug Targets 2021; 23:222-239. [PMID: 34370632 DOI: 10.2174/1389450122666210809094100] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 06/15/2021] [Accepted: 06/16/2021] [Indexed: 11/22/2022]
Abstract
BACKGROUND Secreted proteases are an important class of factors used by bacterial to modulate their extracellular environment through the cleavage of peptides and proteins. These proteases can range from broad, general proteolytic activity to high degrees of substrate specificity. They are often involved in interactions between bacteria and other species, even across kingdoms, allowing bacteria to survive and compete within their niche. As a result, many bacterial proteases are of clinical importance. The immune system is a common target for these enzymes, and bacteria have evolved ways to use these proteases to alter immune responses for their benefit. In addition to the wide variety of human proteins that can be targeted by bacterial proteases, bacteria also use these secreted factors to disrupt competing microbes, ranging from outright antimicrobial activity to disrupting processes like biofilm formation. OBJECTIVE In this review, we address how bacterial proteases modulate host mechanisms of protection from infection and injury, including immune factors and cell barriers. We also discuss the contributions of bacterial proteases to microbe-microbe interactions, including antimicrobial and anti-biofilm dynamics. CONCLUSION Bacterial secreted proteases represent an incredibly diverse group of factors that bacteria use to shape and thrive in their microenvironment. Due to the range of activities and targets of these proteases, some have been noted for having potential as therapeutics. The vast array of bacterial proteases and their targets remains an expanding field of research, and this field has many important implications for human health.
Collapse
Affiliation(s)
- Daniel Hammers
- Department of Biological Sciences, University of Notre Dame, Galvin Hall, Notre Dame, IN 46556, United States
| | - Katelyn Carothers
- Department of Biological Sciences, University of Notre Dame, Galvin Hall, Notre Dame, IN 46556, United States
| | - Shaun Lee
- Department of Biological Sciences, University of Notre Dame, Galvin Hall, Notre Dame, IN 46556, United States
| |
Collapse
|
15
|
Newman JD, Russell MM, Fan L, Wang YX, Gonzalez-Gutierrez G, van Kessel JC. The DNA binding domain of the Vibrio vulnificus SmcR transcription factor is flexible and binds diverse DNA sequences. Nucleic Acids Res 2021; 49:5967-5984. [PMID: 34023896 PMCID: PMC8191795 DOI: 10.1093/nar/gkab387] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 04/23/2021] [Accepted: 04/28/2021] [Indexed: 01/22/2023] Open
Abstract
Quorum sensing gene expression in vibrios is regulated by the LuxR/HapR family of transcriptional factors, which includes Vibrio vulnificus SmcR. The consensus binding site of Vibrio LuxR/HapR/SmcR proteins is palindromic but highly degenerate with sequence variations at each promoter. To examine the mechanism by which SmcR recognizes diverse DNA sites, we generated SmcR separation-of-function mutants that either repress or activate transcription but not both. SmcR N55I is restricted in recognition of single base-pair variations in DNA binding site sequences and thus is defective at transcription activation but retains interaction with RNA polymerase (RNAP) alpha. SmcR S76A, L139R and N142D substitutions disrupt the interaction with RNAP alpha but retain functional DNA binding activity. X-ray crystallography and small angle X-ray scattering data show that the SmcR DNA binding domain exists in two conformations (wide and narrow), and the protein complex forms a mixture of dimers and tetramers in solution. The three RNAP interaction-deficient variants also have two DNA binding domain conformations, whereas SmcR N55I exhibits only the wide conformation. These data support a model in which two mechanisms drive SmcR transcriptional activation: interaction with RNAP and a multi-conformational DNA binding domain that permits recognition of variable DNA sites.
Collapse
Affiliation(s)
- Jane D Newman
- Department of Biology, Indiana University, 1001 E 3rd St, Bloomington, IN 47405, USA.,Department of Molecular and Cellular Biochemistry, Indiana University, 212 S Hawthorne Dr, Bloomington, IN 47405, USA
| | - Meghan M Russell
- Department of Biology, Indiana University, 1001 E 3rd St, Bloomington, IN 47405, USA
| | - Lixin Fan
- Small Angle X-ray Scattering Facility, Center for Structural Biology, National Cancer Institute, National Institutes of Health, Frederick, MD 21702, USA
| | - Yun-Xing Wang
- Small Angle X-ray Scattering Facility, Center for Structural Biology, National Cancer Institute, National Institutes of Health, Frederick, MD 21702, USA
| | - Giovanni Gonzalez-Gutierrez
- Department of Molecular and Cellular Biochemistry, Indiana University, 212 S Hawthorne Dr, Bloomington, IN 47405, USA
| | - Julia C van Kessel
- Department of Biology, Indiana University, 1001 E 3rd St, Bloomington, IN 47405, USA
| |
Collapse
|
16
|
Kang S, Park H, Lee KJ, Lee KH. Transcription activation of two clusters for exopolysaccharide biosynthesis by phosphorylated DctD in Vibrio vulnificus. Environ Microbiol 2021; 23:5364-5377. [PMID: 34110060 DOI: 10.1111/1462-2920.15636] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 05/28/2021] [Accepted: 06/08/2021] [Indexed: 11/28/2022]
Abstract
NtrC-mediated production of exopolysaccharides (EPS), essential components for Vibrio vulnificus biofilms, is highly increased in the presence of dicarboxylic or tricarboxylic acids. Gel-shift assays showed that regulation of the EPS-gene cluster I (EPS-I cluster) by NtrC was direct via binding of phosphorylated NtrC (p-NtrC) to the regulatory region of the EPS-I cluster. In contrast, p-NtrC did not bind to the EPS-II and EPS-III clusters, suggesting that NtrC regulation was not direct and another transcription factor belonging to an NtrC-regulon might play a role in activating their transcription. A candidate transcription factor, DctD, of which expression was induced by NtrC, activated the expression of the EPS-II and EPS-III clusters via direct binding to their upstream regions. Under growth conditions with either dicarboxylic or tricarboxylic acids, the expression of NtrC was induced and the transcription of dctD was activated. Furthermore, DctD exhibited higher transcriptional activity under the conditions with dicarboxylic acids than with tricarboxylic acids. Therefore, this study demonstrates that under dicarboxylate-rich conditions, both the abundance and activity of DctD were markedly induced, which activates the expression of two EPS clusters to maximize biosynthesis of EPS facilitating biofilm maturation in V. vulnificus.
Collapse
Affiliation(s)
- Sebin Kang
- Department of Life Science, Sogang University, Seoul, South Korea
| | - Hana Park
- Department of Life Science, Sogang University, Seoul, South Korea
| | - Kyung-Jo Lee
- Department of Life Science, Sogang University, Seoul, South Korea
| | - Kyu-Ho Lee
- Department of Life Science, Sogang University, Seoul, South Korea
| |
Collapse
|
17
|
Kim SM, Park J, Kim MS, Song H, Jo A, Park H, Kim TS, Choi SH, Park SB. Phenotypic Discovery of an Antivirulence Agent against Vibrio vulnificus via Modulation of Quorum-Sensing Regulator SmcR. ACS Infect Dis 2020; 6:3076-3082. [PMID: 33086782 DOI: 10.1021/acsinfecdis.0c00587] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
An antivirulence agent against Vibrio vulnificus named quoromycin (QM) was discovered by a phenotype-based elastase inhibitor screening. Using the fluorescence difference in two-dimensional gel electrophoresis (FITGE) approach, SmcR, a quorum-sensing master regulator and homologue of LuxR, was identified as the target protein of QM. We confirmed that the direct binding of QM to SmcR inhibits the quorum-sensing signaling pathway by controlling the DNA-binding affinity of SmcR and thus effectively alleviates the virulence of V. vulnificus in vitro and in vivo. QM can be regarded as a novel antivirulence agent for the treatment of V. vulnificus infection.
Collapse
Affiliation(s)
- Seung Min Kim
- Department of Agricultural Biotechnology, Seoul National University, Seoul 08826, Korea
| | - Jongmin Park
- CRI Center for Chemical Proteomics, Department of Chemistry, Seoul National University, Seoul 08826, Korea
| | - Myun Soo Kim
- Division of Life Sciences, School of Life Sciences and Biotechnology, Korea University, Seoul 02841, Korea
| | - Heebum Song
- CRI Center for Chemical Proteomics, Department of Chemistry, Seoul National University, Seoul 08826, Korea
| | - Ala Jo
- CRI Center for Chemical Proteomics, Department of Chemistry, Seoul National University, Seoul 08826, Korea
| | - Hankum Park
- CRI Center for Chemical Proteomics, Department of Chemistry, Seoul National University, Seoul 08826, Korea
| | - Tae Sung Kim
- Division of Life Sciences, School of Life Sciences and Biotechnology, Korea University, Seoul 02841, Korea
| | - Sang Ho Choi
- Department of Agricultural Biotechnology, Seoul National University, Seoul 08826, Korea
| | - Seung Bum Park
- CRI Center for Chemical Proteomics, Department of Chemistry, Seoul National University, Seoul 08826, Korea
| |
Collapse
|
18
|
Pang R, Li Y, Liao K, Guo P, Li Y, Yang X, Zhang S, Lei T, Wang J, Chen M, Wu S, Xue L, Wu Q. Genome- and Proteome-Wide Analysis of Lysine Acetylation in Vibrio vulnificus Vv180806 Reveals Its Regulatory Roles in Virulence and Antibiotic Resistance. Front Microbiol 2020; 11:591287. [PMID: 33250879 PMCID: PMC7674927 DOI: 10.3389/fmicb.2020.591287] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 10/15/2020] [Indexed: 12/31/2022] Open
Abstract
Infection with Vibrio vulnificus is notorious for its atypical clinical manifestations and irreversible disease progression. Lysine acetylation is a conserved post-translational modification (PTM) that plays a critical regulatory role in diverse cellular processes. However, little is known about the role of lysine acetylation on the pathogenesis of V. vulnificus. Here, we report the complete genome sequence and a global profile for protein lysine acetylation of V. vulnificus Vv180806, a highly cefoxitin resistant strain isolated from a mortality case. The assembled genome comprised two circular chromosomes and one circular plasmid; it contained 4,770 protein-coding genes and 153 RNA genes. Phylogenetic analysis revealed genetic homology of this strain with other V. vulnificus strains from food sources. Of all the proteins in this strain, 1,924 (40.34%) were identified to be acetylated at 6,626 sites. The acetylated proteins were enriched in metabolic processes, binding functions, cytoplasm, and multiple central metabolic pathways. Moreover, the acetylation was found in most identified virulence factors of this strain, suggesting its potentially important role in bacterial virulence. Our work provides insights into the genomic and acetylomic features responsible for the virulence and antibiotic resistance of V. vulnificus, which will facilitate future investigations on the pathogenesis of this bacterium.
Collapse
Affiliation(s)
- Rui Pang
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Ying Li
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Kang Liao
- Department of Laboratory Medicine, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Penghao Guo
- Department of Laboratory Medicine, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Yanping Li
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Xiaojuan Yang
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Shuhong Zhang
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Tao Lei
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Juan Wang
- College of Food Science, South China Agricultural University, Guangzhou, China
| | - Moutong Chen
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Shi Wu
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Liang Xue
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Qingping Wu
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| |
Collapse
|
19
|
Chung HY, Kim YT, Kwon JG, Im HH, Ko D, Lee JH, Choi SH. Molecular interaction between methicillin-resistant Staphylococcus aureus (MRSA) and chicken breast reveals enhancement of pathogenesis and toxicity for food-borne outbreak. Food Microbiol 2020; 93:103602. [PMID: 32912577 DOI: 10.1016/j.fm.2020.103602] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 06/27/2020] [Accepted: 07/21/2020] [Indexed: 12/24/2022]
Abstract
To study pathogenesis and toxicity of Staphylococcus aureus in foods, FORC_062 was isolated from a human blood sample and complete genome sequence has a type II SCCmec gene cluster and a type II toxin-antitoxin system, indicating an MRSA strain. Its mobile gene elements has many pathogenic genes involved in host infection, biofilm formation, and various enterotoxin and hemolysin genes. Clinical MRSA is often found in animal foods and ingestion of MRSA-contaminated foods causes human infection. Therefore, it is very important to understand the role of contaminated foods. To elucidate the interaction between clinical MRSA FORC_062 and raw chicken breast, transcriptome analysis was conducted, showing that gene expressions of amino acid biosynthesis and metabolism were specifically down-regulated, suggesting that the strain may import and utilize amino acids from the chicken breast, but not able to synthesize them. However, toxin gene expressions were up-regulated, suggesting that human infection of S. aureus via contaminated food may be more fatal. In addition, the contaminated foods enhance multiple-antibiotic resistance activities and virulence factors in this clinical MRSA. Consequently, MRSA-contaminated food may play a role as a nutritional reservoir as well as in enhancing factor for pathogenesis and toxicity of clinical MRSA for severe food-borne outbreaks.
Collapse
Affiliation(s)
- Han Young Chung
- National Research Laboratory of Molecular Microbiology and Toxicology, Department of Agricultural Biotechnology, And Center for Food Safety and Toxicology, Seoul National University, Seoul, 08826, South Korea; Food-borne Pathogen Omics Research Center (FORC), Seoul National University, Seoul, 08826, South Korea
| | - You-Tae Kim
- Department of Food Science and Biotechnology, Kyung Hee University, Yongin, 17104, South Korea; Food-borne Pathogen Omics Research Center (FORC), Seoul National University, Seoul, 08826, South Korea
| | - Joon-Gi Kwon
- Department of Food Science and Biotechnology, Kyung Hee University, Yongin, 17104, South Korea; Food-borne Pathogen Omics Research Center (FORC), Seoul National University, Seoul, 08826, South Korea
| | - Han Hyeok Im
- National Research Laboratory of Molecular Microbiology and Toxicology, Department of Agricultural Biotechnology, And Center for Food Safety and Toxicology, Seoul National University, Seoul, 08826, South Korea; Food-borne Pathogen Omics Research Center (FORC), Seoul National University, Seoul, 08826, South Korea
| | - Duhyun Ko
- National Research Laboratory of Molecular Microbiology and Toxicology, Department of Agricultural Biotechnology, And Center for Food Safety and Toxicology, Seoul National University, Seoul, 08826, South Korea; Food-borne Pathogen Omics Research Center (FORC), Seoul National University, Seoul, 08826, South Korea
| | - Ju-Hoon Lee
- Department of Food Science and Biotechnology, Kyung Hee University, Yongin, 17104, South Korea; Food-borne Pathogen Omics Research Center (FORC), Seoul National University, Seoul, 08826, South Korea.
| | - Sang Ho Choi
- National Research Laboratory of Molecular Microbiology and Toxicology, Department of Agricultural Biotechnology, And Center for Food Safety and Toxicology, Seoul National University, Seoul, 08826, South Korea; Food-borne Pathogen Omics Research Center (FORC), Seoul National University, Seoul, 08826, South Korea.
| |
Collapse
|
20
|
Choi G, Jang KK, Lim JG, Lee ZW, Im H, Choi SH. The transcriptional regulator IscR integrates host-derived nitrosative stress and iron starvation in activation of the vvhBA operon in Vibrio vulnificus. J Biol Chem 2020; 295:5350-5361. [PMID: 32169898 PMCID: PMC7170529 DOI: 10.1074/jbc.ra120.012724] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 03/09/2020] [Indexed: 12/30/2022] Open
Abstract
For successful infection of their hosts, pathogenic bacteria recognize host-derived signals that induce the expression of virulence factors in a spatiotemporal manner. The fulminating food-borne pathogen Vibrio vulnificus produces a cytolysin/hemolysin protein encoded by the vvhBA operon, which is a virulence factor preferentially expressed upon exposure to murine blood and macrophages. The Fe-S cluster containing transcriptional regulator IscR activates the vvhBA operon in response to nitrosative stress and iron starvation, during which the cellular IscR protein level increases. Here, electrophoretic mobility shift and DNase I protection assays revealed that IscR directly binds downstream of the vvhBA promoter P vvhBA , which is unusual for a positive regulator. We found that in addition to IscR, the transcriptional regulator HlyU activates vvhBA transcription by directly binding upstream of P vvhBA , whereas the histone-like nucleoid-structuring protein (H-NS) represses vvhBA by extensively binding to both downstream and upstream regions of its promoter. Of note, the binding sites of IscR and HlyU overlapped with those of H-NS. We further substantiated that IscR and HlyU outcompete H-NS for binding to the P vvhBA regulatory region, resulting in the release of H-NS repression and vvhBA induction. We conclude that concurrent antirepression by IscR and HlyU at regions both downstream and upstream of P vvhBA provides V. vulnificus with the means of integrating host-derived signal(s) such as nitrosative stress and iron starvation for precise regulation of vvhBA transcription, thereby enabling successful host infection.
Collapse
Affiliation(s)
- Garam Choi
- National Research Laboratory of Molecular Microbiology and Toxicology, Department of Agricultural Biotechnology, and Center for Food Safety and Toxicology, Seoul National University, Seoul 08826, South Korea
| | - Kyung Ku Jang
- National Research Laboratory of Molecular Microbiology and Toxicology, Department of Agricultural Biotechnology, and Center for Food Safety and Toxicology, Seoul National University, Seoul 08826, South Korea
| | - Jong Gyu Lim
- National Research Laboratory of Molecular Microbiology and Toxicology, Department of Agricultural Biotechnology, and Center for Food Safety and Toxicology, Seoul National University, Seoul 08826, South Korea
| | - Zee-Won Lee
- National Research Laboratory of Molecular Microbiology and Toxicology, Department of Agricultural Biotechnology, and Center for Food Safety and Toxicology, Seoul National University, Seoul 08826, South Korea
| | - Hanhyeok Im
- National Research Laboratory of Molecular Microbiology and Toxicology, Department of Agricultural Biotechnology, and Center for Food Safety and Toxicology, Seoul National University, Seoul 08826, South Korea
| | - Sang Ho Choi
- National Research Laboratory of Molecular Microbiology and Toxicology, Department of Agricultural Biotechnology, and Center for Food Safety and Toxicology, Seoul National University, Seoul 08826, South Korea.
| |
Collapse
|
21
|
Mao L, Qin Y, Kang J, Wu B, Huang L, Wang S, Zhang M, Zhang J, Zhang R, Yan Q. Role of LuxR-type regulators in fish pathogenic Aeromonas hydrophila. JOURNAL OF FISH DISEASES 2020; 43:215-225. [PMID: 31770821 DOI: 10.1111/jfd.13114] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 10/16/2019] [Accepted: 10/19/2019] [Indexed: 06/10/2023]
Abstract
LuxR-type transcriptional factors are essential in many bacterial physiological processes. However, there have been no reports on their roles in Aeromonas hydrophila. In this study, six stable silent strains were constructed using shRNA. Significant decreases in the expression levels of luxR05 , luxR08 , luxR19 , luxR11 , luxR164 and luxR165 were shown in their respective strains by qRT-PCR. The luxR05 -RNAi and luxR164 -RNAi exhibit the most significant changes in sensitivity to kanamycin and gentamicin. The luxR05 -RNAi showed minimum biofilm formation and the least motility, while luxR164 -RNAi showed minimum biofilm formation, adhesion, growth and extracellular protease activity compared to the wild-type strain. In summary, the results of this paper suggest that all six luxR genes are involved in multiple physiological processes in A. hydrophila and that the roles of luxR05 and luxR164 are highly significant. The sensitivity of luxR05 -RNAi and luxR164 -RNAi to drugs may be closely related to biofilm formation. The luxR05 may play an important role in the pathogenicity of A. hydrophila by regulating the movement, adhesion and biofilm formation of bacteria, whereas luxR164 may be involved in similar functions by regulating bacterial adhesion, extracellular enzyme activity and growth. These results help further our understanding of the drug resistance and pathogenesis of A. hydrophila.
Collapse
Affiliation(s)
- Leilei Mao
- Fisheries College, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Jimei University, Xiamen, China
| | - Yingxue Qin
- Fisheries College, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Jimei University, Xiamen, China
- Fujian Fisheries Technology Extension Center, Fuzhou, China
| | - Jianping Kang
- Fujian Fisheries Technology Extension Center, Fuzhou, China
| | - Bin Wu
- Fujian Fisheries Technology Extension Center, Fuzhou, China
| | - Lixing Huang
- 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
| | - Mengmeng Zhang
- Fisheries College, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Jimei University, Xiamen, China
| | - Jiahui Zhang
- Fisheries College, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Jimei University, Xiamen, China
| | - Ruixuan Zhang
- 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
- Fujian Fisheries Technology Extension Center, Fuzhou, China
| |
Collapse
|
22
|
Bandara HMHN, Hewavitharana AK, Shaw PN, Smyth HDC, Samaranayake LP. A novel, quorum sensor-infused liposomal drug delivery system suppresses Candida albicans biofilms. Int J Pharm 2020; 578:119096. [PMID: 32006626 DOI: 10.1016/j.ijpharm.2020.119096] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 01/02/2020] [Accepted: 01/28/2020] [Indexed: 10/25/2022]
Abstract
In contrast to the plethora of antibacterial agents, only a handful of antifungals are currently available to treat Candida albicans biofilm-associated infections. Additional novel antibiofilm strategies to eliminate C. albicans biofilm infections are needed. This study aims to improve the efficacy of a widely used azole, fluconazole by co-delivering it with a Pseudomonas aeruginosa quorum sensing molecule (QSM), N-3-oxo-dodecanoyl-L-homoserine lactone (C12AHL) in a liposomal formulation. C12AHL is known to inhibit C. albicans' morphological transition and biofilm formation. Four different formulations of liposomes with fluconazole (L-F), with C12AHL (L-H), with fluconazole and C12AHL (L-HF), and a drug-free control (L-C) were prepared using a thin-film hydration followed by extrusion method, and characterised. The effect of liposomes on colonising (90 min-24 h) and preformed (24 h) C. albicans biofilms were assessed using a standard biofilm assay. Biofilm viability (XTT reduction assay), biomass (Safranin-O staining) and architecture (confocal laser scanning microscopy, CLSM) were determined. Similar efficiencies of fluconazole entrapment were noticed in L-HF and L-F (11.74% vs 10.2%), however, L-HF released greater quantities of fluconazole compared to L-F during 24 h (4.27% vs 0.97%, P < 0.05). The entrapment and release of C12AHL was similar for L-H and L-HF liposomes (33.3% vs 33% and 88.9% vs 92.3% respectively). L-HF treated colonising, and preformed biofilms exhibited >80%, and 60% reduction in their respective viabilities at a fluconazole concentration as low as 5.5 µg/mL compared to 12% and 36%, respective reductions observed in L-F treated biofilms (P < 0.05). CLSM confirmed biofilm disruption, lack of hyphae, and reduction in biomass when treated with L-HF compared to other liposomal preparations. Liposomal co-delivery of C12AHL and fluconazole appears to suppress C. albicans biofilms through efficacious disruption of the biofilm, killing of constituent yeasts, and diminishing their virulence at a significantly lower antifungal dose. Therefore, liposomal co-formulation of C12AHL and fluconazole appears to be a promising approach to improve the efficacy of this common triazole against biofilm-mediated candidal infections.
Collapse
Affiliation(s)
- H M H N Bandara
- Oral Microbiology, Bristol Dental School, University of Bristol, UK.
| | | | - P N Shaw
- School of Pharmacy, The University of Queensland, Australia
| | - H D C Smyth
- College of Pharmacy, The University of Texas at Austin, USA
| | - L P Samaranayake
- College of Dental Medicine, The University of Sharjah, United Arab Emirates
| |
Collapse
|
23
|
Melatonin restores Muc2 depletion induced by V. vulnificus VvpM via melatonin receptor 2 coupling with Gαq. J Biomed Sci 2020; 27:21. [PMID: 31906951 PMCID: PMC6943958 DOI: 10.1186/s12929-019-0606-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Accepted: 12/19/2019] [Indexed: 12/21/2022] Open
Abstract
Background Melatonin (5-methoxy-N-acetyltryptamine), a hormone produced in the pineal gland, has a variety of biological functions as an antioxidant, but a functional role of melatonin in the regulation of intestinal mucin (Muc) production during bacterial infection has yet to be described in detail. In this study, we investigate the effects of melatonin during Muc2 repression elicited by the Gram-negative bacterium V. vulnificus. Methods Mucus-secreting human HT29-MTX cells were used to study the functional role of melatonin during Muc2 depletion induced by the recombinant protein (r) VvpM produced by V. vulnificus. The regulatory effects of melatonin coupling with melatonin receptor 2 (MT2) on the production of reactive oxygen species (ROS), the activation of PKCδ and ERK, and the hypermethylation of the Muc2 promoter as induced by rVvpM were examined. Experimental mouse models of V. vulnificus infection were used to study the role of melatonin and how it neutralizes the bacterial toxin activity related to Muc2 repression. Results Recombinant protein (r) VvpM significantly reduced the level of Muc2 in HT29-MTX cells. The repression of Muc2 induced by rVvpM was significantly restored upon a treatment with melatonin (1 μM), which had been inhibited by the knockdown of MT2 coupling with Gαq and the NADPH oxidase subunit p47 phox. Melatonin inhibited the ROS-mediated phosphorylation of PKCδ and ERK responsible for region-specific hypermethylation in the Muc2 promoter in rVvpM-treated HT29-MTX cells. In the mouse models of V. vulnificus infection, treatment with melatonin maintained the level of Muc2 expression in the intestine. In addition, the mutation of the VvpM gene from V. vulnificus exhibited an effect similar to that of melatonin. Conclusions These results demonstrate that melatonin acting on MT2 inhibits the hypermethylation of the Muc2 promoter to restore the level of Muc2 production in intestinal epithelial cells infected with V. vulnificus.
Collapse
|
24
|
Li G, Wang MY. The role of Vibrio vulnificus virulence factors and regulators in its infection-induced sepsis. Folia Microbiol (Praha) 2019; 65:265-274. [PMID: 31840198 DOI: 10.1007/s12223-019-00763-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2019] [Accepted: 12/03/2019] [Indexed: 12/14/2022]
Abstract
Due to the development of Marine aquaculture, infections caused by Vibrio vulnificus are common all over the world. Symptoms of V. vulnificus infection vary from gastrointestinal illness to septicemia. After infection with V. vulnificus, some patients showed gastrointestinal symptoms, including vomiting, fever, diarrhea, and so on. Others appeared wound infection at the site of contact with bacteria, and even developed sepsis. Once it develops into sepsis, the prognosis of patients is very poor. However, its underlying pathogenic mechanism remains largely undetermined. Growing evidence shows that it can induce primary septicemia mainly via essential virulence factors and regulators. Therefore, it is important to identify the factors that play roles in sepsis. In this review, we systematically expounded the role of V. vulnificus virulence factors and regulators in its infection-induced sepsis in order to provide useful information for the treatment and prevention of V. vulnificus.
Collapse
Affiliation(s)
- Gang Li
- Weihai Clinical Medical School, Cheeloo College of Medicine, Shandong University, Weihai, 264200, China.,Weihai Municipal Hospital, Weihai, 264200, China
| | - Ming-Yi Wang
- Weihai Clinical Medical School, Cheeloo College of Medicine, Shandong University, Weihai, 264200, China. .,Weihai Municipal Hospital, Weihai, 264200, China.
| |
Collapse
|
25
|
Ghosh S, Qureshi A, Purohit H. D-Tryptophan governs biofilm formation rates and bacterial interaction in P. mendocina and S. aureus. J Biosci 2019; 44:3. [PMID: 30837355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Biofilm genesis by Pseudomonasand Staphylococcus sp is associated with biofouling in natural settings. D-Tryptophan (D-Trp) inhibits bacterial biofilms and have been proposed for biofouling control applications. In this study, D-Trp significantly inhibited Pseudomonas mendocina and Staphylococcus aureuscell attachment (biofilm formation) rates on polystyrene96-well microtiter plates in comparison with L-Tryptophan (L-Trp) and mixtures of D-/L-Tryptophan (D-/L-Trp). Theinhibitory effect was greater on P. mendocina,where the rate of cell adherence was declined to 8.79105cells/h from8.09106cells/h (control) inP. mendocina.InS. aureusit was declined to 4.29107cells/h from 9.29107cells/h(control) at 1 mM concentration. It hindered the intracellular communication and adherence in both the strains, as con-firmed by SEM and real time PCR analysis. Addition of D-Trp to preformed biofilms also caused partial disassembly. Intraand interbacterial aggregation were decreased subsequently upon treatment with D-Trp. It repressed the genes involved incell-cell communication, which could be responsible for the diminished biofilm formation of the selected strains. HenceD-Tryptophan has proved to be an effective strategy to control biofilm and may support in the development of surfacecoating technologies.
Collapse
Affiliation(s)
- Saheli Ghosh
- Environmental Biotechnology and Genomics Division, CSIR-National Environmental Engineering Research Institute (NEERI), Nehru Marg, Nagpur 440 020, India
| | | | | |
Collapse
|
26
|
Ghosh S, Qureshi A, Purohit HJ. D-Tryptophan governs biofilm formation rates and bacterial interaction in P. mendocina and S. aureus. J Biosci 2019. [DOI: 10.1007/s12038-018-9841-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
|
27
|
Lee A, Kim MS, Cho D, Jang KK, Choi SH, Kim TS. Vibrio vulnificus RtxA Is a Major Factor Driving Inflammatory T Helper Type 17 Cell Responses in vitro and in vivo. Front Immunol 2018; 9:2095. [PMID: 30283443 PMCID: PMC6157323 DOI: 10.3389/fimmu.2018.02095] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Accepted: 08/24/2018] [Indexed: 12/18/2022] Open
Abstract
T helper type 17 (Th17) cells are a subset of pro-inflammatory T helper cells that mediate host defense and pathological inflammation. We have previously reported that host dendritic cells (DCs) infected with Vibrio vulnificus induce Th17 responses through the production of several pro-inflammatory cytokines, including interleukin (IL)-1β and IL-6. V. vulnificus produces RTX toxin (RtxA), an important virulence factor that determines successful pathophysiology. In this study, we investigated the involvement of RtxA from V. vulnificus in Th17 cell induction through the activation and maturation of DCs. The increased expression of the DC surface marker CD40 caused by V. vulnificus wild-type infection was reduced by rtxA gene mutation in V. vulnificus. The mRNA and protein levels of Th17 polarization-related cytokines also decreased in V. vulnificus rtxA mutant-infected DCs. In addition, the co-culture of Th cells and DCs infected with rtxA mutant V. vulnificus resulted in reduction in DC-mediated Th17 responses. Th17 cell responses in the small intestinal lamina propria decreased in mice inoculated with V. vulnificus rtxA mutant as compared to those inoculated with the wild-type strain. These decreases in DC maturation, Th17-polarizing cytokine secretion, and Th17 responses attributed to rtxA mutation were restored following infection with the rtxA revertant strain. Furthermore, the mutation in the hlyU gene encoding the activator of rtxA1 gene reproduced the results observed with rtxA mutation. Taken together, V. vulnificus, by means of RtxA, induces inflammatory Th17 responses, which may be associated with adaptive responses of the host against V. vulnificus infection.
Collapse
Affiliation(s)
- Arim Lee
- Department of Life Sciences, College of Life Sciences and Biotechnology, Korea University, Seoul, South Korea
| | - Myun Soo Kim
- Department of Life Sciences, College of Life Sciences and Biotechnology, Korea University, Seoul, South Korea
| | - Daeho Cho
- Institute of Convergence Science, Korea University, Seoul, South Korea
| | - Kyung Ku Jang
- National Research Laboratory of Molecular Microbiology and Toxicology, Department of Agricultural Biotechnology, Seoul National University, Seoul, South Korea
| | - Sang Ho Choi
- National Research Laboratory of Molecular Microbiology and Toxicology, Department of Agricultural Biotechnology, Seoul National University, Seoul, South Korea
| | - Tae Sung Kim
- Department of Life Sciences, College of Life Sciences and Biotechnology, Korea University, Seoul, South Korea
| |
Collapse
|
28
|
Chung HY, Lee B, Na EJ, Lee KH, Ryu S, Yoon H, Lee JH, Kim HB, Kim H, Jeong HG, Kim BS, Choi SH. Potential Survival and Pathogenesis of a Novel Strain, Vibrio parahaemolyticus FORC_022, Isolated From a Soy Sauce Marinated Crab by Genome and Transcriptome Analyses. Front Microbiol 2018; 9:1504. [PMID: 30034383 PMCID: PMC6043650 DOI: 10.3389/fmicb.2018.01504] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 06/18/2018] [Indexed: 11/13/2022] Open
Abstract
Vibrio parahaemolyticus can cause gastrointestinal illness through consumption of seafood. Despite frequent food-borne outbreaks of V. parahaemolyticus, only 19 strains have subjected to complete whole-genome analysis. In this study, a novel strain of V. parahaemolyticus, designated FORC_022 (Food-borne pathogen Omics Research Center_022), was isolated from soy sauce marinated crabs, and its genome and transcriptome were analyzed to elucidate the pathogenic mechanisms. FORC_022 did not include major virulence factors of thermostable direct hemolysin (tdh) and TDH-related hemolysin (trh). However, FORC_022 showed high cytotoxicity and had several V. parahaemolyticus islands (VPaIs) and other virulence factors, such as various secretion systems (types I, II, III, IV, and VI), in comparative genome analysis with CDC_K4557 (the most similar strain) and RIMD2210633 (genome island marker strain). FORC_022 harbored additional virulence genes, including accessory cholera enterotoxin, zona occludens toxin, and tight adhesion (tad) locus, compared with CDC_K4557. In addition, O3 serotype specific gene and the marker gene of pandemic O3:K6 serotype (toxRS) were detected in FORC_022. The expressions levels of genes involved in adherence and carbohydrate transporter were high, whereas those of genes involved in motility, arginine biosynthesis, and proline metabolism were low after exposure to crabs. Moreover, the virulence factors of the type III secretion system, tad locus, and thermolabile hemolysin were overexpressed. Therefore, the risk of foodborne-illness may be high following consumption of FORC_022 contaminated crab. These results provided molecular information regarding the survival and pathogenesis of V. parahaemolyticus FORC_022 strain in contaminated crab and may have applications in food safety.
Collapse
Affiliation(s)
- Han Y Chung
- Department of Agricultural Biotechnology, Center for Food Safety and Toxicology, Seoul National University, Seoul, South Korea.,Food-borne Pathogen Omics Research Center (FORC), Seoul National University, Seoul, South Korea
| | - Byungho Lee
- Department of Agricultural Biotechnology, Center for Food Safety and Toxicology, Seoul National University, Seoul, South Korea.,Food-borne Pathogen Omics Research Center (FORC), Seoul National University, Seoul, South Korea
| | - Eun J Na
- Department of Agricultural Biotechnology, Center for Food Safety and Toxicology, Seoul National University, Seoul, South Korea.,Food-borne Pathogen Omics Research Center (FORC), Seoul National University, Seoul, South Korea
| | - Kyu-Ho Lee
- Food-borne Pathogen Omics Research Center (FORC), Seoul National University, Seoul, South Korea.,Department of Life Science, Sogang University, Seoul, South Korea
| | - Sangryeol Ryu
- Department of Agricultural Biotechnology, Center for Food Safety and Toxicology, Seoul National University, Seoul, South Korea.,Food-borne Pathogen Omics Research Center (FORC), Seoul National University, Seoul, South Korea
| | - Hyunjin Yoon
- Food-borne Pathogen Omics Research Center (FORC), Seoul National University, Seoul, South Korea.,Department of Applied Chemistry & Biological Engineering, Ajou University, Suwon, South Korea
| | - Ju-Hoon Lee
- Food-borne Pathogen Omics Research Center (FORC), Seoul National University, Seoul, South Korea.,Department of Food Science and Biotechnology, Kyung Hee University, Yongin, South Korea
| | - Hyeun B Kim
- Food-borne Pathogen Omics Research Center (FORC), Seoul National University, Seoul, South Korea.,Department of Animal Resources Science, Dankook University, Cheonan, South Korea
| | - Heebal Kim
- Food-borne Pathogen Omics Research Center (FORC), Seoul National University, Seoul, South Korea.,Department of Animal Science and Biotechnology, Seoul National University, Seoul, South Korea
| | - Hee G Jeong
- Food-borne Pathogen Omics Research Center (FORC), Seoul National University, Seoul, South Korea.,Department of Food Science and Technology, Chungnam National University, Daejeon, South Korea
| | - Bong-Soo Kim
- Food-borne Pathogen Omics Research Center (FORC), Seoul National University, Seoul, South Korea.,Department of Life Science, Multidisciplinary Genome Institute, Hallym University, Chuncheon, South Korea
| | - Sang H Choi
- Department of Agricultural Biotechnology, Center for Food Safety and Toxicology, Seoul National University, Seoul, South Korea.,Food-borne Pathogen Omics Research Center (FORC), Seoul National University, Seoul, South Korea
| |
Collapse
|
29
|
Abstract
Pathogenic Vibrio species cause diseases in diverse marine animals reared in aquaculture. Since their pathogenesis, persistence, and survival in marine environments are regulated by quorum sensing (QS), QS interference has attracted attention as a means to control these bacteria in aquatic settings. A few QS inhibitors of Vibrio species have been reported, but detailed molecular mechanisms are lacking. Here, we identified a novel, potent, and selective Vibrio QS inhibitor, named QStatin [1-(5-bromothiophene-2-sulfonyl)-1H-pyrazole], which affects Vibrio harveyi LuxR homologues, the well-conserved master transcriptional regulators for QS in Vibrio species. Crystallographic and biochemical analyses showed that QStatin binds tightly to a putative ligand-binding pocket in SmcR, the LuxR homologue in V. vulnificus, and changes the flexibility of the protein, thereby altering its transcription regulatory activity. Transcriptome analysis revealed that QStatin results in SmcR dysfunction, affecting the expression of SmcR regulon required for virulence, motility/chemotaxis, and biofilm dynamics. Notably, QStatin attenuated representative QS-regulated phenotypes in various Vibrio species, including virulence against the brine shrimp (Artemia franciscana). Together, these results provide molecular insights into the mechanism of action of an effective, sustainable QS inhibitor that is less susceptible to resistance than other antimicrobial agents and useful in controlling the virulence of Vibrio species in aquacultures.IMPORTANCE Yields of aquaculture, such as penaeid shrimp hatcheries, are greatly affected by vibriosis, a disease caused by pathogenic Vibrio infections. Since bacterial cell-to-cell communication, known as quorum sensing (QS), regulates pathogenesis of Vibrio species in marine environments, QS inhibitors have attracted attention as alternatives to conventional antibiotics in aquatic settings. Here, we used target-based high-throughput screening to identify QStatin, a potent and selective inhibitor of V. harveyi LuxR homologues, which are well-conserved master QS regulators in Vibrio species. Structural and biochemical analyses revealed that QStatin binds tightly to a putative ligand-binding pocket on SmcR, the LuxR homologue in V. vulnificus, and affects expression of QS-regulated genes. Remarkably, QStatin attenuated diverse QS-regulated phenotypes in various Vibrio species, including pathogenesis against brine shrimp, with no impact on bacterial viability. Taken together, the results suggest that QStatin may be a sustainable antivibriosis agent useful in aquacultures.
Collapse
|
30
|
Abstract
One common feature of biofilm development is the active dispersal of cells from the mature biofilm, which completes the biofilm life cycle and allows for the subsequent colonization of new habitats. Dispersal is likely to be critical for species survival and appears to be a precisely regulated process that involves a complex network of genes and signal transduction systems. Sophisticated molecular mechanisms control the transition of sessile biofilm cells into dispersal cells and their coordinated detachment and release in the bulk liquid. Dispersal cells appear to be specialized and exhibit a unique phenotype different from biofilm or planktonic bacteria. Further, the dispersal population is characterized by a high level of heterogeneity, reminiscent of, but distinct from, that in the biofilm, which could potentially allow for improved colonization under various environmental conditions. Here we review recent advances in characterizing the molecular mechanisms that regulate biofilm dispersal events and the impact of dispersal in a broader ecological context. Several strategies that exploit the mechanisms controlling biofilm dispersal to develop as applications for biofilm control are also presented.
Collapse
|
31
|
Role of Heat Shock Proteases in Quorum-Sensing-Mediated Regulation of Biofilm Formation by Vibrio Species. mBio 2018; 9:mBio.02086-17. [PMID: 29295912 PMCID: PMC5750401 DOI: 10.1128/mbio.02086-17] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Capsular polysaccharide (CPS) is essential for the dispersal of biofilms formed by the pathogenic bacterium Vibrio vulnificus. CPS production is induced by the quorum-sensing (QS) master regulator SmcR when biofilms mature. However, V. vulnificus biofilms formed under heat shock conditions did not exhibit the dispersion stage. Transcripts of the CPS gene cluster were at basal levels in the heat-exposed cell owing to reduced cellular levels of SmcR. At least two proteases induced by heat shock, ClpPA and Lon, were responsible for determining the instability of SmcR. In vitro and in vivo assays demonstrated that SmcR levels were regulated via proteolysis by these proteases, with preferential proteolysis of monomeric SmcR. Thus, CPS production was not induced by QS when bacteria were heat treated. Further studies performed with other Vibrio species demonstrated that high temperature deactivated the QS circuits by increased proteolysis of their QS master regulators, thus resulting in alterations to the QS-regulated phenotypes, including biofilm formation. The term "quorum-sensing mechanism" is used to describe diverse bacterial cell density-dependent activities that are achieved by sensing of the signaling molecules and subsequent signal transduction to the master regulators. These well-known bacterial regulatory systems regulate the expression of diverse virulence factors and the construction of biofilms in pathogenic bacteria. There have been numerous studies designed to control bacterial quorum sensing by using small molecules to antagonize the quorum-sensing regulatory components or to interfere with the signaling molecules. In the present study, we showed that the quorum-sensing regulatory circuits of pathogenic Vibrio species were deactivated by heat shock treatment via highly increased proteolysis of the master transcription factors. Our results showed a new mode of quorum deactivation which can be achieved under conditions of high but nonlethal temperature even if the ambient signaling molecules may reach the levels representing high cell density.
Collapse
|
32
|
The stringent response promotes biofilm dispersal in Pseudomonas putida. Sci Rep 2017; 7:18055. [PMID: 29273811 PMCID: PMC5741744 DOI: 10.1038/s41598-017-18518-0] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Accepted: 12/12/2017] [Indexed: 01/08/2023] Open
Abstract
Biofilm dispersal is a genetically programmed response enabling bacterial cells to exit the biofilm in response to particular physiological or environmental conditions. In Pseudomonas putida biofilms, nutrient starvation triggers c-di-GMP hydrolysis by phosphodiesterase BifA, releasing inhibition of protease LapG by the c-di-GMP effector protein LapD, and resulting in proteolysis of the adhesin LapA and the subsequent release of biofilm cells. Here we demonstrate that the stringent response, a ubiquitous bacterial stress response, is accountable for relaying the nutrient stress signal to the biofilm dispersal machinery. Mutants lacking elements of the stringent response - (p)ppGpp sythetases [RelA and SpoT] and/or DksA - were defective in biofilm dispersal. Ectopic (p)ppGpp synthesis restored biofilm dispersal in a ∆relA ∆spoT mutant. In vivo gene expression analysis showed that (p)ppGpp positively regulates transcription of bifA, and negatively regulates transcription of lapA and the lapBC, and lapE operons, encoding a LapA-specific secretion system. Further in vivo and in vitro characterization revealed that the PbifA promoter is dependent on the flagellar σ factor FliA, and positively regulated by ppGpp and DksA. Our results indicate that the stringent response stimulates biofilm dispersal under nutrient limitation by coordinately promoting LapA proteolysis and preventing de novo LapA synthesis and secretion.
Collapse
|
33
|
Ammendola S, D'Amico Y, Chirullo B, Drumo R, Ciavardelli D, Pasquali P, Battistoni A. Zinc is required to ensure the expression of flagella and the ability to form biofilms in Salmonella enterica sv Typhimurium. Metallomics 2017; 8:1131-1140. [PMID: 27730246 DOI: 10.1039/c6mt00108d] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Zinc is known to play a central role in bacterial physiology and pathogenesis. Here, we report that the accumulation of FliC, the structural subunit of Salmonella phase 1 flagella, is sharply reduced in a znuABC Salmonella enterica sv. Typhimurium strain grown in zinc-poor media. Consequently, this mutant strain lacks motility, unless it grows in zinc-replete environments. This phenotype is the consequence of a general downregulation of all the genes involved in the biosynthesis of flagella, suggesting that zinc is the cofactor of proteins involved in the initiation of the transcriptional regulatory cascade leading to flagella assembly. Competition experiments in mice demonstrated that aflagellated (fliBfljC) and znuABC strains are outcompeted by the wild type strain in the gastrointestinal tract. The fliBfljC strain overgrows a fliCfljBznuABC mutant strain, but the difference in gut colonization between these two strains is less striking than that between the wild type and the znuABC strains, suggesting that the downregulation of flagella contributes to the loss of virulence of Salmonella znuABC. The absence of either flagella or ZnuABC also impairs the ability of S. Typhimurium to produce biofilms. Zinc suppresses this defect in the znuABC mutant but not in the aflagellated strains, highlighting the role of flagella in biofilm organization. We have also observed an increased production of the quorum sensing signal AI-2 in the znuABC strain sensing zinc deprivation, that may further contribute to the reduced ability to form biofilms. On the whole, our study reveals novel roles of zinc in Salmonella motility and intercellular communication.
Collapse
Affiliation(s)
- Serena Ammendola
- Dipartimento di Biologia, Università di Roma "Tor Vergata", Via della Ricerca Scientifica, 00133 Rome, Italy.
| | - Ylenia D'Amico
- Dipartimento di Biologia, Università di Roma "Tor Vergata", Via della Ricerca Scientifica, 00133 Rome, Italy.
| | - Barbara Chirullo
- Department of Veterinary Public Health and Food Safety, Istituto Superiore di Sanità, Rome, Italy
| | - Rosanna Drumo
- Department of Veterinary Public Health and Food Safety, Istituto Superiore di Sanità, Rome, Italy
| | | | - Paolo Pasquali
- Department of Veterinary Public Health and Food Safety, Istituto Superiore di Sanità, Rome, Italy
| | - Andrea Battistoni
- Dipartimento di Biologia, Università di Roma "Tor Vergata", Via della Ricerca Scientifica, 00133 Rome, Italy. and Interuniversity Consortium, National Institute Biostructures and Biosystems (INBB), Rome, Italy
| |
Collapse
|
34
|
Lee A, Lim HX, Kim MS, Cho D, Jang KK, Choi SH, Kim TS. Vibrio vulnificus infection induces the maturation and activation of dendritic cells with inflammatory Th17-polarizing ability. Int J Mol Med 2017; 41:531-540. [PMID: 29115398 DOI: 10.3892/ijmm.2017.3230] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 10/27/2017] [Indexed: 11/06/2022] Open
Abstract
Vibrio vulnificus (V. vulnificus) is a gram-negative bacterium, which causes life-threatening septicemia and gastroenteritis through the consumption of contaminated seafood or wound infection. In addition, V. vulnificus infection is known to stimulate the production of several pro-inflammatory cytokines, which are associated with inflammatory responses mediated predominantly by dendritic cells (DCs), functioning as antigen-presenting cells. The present study aimed to investigate whether V. vulnificus infection induced the maturation and activation of murine DCs, which have the ability to polarize T helper (Th) cells into Th17 cells. Dysregulated Th17 cell responses are known to cause tissue damage, promoting the penetration of pathogens; however, Th17 cells are also involved in host defense against infection. Infection with V. vulnificus significantly increased the expression of cell surface molecules, including CD40, CD80 and major histocompatibility complex class II, leading to the maturation and activation of DCs. In the present study, the analysis of the cytokine profiles of DCs upon infection with V. vulnificus revealed the preferential production of interleukin-1β (IL-1β) and IL-6, through which V. vulnificus-infected DCs induced the polarization of Th17 cells when naïve CD4+ T cells were co-incubated. The reduction of Th17 cell generation through the use of anti-IL-6 neutralizing antibodies indicated that the Th17-polarizing capacity of V. vulnificus was predominantly dependent on DC-derived IL-6. The in vivo administration of V. vulnificus-infected DCs consistently increased the Th17 cell population in the lymph nodes of mice. Finally, the oral administration of V. vulnificus in mice also increased Th17 cell responses in the lamina propria of the small intestine. These results collectively demonstrated that V. vulnificus induced inflammatory Th17 cell responses via DCs, which may be associated with the immunopathological effects caused by V. vulnificus infection.
Collapse
Affiliation(s)
- Arim Lee
- Department of Life Sciences, College of Life Sciences and Biotechnology, Korea University, Seoul 136-701, Republic of Korea
| | - Hui Xuan Lim
- Department of Life Sciences, College of Life Sciences and Biotechnology, Korea University, Seoul 136-701, Republic of Korea
| | - Myun Soo Kim
- Department of Life Science, Sookmyung Women's University, Seoul 140-742, Republic of Korea
| | - Daeho Cho
- Department of Life Science, Sookmyung Women's University, Seoul 140-742, Republic of Korea
| | - Kyung Ku Jang
- National Research Laboratory of Molecular Microbiology and Toxicology, Department of Agricultural Biotechnology, Seoul National University, Seoul 151-921, Republic of Korea
| | - Sang Ho Choi
- National Research Laboratory of Molecular Microbiology and Toxicology, Department of Agricultural Biotechnology, Seoul National University, Seoul 151-921, Republic of Korea
| | - Tae Sung Kim
- Department of Life Sciences, College of Life Sciences and Biotechnology, Korea University, Seoul 136-701, Republic of Korea
| |
Collapse
|
35
|
An Update on the Sociomicrobiology of Quorum Sensing in Gram-Negative Biofilm Development. Pathogens 2017; 6:pathogens6040051. [PMID: 29065453 PMCID: PMC5750575 DOI: 10.3390/pathogens6040051] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Revised: 10/12/2017] [Accepted: 10/19/2017] [Indexed: 11/16/2022] Open
Abstract
Bacteria are social creatures that are able to interact and coordinate behaviors with each other in a multitude of ways. The study of such group behaviors in microbes was coined “sociomicrobiology” in 2005. Two such group behaviors in bacteria are quorum sensing (QS) and biofilm formation. At a very basic level, QS is the ability to sense bacterial density via cell-to-cell signaling using self-produced signals called autoinducers, and biofilms are aggregates of cells that are attached to one another via a self-produced, extracellular matrix. Since cells in biofilm aggregates are in close proximity, biofilms represent an ecologically relevant environment for QS. While QS is known to affect biofilm formation in both Gram-negative and Gram-positive species, in this review, we will focus exclusively on Gram-negative bacteria, with an emphasis on Pseudomonas aeruginosa. We will begin by describing QS systems in P. aeruginosa and how they affect P. aeruginosa biofilm formation. We then expand our review to other Gram-negative bacteria and conclude with interesting questions with regard to the effect of biofilms on QS.
Collapse
|
36
|
Singh PK, Bartalomej S, Hartmann R, Jeckel H, Vidakovic L, Nadell CD, Drescher K. Vibrio cholerae Combines Individual and Collective Sensing to Trigger Biofilm Dispersal. Curr Biol 2017; 27:3359-3366.e7. [PMID: 29056457 PMCID: PMC5678073 DOI: 10.1016/j.cub.2017.09.041] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 07/19/2017] [Accepted: 09/19/2017] [Indexed: 01/07/2023]
Abstract
Bacteria can generate benefits for themselves and their kin by living in multicellular, matrix-enclosed communities, termed biofilms, which are fundamental to microbial ecology and the impact bacteria have on the environment, infections, and industry [1, 2, 3, 4, 5, 6]. The advantages of the biofilm mode of life include increased stress resistance and access to concentrated nutrient sources [3, 7, 8]. However, there are also costs associated with biofilm growth, including the metabolic burden of biofilm matrix production, increased resource competition, and limited mobility inside the community [9, 10, 11]. The decision-making strategies used by bacteria to weigh the costs between remaining in a biofilm or actively dispersing are largely unclear, even though the dispersal transition is a central aspect of the biofilm life cycle and critical for infection transmission [12, 13, 14]. Using a combination of genetic and novel single-cell imaging approaches, we show that Vibrio cholerae integrates dual sensory inputs to control the dispersal response: cells use the general stress response, which can be induced via starvation, and they also integrate information about the local cell density and molecular transport conditions in the environment via the quorum sensing apparatus. By combining information from individual (stress response) and collective (quorum sensing) avenues of sensory input, biofilm-dwelling bacteria can make robust decisions to disperse from large biofilms under distress, while preventing premature dispersal when biofilm populations are small. These insights into triggers and regulators of biofilm dispersal are a key step toward actively inducing biofilm dispersal for technological and medical applications, and for environmental control of biofilms. Cells in V. cholerae biofilms decide to disperse by combining two sensory mechanisms Quorum sensing and RpoS provide information on different environmental parameters Integration of both sensory inputs yields robust and optimal dispersal decisions
Collapse
Affiliation(s)
- Praveen K Singh
- Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Strasse 10, Marburg 35043, Germany
| | - Sabina Bartalomej
- Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Strasse 10, Marburg 35043, Germany
| | - Raimo Hartmann
- Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Strasse 10, Marburg 35043, Germany
| | - Hannah Jeckel
- Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Strasse 10, Marburg 35043, Germany; Department of Physics, Philipps-Universität Marburg, Renthof 6, Marburg 35032, Germany
| | - Lucia Vidakovic
- Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Strasse 10, Marburg 35043, Germany
| | - Carey D Nadell
- Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Strasse 10, Marburg 35043, Germany
| | - Knut Drescher
- Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Strasse 10, Marburg 35043, Germany; Department of Physics, Philipps-Universität Marburg, Renthof 6, Marburg 35032, Germany.
| |
Collapse
|
37
|
Lee SJ, Jung YH, Kim JS, Lee HJ, Lee SH, Lee KH, Jang KK, Choi SH, Han HJ. A Vibrio vulnificus VvpM Induces IL-1β Production Coupled with Necrotic Macrophage Death via Distinct Spatial Targeting by ANXA2. Front Cell Infect Microbiol 2017; 7:352. [PMID: 28848713 PMCID: PMC5554522 DOI: 10.3389/fcimb.2017.00352] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Accepted: 07/21/2017] [Indexed: 12/23/2022] Open
Abstract
An inflammatory form of phagocyte death evoked by the Gram-negative bacterium Vibrio (V.) vulnificus (WT) is one of hallmarks to promote their colonization, but the virulence factor and infectious mechanism involved in this process remain largely unknown. Here, we identified extracellular metalloprotease VvpM as a new virulence factor and investigated the molecular mechanism of VvpM which acts during the regulation of the inflammatory form of macrophage death and bacterial colonization. Mutation of the vvpM gene appeared to play major role in the prevention of IL-1β production due to V. vulnificus infection in macrophage. However, the recombinant protein (r) VvpM caused IL-1β production coupled with necrotic cell death, which is highly susceptible to the knockdown of annexin A2 (ANXA2) located in both membrane lipid and non-lipid rafts. In lipid rafts, rVvpM recruited NOX enzymes coupled with ANXA2 to facilitate the production of ROS responsible for the epigenetic and transcriptional regulation of NF-κB in the IL-1β promoter. rVvpM acting on non-lipid rafts increased LC3 puncta formation and autophagic flux, which are required for the mRNA expression of Atg5 involved in the autophagosome formation process. The autophagy activation caused by rVvpM induced NLRP3 inflammasome-dependent caspase-1 activation in the promoting of IL-1β production. In mouse models of V. vulnificus infection, the VvpM mutant failed to elevate the level of pro-inflammatory responses closely related to IL-1β production and prevented bacterial colonization. These findings delineate VvpM efficiently regulates two pathogenic pathways that stimulate NF-κB-dependent IL-1β production and autophagy-mediated NLRP3 inflammasome via distinct spatial targeting by ANXA2.
Collapse
Affiliation(s)
- Sei-Jung Lee
- Department of Pharmaceutical Engineering, Daegu Haany UniversityGyeongsan, South Korea
| | - Young Hyun Jung
- Department of Veterinary Physiology, College of Veterinary Medicine, Research Institute for Veterinary Science and BK21 PLUS Program for Creative Veterinary Science Research Center, Seoul National UniversitySeoul, South Korea
| | - Jun Sung Kim
- Department of Veterinary Physiology, College of Veterinary Medicine, Research Institute for Veterinary Science and BK21 PLUS Program for Creative Veterinary Science Research Center, Seoul National UniversitySeoul, South Korea
| | - Hyun Jik Lee
- Department of Veterinary Physiology, College of Veterinary Medicine, Research Institute for Veterinary Science and BK21 PLUS Program for Creative Veterinary Science Research Center, Seoul National UniversitySeoul, South Korea
| | - Sang Hun Lee
- Medical Science Research Institute, Soonchunhyang University Seoul HospitalSeoul, South Korea
- Departments of Biochemistry, Soonchunhyang University College of MedicineCheonan, South Korea
| | - Kyu-Ho Lee
- Department of Life Science, Sogang UniversitySeoul, South Korea
| | - Kyung Ku Jang
- National Research Laboratory of Molecular Microbiology and Toxicology, Department of Agricultural Biotechnology, Center for Food Safety and Toxicology, Seoul National UniversitySeoul, South Korea
| | - Sang Ho Choi
- National Research Laboratory of Molecular Microbiology and Toxicology, Department of Agricultural Biotechnology, Center for Food Safety and Toxicology, Seoul National UniversitySeoul, South Korea
| | - Ho Jae Han
- Department of Veterinary Physiology, College of Veterinary Medicine, Research Institute for Veterinary Science and BK21 PLUS Program for Creative Veterinary Science Research Center, Seoul National UniversitySeoul, South Korea
| |
Collapse
|
38
|
Guilhen C, Forestier C, Balestrino D. Biofilm dispersal: multiple elaborate strategies for dissemination of bacteria with unique properties. Mol Microbiol 2017; 105:188-210. [PMID: 28422332 DOI: 10.1111/mmi.13698] [Citation(s) in RCA: 110] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/15/2017] [Indexed: 01/22/2023]
Abstract
In most environments, microorganisms evolve in a sessile mode of growth, designated as biofilm, which is characterized by cells embedded in a self-produced extracellular matrix. Although a biofilm is commonly described as a "cozy house" where resident bacteria are protected from aggression, bacteria are able to break their biofilm bonds and escape to colonize new environments. This regulated process is observed in a wide variety of species; it is referred to as biofilm dispersal, and is triggered in response to various environmental and biological signals. The first part of this review reports the main regulatory mechanisms and effectors involved in biofilm dispersal. There is some evidence that dispersal is a necessary step between the persistence of bacteria inside biofilm and their dissemination. In the second part, an overview of the main methods used so far to study the dispersal process and to harvest dispersed bacteria was provided. Then focus was on the properties of the biofilm-dispersed bacteria and the fundamental role of the dispersal process in pathogen dissemination within a host organism. In light of the current body of knowledge, it was suggested that dispersal acts as a potent means of disseminating bacteria with enhanced colonization properties in the surrounding environment.
Collapse
Affiliation(s)
- Cyril Guilhen
- Laboratoire Microorganismes : Génome et Environnement, UMR CNRS 6023, Université Clermont Auvergne, Clermont Ferrand, F-63001, France
| | - Christiane Forestier
- Laboratoire Microorganismes : Génome et Environnement, UMR CNRS 6023, Université Clermont Auvergne, Clermont Ferrand, F-63001, France
| | - Damien Balestrino
- Laboratoire Microorganismes : Génome et Environnement, UMR CNRS 6023, Université Clermont Auvergne, Clermont Ferrand, F-63001, France
| |
Collapse
|
39
|
Development of an HTS system to identify natural chemicals that specifically inhibit Escherichia coli O157:H7 adhesion to host cells. Food Control 2017. [DOI: 10.1016/j.foodcont.2016.08.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
40
|
Kado T, Kashimoto T, Yamazaki K, Ueno S. Importance of fumarate and nitrate reduction regulatory protein for intestinal proliferation ofVibrio vulnificus. FEMS Microbiol Lett 2016; 364:fnw274. [DOI: 10.1093/femsle/fnw274] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 07/28/2016] [Accepted: 12/02/2016] [Indexed: 11/12/2022] Open
|
41
|
Petrova OE, Sauer K. Escaping the biofilm in more than one way: desorption, detachment or dispersion. Curr Opin Microbiol 2016; 30:67-78. [PMID: 26826978 DOI: 10.1016/j.mib.2016.01.004] [Citation(s) in RCA: 140] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Revised: 01/07/2016] [Accepted: 01/08/2016] [Indexed: 12/15/2022]
Abstract
Biofilm bacteria have developed escape strategies to avoid stresses associated with biofilm growth, respond to changing environmental conditions, and disseminate to new locations. An ever-expanding body of research suggests that cellular release from biofilms is distinct from a simple reversal of attachment and reversion to a planktonic mode of growth, with biofilm dispersion involving sensing of specific cues, regulatory signal transduction, and consequent physiological alterations. However, dispersion is only one of many ways to escape the biofilm mode of growth. The present review is aimed at distinguishing this active and regulated process of dispersion from the passive processes of desorption and detachment by highlighting the regulatory processes and distinct phenotypes specific to dispersed cells.
Collapse
Affiliation(s)
- Olga E Petrova
- Department of Biological Sciences, Binghamton Biofilm Research Center, Binghamton University, Binghamton, NY 13902, United States
| | - Karin Sauer
- Department of Biological Sciences, Binghamton Biofilm Research Center, Binghamton University, Binghamton, NY 13902, United States.
| |
Collapse
|
42
|
Jang KK, Gil SY, Lim JG, Choi SH. Regulatory Characteristics of Vibrio vulnificus gbpA Gene Encoding a Mucin-binding Protein Essential for Pathogenesis. J Biol Chem 2016; 291:5774-5787. [PMID: 26755724 DOI: 10.1074/jbc.m115.685321] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Indexed: 12/21/2022] Open
Abstract
Binding to mucin is the initial step for enteropathogens to establish pathogenesis. An open reading frame, gbpA, of Vibrio vulnificus was identified and characterized in this study. Compared with wild type, the gbpA mutant was impaired in binding to mucin-agar and the mucin-secreting HT29-methotrexate cells, and the impaired mucin binding was restored by the purified GbpA provided exogenously. The gbpA mutant had attenuated virulence and ability of intestinal colonization in a mouse model, indicating that GbpA is a mucin-binding protein and essential for pathogenesis of V. vulnificus. The gbpA transcription was growth phase-dependent, reaching a maximum during the exponential phase. The Fe-S cluster regulator (IscR) and the cyclic AMP receptor protein (CRP) coactivated, whereas SmcR, a LuxR homologue, repressed gbpA. The cellular levels of IscR, CRP, and SmcR were not significantly affected by one another, indicating that the regulator proteins function cooperatively to regulate gbpA rather than sequentially in a regulatory cascade. The regulatory proteins directly bind upstream of the gbpA promoter PgbpA. DNase I protection assays, together with the deletion analyses of PgbpA, demonstrated that IscR binds to two specific sequences centered at -164.5 and -106, and CRP and SmcR bind specifically to the sequences centered at -68 and -45, respectively. Furthermore, gbpA was induced by exposure to H2O2, and the induction appeared to be mediated by elevated intracellular levels of IscR. Consequently, the combined results indicated that IscR, CRP, and SmcR cooperate for precise regulation of gbpA during the V. vulnificus pathogenesis.
Collapse
Affiliation(s)
- Kyung Ku Jang
- From the National Research Laboratory of Molecular Microbiology and Toxicology, Department of Agricultural Biotechnology, Center for Food Safety and Toxicology, Seoul National University, Seoul 151-921, South Korea
| | - So Yeon Gil
- From the National Research Laboratory of Molecular Microbiology and Toxicology, Department of Agricultural Biotechnology, Center for Food Safety and Toxicology, Seoul National University, Seoul 151-921, South Korea
| | - Jong Gyu Lim
- From the National Research Laboratory of Molecular Microbiology and Toxicology, Department of Agricultural Biotechnology, Center for Food Safety and Toxicology, Seoul National University, Seoul 151-921, South Korea
| | - Sang Ho Choi
- From the National Research Laboratory of Molecular Microbiology and Toxicology, Department of Agricultural Biotechnology, Center for Food Safety and Toxicology, Seoul National University, Seoul 151-921, South Korea.
| |
Collapse
|
43
|
Lee SJ, Jung YH, Ryu JM, Jang KK, Choi SH, Han HJ. VvpE mediates the intestinal colonization of Vibrio vulnificus by the disruption of tight junctions. Int J Med Microbiol 2016; 306:10-9. [DOI: 10.1016/j.ijmm.2015.10.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Revised: 09/17/2015] [Accepted: 10/26/2015] [Indexed: 01/01/2023] Open
|
44
|
Lee SJ, Jung YH, Song EJ, Jang KK, Choi SH, Han HJ. Vibrio vulnificus VvpE Stimulates IL-1β Production by the Hypomethylation of the IL-1β Promoter and NF-κB Activation via Lipid Raft–Dependent ANXA2 Recruitment and Reactive Oxygen Species Signaling in Intestinal Epithelial Cells. THE JOURNAL OF IMMUNOLOGY 2015; 195:2282-2293. [DOI: 10.4049/jimmunol.1500951] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/30/2023]
Abstract
Abstract
An inflammatory response is a hallmark of necrosis evoked by bacterial pathogens. Vibrio vulnificus, VvpE, is an elastase that is responsible for tissue necrosis and inflammation; however, the molecular mechanism by which it regulates host cell death has not been characterized. In the present study, we investigate the cellular mechanism of VvpE with regard to host cell death and the inflammatory response of human intestinal epithelial (INT-407) cells. The recombinant protein (r)VvpE (50 pg/ml) caused cytotoxicity mainly via necrosis coupled with IL-1β production. The necrotic cell death induced by rVvpE is highly susceptible to the knockdown of annexin A (ANXA)2 and the sequestration of membrane cholesterol. We found that rVvpE induces the recruitment of NADPH oxidase 2 and neutrophil cytosolic factor 1 into membrane lipid rafts coupled with ANXA2 to facilitate the production of reactive oxygen species (ROS). The bacterial signaling of rVvpE through ROS production is uniquely mediated by the phosphorylation of redox-sensitive transcription factor NF-κB. The silencing of NF-κB inhibited IL-1β production during necrosis. rVvpE induced hypomethylation and region-specific transcriptional occupancy by NF-κB in the IL-1β promoter and has the ability to induce pyroptosis via NOD-, LRR-, and pyrin domain–containing 3 inflammasome. In a mouse model of V. vulnificus infection, the mutation of the vvpE gene from V. vulnificus negated the proinflammatory responses and maintained the physiological levels of the proliferation and migration of enterocytes. These results demonstrate that VvpE induces the hypomethylation of the IL-1β promoter and the transcriptional regulation of NF-κB through lipid raft–dependent ANXA2 recruitment and ROS signaling to promote IL-1β production in intestinal epithelial cells.
Collapse
Affiliation(s)
- Sei-Jung Lee
- *Department of Veterinary Physiology, College of Veterinary Medicine, Research Institute for Veterinary Science, Seoul National University, Seoul 151-741, South Korea
- †Brain Korea 21 Program for Leading Universities and Students (BK21 PLUS) Creative Veterinary Research Center, Seoul National University, Seoul 151-741, South Korea; and
| | - Young Hyun Jung
- *Department of Veterinary Physiology, College of Veterinary Medicine, Research Institute for Veterinary Science, Seoul National University, Seoul 151-741, South Korea
- †Brain Korea 21 Program for Leading Universities and Students (BK21 PLUS) Creative Veterinary Research Center, Seoul National University, Seoul 151-741, South Korea; and
| | - Eun Ju Song
- *Department of Veterinary Physiology, College of Veterinary Medicine, Research Institute for Veterinary Science, Seoul National University, Seoul 151-741, South Korea
- †Brain Korea 21 Program for Leading Universities and Students (BK21 PLUS) Creative Veterinary Research Center, Seoul National University, Seoul 151-741, South Korea; and
| | - Kyung Ku Jang
- ‡Department of Agricultural Biotechnology, National Research Laboratory of Molecular Microbiology and Toxicology, and Center for Food Safety and Toxicology, Seoul National University, Seoul 151-921, South Korea
| | - Sang Ho Choi
- ‡Department of Agricultural Biotechnology, National Research Laboratory of Molecular Microbiology and Toxicology, and Center for Food Safety and Toxicology, Seoul National University, Seoul 151-921, South Korea
| | - Ho Jae Han
- *Department of Veterinary Physiology, College of Veterinary Medicine, Research Institute for Veterinary Science, Seoul National University, Seoul 151-741, South Korea
- †Brain Korea 21 Program for Leading Universities and Students (BK21 PLUS) Creative Veterinary Research Center, Seoul National University, Seoul 151-741, South Korea; and
| |
Collapse
|
45
|
Antimicrobial potential of Leuconostoc species against E. coli O157:H7 in ground meat. ACTA ACUST UNITED AC 2015. [DOI: 10.1007/s13765-015-0112-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
|
46
|
Lee MN, Kim SK, Li XH, Lee JH. Bacterial virulence analysis using brine shrimp as an infection model in relation to the importance of quorum sensing and proteases. J GEN APPL MICROBIOL 2015; 60:169-74. [PMID: 25420421 DOI: 10.2323/jgam.60.169] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Brine shrimp are aquatic crustaceans belonging to a genus of Artemia. This organism is widely used for testing the toxicity of chemicals. In this study, brine shrimp were evaluated as an infection model organism to study bacterial virulence. Artemia nauplii were infected with various pathogenic bacteria, such as Vibrio vulnificus, Pseudomonas aeruginosa, Burkholderia vietnamiensis, Staphylococcus aureus, and Escherichia coli, and the susceptibility to these bacteria was investigated by counting the survival of the infected nauplii. While all of the tested bacteria have significant virulence to brine shrimp, killing the nauplii in a few days, V. vulnificus showed the strongest virulence. P. aeruginosa also showed a dose-dependent virulence to brine shrimp, but the virulence was weaker than that of V. vulnificus. The virulence tests using the virulence-attenuated mutants of V. vulnificus and P. aeruginosa, such as quorum sensing (QS) mutants or protease-deficient mutants showed a significant attenuation of virulence, demonstrating that the QS mechanism is important in the virulence of these bacteria to brine shrimp. B. vietnamiensis, S. aureus, and E. coli were also virulent to brine shrimp and the virulence was correlated with dosage within 24 h under our conditions. Salmonella enterica Typhimurium and Bacillus subtilis were also virulent to brine shrimp, but the virulence was weak and slowly exerted compared with that of other bacteria. Taken together, we suggest that brine shrimp are a good infection model to assay bacterial virulence, especially for V. vulnificus and P. aeruginosa, and QS is important in the bacterial virulence to brine shrimp.
Collapse
Affiliation(s)
- Mi-Nan Lee
- Department of Pharmacy, College of Pharmacy, Pusan National University
| | | | | | | |
Collapse
|
47
|
Vibrio vulnificus VvpE inhibits mucin 2 expression by hypermethylation via lipid raft-mediated ROS signaling in intestinal epithelial cells. Cell Death Dis 2015; 6:e1787. [PMID: 26086960 PMCID: PMC4669833 DOI: 10.1038/cddis.2015.152] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Revised: 05/08/2015] [Accepted: 05/08/2015] [Indexed: 02/07/2023]
Abstract
Mucin is an important physical barrier against enteric pathogens. VvpE is an elastase encoded by Gram-negative bacterium Vibrio vulnificus; however, the functional role of VvpE in intestinal mucin (Muc) production is yet to be elucidated. The recombinant protein (r) VvpE significantly reduced the level of Muc2 in human mucus-secreting HT29-MTX cells. The repression of Muc2 induced by rVvpE was highly susceptible to the knockdown of intelectin-1b (ITLN) and sequestration of cholesterol by methyl-β-cyclodextrin. We found that rVvpE induces the recruitment of NADPH oxidase 2 and neutrophil cytosolic factor 1 into the membrane lipid rafts coupled with ITLN to facilitate the production of reactive oxygen species (ROS). The bacterial signaling of rVvpE through ROS production is uniquely mediated by the phosphorylation of ERK, which was downregulated by the silencing of the PKCδ. Moreover, rVvpE induced region-specific methylation in the Muc2 promoter to promote the transcriptional repression of Muc2. In two mouse models of V. vulnificus infection, the mutation of the vvpE gene from V. vulnificus exhibited an increased survival rate and maintained the level of Muc2 expression in intestine. These results demonstrate that VvpE inhibits Muc2 expression by hypermethylation via lipid raft-mediated ROS signaling in the intestinal epithelial cells.
Collapse
|
48
|
Effects of elevated intracellular cyclic di-GMP levels on biofilm formation and transcription profiles of Vibrio vulnificus. Food Sci Biotechnol 2015. [DOI: 10.1007/s10068-015-0100-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
|
49
|
Abstract
Biofilms are resilient, surface-associated communities of cells with specialized properties (e.g., resistance to drugs and mechanical forces) that are distinct from those of suspension (planktonic) cultures. Biofilm formation by the opportunistic human fungal pathogen Candida albicans is medically relevant because C. albicans infections are highly correlated with implanted medical devices, which provide efficient substrates for biofilm formation; moreover, biofilms are inherently resistant to antifungal drugs. Biofilms are also important for C. albicans to colonize diverse niches of the human host. Here, we describe four core members of a conserved histone deacetylase complex in C. albicans (Set3, Hos2, Snt1, and Sif2) and explore the effects of their mutation on biofilm formation. We find that these histone deacetylase complex members are needed for proper biofilm formation, including dispersal of cells from biofilms and multifactorial drug resistance. Our results underscore the importance of the physical properties of biofilms in contributing to drug resistance and dispersal and lay a foundation for new strategies to target biofilm dispersal as a potential antifungal intervention. Through the formation of biofilms—surface-associated communities of cells—microorganisms can establish infections, become drug resistant, and evade the host immune system. Here we investigate how four core members of a conserved histone deacetylase complex mediate biofilm formation by Candida albicans, the major fungal pathogen of humans. We show that this histone deacetylase complex is required for biofilm dispersal, a process through which cells leave the biofilm to establish new infections. We also show that the deacetylase complex mediates biofilm drug resistance. This work provides new insight into how the physical properties of biofilms affect dispersal and drug resistance and suggests new potential antifungal strategies that could be effective against biofilms.
Collapse
|
50
|
Quorum sensing-dependent metalloprotease VvpE is important in the virulence of Vibrio vulnificus to invertebrates. Microb Pathog 2014; 71-72:8-14. [DOI: 10.1016/j.micpath.2014.04.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Revised: 04/04/2014] [Accepted: 04/07/2014] [Indexed: 11/18/2022]
|