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Zhang Q, Alter T, Fleischmann S. Non-O1/Non-O139 Vibrio cholerae-An Underestimated Foodborne Pathogen? An Overview of Its Virulence Genes and Regulatory Systems Involved in Pathogenesis. Microorganisms 2024; 12:818. [PMID: 38674762 PMCID: PMC11052320 DOI: 10.3390/microorganisms12040818] [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: 02/29/2024] [Revised: 04/05/2024] [Accepted: 04/15/2024] [Indexed: 04/28/2024] Open
Abstract
In recent years, the number of foodborne infections with non-O1 and non-O139 Vibrio cholerae (NOVC) has increased worldwide. These have ranged from sporadic infection cases to localized outbreaks. The majority of case reports describe self-limiting gastroenteritis. However, severe gastroenteritis and even cholera-like symptoms have also been described. All reported diarrheal cases can be traced back to the consumption of contaminated seafood. As climate change alters the habitats and distribution patterns of aquatic bacteria, there is a possibility that the number of infections and outbreaks caused by Vibrio spp. will further increase, especially in countries where raw or undercooked seafood is consumed or clean drinking water is lacking. Against this background, this review article focuses on a possible infection pathway and how NOVC can survive in the human host after oral ingestion, colonize intestinal epithelial cells, express virulence factors causing diarrhea, and is excreted by the human host to return to the environment.
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Affiliation(s)
| | | | - Susanne Fleischmann
- Institute of Food Safety and Food Hygiene, School of Veterinary Medicine, Freie Universität Berlin, Königsweg 69, 14163 Berlin, Germany; (Q.Z.); (T.A.)
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2
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Qin ZX, Chen GZ, Bao W, Ma Y, Yang XM, Yi CR, Luo M, Hu J, Liu Z. Magnetic chitin beads (MCB) coated with Vibrio cholerae reveals transcriptome dynamics in adult mice with a complex gut microbiota. Gut Microbes 2023; 15:2274125. [PMID: 37934002 PMCID: PMC10631443 DOI: 10.1080/19490976.2023.2274125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 10/18/2023] [Indexed: 11/08/2023] Open
Abstract
Vibrio cholerae adapts to the host environment by altering gene expression. Because of the complexity of the gut microbiome, current in vivo V. cholerae transcriptome studies have focused on microbiota-undeveloped conditions, neglecting the interaction between the host's commensal gut microbiota and V. cholerae. In this study, we analyzed the transcriptome of fully colonized adult mice in vivo using V. cholerae coated-magnetic chitin beads (vcMCB). This provides a simple yet powerful method for obtaining high-quality RNA from V. cholerae during colonization in mice. The transcriptome of V. cholerae recovered from adult mice infected with vcMCB shows differential expression of several genes when compared to V. cholerae recovered from the infant mouse and infant rabbit model. Some of these genes were also observed to be differentially expressed in previous studies of V. cholera recovered from human infection when compared to V. cholerae grown in vitro. In particular, we confirmed that V. cholerae resists the inhibitory effects of low pH and formic acid from gut microbiota, such as Anaerostipes caccae and Dorea formicigenerans, by downregulating vc1080. We propose that the vc1080 product may protect V. cholerae from formic acid stress through a novel acid tolerance response mechanism. Transcriptomic data obtained using the vcMCB system provide new perspectives on the interaction between V. cholerae and the gut microbiota, and this approach can also be applied to studies of other pathogenic bacteria.
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Affiliation(s)
- Zi-Xin Qin
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Guo-Zhong Chen
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Wei Bao
- National Engineering Research Center for Nanomedicine, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Yao Ma
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Xiao-Man Yang
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Chun-Rong Yi
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Mei Luo
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Jun Hu
- National Engineering Research Center for Nanomedicine, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Zhi Liu
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
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3
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Byun H, Brockett MR, Pu Q, Hrycko AJ, Beld J, Zhu J. An Intestinal Bacillus velezensis Isolate Displays Broad-Spectrum Antibacterial Activity and Prevents Infection of Both Gram-Positive and Gram-Negative Pathogens In Vivo. J Bacteriol 2023; 205:e0013323. [PMID: 37195186 PMCID: PMC10294632 DOI: 10.1128/jb.00133-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 04/24/2023] [Indexed: 05/18/2023] Open
Abstract
The increasing prevalence of drug-resistant bacteria has significantly diminished the effectiveness of antibiotics in clinical settings, leading to the emergence of untreatable bacterial infections. To address this public health challenge, the gut microbiome represents a promising source of novel antimicrobial therapeutics. In this study, we screened mouse intestinal isolates for growth inhibitory activity against the human enteric pathogen Vibrio cholerae and identified a strain of spore-forming Bacillus velezensis, named BVM7, that produced a potent antibiotic with activity against V. cholerae and a broad spectrum of enteric and opportunistic pathogens. Characterization of the antimicrobial compounds produced by BVM7 revealed that they were primarily secreted antimicrobial peptides (AMPs) produced during stationary-phase growth. Furthermore, our results showed that introducing either BVM7 vegetative cells or spores into mice precolonized with V. cholerae or Enterococcus faecalis significantly reduced the burden of infection. Interestingly, we also observed that BVM7 was sensitive to a group of Lactobacillus probiotic strains and that inoculation of Lactobacilli could eliminate BVM7 and potentially restore the native gut microbiome. These findings highlight the potential of bacteria from the gut microbiome as a source for novel antimicrobial compounds and a tool for managing bacterial infections by in situ bio-delivery of multiple AMPs. IMPORTANCE The rise of antibiotic-resistant pathogens poses a challenge to public health. The gut microbiome presents a promising source of new antimicrobials and treatments. By screening murine gut commensals, we found a spore-forming Bacillus velezensis strain, BVM7, that exhibited antimicrobial activity toward a wide array of enteric and opportunistic bacterial pathogens. In addition to showing that this killing effect occurred through the action of secreted antimicrobial peptides (AMPs), we demonstrate that BVM7 vegetative cells and spores can be used to treat infections of both Gram-positive and Gram-negative pathogens in vivo. By expanding our knowledge of the antimicrobial properties of bacteria in the gut microbiome, we hope to contribute insights for developing novel drugs and therapeutic interventions.
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Affiliation(s)
- Hyuntae Byun
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Mary R. Brockett
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Qinqin Pu
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Andrew J. Hrycko
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Joris Beld
- Department of Microbiology & Immunology, College of Medicine, Drexel University, Philadelphia, Pennsylvania, USA
| | - Jun Zhu
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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4
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Dps-dependent in vivo mutation enhances long-term host adaptation in Vibrio cholerae. PLoS Pathog 2023; 19:e1011250. [PMID: 36928244 PMCID: PMC10104298 DOI: 10.1371/journal.ppat.1011250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 04/14/2023] [Accepted: 02/27/2023] [Indexed: 03/18/2023] Open
Abstract
As one of the most successful pathogenic organisms, Vibrio cholerae (V. cholerae) has evolved sophisticated regulatory mechanisms to overcome host stress. During long-term colonization by V. cholerae in adult mice, many spontaneous nonmotile mutants (approximately 10% at the fifth day post-infection) were identified. These mutations occurred primarily in conserved regions of the flagellar regulator genes flrA, flrC, and rpoN, as shown by Sanger and next-generation sequencing, and significantly increased fitness during colonization in adult mice. Intriguingly, instead of key genes in DNA repair systems (mutS, nfo, xthA, uvrA) or ROS and RNS scavenging systems (katG, prxA, hmpA), which are generally thought to be associated with bacterial mutagenesis, we found that deletion of the cyclin gene dps significantly increased the mutation rate (up to 53% at the fifth day post-infection) in V. cholerae. We further determined that the dpsD65A and dpsF46E point mutants showed a similar mutagenesis profile as the Δdps mutant during long-term colonization in mice, which strongly indicated that the antioxidative function of Dps directly contributes to the development of V. cholerae nonmotile mutants. Methionine metabolism pathway may be one of the mechanism for ΔflrA, ΔflrC and ΔrpoN mutant increased colonization in adult mice. Our results revealed a new phenotype in which V. cholerae fitness increases in the host gut via spontaneous production nonmotile mutants regulated by cyclin Dps, which may represent a novel adaptation strategy for directed evolution of pathogens in the host.
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5
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Muhammad AY, Amonov M, Murugaiah C, Baig AA, Yusoff M. Intestinal colonization against Vibrio cholerae: host and microbial resistance mechanisms. AIMS Microbiol 2023; 9:346-374. [PMID: 37091815 PMCID: PMC10113163 DOI: 10.3934/microbiol.2023019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Revised: 03/22/2023] [Accepted: 03/27/2023] [Indexed: 04/25/2023] Open
Abstract
Vibrio cholerae is a non-invasive enteric pathogen known to cause a major public health problem called cholera. The pathogen inhabits the aquatic environment while outside the human host, it is transmitted into the host easily through ingesting contaminated food and water containing the vibrios, thus causing diarrhoea and vomiting. V. cholerae must resist several layers of colonization resistance mechanisms derived from the host or the gut commensals to successfully survive, grow, and colonize the distal intestinal epithelium, thus causing an infection. The colonization resistance mechanisms derived from the host are not specific to V. cholerae but to all invading pathogens. However, some of the gut commensal-derived colonization resistance may be more specific to the pathogen, making it more challenging to overcome. Consequently, the pathogen has evolved well-coordinated mechanisms that sense and utilize the anti-colonization factors to modulate events that promote its survival and colonization in the gut. This review is aimed at discussing how V. cholerae interacts and resists both host- and microbe-specific colonization resistance mechanisms to cause infection.
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Affiliation(s)
| | - Malik Amonov
- Faculty of Medicine, Universiti Sultan Zainal Abidin, Malaysia
- * Correspondence: ; Tel: +60189164478
| | | | - Atif Amin Baig
- University Institute of Public Health, Faculty of Allied Health Sciences, The University of Lahore, Pakistan
| | - Marina Yusoff
- Faculty of Medicine, Universiti Sultan Zainal Abidin, Malaysia
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Chen J, Byun H, She Q, Liu Z, Ruggeberg KG, Pu Q, Jung IJ, Zhu D, Brockett MR, Hsiao A, Zhu J. S-Nitrosylation of the virulence regulator AphB promotes Vibrio cholerae pathogenesis. PLoS Pathog 2022; 18:e1010581. [PMID: 35714156 PMCID: PMC9246220 DOI: 10.1371/journal.ppat.1010581] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 06/30/2022] [Accepted: 05/10/2022] [Indexed: 11/19/2022] Open
Abstract
Vibrio cholerae is the etiologic agent of the severe human diarrheal disease cholera. To colonize mammalian hosts, this pathogen must defend against host-derived toxic compounds, such as nitric oxide (NO) and NO-derived reactive nitrogen species (RNS). RNS can covalently add an NO group to a reactive cysteine thiol on target proteins, a process called protein S-nitrosylation, which may affect bacterial stress responses. To better understand how V. cholerae regulates nitrosative stress responses, we profiled V. cholerae protein S-nitrosylation during RNS exposure. We identified an S-nitrosylation of cysteine 235 of AphB, a LysR-family transcription regulator that activates the expression of tcpP, which activates downstream virulence genes. Previous studies show that AphB C235 is sensitive to O2 and reactive oxygen species (ROS). Under microaerobic conditions, AphB formed dimer and directly repressed transcription of hmpA, encoding a flavohemoglobin that is important for NO resistance of V. cholerae. We found that tight regulation of hmpA by AphB under low nitrosative stress was important for V. cholerae optimal growth. In the presence of NO, S-nitrosylation of AphB abolished AphB activity, therefore relieved hmpA expression. Indeed, non-modifiable aphBC235S mutants were sensitive to RNS in vitro and drastically reduced colonization of the RNS-rich mouse small intestine. Finally, AphB S-nitrosylation also decreased virulence gene expression via debilitation of tcpP activation, and this regulation was also important for V. cholerae RNS resistance in vitro and in the gut. These results suggest that the modulation of the activity of virulence gene activator AphB via NO-dependent protein S-nitrosylation is critical for V. cholerae RNS resistance and colonization.
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Affiliation(s)
- Jiandong Chen
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Hyuntae Byun
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Qianxuan She
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Zhi Liu
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Karl-Gustav Ruggeberg
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Qinqin Pu
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - I-Ji Jung
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Dehao Zhu
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Mary R. Brockett
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Ansel Hsiao
- Department of Microbiology & Plant Pathology, University of California Riverside, Riverside, California, United States of America
| | - Jun Zhu
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- * E-mail:
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7
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Proteome Expression and Survival Strategies of a Proteorhodopsin-Containing Vibrio Strain under Carbon and Nitrogen Limitation. mSystems 2022; 7:e0126321. [PMID: 35384695 PMCID: PMC9040609 DOI: 10.1128/msystems.01263-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Photoheterotrophy is a widespread mode of microbial metabolism, notably in the oligotrophic surface ocean, where microbes experience chronic nutrient limitation. One especially widespread form of photoheterotrophy is based on proteorhodopsin (PR), which uses light to generate proton motive force that can drive ATP synthesis, flagellar movement, or nutrient uptake. To clarify the physiological benefits conferred by PR under nutrient stress conditions, we quantified protein-level gene expression of Vibrio campbellii CAIM 519 under both carbon and nitrogen limitation and under both light and dark conditions. Using a novel membrane proteomics strategy, we determined that PR expression is higher under C limitation than N limitation but is not light regulated. Despite expression of PR photosystems, V. campbellii does not exhibit any growth or survival advantages in the light and only a few proteins show significant expression differences between light and dark conditions. While protein-level proteorhodopsin expression in V. campbellii is clearly responsive to nutrient limitation, photoheterotrophy does not appear to play a central role in the survival physiology of this organism under these nutrient stress conditions. C limitation and N limitation, however, result in very different survival responses: under N-limited conditions, viability declines, cultivability is lost rapidly, central carbon flux through the Entner-Doudoroff pathway is increased, and ammonium is assimilated via the GS-GOGAT pathway. In contrast, C limitation drives cell dwarfing with maintenance of viability, as well as utilization of the glyoxylate shunt, glutamate dehydrogenase and anaplerotic C fixation, and a stringent response mediated by the Pho regulon. IMPORTANCE Understanding the nutrient stress responses of proteorhodopsin-bearing microbes like Vibrio campbellii yields insights into microbial contributions to nutrient cycling, lifestyles of emerging pathogens in aquatic environments, and protein-level adaptations implemented during times of nutrient limitation. In addition to its broad taxonomic and geographic prevalence, the physiological role of PR is diverse, so we developed a novel proteomics strategy to quantify its expression at the protein level. We found that proteorhodopsin expression levels in this wild-type photoheterotroph under these experimental conditions, while higher under C than under N limitation, do not afford measurable light-driven growth or survival advantages. Additionally, this work links differential protein expression patterns between C- and N-limited cultures to divergent stationary-phase survival phenotypes.
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8
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Nitric oxide stimulates type IV MSHA pilus retraction in Vibrio cholerae via activation of the phosphodiesterase CdpA. Proc Natl Acad Sci U S A 2022; 119:2108349119. [PMID: 35135874 PMCID: PMC8851539 DOI: 10.1073/pnas.2108349119] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/21/2021] [Indexed: 01/30/2023] Open
Abstract
All organisms sense and respond to their environments. One way bacteria interact with their surroundings is by dynamically extending and retracting filamentous appendages from their surface called pili. While pili are critical for many functions, such as attachment, motility, and DNA uptake, the factors that regulate their dynamic activity are poorly understood. Here, we describe how an environmental signal induces a signaling pathway to promote the retraction of mannose-sensitive hemagglutinin pili in Vibrio cholerae. The retraction of these pili promotes the detachment of V. cholerae from a surface and may provide a means by which V. cholerae can respond to changes in its environment. Bacteria use surface appendages called type IV pili to perform diverse activities including DNA uptake, twitching motility, and attachment to surfaces. The dynamic extension and retraction of pili are often required for these activities, but the stimuli that regulate these dynamics remain poorly characterized. To address this question, we study the bacterial pathogen Vibrio cholerae, which uses mannose-sensitive hemagglutinin (MSHA) pili to attach to surfaces in aquatic environments as the first step in biofilm formation. Here, we use a combination of genetic and cell biological approaches to describe a regulatory pathway that allows V. cholerae to rapidly abort biofilm formation. Specifically, we show that V. cholerae cells retract MSHA pili and detach from a surface in a diffusion-limited, enclosed environment. This response is dependent on the phosphodiesterase CdpA, which decreases intracellular levels of cyclic-di-GMP to induce MSHA pilus retraction. CdpA contains a putative nitric oxide (NO)–sensing NosP domain, and we demonstrate that NO is necessary and sufficient to stimulate CdpA-dependent detachment. Thus, we hypothesize that the endogenous production of NO (or an NO-like molecule) in V. cholerae stimulates the retraction of MSHA pili. These results extend our understanding of how environmental cues can be integrated into the complex regulatory pathways that control pilus dynamic activity and attachment in bacterial species.
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9
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Wang J, Childers WS. The Future Potential of Biosensors to Investigate the Gut-Brain Axis. Front Bioeng Biotechnol 2022; 9:826479. [PMID: 35096802 PMCID: PMC8795891 DOI: 10.3389/fbioe.2021.826479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 12/28/2021] [Indexed: 11/13/2022] Open
Abstract
The multifaceted and heterogeneous nature of depression presents challenges in pinpointing treatments. Among these contributions are the interconnections between the gut microbiome and neurological function termed the gut-brain axis. A diverse range of microbiome-produced metabolites interact with host signaling and metabolic pathways through this gut-brain axis relationship. Therefore, biosensor detection of gut metabolites offers the potential to quantify the microbiome's contributions to depression. Herein we review synthetic biology strategies to detect signals that indicate gut-brain axis dysregulation that may contribute to depression. We also highlight future challenges in developing living diagnostics of microbiome conditions influencing depression.
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Affiliation(s)
| | - W. Seth Childers
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, United States
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10
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Zhou Y, Pu Q, Chen J, Hao G, Gao R, Ali A, Hsiao A, Stock AM, Goulian M, Zhu J. Thiol-based functional mimicry of phosphorylation of the two-component system response regulator ArcA promotes pathogenesis in enteric pathogens. Cell Rep 2021; 37:110147. [PMID: 34936880 PMCID: PMC8728512 DOI: 10.1016/j.celrep.2021.110147] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 10/06/2021] [Accepted: 11/24/2021] [Indexed: 11/30/2022] Open
Abstract
Pathogenic bacteria can rapidly respond to stresses such as reactive oxygen species (ROS) using reversible redox-sensitive oxidation of cysteine thiol (-SH) groups in regulators. Here, we use proteomics to profile reversible ROS-induced thiol oxidation in Vibrio cholerae, the etiologic agent of cholera, and identify two modified cysteines in ArcA, a regulator of global carbon oxidation that is phosphorylated and activated under low oxygen. ROS abolishes ArcA phosphorylation but induces the formation of an intramolecular disulfide bond that promotes ArcA-ArcA interactions and sustains activity. ArcA cysteines are oxidized in cholera patient stools, and ArcA thiol oxidation drives in vitro ROS resistance, colonization of ROS-rich guts, and environmental survival. In other pathogens, such as Salmonella enterica, oxidation of conserved cysteines of ArcA orthologs also promotes ROS resistance, suggesting a common role for ROS-induced ArcA thiol oxidation in modulating ArcA activity, allowing for a balance of expression of stress- and pathogenesis-related genetic programs.
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Affiliation(s)
- Yitian Zhou
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Qinqin Pu
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jiandong Chen
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Guijuan Hao
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Rong Gao
- Center for Advanced Biotechnology and Medicine, Department of Biochemistry and Molecular Biology, Rutgers University-Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA
| | - Afsar Ali
- Department of Environmental and Global Health, College of Public Health and Health Professions and Emerging Pathogens Institute, University of Florida, Gainesville, FL 32610, USA
| | - Ansel Hsiao
- Department of Microbiology & Plant Pathology, University of California, Riverside, Riverside, CA 92521, USA
| | - Ann M Stock
- Center for Advanced Biotechnology and Medicine, Department of Biochemistry and Molecular Biology, Rutgers University-Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA
| | - Mark Goulian
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jun Zhu
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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11
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Wan X, Brynildsen MP. Robustness of nitric oxide detoxification to nitrogen starvation in Escherichia coli requires RelA. Free Radic Biol Med 2021; 176:286-297. [PMID: 34624482 DOI: 10.1016/j.freeradbiomed.2021.10.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 10/04/2021] [Indexed: 01/18/2023]
Abstract
Reactive nitrogen species and nutrient deprivation are two elements of the immune response used to eliminate pathogens within phagosomes. Concomitantly, pathogenic bacteria have evolved defense systems to cope with phagosomal stressors, which include enzymes that detoxify nitric oxide (•NO) and respond to nutrient scarcity. A deeper understanding of how those defense systems are deployed under adverse conditions that contain key elements of phagosomes will facilitate targeting of those systems for therapeutic purposes. Here we investigated how Escherichia coli detoxifies •NO in the absence of useable nitrogen, because nitrogen availability is limited in phagosomes due to the removal of nitrogenous compounds (e.g., amino acids). We hypothesized that nitrogen starvation would impair •NO detoxification by E. coli because it depresses translation rates and the main E. coli defense enzyme, Hmp, is synthesized in response to •NO. However, we found that E. coli detoxifies •NO at the same rate regardless of whether useable nitrogen was present. We confirmed that the nitrogen in •NO and its autoxidation products could not be used by E. coli under our experimental conditions, and discovered that •NO eliminated differences in carbon and oxygen consumption between nitrogen-replete and nitrogen-starved cultures. Interestingly, E. coli does not consume measurable extracellular nitrogen during •NO stress despite the need to translate defense enzymes. Further, we found that RelA, which responds to uncharged tRNA, was required to observe the robustness of •NO detoxification to nitrogen starvation. These data demonstrate that E. coli is well poised to detoxify •NO in the absence of useable nitrogen and suggest that the stringent response could be a useful target to potentiate the antibacterial activity of •NO.
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Affiliation(s)
- Xuanqing Wan
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ, 08544, USA
| | - Mark P Brynildsen
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ, 08544, USA.
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12
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Correa Velez KE, Norman RS. Transcriptomic Analysis Reveals That Municipal Wastewater Effluent Enhances Vibrio vulnificus Growth and Virulence Potential. Front Microbiol 2021; 12:754683. [PMID: 34759904 PMCID: PMC8573347 DOI: 10.3389/fmicb.2021.754683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 09/24/2021] [Indexed: 11/13/2022] Open
Abstract
Vibrio vulnificus is an opportunistic pathogen indigenous to estuarine and marine environments and associated with aquatic organisms. Vibrio vulnificus is of utmost importance because it causes 95% of the seafood-related deaths in the United States due to rapid progression of septicemia. Changes in environmental parameters associated with climate change and coastal population expansion are altering geographical constraints, resulting in increased Vibrio spread, exposure, and rates of infection. In addition, coastal population expansion is resulting in increased input of treated municipal sewage into areas that are also experiencing increased Vibrio proliferation. This study aimed to better understand the influence of treated sewage effluent on effluent-receiving microbial communities using Vibrio as a model of an opportunistic pathogen. Integrated transcriptomic approaches were used to analyze the changes in overall gene expression of V. vulnificus NBRC 15645 exposed to wastewater treatment plant (WWTP) effluent for a period of 6h using a modified seawater yeast extract media that contained 0, 50, and 100% filtered WWTP effluent. RNA-seq reads were mapped, annotated, and analyzed to identify differentially expressed genes using the Pathosystems Resource Integration Center analysis tool. The study revealed that V. vulnificus responds to wastewater effluent exposure by activating cyclic-di-GMP-influenced biofilm development. Also, genes involved in crucial functions, such as nitrogen metabolism and bacterial attachment, were upregulated depending on the presence of treated municipal sewage. This altered gene expression increased V. vulnificus growth and proliferation and enhanced genes and pathways involved in bacterial survival during the early stages of infection in a host. These factors represent a potential public health risk due to exposure to environmental reservoirs of potentially Vibrio strains with enhanced virulence profiles in coastal areas.
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Affiliation(s)
- Karlen Enid Correa Velez
- Department of Environmental Health Sciences, University of South Carolina, Columbia, SC, United States
- Department of Environmental Health Sciences, NIEHS Center for Oceans and Human Health and Climate Change Interactions, University of South Carolina, Columbia, SC, United States
| | - Robert Sean Norman
- Department of Environmental Health Sciences, University of South Carolina, Columbia, SC, United States
- Department of Environmental Health Sciences, NIEHS Center for Oceans and Human Health and Climate Change Interactions, University of South Carolina, Columbia, SC, United States
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13
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Shi M, Zheng Y, Wang X, Wang Z, Yang M. Two regulatory factors of Vibrio cholerae activating the mannose-sensitive haemagglutinin pilus expression is important for biofilm formation and colonization in mice. MICROBIOLOGY-SGM 2021; 167. [PMID: 34665117 DOI: 10.1099/mic.0.001098] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Vibrio cholerae the causative agent of cholera, uses a large number of coordinated transcriptional regulatory events to transition from its environmental reservoir to the host intestine, which is its preferred colonization site. Transcription of the mannose-sensitive haemagglutinin pilus (MSHA), which aids the persistence of V. cholerae in aquatic environments, but causes its clearance by host immune defenses, was found to be regulated by a yet unknown mechanism during the infection cycle of V. cholerae. In this study, genomic expression library screening revealed that two regulators, VC1371 and VcRfaH, are able to positively activate the transcription of MSHA operon. VC1371 is localized and active in the cell membrane. Deletion of vc1371 or VcrfaH genes in V. cholerae resulted in less MshA protein production and less efficiency of biofilm formation compared to that in the wild-type strain. An adult mouse model showed that the mutants with vc1371 or VcrfaH deletion colonized less efficiently than the wild-type; the VcrfaH deletion mutant showed less colonization efficiency in the infant mouse model. The findings strongly suggested that the two regulators, namely VC1371 and VcRfaH, which are involved in the regulation of MSHA expression, play an important role in V. cholerae biofilm formation and colonization in mice.
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Affiliation(s)
- Mengting Shi
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Lin'an District, 311300, Hangzhou, Zhejiang, PR China.,College of Animal Science and Technology, College of Veterinary Medicine, Zhejiang A&F University, Lin'an District, 311300, Hangzhou, Zhejiang, PR China
| | - Yue Zheng
- College of Animal Science and Technology, College of Veterinary Medicine, Zhejiang A&F University, Lin'an District, 311300, Hangzhou, Zhejiang, PR China
| | - Xianghong Wang
- College of Life Science, Nanjing Agricultural University, Nanjing 210095, Jiangsu Province, PR China
| | - Zhengjia Wang
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Lin'an District, 311300, Hangzhou, Zhejiang, PR China
| | - Menghua Yang
- College of Animal Science and Technology, College of Veterinary Medicine, Zhejiang A&F University, Lin'an District, 311300, Hangzhou, Zhejiang, PR China
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14
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Bath PM, Coleman CM, Gordon AL, Lim WS, Webb AJ. Nitric oxide for the prevention and treatment of viral, bacterial, protozoal and fungal infections. F1000Res 2021; 10:536. [PMID: 35685687 PMCID: PMC9171293 DOI: 10.12688/f1000research.51270.2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/15/2021] [Indexed: 12/15/2022] Open
Abstract
Although the antimicrobial potential of nitric oxide (NO) is widely published, it is little used clinically. NO is a key signalling molecule modulating vascular, neuronal, inflammatory and immune responses. Endogenous antimicrobial activity is largely mediated by high local NO concentrations produced by cellular inducible nitric oxide synthase, and by derivative reactive nitrogen oxide species including peroxynitrite and S-nitrosothiols. NO may be taken as dietary substrate (inorganic nitrate, L-arginine), and therapeutically as gaseous NO, and transdermal, sublingual, oral, intranasal and intravenous nitrite or nitrate. Numerous preclinical studies have demonstrated that NO has generic static and cidal activities against viruses (including β-coronaviruses such as SARS-CoV-2), bacteria, protozoa and fungi/yeasts in vitro. Therapeutic effects have been seen in animal models in vivo, and phase II trials have demonstrated that NO donors can reduce microbial infection. Nevertheless, excess NO, as occurs in septic shock, is associated with increased morbidity and mortality. In view of the dose-dependent positive and negative effects of NO, safety and efficacy trials of NO and its donors are needed for assessing their role in the prevention and treatment of infections. Trials should test dietary inorganic nitrate for pre- or post-exposure prophylaxis and gaseous NO or oral, topical or intravenous nitrite and nitrate for treatment of mild-to-severe infections, including due to SARS-CoV-2 (COVID-19). This review summarises the evidence base from in vitro, in vivo and early phase clinical studies of NO activity in viral, bacterial, protozoal and fungal infections.
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Affiliation(s)
- Philip M Bath
- Stroke Trials Unit, Division of Clinical Neuroscience, University of Nottingham, Nottingham, Notts, NG7 2UH, UK
- Stroke, Nottingham University Hospitals NHS Trust, Nottingham, Notts, NG7 2UH, UK
| | - Christopher M Coleman
- Division of Infection, Immunity and Microbes, School of Life Sciences, University of Nottingham, Nottingham, Notts, NG7 2UH, UK
| | - Adam L Gordon
- Unit of Injury, Inflammation and Recovery Sciences, University of Nottingham, Derby, Derbyshire, DE22 3NE, UK
- NIHR Applied Research Collaboration-East Midlands (ARC-EM), Nottingham, Notts, UK
| | - Wei Shen Lim
- Respiratory Medicine, Nottingham University Hospitals NHS Trust, Nottingham, NG5 1PB, UK
| | - Andrew J Webb
- Clinical Pharmacology, School of Cardiovascular Medicine & Sciences, Kings College London British Heart Foundation Centre of Research Excellence, St Thomas' Hospital, London, SE1 7EH, UK
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15
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Bath PM, Coleman CM, Gordon AL, Lim WS, Webb AJ. Nitric oxide for the prevention and treatment of viral, bacterial, protozoal and fungal infections. F1000Res 2021; 10:536. [PMID: 35685687 PMCID: PMC9171293 DOI: 10.12688/f1000research.51270.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/21/2021] [Indexed: 12/18/2023] Open
Abstract
Although the antimicrobial potential of nitric oxide (NO) is widely published, it is little used clinically. NO is a key signalling molecule modulating vascular, neuronal, inflammatory and immune responses. Endogenous antimicrobial activity is largely mediated by high local NO concentrations produced by cellular inducible nitric oxide synthase, and by derivative reactive nitrogen oxide species including peroxynitrite and S-nitrosothiols. NO may be taken as dietary substrate (inorganic nitrate, L-arginine), and therapeutically as gaseous NO, and transdermal, sublingual, oral, intranasal and intravenous nitrite or nitrate. Numerous preclinical studies have demonstrated that NO has generic static and cidal activities against viruses (including β-coronaviruses such as SARS-CoV-2), bacteria, protozoa and fungi/yeasts in vitro. Therapeutic effects have been seen in animal models in vivo, and phase II trials have demonstrated that NO donors can reduce microbial infection. Nevertheless, excess NO, as occurs in septic shock, is associated with increased morbidity and mortality. In view of the dose-dependent positive and negative effects of NO, safety and efficacy trials of NO and its donors are needed for assessing their role in the prevention and treatment of infections. Trials should test dietary inorganic nitrate for pre- or post-exposure prophylaxis and gaseous NO or oral, topical or intravenous nitrite and nitrate for treatment of mild-to-severe infections, including due to SARS-CoV-2 (COVID-19). This review summarises the evidence base from in vitro, in vivo and early phase clinical studies of NO activity in viral, bacterial, protozoal and fungal infections.
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Affiliation(s)
- Philip M. Bath
- Stroke Trials Unit, Division of Clinical Neuroscience, University of Nottingham, Nottingham, Notts, NG7 2UH, UK
- Stroke, Nottingham University Hospitals NHS Trust, Nottingham, Notts, NG7 2UH, UK
| | - Christopher M. Coleman
- Division of Infection, Immunity and Microbes, School of Life Sciences, University of Nottingham, Nottingham, Notts, NG7 2UH, UK
| | - Adam L. Gordon
- Unit of Injury, Inflammation and Recovery Sciences, University of Nottingham, Derby, Derbyshire, DE22 3NE, UK
- NIHR Applied Research Collaboration-East Midlands (ARC-EM), Nottingham, Notts, UK
| | - Wei Shen Lim
- Respiratory Medicine, Nottingham University Hospitals NHS Trust, Nottingham, NG5 1PB, UK
| | - Andrew J. Webb
- Clinical Pharmacology, School of Cardiovascular Medicine & Sciences, Kings College London British Heart Foundation Centre of Research Excellence, St Thomas' Hospital, London, SE1 7EH, UK
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16
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Choi G, Kim D, Im H, Choi SH. A Nitric Oxide-Responsive Transcriptional Regulator NsrR Cooperates With Lrp and CRP to Tightly Control the hmpA Gene in Vibrio vulnificus. Front Microbiol 2021; 12:681196. [PMID: 34093504 PMCID: PMC8175989 DOI: 10.3389/fmicb.2021.681196] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 04/23/2021] [Indexed: 12/12/2022] Open
Abstract
Nitric oxide (NO) is an important antimicrobial effector produced by the host innate immune system to counteract invading pathogens. To survive and establish a successful infection, a fulminating human pathogen Vibrio vulnificus expresses the hmpA gene encoding an NO dioxygenase in an NO-responsive manner. In this study, we identified an Rrf2-family transcriptional regulator NsrR that is predicted to contain the Fe-S cluster coordinated by three cysteine residues. Transcriptome analysis showed that NsrR controls the expression of multiple genes potentially involved in nitrosative stress responses. Particularly, NsrR acts as a strong repressor of hmpA transcription and relieves the repression of hmpA upon exposure to NO. Notably, nsrR and hmpA are transcribed divergently, and their promoter regions overlap with each other. Molecular biological analyses revealed that NsrR directly binds to this overlapping promoter region, which is alleviated by loss of the Fe-S cluster, leading to the subsequent derepression of hmpA under nitrosative stress. We further found that a leucine-responsive regulatory protein (Lrp) negatively regulates hmpA in an NsrR-dependent manner by directly binding to the promoter region, presumably resulting in a DNA conformation change to support the repression by NsrR. Meanwhile, a cyclic AMP receptor protein (CRP) positively regulates hmpA probably through repression of nsrR and lrp by directly binding to each promoter region in a sequential cascade. Altogether, this collaborative regulation of NsrR along with Lrp and CRP enables an elaborate control of hmpA transcription, contributing to survival under host-derived nitrosative stress and thereby the pathogenesis of V. vulnificus.
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Affiliation(s)
- Garam Choi
- National Research Laboratory of Molecular Microbiology and Toxicology, Department of Agricultural Biotechnology, Seoul National University, Seoul, South Korea
- Center for Food and Bioconvergence, Seoul National University, Seoul, South Korea
| | - Dukyun Kim
- National Research Laboratory of Molecular Microbiology and Toxicology, Department of Agricultural Biotechnology, Seoul National University, Seoul, South Korea
| | - Hanhyeok Im
- National Research Laboratory of Molecular Microbiology and Toxicology, Department of Agricultural Biotechnology, Seoul National University, Seoul, South Korea
- Center for Food and Bioconvergence, 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
- Center for Food and Bioconvergence, Seoul National University, Seoul, South Korea
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17
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Phenn J, Pané-Farré J, Meukow N, Klein A, Troitzsch A, Tan P, Fuchs S, Wagner GE, Lichtenegger S, Steinmetz I, Kohler C. RegAB Homolog of Burkholderia pseudomallei is the Master Regulator of Redox Control and involved in Virulence. PLoS Pathog 2021; 17:e1009604. [PMID: 34048488 PMCID: PMC8191878 DOI: 10.1371/journal.ppat.1009604] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 06/10/2021] [Accepted: 05/03/2021] [Indexed: 12/23/2022] Open
Abstract
Burkholderia pseudomallei, the etiological agent of melioidosis in humans and animals, often occupies environmental niches and infection sites characterized by limited concentrations of oxygen. Versatile genomic features enable this pathogen to maintain its physiology and virulence under hypoxia, but the crucial regulatory networks employed to switch from oxygen dependent respiration to alternative terminal electron acceptors (TEA) like nitrate, remains poorly understood. Here, we combined a Tn5 transposon mutagenesis screen and an anaerobic growth screen to identify a two-component signal transduction system with homology to RegAB. We show that RegAB is not only essential for anaerobic growth, but also for full virulence in cell lines and a mouse infection model. Further investigations of the RegAB regulon, using a global transcriptomic approach, identified 20 additional regulators under transcriptional control of RegAB, indicating a superordinate role of RegAB in the B. pseudomallei anaerobiosis regulatory network. Of the 20 identified regulators, NarX/L and a FNR homolog were selected for further analyses and a role in adaptation to anaerobic conditions was demonstrated. Growth experiments identified nitrate and intermediates of the denitrification process as the likely signal activateing RegAB, NarX/L, and probably of the downstream regulators Dnr or NsrR homologs. While deletions of individual genes involved in the denitrification process demonstrated their important role in anaerobic fitness, they showed no effect on virulence. This further highlights the central role of RegAB as the master regulator of anaerobic metabolism in B. pseudomallei and that the complete RegAB-mediated response is required to achieve full virulence. In summary, our analysis of the RegAB-dependent modulon and its interconnected regulons revealed a key role for RegAB of B. pseudomallei in the coordination of the response to hypoxic conditions and virulence, in the environment and the host.
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Affiliation(s)
- Julia Phenn
- Friedrich Loeffler Institute of Medical Microbiology, University Medicine Greifswald, Greifswald, Germany
| | - Jan Pané-Farré
- SYNMIKRO Research Center and Department of Chemistry, Philipps-University Marburg, Marburg, Germany
| | - Nikolai Meukow
- Friedrich Loeffler Institute of Medical Microbiology, University Medicine Greifswald, Greifswald, Germany
| | - Annelie Klein
- Friedrich Loeffler Institute of Medical Microbiology, University Medicine Greifswald, Greifswald, Germany
| | - Anne Troitzsch
- Department for Microbial Physiology and Molecular Biology, University Greifswald, Greifswald, Germany
| | - Patrick Tan
- Genome Institute of Singapore, Singapore, Republic of Singapore
- Duke-NUS Medical School Singapore, Singapore, Republic of Singapore
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, Republic of Singapore
| | - Stephan Fuchs
- FG13 Nosocomial Pathogens and Antibiotic Resistances, Robert Koch Institute, Wernigerode, Germany
| | - Gabriel E Wagner
- Institute of Hygiene, Microbiology and Environmental Medicine, Medical University Graz, Graz, Austria
| | - Sabine Lichtenegger
- Institute of Hygiene, Microbiology and Environmental Medicine, Medical University Graz, Graz, Austria
| | - Ivo Steinmetz
- Friedrich Loeffler Institute of Medical Microbiology, University Medicine Greifswald, Greifswald, Germany
- Institute of Hygiene, Microbiology and Environmental Medicine, Medical University Graz, Graz, Austria
| | - Christian Kohler
- Friedrich Loeffler Institute of Medical Microbiology, University Medicine Greifswald, Greifswald, Germany
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18
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Buijs Y, Isbrandt T, Zhang SD, Larsen TO, Gram L. The Antibiotic Andrimid Produced by Vibrio coralliilyticus Increases Expression of Biosynthetic Gene Clusters and Antibiotic Production in Photobacterium galatheae. Front Microbiol 2020; 11:622055. [PMID: 33424823 PMCID: PMC7793655 DOI: 10.3389/fmicb.2020.622055] [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: 10/27/2020] [Accepted: 11/30/2020] [Indexed: 01/12/2023] Open
Abstract
The development and spread of multidrug resistant pathogens have reinforced the urgency to find novel natural products with antibiotic activity. In bacteria, orphan biosynthetic gene clusters (BGCs) far outnumber the BGCs for which chemistry is known, possibly because they are transcriptionally silent under laboratory conditions. A strategy to trigger the production of this biosynthetic potential is to challenge the microorganism with low concentrations of antibiotics, and by using a Burkholderia genetic reporter strain (Seyedsayamdost, Proc Natl Acad Sci 111:7266-7271), we found BGC unsilencing activity for the antimicrobial andrimid, produced by the marine bacterium Vibrio coralliilyticus. Next, we challenged another marine Vibrionaceae, Photobacterium galatheae, carrier of seven orphan BGCs with sub-inhibitory concentrations of andrimid. A combined approach of transcriptional and chemical measurements of andrimid-treated P. galatheae cultures revealed a 10-fold upregulation of an orphan BGC and, amongst others, a 1.6-2.2-fold upregulation of the gene encoding the core enzyme for biosynthesis of holomycin. Also, addition of andrimid caused an increase, based on UV-Vis peak area, of 4-fold in production of the antibiotic holomycin. Transcriptional measurements of stress response related genes in P. galatheae showed a co-occurrence of increased transcript levels of rpoS (general stress response) and andrimid induced holomycin overproduction, while in trimethoprim treated cultures attenuation of holomycin production coincided with a transcriptional increase of recA (SOS stress response). This study shows that using antimicrobial compounds as activators of secondary metabolism can be a useful strategy in eliciting biosynthetic gene clusters and facilitate natural product discovery. Potentially, such interactions could also have ecological relevant implications.
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Affiliation(s)
| | | | | | | | - Lone Gram
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Lyngby, Denmark
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19
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Hsiao A, Zhu J. Pathogenicity and virulence regulation of Vibrio cholerae at the interface of host-gut microbiome interactions. Virulence 2020; 11:1582-1599. [PMID: 33172314 PMCID: PMC7671094 DOI: 10.1080/21505594.2020.1845039] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 10/27/2020] [Accepted: 10/28/2020] [Indexed: 12/12/2022] Open
Abstract
The Gram-negative bacterium Vibrio cholerae is responsible for the severe diarrheal pandemic disease cholera, representing a major global public health concern. This pathogen transitions from aquatic reservoirs into epidemics in human populations, and has evolved numerous mechanisms to sense this transition in order to appropriately regulate its gene expression for infection. At the intersection of pathogen and host in the gastrointestinal tract lies the community of native gut microbes, the gut microbiome. It is increasingly clear that the diversity of species and biochemical activities within the gut microbiome represents a driver of infection outcome, through their ability to manipulate the signals used by V. cholerae to regulate virulence and fitness in vivo. A better mechanistic understanding of how commensal microbial action interacts with V. cholerae pathogenesis may lead to novel prophylactic and therapeutic interventions for cholera. Here, we review a subset of this burgeoning field of research.
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Affiliation(s)
- Ansel Hsiao
- Department of Microbiology & Plant Pathology, University of California Riverside, Riverside, CA, USA
| | - Jun Zhu
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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20
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Byun H, Jung IJ, Chen J, Larios Valencia J, Zhu J. Siderophore piracy enhances Vibrio cholerae environmental survival and pathogenesis. MICROBIOLOGY-SGM 2020; 166:1038-1046. [PMID: 33074088 DOI: 10.1099/mic.0.000975] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Vibrio cholerae, the aetiological agent of cholera, possesses multiple iron acquisition systems, including those for the transport of siderophores. How these systems benefit V. cholerae in low-iron, polymicrobial communities in environmental settings or during infection remains poorly understood. Here, we demonstrate that in iron-limiting conditions, co-culture of V. cholerae with a number of individual siderophore-producing microbes significantly promoted V. cholerae growth in vitro. We further show that in the host environment with low iron, V. cholerae colonizes better in adult mice in the presence of the siderophore-producing commensal Escherichia coli. Taken together, our results suggest that in aquatic reservoirs or during infection, V. cholerae may overcome environmental and host iron restriction by hijacking siderophores from other microbes.
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Affiliation(s)
- Hyuntae Byun
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - I-Ji Jung
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jiandong Chen
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jessie Larios Valencia
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jay Zhu
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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21
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Ramamurthy T, Nandy RK, Mukhopadhyay AK, Dutta S, Mutreja A, Okamoto K, Miyoshi SI, Nair GB, Ghosh A. Virulence Regulation and Innate Host Response in the Pathogenicity of Vibrio cholerae. Front Cell Infect Microbiol 2020; 10:572096. [PMID: 33102256 PMCID: PMC7554612 DOI: 10.3389/fcimb.2020.572096] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 08/19/2020] [Indexed: 02/06/2023] Open
Abstract
The human pathogen Vibrio cholerae is the causative agent of severe diarrheal disease known as cholera. Of the more than 200 "O" serogroups of this pathogen, O1 and O139 cause cholera outbreaks and epidemics. The rest of the serogroups, collectively known as non-O1/non-O139 cause sporadic moderate or mild diarrhea and also systemic infections. Pathogenic V. cholerae circulates between nutrient-rich human gut and nutrient-deprived aquatic environment. As an autochthonous bacterium in the environment and as a human pathogen, V. cholerae maintains its survival and proliferation in these two niches. Growth in the gastrointestinal tract involves expression of several genes that provide bacterial resistance against host factors. An intricate regulatory program involving extracellular signaling inputs is also controlling this function. On the other hand, the ability to store carbon as glycogen facilitates bacterial fitness in the aquatic environment. To initiate the infection, V. cholerae must colonize the small intestine after successfully passing through the acid barrier in the stomach and survive in the presence of bile and antimicrobial peptides in the intestinal lumen and mucus, respectively. In V. cholerae, virulence is a multilocus phenomenon with a large functionally associated network. More than 200 proteins have been identified that are functionally linked to the virulence-associated genes of the pathogen. Several of these genes have a role to play in virulence and/or in functions that have importance in the human host or the environment. A total of 524 genes are differentially expressed in classical and El Tor strains, the two biotypes of V. cholerae serogroup O1. Within the host, many immune and biological factors are able to induce genes that are responsible for survival, colonization, and virulence. The innate host immune response to V. cholerae infection includes activation of several immune protein complexes, receptor-mediated signaling pathways, and other bactericidal proteins. This article presents an overview of regulation of important virulence factors in V. cholerae and host response in the context of pathogenesis.
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Affiliation(s)
| | - Ranjan K Nandy
- Division of Bacteriology, National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Asish K Mukhopadhyay
- Division of Bacteriology, National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Shanta Dutta
- Division of Bacteriology, National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Ankur Mutreja
- Global Health-Infectious Diseases, Department of Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Keinosuke Okamoto
- Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan.,Collaborative Research Center of Okayama University for Infectious Diseases in India, National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Shin-Ichi Miyoshi
- Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - G Balakrish Nair
- Microbiome Laboratory, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, India
| | - Amit Ghosh
- Division of Bacteriology, National Institute of Cholera and Enteric Diseases, Kolkata, India
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22
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Baranova DE, Willsey GG, Levinson KJ, Smith C, Wade J, Mantis NJ. Transcriptional profiling of Vibrio cholerae O1 following exposure to human anti- lipopolysaccharide monoclonal antibodies. Pathog Dis 2020; 78:ftaa029. [PMID: 32589220 PMCID: PMC7371154 DOI: 10.1093/femspd/ftaa029] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Accepted: 06/22/2020] [Indexed: 02/04/2023] Open
Abstract
Following an episode of cholera, a rapidly dehydrating, watery diarrhea caused by the Gram-negative bacterium, Vibrio cholerae O1, humans mount a robust anti-lipopolysaccharide (LPS) antibody response that is associated with immunity to subsequent re-infection. In neonatal mouse and rabbit models of cholera, passively administered anti-LPS polyclonal and monoclonal (MAb) antibodies reduce V. cholerae colonization of the intestinal epithelia by inhibiting bacterial motility and promoting vibrio agglutination. Here we demonstrate that human anti-LPS IgG MAbs also arrest V. cholerae motility and induce bacterial paralysis. A subset of those MAbs also triggered V. cholerae to secrete an extracellular matrix (ECM). To identify changes in gene expression that accompany antibody exposure and that may account for motility arrest and ECM production, we subjected V. cholerae O1 El Tor to RNA-seq analysis after treatment with ZAC-3 IgG, a high affinity MAb directed against the core/lipid A region of LPS. We identified > 160 genes whose expression was altered following ZAC-3 IgG treatment, although canonical outer membrane stress regulons were not among them. ompS (VCA1028), a porin associated with virulence and indirectly regulated by ToxT, and norR (VCA0182), a σ54-dependent transcription factor involved in late stages of infection, were two upregulated genes worth noting.
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Affiliation(s)
- Danielle E Baranova
- Department of Biomedical Sciences, University at Albany, 1400 Washington Ave, Albany NY 12222
- Division of Infectious Diseases, Wadsworth Center, NYS Department of Health, 120 New Scotland Ave, Albany NY 12208
| | - Graham G Willsey
- Division of Infectious Diseases, Wadsworth Center, NYS Department of Health, 120 New Scotland Ave, Albany NY 12208
| | - Kara J Levinson
- Department of Biomedical Sciences, University at Albany, 1400 Washington Ave, Albany NY 12222
- Division of Infectious Diseases, Wadsworth Center, NYS Department of Health, 120 New Scotland Ave, Albany NY 12208
| | - Carol Smith
- Division of Molecular Genetics, Wadsworth Center, NYS Department of Health, 120 New Scotland Ave, Albany NY 12208
| | - Joseph Wade
- Department of Biomedical Sciences, University at Albany, 1400 Washington Ave, Albany NY 12222
- Division of Molecular Genetics, Wadsworth Center, NYS Department of Health, 120 New Scotland Ave, Albany NY 12208
| | - Nicholas J Mantis
- Department of Biomedical Sciences, University at Albany, 1400 Washington Ave, Albany NY 12222
- Division of Infectious Diseases, Wadsworth Center, NYS Department of Health, 120 New Scotland Ave, Albany NY 12208
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23
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Espinoza-Vergara G, Hoque MM, McDougald D, Noorian P. The Impact of Protozoan Predation on the Pathogenicity of Vibrio cholerae. Front Microbiol 2020; 11:17. [PMID: 32038597 PMCID: PMC6985070 DOI: 10.3389/fmicb.2020.00017] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Accepted: 01/07/2020] [Indexed: 12/16/2022] Open
Abstract
In the aquatic environment, Vibrio spp. interact with many living organisms that can serve as a replication niche, including heterotrophic protists, or protozoa. Protozoa engulf bacteria and package them into phagosomes where the cells are exposed to low pH, antimicrobial peptides, reactive oxygen/nitrogen species, proteolytic enzymes, and low concentrations of essential metal ions such as iron. However, some bacteria can resist these digestive processes. For example, Vibrio cholerae and Vibrio harveyi can resist intracellular digestion. In order to survive intracellularly, bacteria have acquired and/or developed specific factors that help them to resist the unfavorable conditions encountered inside of the phagosomes. Many of these intra-phagosomal factors used to kill and digest bacteria are highly conserved between eukaryotic cells and thus are also expressed by the innate immune system in the gastrointestinal tract as the first line of defense against bacterial pathogens. Since pathogenic bacteria have been shown to be hypervirulent after they have passed through protozoa, the resistance to digestion by protist hosts in their natural environment plays a key role in enhancing the infectious potential of pathogenic Vibrio spp. This review will investigate the current knowledge in interactions of bacteria with protozoa and human host to better understand the mechanisms used by both protozoa and human hosts to kill bacteria and the bacterial response to them.
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Affiliation(s)
- Gustavo Espinoza-Vergara
- Faculty of Science, The ithree Institute, University of Technology Sydney, Sydney, NSW, Australia
| | - M Mozammel Hoque
- Faculty of Science, The ithree Institute, University of Technology Sydney, Sydney, NSW, Australia
| | - Diane McDougald
- Faculty of Science, The ithree Institute, University of Technology Sydney, Sydney, NSW, Australia.,Faculty of Science, Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | - Parisa Noorian
- Faculty of Science, The ithree Institute, University of Technology Sydney, Sydney, NSW, Australia
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Abstract
Nitric oxide (NO) is a radical that is used as an attack molecule by immune cells. NO can interact and damage a range of biomolecules, and the biological outcome for bacteria assaulted with NO will be governed by how the radical distributes within their biochemical reaction networks. Measurement of those NO fluxes is complicated by the low abundance and transience of many of its reaction products. To overcome this challenge, we use computational modeling to translate measurements of several biochemical species (e.g., NO, O2, NO2-) into NO flux distributions. In this chapter, we provide a detailed protocol, which includes experimental measurements and computational modeling, to estimate the NO flux distribution in an Escherichia coli culture. Those fluxes will have uncertainty associated with them and we also discuss how further experiments and modeling can be employed for flux refinement.
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Affiliation(s)
| | - Xuanqing Wan
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ, USA
| | - Mark P Brynildsen
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ, USA.
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25
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Kim D, Na EJ, Kim S, Kim JS, Jung YH, Cao J, Han HJ, Bang IS, Yoo JW, Ha NC, Choi SH. Transcriptomic Identification and Biochemical Characterization of HmpA, a Nitric Oxide Dioxygenase, Essential for Pathogenesis of Vibrio vulnificus. Front Microbiol 2019; 10:2208. [PMID: 31616401 PMCID: PMC6768983 DOI: 10.3389/fmicb.2019.02208] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Accepted: 09/09/2019] [Indexed: 12/29/2022] Open
Abstract
Nitric oxide (NO) and its derivatives are important effectors of host innate immunity, disrupting cellular function of infecting pathogens. Transcriptome analysis of Vibrio vulnificus, an opportunistic human pathogen, identified a set of genes induced upon exposure to NO. Among them, VvhmpA (V. vulnificus hmpA), encoding a multidomain NO dioxygenase, was the most greatly induced upon exposure to NO and was thus further characterized. Absorption spectra demonstrated that VvHmpA is a heme protein in which the heme iron can exist in either reduced, NO-bound, or oxidized state. Biochemical studies revealed that VvHmpA is a flavohemoglobin containing equimolar amounts of heme and FAD as cofactors. The KM and kcat values of VvHmpA for NO at 37°C, the temperature encountered by V. vulnificus in the host, were greater than those at 30°C, indicating that VvHmpA detoxifies high levels of NO effectively during infection. Compared with the wild type, the VvhmpA mutant exhibited a lower NO-decomposition activity and impaired growth in the presence of NO in vitro. Also, the cytotoxicity and survival of the VvhmpA mutant infecting the NO-producing murine macrophage cells were lower than those of the wild type. Furthermore, the mouse lethality of the VvhmpA mutant was reduced compared to that of the parental wild type. The combined results revealed that VvHmpA is a potent virulence factor that is induced upon exposure to NO and important for the survival and pathogenesis of V. vulnificus during infection.
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Affiliation(s)
- Dukyun Kim
- National Research Laboratory of Molecular Microbiology and Toxicology, Seoul National University, Seoul, South Korea.,Department of Agricultural Biotechnology, and Center for Food Safety and Toxicology, Seoul National University, Seoul, South Korea
| | - Eun Jung Na
- National Research Laboratory of Molecular Microbiology and Toxicology, Seoul National University, Seoul, South Korea.,Department of Agricultural Biotechnology, and Center for Food Safety and Toxicology, Seoul National University, Seoul, South Korea
| | - Suhyeon Kim
- Department of Agricultural Biotechnology, and Center for Food Safety and Toxicology, Seoul National University, Seoul, South Korea
| | - Jung Sung Kim
- Department of Microbiology and Immunology, Chosun University School of Dentistry, Gwangju, South Korea
| | - Young Hyun Jung
- Department of Veterinary Physiology, College of Veterinary Medicine, Research Institute for Veterinary Medicine, BK21 PLUS Creative Veterinary Research Center, Seoul National University, Seoul, South Korea
| | - Jiafu Cao
- College of Pharmacy, Pusan National University, Busan, South Korea
| | - Ho Jae Han
- Department of Veterinary Physiology, College of Veterinary Medicine, Research Institute for Veterinary Medicine, BK21 PLUS Creative Veterinary Research Center, Seoul National University, Seoul, South Korea
| | - Iel Soo Bang
- Department of Microbiology and Immunology, Chosun University School of Dentistry, Gwangju, South Korea
| | - Jin-Wook Yoo
- College of Pharmacy, Pusan National University, Busan, South Korea
| | - Nam-Chul Ha
- Department of Agricultural Biotechnology, and Center for Food Safety and Toxicology, Seoul National University, Seoul, South Korea
| | - Sang Ho Choi
- National Research Laboratory of Molecular Microbiology and Toxicology, Seoul National University, Seoul, South Korea.,Department of Agricultural Biotechnology, and Center for Food Safety and Toxicology, Seoul National University, Seoul, South Korea
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26
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Berger A, Boscari A, Frendo P, Brouquisse R. Nitric oxide signaling, metabolism and toxicity in nitrogen-fixing symbiosis. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:4505-4520. [PMID: 30968126 DOI: 10.1093/jxb/erz159] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Accepted: 03/28/2019] [Indexed: 05/13/2023]
Abstract
Interactions between legumes and rhizobia lead to the establishment of a symbiotic relationship characterized by the formation of a new organ, the nodule, which facilitates the fixation of atmospheric nitrogen (N2) by nitrogenase through the creation of a hypoxic environment. Significant amounts of nitric oxide (NO) accumulate at different stages of nodule development, suggesting that NO performs specific signaling and/or metabolic functions during symbiosis. NO, which regulates nodule gene expression, accumulates to high levels in hypoxic nodules. NO accumulation is considered to assist energy metabolism within the hypoxic environment of the nodule via a phytoglobin-NO-mediated respiration process. NO is a potent inhibitor of the activity of nitrogenase and other plant and bacterial enzymes, acting as a developmental signal in the induction of nodule senescence. Hence, key questions concern the relative importance of the signaling and metabolic functions of NO versus its toxic action and how NO levels are regulated to be compatible with nitrogen fixation functions. This review analyses these paradoxical roles of NO at various stages of symbiosis, and highlights the role of plant phytoglobins and bacterial hemoproteins in the control of NO accumulation.
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Patra SK, Samaddar S, Sinha N, Ghosh S. Reactive nitrogen species induced catalases promote a novel nitrosative stress tolerance mechanism in Vibrio cholerae. Nitric Oxide 2019; 88:35-44. [PMID: 30981896 DOI: 10.1016/j.niox.2019.04.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 03/04/2019] [Accepted: 04/09/2019] [Indexed: 11/18/2022]
Abstract
Vibrio cholerae faces nitrosative stress during successful colonization in intestine. Very little information is available on the nitrosative stress protective mechanisms of V. cholerae. Reports show that NorR regulon control two genes hmpA and nnrS responsible for nitric oxide (NO) detoxification in V. cholerae. In the present study we first time report a novel role of V. cholerae catalases under nitrosative stress. Using zymogram analysis of catalase we showed that KatB and KatG activity were induced within 30 min in V. cholerae in the presence of sodium nitroprusside (SNP), a NO donor compound. Surprisingly, V. cholerae cell survival was found to be decreased under nitrosative stress if catalase activities were blocked by ATz, a catalase inhibitor. Flow cytometry study was conducted to detect reactive oxygen species (ROS) and reactive nitrogen species (RNS) using DHE and DHR123, fluorescent probes respectively. Short exposure of SNP to V. cholerae did not generate ROS but RNS was detectable within 30 min. Total glutathione content was increased in V. cholerae cells under nitrosative stress. Furthermore, Superoxide dismutase (SOD) and Glutathione reductase (GR) activities remained unchanged under nitrosative stress in V. cholerae indicated antioxidant role of NO which could produce peroxynitrite. To investigate the role of catalase induction under nitrosative stress in V. cholerae, we conducted peroxynitrite reductase assay using cell lysates. Interestingly, SNP treated V. cholerae cell lysates showed lowest DHR123 oxidation compared to the control set. The extent of DHR123 oxidation was more in V. cholerae cell lysate when catalases were blocked by ATz.
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Affiliation(s)
- Sourav Kumar Patra
- Department of Biochemistry, University of Calcutta, 35, Ballygunge Circular Road, Kolkata, 700019, West Bengal, India
| | - Sourabh Samaddar
- Bose Institute, P-1/12, CIT Road Scheme VIIM, Kolkata, 700 054, West Bengal, India
| | - Nilanjan Sinha
- Department of Biochemistry, University of Calcutta, 35, Ballygunge Circular Road, Kolkata, 700019, West Bengal, India
| | - Sanjay Ghosh
- Department of Biochemistry, University of Calcutta, 35, Ballygunge Circular Road, Kolkata, 700019, West Bengal, India.
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28
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Abstract
The genus Vibrio includes serious human pathogens, and mollusks are a significant reservoir for species such as V. vulnificus. Vibrio species encode PecS, a member of the multiple antibiotic resistance regulator (MarR) family of transcription factors; pecS is divergently oriented to pecM, which encodes an efflux pump. We report here that Vibrio species feature frequent duplications of pecS-pecM genes, suggesting evolutionary pressures to respond to distinct environmental situations. The single V. vulnificus PecS binds two sites within the pecS-pecM intergenic region with Kd = 0.3 ± 0.1 nM, a binding that is attenuated by the ligands xanthine and urate, except when promoter DNA is saturated with PecS. A unique target is found in the intergenic region between genes encoding the nitric oxide sensing transcription factor, NsrR, and nod; the nod-encoded nitric oxide dioxygenase is important for preventing nitric oxide stress. Reporter gene assays show that PecS-mediated repression of gene expression can be relieved in presence of ligand. Since xanthine and urate are produced as part of the oxidative burst during host defenses and under molluscan hypoxia, we propose that these intermediates in the host purine degradation pathway function to promote bacterial survival during hypoxia and oxidative stress.
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CitAB Two-Component System-Regulated Citrate Utilization Contributes to Vibrio cholerae Competitiveness with the Gut Microbiota. Infect Immun 2019; 87:IAI.00746-18. [PMID: 30559220 DOI: 10.1128/iai.00746-18] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2018] [Accepted: 12/09/2018] [Indexed: 01/05/2023] Open
Abstract
Citrate is a ubiquitous compound and can be utilized by many bacterial species, including enteric pathogens, as a carbon and energy source. Genes involved in citrate utilization have been extensively studied in some enteric bacteria, such as Klebsiella pneumoniae; however, their role in pathogenesis is still not clear. In this study, we investigated citrate utilization and regulation in Vibrio cholerae, the causative agent of cholera. The putative anaerobic citrate fermentation genes in V. cholerae, consisting of citCDEFXG, citS-oadGAB, and the two-component system (TCS) genes citAB, are highly homologous to those in K. pneumoniae Deletion analysis shows that these cit genes are essential for V. cholerae growth when citrate is the sole carbon source. The expression of citC and citS operons was dependent on citrate and CitAB, whose transcription was autorepressed and regulated by another TCS regulator, ArcA. In addition, citrate fermentation was under the control of catabolite repression. Mouse colonization experiments showed that V. cholerae can utilize citrate in vivo using the citrate fermentation pathway and that V. cholerae likely needs to compete with other members of the gut microbiota to access citrate in the gut.
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The SOS Response Mediates Sustained Colonization of the Mammalian Gut. Infect Immun 2019; 87:IAI.00711-18. [PMID: 30510108 DOI: 10.1128/iai.00711-18] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 11/26/2018] [Indexed: 12/12/2022] Open
Abstract
Bacteria have a remarkable ability to survive, persist, and ultimately adapt to environmental challenges. A ubiquitous environmental hazard is DNA damage, and most bacteria have evolved a network of genes to combat genotoxic stress. This network is known as the SOS response and aids in bacterial survival by regulating genes involved in DNA repair and damage tolerance. Recently, the SOS response has been shown to play an important role in bacterial pathogenesis, and yet the role of the SOS response in nonpathogenic organisms and in physiological settings remains underexplored. Using a commensal Escherichia coli strain, MP1, we showed that the SOS response plays a vital role during colonization of the murine gut. In an unperturbed environment, the SOS-off mutant is impaired for stable colonization relative to a wild-type strain, suggesting the presence of genotoxic stress in the mouse gut. We evaluated the possible origins of genotoxic stress in the mouse gut by examining factors associated with the host versus the competing commensal organisms. In a dextran sulfate sodium (DSS) colitis model, the SOS-off colonization defect persisted but was not exacerbated. In contrast, in a germ-free model, the SOS-off mutant colonized with efficiency equal to that seen with the wild-type strain, suggesting that competing commensal organisms might be a significant source of genotoxic stress. This report extends our understanding of the importance of a functional SOS response for bacterial fitness in the context of a complex physiological environment and highlights the SOS response as a possible mechanism that contributes to ongoing genomic changes, including potential antibiotic resistance, in the microbiome of healthy hosts.
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Wang H, Xing X, Wang J, Pang B, Liu M, Larios-Valencia J, Liu T, Liu G, Xie S, Hao G, Liu Z, Kan B, Zhu J. Hypermutation-induced in vivo oxidative stress resistance enhances Vibrio cholerae host adaptation. PLoS Pathog 2018; 14:e1007413. [PMID: 30376582 PMCID: PMC6226196 DOI: 10.1371/journal.ppat.1007413] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 11/09/2018] [Accepted: 10/18/2018] [Indexed: 01/08/2023] Open
Abstract
Bacterial pathogens are highly adaptable organisms, a quality that enables them to overcome changing hostile environments. For example, Vibrio cholerae, the causative agent of cholera, is able to colonize host small intestines and combat host-produced reactive oxygen species (ROS) during infection. To dissect the molecular mechanisms utilized by V. cholerae to overcome ROS in vivo, we performed a whole-genome transposon sequencing analysis (Tn-seq) by comparing gene requirements for colonization using adult mice with and without the treatment of the antioxidant, N-acetyl cysteine. We found that mutants of the methyl-directed mismatch repair (MMR) system, such as MutS, displayed significant colonization advantages in untreated, ROS-rich mice, but not in NAC-treated mice. Further analyses suggest that the accumulation of both catalase-overproducing mutants and rugose colony variants in NAC- mice was the leading cause of mutS mutant enrichment caused by oxidative stress during infection. We also found that rugose variants could revert back to smooth colonies upon aerobic, in vitro culture. Additionally, the mutation rate of wildtype colonized in NAC- mice was significantly higher than that in NAC+ mice. Taken together, these findings support a paradigm in which V. cholerae employs a temporal adaptive strategy to battle ROS during infection, resulting in enriched phenotypes. Moreover, ΔmutS passage and complementation can be used to model hypermuation in diverse pathogens to identify novel stress resistance mechanisms. Cholera is a devastating diarrheal disease that is still endemic to many developing nations, with the worst outbreak in history having occurred recently in Yemen. Vibrio cholerae, the causative agent of cholera, transitions from aquatic reservoirs to the human gastrointestinal tract, where it expresses virulence factors to facilitate colonization of the small intestines and to combat host innate immune effectors, such as reactive oxygen species (ROS). We applied a genome-wide transposon screen (Tn-seq) and identified that deletion of mutS, which is part of DNA mismatch repair system, drastically increased colonization in ROS-rich mice. The deletion of mutS led to the accumulation of catalase-overproducing mutants and a high frequency rugose phenotype when exposed to ROS selective pressures in vivo. Additionally, ROS elevated mutation frequency in wildtype, both in vitro and in vivo. Our data imply that V. cholerae may modulate mutation frequency as a temporal adaptive strategy to overcome oxidative stress and to enhance infectivity.
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Affiliation(s)
- Hui Wang
- Department of Microbiology, Nanjing Agricultural University, Nanjing, China
- * E-mail: (HW); (JH)
| | - Xiaolin Xing
- Department of Microbiology, Nanjing Agricultural University, Nanjing, China
| | - Jipeng Wang
- Department of Microbiology, Nanjing Agricultural University, Nanjing, China
| | - Bo Pang
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Ming Liu
- Department of Microbiology, Nanjing Agricultural University, Nanjing, China
| | - Jessie Larios-Valencia
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States of America
| | - Tao Liu
- Department of Microbiology, Nanjing Agricultural University, Nanjing, China
| | - Ge Liu
- Department of Microbiology, Nanjing Agricultural University, Nanjing, China
| | - Saijun Xie
- Department of Microbiology, Nanjing Agricultural University, Nanjing, China
| | - Guijuan Hao
- Department of Microbiology, Nanjing Agricultural University, Nanjing, China
| | - Zhi Liu
- Department of Biotechnology, Huazhong University of Science and Technology, Wuhan, China
| | - Biao Kan
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Jun Zhu
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States of America
- * E-mail: (HW); (JH)
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Abstract
The abundance of oxidants and reductants must be balanced for an organism to thrive. Bacteria have evolved methods to prevent redox imbalances and to mitigate their deleterious consequences through the expression of detoxification enzymes, antioxidants, and systems to repair or degrade damaged proteins and DNA. Regulating these processes in response to redox changes requires sophisticated surveillance strategies ranging from metal chelation to direct sensing of toxic reactive oxygen species. In the case of bacterial pathogens, stress that threatens to disrupt redox homeostasis can derive from endogenous sources (produced by the bacteria) or exogenous sources (produced by the host). This minireview summarizes the sources of redox stress encountered during infection, the mechanisms by which bacterial pathogens diminish the damaging effects of redox stress, and the clever ways some organisms have evolved to thrive in the face of redox challenges during infection.
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The anti-apoptotic and anti-inflammatory effect of Lactobacillus acidophilus on Shigella sonnei and Vibrio cholerae interaction with intestinal epithelial cells: A comparison between invasive and non-invasive bacteria. PLoS One 2018; 13:e0196941. [PMID: 29874233 PMCID: PMC5991357 DOI: 10.1371/journal.pone.0196941] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Accepted: 04/23/2018] [Indexed: 02/01/2023] Open
Abstract
The aim of this study was to compare the effect of Lactobacillus acidophilus on the attachment, invasion, and interaction of Shigella sonnei and Vibrio cholerae with Caco-2 epithelial cells. Also, the anti-apoptotic and anti-inflammatory effect of L. acidophilus was investigated on S. sonnei and V. cholerae interaction with Caco-2 cells as the representatives of invasive and non-invasive intestinal bacteria. It was found that pretreatment with L. acidophilus significantly prevented from adherence and internalization of S. sonnei/V. cholerae and reduced the expression of tumour necrosis factor-α and interleukin-8 in host cells. No significant difference was observed in inhibitory effect of Lactobacilli in V. cholerae and S. sonnei attachment, emphasizing on the role of lactobacilli as a physical barrier in inhibiting direct contact with host cell by competitive exclusion, which may affect attachment and subsequent internalization of both invasive and non-invasive pathogenic bacteria in a same scale. The evaluation of early and late apoptosis in Caco-2 cells exposed to V. cholerae/S. sonnei and pretreated by L. acidophilus indicated no remarkable difference in L. acidophilus anti-apoptotic effect on Caco-2 cells against invasive and non-invasive bacterial infection. Moreover, L. acidophilus by itself showed no apoptotic effect on Caco-2 cells. Statistical analysis revealed that L. acidophilus in S. sonnei infected cells was able to reduce pro-inflammatory immune responses (TNF-α, IL-8 and IL-1β) and NO and PGE2 secretion more strongly compared with V. cholerae infected cells. These data showed for the first time that the protective effect of Lactobacilli, as a probiotic bacterium, in interaction suppression was more in invasive bacteria including S. sonnei than in non-invasive V. cholerae.
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Mauffrey F, Cucaita A, Constant P, Villemur R. Denitrifying metabolism of the methylotrophic marine bacterium Methylophaga nitratireducenticrescens strain JAM1. PeerJ 2017; 5:e4098. [PMID: 29201569 PMCID: PMC5710167 DOI: 10.7717/peerj.4098] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 11/06/2017] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Methylophaga nitratireducenticrescens strain JAM1 is a methylotrophic, marine bacterium that was isolated from a denitrification reactor treating a closed-circuit seawater aquarium. It can sustain growth under anoxic conditions by reducing nitrate ([Formula: see text]) to nitrite ([Formula: see text]). These physiological traits are attributed to gene clusters that encode two dissimilatory nitrate reductases (Nar). Strain JAM1 also contains gene clusters encoding two nitric oxide (NO) reductases and one nitrous oxide (N2O) reductase, suggesting that NO and N2O can be reduced by strain JAM1. Here we characterized further the denitrifying activities of M. nitratireducenticrescens JAM1. METHODS Series of oxic and anoxic cultures of strain JAM1 were performed with N2O, [Formula: see text] or sodium nitroprusside, and growth and N2O, [Formula: see text], [Formula: see text] and N2 concentrations were measured. Ammonium ([Formula: see text])-free cultures were also tested to assess the dynamics of N2O, [Formula: see text] and [Formula: see text]. Isotopic labeling of N2O was performed in 15NH4+-amended cultures. Cultures with the JAM1ΔnarG1narG2 double mutant were performed to assess the involvement of the Nar systems on N2O production. Finally, RT-qPCR was used to measure the gene expression levels of the denitrification genes cytochrome bc-type nitric oxide reductase (cnorB1 and cnorB2) and nitrous oxide reductase (nosZ), and also nnrS and norR that encode NO-sensitive regulators. RESULTS Strain JAM1 can reduce NO to N2O and N2O to N2 and can sustain growth under anoxic conditions by reducing N2O as the sole electron acceptor. Although strain JAM1 lacks a gene encoding a dissimilatory [Formula: see text] reductase, [Formula: see text]-amended cultures produce N2O, representing up to 6% of the N-input. [Formula: see text] was shown to be the key intermediate of this production process. Upregulation in the expression of cnorB1, cnorB2, nnrS and norR during the growth and the N2O accumulation phases suggests NO production in strain JAM1 cultures. DISCUSSION By showing that all the three denitrification reductases are active, this demonstrates that M. nitratireducenticrescens JAM1 is one of many bacteria species that maintain genes associated primarily with denitrification, but not necessarily related to the maintenance of the entire pathway. The reason to maintain such an incomplete pathway could be related to the specific role of strain JAM1 in the denitrifying biofilm of the denitrification reactor from which it originates. The production of N2O in strain JAM1 did not involve Nar, contrary to what was demonstrated in Escherichia coli. M. nitratireducenticrescens JAM1 is the only reported Methylophaga species that has the capacity to grow under anoxic conditions by using [Formula: see text] and N2O as sole electron acceptors for its growth. It is also one of a few marine methylotrophs that is studied at the physiological and genetic levels in relation to its capacity to perform denitrifying activities.
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Affiliation(s)
- Florian Mauffrey
- INRS–Institut Armand-Frappier, Laval, Québec, Canada
- Laboratoire de santé publique du Québec, Ste-Anne-de-Bellevue, Québec, Canada
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Abstract
Infectious diseases kill nearly 9 million people annually. Bacterial pathogens are responsible for a large proportion of these diseases, and the bacterial agents of pneumonia, diarrhea, and tuberculosis are leading causes of death and disability worldwide. Increasingly, the crucial role of nonhost environments in the life cycle of bacterial pathogens is being recognized. Heightened scrutiny has been given to the biological processes impacting pathogen dissemination and survival in the natural environment, because these processes are essential for the transmission of pathogenic bacteria to new hosts. This chapter focuses on the model environmental pathogen Vibrio cholerae to describe recent advances in our understanding of how pathogens survive between hosts and to highlight the processes necessary to support the cycle of environmental survival, transmission, and dissemination. We describe the physiological and molecular responses of V. cholerae to changing environmental conditions, focusing on its survival in aquatic reservoirs between hosts and its entry into and exit from human hosts.
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OxyR2 Modulates OxyR1 Activity and Vibrio cholerae Oxidative Stress Response. Infect Immun 2017; 85:IAI.00929-16. [PMID: 28138024 DOI: 10.1128/iai.00929-16] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 01/25/2017] [Indexed: 12/29/2022] Open
Abstract
Bacteria have developed capacities to deal with different stresses and adapt to different environmental niches. The human pathogen Vibrio cholerae, the causative agent of the severe diarrheal disease cholera, utilizes the transcriptional regulator OxyR to activate genes related to oxidative stress resistance, including peroxiredoxin PrxA, in response to hydrogen peroxide. In this study, we identified another OxyR homolog in V. cholerae, which we named OxyR2, and we renamed the previous OxyR OxyR1. We found that OxyR2 is required to activate its divergently transcribed gene ahpC, encoding an alkylhydroperoxide reductase, independently of H2O2 A conserved cysteine residue in OxyR2 is critical for this function. Mutation of either oxyR2 or ahpC rendered V. cholerae more resistant to H2O2 RNA sequencing analyses indicated that OxyR1-activated oxidative stress-resistant genes were highly expressed in oxyR2 mutants even in the absence of H2O2 Further genetic analyses suggest that OxyR2-activated AhpC modulates OxyR1 activity by maintaining low intracellular concentrations of H2O2 Furthermore, we showed that ΔoxyR2 and ΔahpC mutants were less fit when anaerobically grown bacteria were exposed to low levels of H2O2 or incubated in seawater. These results suggest that OxyR2 and AhpC play important roles in the V. cholerae oxidative stress response.
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Xia X, Larios-Valencia J, Liu Z, Xiang F, Kan B, Wang H, Zhu J. OxyR-activated expression of Dps is important for Vibrio cholerae oxidative stress resistance and pathogenesis. PLoS One 2017; 12:e0171201. [PMID: 28151956 PMCID: PMC5289545 DOI: 10.1371/journal.pone.0171201] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2016] [Accepted: 01/18/2017] [Indexed: 11/19/2022] Open
Abstract
Vibrio cholerae is the causative agent of cholera, a dehydrating diarrheal disease. This Gram-negative pathogen is able to modulate its gene expression in order to combat stresses encountered in both aquatic and host environments, including stress posed by reactive oxygen species (ROS). In order to further the understanding of V. cholerae’s transcriptional response to ROS, we performed an RNA sequencing analysis to determine the transcriptional profile of V. cholerae when exposed to hydrogen hydroperoxide. Of 135 differentially expressed genes, VC0139 was amongst the genes with the largest induction. VC0139 encodes a protein homologous to the DPS (DNA-binding protein from starved cells) protein family, which are widely conserved and are implicated in ROS resistance in other bacteria. Using a promoter reporter assay, we show that during exponential growth, dps is induced by H2O2 in a manner dependent on the ROS-sensing transcriptional regulator, OxyR. Upon entry into stationary phase, the major stationary phase regulator RpoS is required to transcribe dps. Deletion of dps impaired V. cholerae resistance to both inorganic and organic hydroperoxides. Furthermore, we show that Dps is involved in resistance to multiple environmental stresses. Finally, we found that Dps is important for V. cholerae adult mouse colonization, but becomes dispensable in the presence of antioxidants. Taken together, our results suggest that Dps plays vital roles in both V. cholerae stress resistance and pathogenesis.
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Affiliation(s)
- Xiaoyun Xia
- College of Life Sciences, Nanjing Agricultural University, Nanjing, China
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Jessie Larios-Valencia
- Department of Microbiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Zhi Liu
- Department of Microbiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States of America
- Department of Biotechnology, Huazhong University of Science and Technology, Wuhan, China
| | - Fu Xiang
- College of Life Sciences, Huanggang Normal University, Huanggang, China
| | - Biao Kan
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
| | - Hui Wang
- College of Life Sciences, Nanjing Agricultural University, Nanjing, China
- * E-mail: (HW); (JZ)
| | - Jun Zhu
- College of Life Sciences, Nanjing Agricultural University, Nanjing, China
- Department of Microbiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States of America
- * E-mail: (HW); (JZ)
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Patra SK, Bag PK, Ghosh S. Nitrosative Stress Response in Vibrio cholerae: Role of S-Nitrosoglutathione Reductase. Appl Biochem Biotechnol 2016; 182:871-884. [PMID: 28000045 DOI: 10.1007/s12010-016-2367-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2016] [Accepted: 12/12/2016] [Indexed: 10/20/2022]
Abstract
Vibrio cholerae, the causative agent of cholera, poses serious threats to humans worldwide. V. cholerae faces host inflammatory response and encounters nitrosative stress before establishing successful colonization. It is not clear how V. cholerae combats nitric oxide and reactive nitrogen species. In the present study, we used three clinical strains of V. cholerae and tested their nitrosative stress response pattern towards sodium nitroprusside (SNP) and S-Nitrosoglutathione (GSNO). Among them, V. cholerae, belonging to both O1 and O139 serotypes, showed moderate resistance to SNP and GSNO. However, a V. cholerae strain belonging to non O1 and non O139 showed sensitivity to SNP but resistance towards GSNO. Reduced glutathione and glutathione reductase play a significant role to combat nitrosative stress in V. cholerae. This is the first report where we show the presence of GSNO reductase activity in V. cholerae and that it plays an important role to detoxify S-Nitrosoglutathione. GSNO reductase activity of V. cholerae was regulated by posttranslational modification through S-nitrosylation under in vitro conditions which could be reversed by dithiothreitol (DTT). In addition, we show that biofilm formation remained unaffected under nitrosative stress in V. cholerae.
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Affiliation(s)
- Sourav Kumar Patra
- Department of Biochemistry, University of Calcutta, 35, Ballygunge Circular Road, Kolkata, West Bengal, 700019, India
| | - Prasanta Kumar Bag
- Department of Biochemistry, University of Calcutta, 35, Ballygunge Circular Road, Kolkata, West Bengal, 700019, India
| | - Sanjay Ghosh
- Department of Biochemistry, University of Calcutta, 35, Ballygunge Circular Road, Kolkata, West Bengal, 700019, India.
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Liu Z, Wang H, Zhou Z, Sheng Y, Naseer N, Kan B, Zhu J. Thiol-based switch mechanism of virulence regulator AphB modulates oxidative stress response in Vibrio cholerae. Mol Microbiol 2016; 102:939-949. [PMID: 27625149 DOI: 10.1111/mmi.13524] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/07/2016] [Indexed: 11/30/2022]
Abstract
Bacterial pathogens display versatile gene expression to adapt to changing surroundings. For example, Vibrio cholerae, the causative agent of cholera, utilizes distinct genetic programs to combat reactive oxygen species (ROS) in aquatic environments or during host infection. We previously reported that the virulence activator AphB in V. cholerae is involved in ROS resistance. Here by performing a genetic screen, we show that AphB represses ROS resistance gene ohrA, which is also repressed by another regulator, OhrR. Reduced forms of both AphB and OhrR directly bind to the ohrA promoter and repress its expression, whereas organic hydroperoxides such as cumene hydroperoxide (CHP) deactivate AphB and OhrR. OhrA is critical for V. cholerae adult mouse colonization but is dispensable when the mice are treated with antioxidants. Furthermore, similar to our previous finding that AphB and OhrR exhibit different reduction rates during the shift from oxic to anoxic environments, we found that AphB is also oxidized more slowly than OhrR under peroxide stress or exposure to oxygen. This differential regulation optimizes the expression of ohrA and contributes to V. cholerae's ability to survive in a variety of environmental niches that contain different levels of ROS.
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Affiliation(s)
- Zhi Liu
- Department of Biotechnology, Huazhong University of Science and Technology, Wuhan, China.,Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Hui Wang
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA.,Department of Microbiology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Zhigang Zhou
- Division of Microbiology, Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Ying Sheng
- Department of Microbiology, Nanjing Agricultural University, Nanjing, 210095, China.,Division of Bacterial Infectious Diseases, State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, 102206, China
| | - Nawar Naseer
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Biao Kan
- Division of Bacterial Infectious Diseases, State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, 102206, China
| | - Jun Zhu
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
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Abstract
Nitric oxide (NO) is a freely diffusible, radical gas that has now been established as an integral signaling molecule in eukaryotes and bacteria. It has been demonstrated that NO signaling is initiated upon ligation to the heme iron of an H-NOX domain in mammals and in some bacteria. Bacterial H-NOX proteins have been found to interact with enzymes that participate in signaling pathways and regulate bacterial processes such as quorum sensing, biofilm formation, and symbiosis. Here, we review the biochemical characterization of these signaling pathways and, where available, describe how ligation of NO to H-NOX specifically regulates the activity of these pathways and their associated bacterial phenotypes.
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Affiliation(s)
- Lisa-Marie Nisbett
- Graduate Program in Biochemistry and Structural Biology, Stony Brook University, Stony Brook, NY, 11794-3400
| | - Elizabeth M. Boon
- Department of Chemistry, Stony Brook University, Stony Brook, NY, 11794-3400
- Institute of Chemical Biology & Drug Discovery, Stony Brook University, Stony Brook, NY, 11794-3400
- Graduate Program in Biochemistry and Structural Biology, Stony Brook University, Stony Brook, NY, 11794-3400
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Host-Derived Sialic Acids Are an Important Nutrient Source Required for Optimal Bacterial Fitness In Vivo. mBio 2016; 7:e02237-15. [PMID: 27073099 PMCID: PMC4959520 DOI: 10.1128/mbio.02237-15] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
A major challenge facing bacterial intestinal pathogens is competition for nutrient sources with the host microbiota. Vibrio cholerae is an intestinal pathogen that causes cholera, which affects millions each year; however, our knowledge of its nutritional requirements in the intestinal milieu is limited. In this study, we demonstrated that V. cholerae can grow efficiently on intestinal mucus and its component sialic acids and that a tripartite ATP-independent periplasmic SiaPQM strain, transporter-deficient mutant NC1777, was attenuated for colonization using a streptomycin-pretreated adult mouse model. In in vivo competition assays, NC1777 was significantly outcompeted for up to 3 days postinfection. NC1777 was also significantly outcompeted in in vitro competition assays in M9 minimal medium supplemented with intestinal mucus, indicating that sialic acid uptake is essential for fitness. Phylogenetic analyses demonstrated that the ability to utilize sialic acid was distributed among 452 bacterial species from eight phyla. The majority of species belonged to four phyla, Actinobacteria (members of Actinobacillus, Corynebacterium, Mycoplasma, and Streptomyces), Bacteroidetes (mainly Bacteroides, Capnocytophaga, and Prevotella), Firmicutes (members of Streptococcus, Staphylococcus, Clostridium, and Lactobacillus), and Proteobacteria (including Escherichia, Shigella, Salmonella, Citrobacter, Haemophilus, Klebsiella, Pasteurella, Photobacterium, Vibrio, and Yersinia species), mostly commensals and/or pathogens. Overall, our data demonstrate that the ability to take up host-derived sugars and sialic acid specifically allows V. cholerae a competitive advantage in intestinal colonization and that this is a trait that is sporadic in its occurrence and phylogenetic distribution and ancestral in some genera but horizontally acquired in others. Sialic acids are nine carbon amino sugars that are abundant on all mucous surfaces. The deadly human pathogen Vibrio cholerae contains the genes required for scavenging, transport, and catabolism of sialic acid. We determined that the V. cholerae SiaPQM transporter is essential for sialic acid transport and that this trait allows the bacterium to outcompete noncatabolizers in vivo. We also showed that the ability to take up and catabolize sialic acid is prevalent among both commensals and pathogens that colonize the oral cavity and the respiratory, intestinal, and urogenital tracts. Phylogenetic analysis determined that the sialic acid catabolism phenotype is ancestral in some genera such as Yersinia, Streptococcus, and Staphylococcus and is acquired by horizontal gene transfer in others such as Vibrio, Aeromonas, and Klebsiella. The data demonstrate that this trait has evolved multiple times in different lineages, indicating the importance of specialized metabolism to niche expansion.
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42
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Robinson JL, Brynildsen MP. Construction and Experimental Validation of a Quantitative Kinetic Model of Nitric Oxide Stress in Enterohemorrhagic Escherichia coli O157:H7. Bioengineering (Basel) 2016; 3:E9. [PMID: 28952571 PMCID: PMC5597167 DOI: 10.3390/bioengineering3010009] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2015] [Accepted: 02/01/2016] [Indexed: 12/20/2022] Open
Abstract
Enterohemorrhagic Escherichia coli (EHEC) are responsible for large outbreaks of hemorrhagic colitis, which can progress to life-threatening hemolytic uremic syndrome (HUS) due to the release of Shiga-like toxins (Stx). The presence of a functional nitric oxide (NO·) reductase (NorV), which protects EHEC from NO· produced by immune cells, was previously found to correlate with high HUS incidence, and it was shown that NorV activity enabled prolonged EHEC survival and increased Stx production within macrophages. To enable quantitative study of EHEC NO· defenses and facilitate the development of NO·-potentiating therapeutics, we translated an existing kinetic model of the E. coli K-12 NO· response to an EHEC O157:H7 strain. To do this, we trained uncertain model parameters on measurements of [NO·] and [O₂] in EHEC cultures, assessed parametric and prediction uncertainty with the use of a Markov chain Monte Carlo approach, and confirmed the predictive accuracy of the model with experimental data from genetic mutants lacking NorV or Hmp (NO· dioxygenase). Collectively, these results establish a methodology for the translation of quantitative models of NO· stress in model organisms to pathogenic sub-species, which is a critical step toward the application of these models for the study of infectious disease.
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Affiliation(s)
- Jonathan L Robinson
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA.
| | - Mark P Brynildsen
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA.
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Torres M, Simon J, Rowley G, Bedmar E, Richardson D, Gates A, Delgado M. Nitrous Oxide Metabolism in Nitrate-Reducing Bacteria: Physiology and Regulatory Mechanisms. Adv Microb Physiol 2016; 68:353-432. [PMID: 27134026 DOI: 10.1016/bs.ampbs.2016.02.007] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Nitrous oxide (N2O) is an important greenhouse gas (GHG) with substantial global warming potential and also contributes to ozone depletion through photochemical nitric oxide (NO) production in the stratosphere. The negative effects of N2O on climate and stratospheric ozone make N2O mitigation an international challenge. More than 60% of global N2O emissions are emitted from agricultural soils mainly due to the application of synthetic nitrogen-containing fertilizers. Thus, mitigation strategies must be developed which increase (or at least do not negatively impact) on agricultural efficiency whilst decrease the levels of N2O released. This aim is particularly important in the context of the ever expanding population and subsequent increased burden on the food chain. More than two-thirds of N2O emissions from soils can be attributed to bacterial and fungal denitrification and nitrification processes. In ammonia-oxidizing bacteria, N2O is formed through the oxidation of hydroxylamine to nitrite. In denitrifiers, nitrate is reduced to N2 via nitrite, NO and N2O production. In addition to denitrification, respiratory nitrate ammonification (also termed dissimilatory nitrate reduction to ammonium) is another important nitrate-reducing mechanism in soil, responsible for the loss of nitrate and production of N2O from reduction of NO that is formed as a by-product of the reduction process. This review will synthesize our current understanding of the environmental, regulatory and biochemical control of N2O emissions by nitrate-reducing bacteria and point to new solutions for agricultural GHG mitigation.
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Blanquet P, Silva L, Catrice O, Bruand C, Carvalho H, Meilhoc E. Sinorhizobium meliloti Controls Nitric Oxide-Mediated Post-Translational Modification of a Medicago truncatula Nodule Protein. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2015; 28:1353-63. [PMID: 26422404 DOI: 10.1094/mpmi-05-15-0118-r] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Nitric oxide (NO) is involved in various plant-microbe interactions. In the symbiosis between soil bacterium Sinorhizobium meliloti and model legume Medicago truncatula, NO is required for an optimal establishment of the interaction but is also a signal for nodule senescence. Little is known about the molecular mechanisms responsible for NO effects in the legume-rhizobium interaction. Here, we investigate the contribution of the bacterial NO response to the modulation of a plant protein post-translational modification in nitrogen-fixing nodules. We made use of different bacterial mutants to finely modulate NO levels inside M. truncatula root nodules and to examine the consequence on tyrosine nitration of the plant glutamine synthetase, a protein responsible for assimilation of the ammonia released by nitrogen fixation. Our results reveal that S. meliloti possesses several proteins that limit inactivation of plant enzyme activity via NO-mediated post-translational modifications. This is the first demonstration that rhizobia can impact the course of nitrogen fixation by modulating the activity of a plant protein.
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Affiliation(s)
- Pauline Blanquet
- 1 Institut National de la Recherche Agronomique, Laboratoire des Interactions Plantes-Microorganismes, UMR441, Castanet-Tolosan, France
- 2 Centre National de la Recherche Scientifique, Laboratoire des Interactions Plantes-Microorganismes, UMR2594, Castanet-Tolosan, France; and
| | - Liliana Silva
- 3 Laboratório de Biologia Molecular da Assimilação do Azoto, Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua do Campo Alegre 823, 4150-180 Porto, Portugal
| | - Olivier Catrice
- 1 Institut National de la Recherche Agronomique, Laboratoire des Interactions Plantes-Microorganismes, UMR441, Castanet-Tolosan, France
- 2 Centre National de la Recherche Scientifique, Laboratoire des Interactions Plantes-Microorganismes, UMR2594, Castanet-Tolosan, France; and
| | - Claude Bruand
- 1 Institut National de la Recherche Agronomique, Laboratoire des Interactions Plantes-Microorganismes, UMR441, Castanet-Tolosan, France
- 2 Centre National de la Recherche Scientifique, Laboratoire des Interactions Plantes-Microorganismes, UMR2594, Castanet-Tolosan, France; and
| | - Helena Carvalho
- 3 Laboratório de Biologia Molecular da Assimilação do Azoto, Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua do Campo Alegre 823, 4150-180 Porto, Portugal
| | - Eliane Meilhoc
- 1 Institut National de la Recherche Agronomique, Laboratoire des Interactions Plantes-Microorganismes, UMR441, Castanet-Tolosan, France
- 2 Centre National de la Recherche Scientifique, Laboratoire des Interactions Plantes-Microorganismes, UMR2594, Castanet-Tolosan, France; and
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45
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Mehta HH, Liu Y, Zhang MQ, Spiro S. Genome-wide analysis of the response to nitric oxide in uropathogenic Escherichia coli CFT073. Microb Genom 2015; 1:e000031. [PMID: 28348816 PMCID: PMC5320621 DOI: 10.1099/mgen.0.000031] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 09/07/2015] [Indexed: 12/30/2022] Open
Abstract
Uropathogenic Escherchia coli (UPEC) is the causative agent of urinary tract infections. Nitric oxide (NO) is a toxic water-soluble gas that is encountered by UPEC in the urinary tract. Therefore, UPEC probably requires mechanisms to detoxify NO in the host environment. Thus far, flavohaemoglobin (Hmp), an NO denitrosylase, is the only demonstrated NO detoxification system in UPEC. Here we show that, in E. coli strain CFT073, the NADH-dependent NO reductase flavorubredoxin (FlRd) also plays a major role in NO scavenging. We generated a mutant that lacks all known and candidate NO detoxification pathways (Hmp, FlRd and the respiratory nitrite reductase, NrfA). When grown and assayed anaerobically, this mutant expresses an NO-inducible NO scavenging activity, pointing to the existence of a novel detoxification mechanism. Expression of this activity is inducible by both NO and nitrate, and the enzyme is membrane-associated. Genome-wide transcriptional profiling of UPEC grown under anaerobic conditions in the presence of nitrate (as a source of NO) highlighted various aspects of the response of the pathogen to nitrate and NO. Several virulence-associated genes are upregulated, suggesting that host-derived NO is a potential regulator of UPEC virulence. Chromatin immunoprecipitation and sequencing was used to evaluate the NsrR regulon in CFT073. We identified 49 NsrR binding sites in promoter regions in the CFT073 genome, 29 of which were not previously identified in E. coli K-12. NsrR may regulate some CFT073 genes that do not have homologues in E. coli K-12.
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Affiliation(s)
- Heer H. Mehta
- Department of Biological Sciences, University of Texas at Dallas, 800 W Campbell Road, Richardson, TX 75080, USA
| | - Yuxuan Liu
- Department of Biological Sciences, University of Texas at Dallas, 800 W Campbell Road, Richardson, TX 75080, USA
- Center for Systems Biology, University of Texas at Dallas, 800 W Campbell Road, Richardson, TX 75080, USA
| | - Michael Q. Zhang
- Department of Biological Sciences, University of Texas at Dallas, 800 W Campbell Road, Richardson, TX 75080, USA
- Center for Systems Biology, University of Texas at Dallas, 800 W Campbell Road, Richardson, TX 75080, USA
| | - Stephen Spiro
- Department of Biological Sciences, University of Texas at Dallas, 800 W Campbell Road, Richardson, TX 75080, USA
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46
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An ensemble-guided approach identifies ClpP as a major regulator of transcript levels in nitric oxide-stressed Escherichia coli. Metab Eng 2015; 31:22-34. [DOI: 10.1016/j.ymben.2015.06.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Revised: 03/21/2015] [Accepted: 06/15/2015] [Indexed: 11/23/2022]
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47
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Dual Zinc Transporter Systems in Vibrio cholerae Promote Competitive Advantages over Gut Microbiome. Infect Immun 2015. [PMID: 26195552 DOI: 10.1128/iai.00447-15] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Zinc is an essential trace metal required for numerous cellular processes in all forms of life. In order to maintain zinc homeostasis, bacteria have developed several transport systems to regulate its uptake. In this study, we investigated zinc transport systems in the enteric pathogen Vibrio cholerae, the causative agent of cholera. Bioinformatic analysis predicts that two gene clusters, VC2081 to VC2083 (annotated as zinc utilization genes znuABC) and VC2551 to VC2555 (annotated as zinc-regulated genes zrgABCDE), are regulated by the putative zinc uptake regulator Zur. Using promoter reporter and biochemical assays, we confirmed that Zur represses znuABC and zrgABCDE promoters in a Zn(2+)-dependent manner. Under Zn(2+)-limiting conditions, we found that mutations in either the znuABC or zrgABCDE gene cluster affect bacterial growth, with znuABC mutants displaying a more severe growth defect, suggesting that both ZnuABC and ZrgABCDE are involved in Zn(2+) uptake and that ZnuABC plays the predominant role. Furthermore, we reveal that ZnuABC and ZrgABCDE are important for V. cholerae colonization in both infant and adult mouse models, particularly in the presence of other intestinal microbiota. Collectively, our studies indicate that these two zinc transporter systems play vital roles in maintaining zinc homeostasis during V. cholerae growth and pathogenesis.
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48
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ELGAML ABDELAZIZ, MIYOSHI SHINICHI. Presence of Nitric Oxide-Sensing Systems in the Human Pathogen Vibrio vulnificus. Biocontrol Sci 2015; 20:199-203. [DOI: 10.4265/bio.20.199] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Affiliation(s)
- ABDELAZIZ ELGAML
- Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University
- Microbiology and Immunology Department, Faculty of Pharmacy, Mansoura University
| | - SHIN-ICHI MIYOSHI
- Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University
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49
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Green J, Rolfe MD, Smith LJ. Transcriptional regulation of bacterial virulence gene expression by molecular oxygen and nitric oxide. Virulence 2014; 5:794-809. [PMID: 25603427 PMCID: PMC4601167 DOI: 10.4161/viru.27794] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Molecular oxygen (O2) and nitric oxide (NO) are diatomic gases that play major roles in infection. The host innate immune system generates reactive oxygen species and NO as bacteriocidal agents and both require O2 for their production. Furthermore, the ability to adapt to changes in O2 availability is crucial for many bacterial pathogens, as many niches within a host are hypoxic. Pathogenic bacteria have evolved transcriptional regulatory systems that perceive these gases and respond by reprogramming gene expression. Direct sensors possess iron-containing co-factors (iron–sulfur clusters, mononuclear iron, heme) or reactive cysteine thiols that react with O2 and/or NO. Indirect sensors perceive the physiological effects of O2 starvation. Thus, O2 and NO act as environmental cues that trigger the coordinated expression of virulence genes and metabolic adaptations necessary for survival within a host. Here, the mechanisms of signal perception by key O2- and NO-responsive bacterial transcription factors and the effects on virulence gene expression are reviewed, followed by consideration of these aspects of gene regulation in two major pathogens, Staphylococcus aureus and Mycobacterium tuberculosis.
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Key Words
- AIP, autoinducer peptide
- Arc, Aerobic respiratory control
- FNR
- FNR, fumarate nitrate reduction regulator
- GAF, cGMP-specific phosphodiesterase-adenylyl cyclase-FhlA domain
- Isc, iron–sulfur cluster biosynthesis machinery
- Mycobacterium tuberculosis
- NOX, NADPH oxidase
- PAS, Per-Amt-Sim domain
- RNS, reactive nitrogen species
- ROS, reactive oxygen species
- Staphylococcus aureus
- TB, tuberculosis
- WhiB-like proteins
- iNOS, inducible nitric oxide synthase
- iron–sulfur cluster
- nitric oxide sensors
- oxygen sensors
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Affiliation(s)
- Jeffrey Green
- a Krebs Institute; Molecular Biology & Biotechnology; University of Sheffield ; Western Bank , Sheffield , UK
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50
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Pei J, Li W, Kinch LN, Grishin NV. Conserved evolutionary units in the heme-copper oxidase superfamily revealed by novel homologous protein families. Protein Sci 2014; 23:1220-34. [PMID: 24931479 DOI: 10.1002/pro.2503] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Accepted: 06/11/2014] [Indexed: 01/04/2023]
Abstract
The heme-copper oxidase (HCO) superfamily includes HCOs in aerobic respiratory chains and nitric oxide reductases (NORs) in the denitrification pathway. The HCO/NOR catalytic subunit has a core structure consisting of 12 transmembrane helices (TMHs) arranged in three-fold rotational pseudosymmetry, with six conserved histidines for heme and metal binding. Using sensitive sequence similarity searches, we detected a number of novel HCO/NOR homologs and named them HCO Homology (HCOH) proteins. Several HCOH families possess only four TMHs that exhibit the most pronounced similarity to the last four TMHs (TMHs 9-12) of HCOs/NORs. Encoded by independent genes, four-TMH HCOH proteins represent a single evolutionary unit (EU) that relates to each of the three homologous EUs of HCOs/NORs comprising TMHs 1-4, TMHs 5-8, and TMHs 9-12. Single-EU HCOH proteins could form homotrimers or heterotrimers to maintain the general structure and ligand-binding sites defined by the HCO/NOR catalytic subunit fold. The remaining HCOH families, including NnrS, have 12-TMHs and three EUs. Most three-EU HCOH proteins possess two conserved histidines and could bind a single heme. Limited experimental studies and genomic context analysis suggest that many HCOH proteins could function in the denitrification pathway and in detoxification of reactive molecules such as nitric oxide. HCO/NOR catalytic subunits exhibit remarkable structural similarity to the homotrimers of MAPEG (membrane-associated proteins in eicosanoid and glutathione metabolism) proteins. Gene duplication, fusion, and fission likely play important roles in the evolution of HCOs/NORs and HCOH proteins.
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Affiliation(s)
- Jimin Pei
- Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas, 75390
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