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Zhang T, Ji S, Zhang M, Wu F, Li X, Luo X, Huang Q, Li M, Zhang Y, Lu R. Effect of capsular polysaccharide phase variation on biofilm formation, motility and gene expression in Vibrio vulnificus. Gut Pathog 2024; 16:40. [PMID: 39075606 PMCID: PMC11287873 DOI: 10.1186/s13099-024-00620-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Accepted: 05/25/2024] [Indexed: 07/31/2024] Open
Abstract
Vibrio vulnificus, a significant marine pathogen, undergoes opaque (Op)-translucent (Tr) colony switching based on whether capsular polysaccharide (CPS) is produced. CPS phase variation is sometime accompanied by genetic variation or down-regulation of particular genes, such as wzb. In addition, CPS prevents biofilm formation and is important to the virulence of V. vulnificus. However, the extent to which there is a difference in gene expression between Tr and Op colonies and the impact of CPS phase variation on other behaviors of V. vulnificus remain unknown. In this work, the data have shown that CPS phase variation of V. vulnificus is affected by incubation time. Tr and Op strains exhibited similar growth rates. However, Tr strains had enhanced biofilm formation capacities but reduced swimming motility compared to Op strains. The RNA-seq assay revealed 488 differentially expressed genes, with 214 downregulated and 274 upregulated genes, between Tr and Op colonies. Genes associated with Tad pili and CPS were downregulated, whereas those involved in flagellum were upregulated, in Tr colonies compared with Op colonies. In addition, 9 putative c-di-GMP metabolism-associated genes and 28 genes encoding putative regulators were significantly differentially expressed, suggesting that CPS phase variation is probably strictly regulated in V. vulnificus. Moreover, 8 genes encoding putative porins were also differentially expressed between the two phenotypic colonies, indicating that bacterial outer membrane was remodeled during CPS phase variation. In brief, this work highlighted the gene expression profiles associated with CPS phase variation, but more studies should be performed to disclose the intrinsic mechanisms in the future.
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Affiliation(s)
- Tingting Zhang
- Department of Clinical Laboratory, Nantong Third People's Hospital, Affiliated Nantong Hospital 3 of Nantong University, Nantong, Jiangsu, 226006, China
- School of Medicine, Nantong University, Nantong, Jiangsu, 226019, China
| | - Shenjie Ji
- Department of Clinical Laboratory, Qidong People's Hospital, Qidong, Jiangsu, 226200, China
| | - Miaomiao Zhang
- Department of Clinical Laboratory, Nantong Third People's Hospital, Affiliated Nantong Hospital 3 of Nantong University, Nantong, Jiangsu, 226006, China
| | - Fei Wu
- Department of Clinical Laboratory, Nantong Third People's Hospital, Affiliated Nantong Hospital 3 of Nantong University, Nantong, Jiangsu, 226006, China
| | - Xue Li
- Department of Clinical Laboratory, Nantong Third People's Hospital, Affiliated Nantong Hospital 3 of Nantong University, Nantong, Jiangsu, 226006, China
| | - Xi Luo
- Department of Clinical Laboratory, Nantong Third People's Hospital, Affiliated Nantong Hospital 3 of Nantong University, Nantong, Jiangsu, 226006, China
| | - Qinglian Huang
- Department of Clinical Laboratory, Nantong Third People's Hospital, Affiliated Nantong Hospital 3 of Nantong University, Nantong, Jiangsu, 226006, China
- School of Medicine, Nantong University, Nantong, Jiangsu, 226019, China
- Department of Clinical Laboratory, Qidong People's Hospital, Qidong, Jiangsu, 226200, China
| | - Min Li
- Department of Gastroenterology and Clinical Laboratory, Nantong Third People's Hospital, Affiliated Nantong Hospital 3 of Nantong University, Nantong, Jiangsu, 226006, China
| | - Yiquan Zhang
- Department of Clinical Laboratory, Nantong Third People's Hospital, Affiliated Nantong Hospital 3 of Nantong University, Nantong, Jiangsu, 226006, China.
| | - Renfei Lu
- Department of Clinical Laboratory, Nantong Third People's Hospital, Affiliated Nantong Hospital 3 of Nantong University, Nantong, Jiangsu, 226006, China.
- School of Medicine, Nantong University, Nantong, Jiangsu, 226019, China.
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2
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Lavado-Benito C, Murillo J, Martínez-Gil M, Ramos C, Rodríguez-Moreno L. GacA reduces virulence and increases competitiveness in planta in the tumorigenic olive pathogen Pseudomonas savastanoi pv. savastanoi. FRONTIERS IN PLANT SCIENCE 2024; 15:1347982. [PMID: 38375080 PMCID: PMC10875052 DOI: 10.3389/fpls.2024.1347982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Accepted: 01/08/2024] [Indexed: 02/21/2024]
Abstract
GacS/GacA is a widely distributed two-component system playing an essential role as a key global regulator, although its characterization in phytopathogenic bacteria has been deeply biased, being intensively studied in pathogens of herbaceous plants but barely investigated in pathogens of woody hosts. P. savastanoi pv. savastanoi (Psv) is characterized by inducing tumours in the stem and branches of olive trees. In this work, the model strain Psv NCPPB 3335 and a mutant derivative with a complete deletion of gene gacA were subjected to RNA-Seq analyses in a minimum medium and a medium mimicking in planta conditions, accompanied by RT-qPCR analyses of selected genes and phenotypic assays. These experiments indicated that GacA participates in the regulation of at least 2152 genes in strain NCPPB 3335, representing 37.9 % of the annotated CDSs. GacA also controls the expression of diverse rsm genes, and modulates diverse phenotypes, including motility and resistance to oxidative stresses. As occurs with other P. syringae pathovars of herbaceous plants, GacA regulates the expression of the type III secretion system and cognate effectors. In addition, GacA also regulates the expression of WHOP genes, specifically encoded in P. syringe strains isolated from woody hosts, and genes for the biosynthesis of phytohormones. A gacA mutant of NCPPB 3335 showed increased virulence, producing large immature tumours with high bacterial populations, but showed a significantly reduced competitiveness in planta. Our results further extend the role of the global regulator GacA in the virulence and fitness of a P. syringae pathogen of woody hosts.
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Affiliation(s)
- Carla Lavado-Benito
- Área de Genética, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Málaga, Spain
| | - Jesús Murillo
- Institute for Multidisciplinary Research in Applied Biology, Universidad Pública de Navarra (UPNA), Edificio de Agrobiotecnología, Mutilva Baja, Spain
| | - Marta Martínez-Gil
- Área de Genética, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain
| | - Cayo Ramos
- Área de Genética, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Málaga, Spain
| | - Luis Rodríguez-Moreno
- Área de Genética, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Málaga, Spain
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3
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Waidner LA, Potdukhe TV. Tools to Enumerate and Predict Distribution Patterns of Environmental Vibrio vulnificus and Vibrio parahaemolyticus. Microorganisms 2023; 11:2502. [PMID: 37894160 PMCID: PMC10609196 DOI: 10.3390/microorganisms11102502] [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: 09/07/2023] [Revised: 09/28/2023] [Accepted: 10/03/2023] [Indexed: 10/29/2023] Open
Abstract
Vibrio vulnificus (Vv) and Vibrio parahaemolyticus (Vp) are water- and foodborne bacteria that can cause several distinct human diseases, collectively called vibriosis. The success of oyster aquaculture is negatively impacted by high Vibrio abundances. Myriad environmental factors affect the distribution of pathogenic Vibrio, including temperature, salinity, eutrophication, extreme weather events, and plankton loads, including harmful algal blooms. In this paper, we synthesize the current understanding of ecological drivers of Vv and Vp and provide a summary of various tools used to enumerate Vv and Vp in a variety of environments and environmental samples. We also highlight the limitations and benefits of each of the measurement tools and propose example alternative tools for more specific enumeration of pathogenic Vv and Vp. Improvement of molecular methods can tighten better predictive models that are potentially important for mitigation in more controlled environments such as aquaculture.
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Affiliation(s)
- Lisa A. Waidner
- Hal Marcus College of Science and Engineering, University of West Florida, 11000 University Pkwy, Building 58, Room 108, Pensacola, FL 32514, USA
| | - Trupti V. Potdukhe
- GEMS Program, College of Medicine, University of Illinois Chicago, 1853 W. Polk St., Chicago, IL 60612, USA;
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4
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Lu K, Li Y, Chen R, Yang H, Wang Y, Xiong W, Xu F, Yuan Q, Liang H, Xiao X, Huang R, Chen Z, Tian C, Wang S. Pathogenic mechanism of Vibrio vulnificus infection. Future Microbiol 2023; 18:373-383. [PMID: 37158065 DOI: 10.2217/fmb-2022-0243] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/10/2023] Open
Abstract
Vibrio vulnificus is a fatal, opportunistic human pathogen transmitted through the consumption of raw/undercooked seafood or direct contact. V. vulnificus infection progresses rapidly and has severe consequences; some cases may require amputation or result in death. Growing evidence suggests that V. vulnificus virulence factors and regulators play a large role in disease progression, involving host resistance, cellular damage, iron acquisition, virulence regulation and host immune responses. Its disease mechanism remains largely undefined. Further evaluation of pathogenic mechanisms is important for selecting appropriate measures to prevent and treat V. vulnificus infection. In this review, the possible pathogenesis of V. vulnificus infection is described to provide a reference for treatment and prevention.
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Affiliation(s)
- Kun Lu
- Department of Neurosurgery, First Naval Hospital of Southern Theater Command, Zhanjiang, 524000, China
| | - Yang Li
- Department of Neurosurgery, First Naval Hospital of Southern Theater Command, Zhanjiang, 524000, China
| | - Rui Chen
- Department of Orthopedics, First Naval Hospital of Southern Theater Command, Zhanjiang, 524000, China
| | - Hua Yang
- Department of Neurosurgery, First Naval Hospital of Southern Theater Command, Zhanjiang, 524000, China
| | - Yong Wang
- Hemodialysis Center, First Naval Hospital of Southern Theater Command, Zhanjiang, 524000, China
| | - Wei Xiong
- Department of Neurosurgery, First Naval Hospital of Southern Theater Command, Zhanjiang, 524000, China
| | - Fang Xu
- Department of Neurosurgery, First Naval Hospital of Southern Theater Command, Zhanjiang, 524000, China
| | - Qijun Yuan
- Department of Neurosurgery, First Naval Hospital of Southern Theater Command, Zhanjiang, 524000, China
| | - Haihui Liang
- Department of Neurosurgery, First Naval Hospital of Southern Theater Command, Zhanjiang, 524000, China
| | - Xian Xiao
- Department of Neurosurgery, First Naval Hospital of Southern Theater Command, Zhanjiang, 524000, China
| | - Renqiang Huang
- Department of Neurosurgery, First Naval Hospital of Southern Theater Command, Zhanjiang, 524000, China
| | - Zhipeng Chen
- Department of Neurosurgery, First Naval Hospital of Southern Theater Command, Zhanjiang, 524000, China
| | - Chunou Tian
- Department of Neurosurgery, First Naval Hospital of Southern Theater Command, Zhanjiang, 524000, China
| | - Songqing Wang
- Department of Neurosurgery, First Naval Hospital of Southern Theater Command, Zhanjiang, 524000, China
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5
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Conrad JW, Harwood VJ. Sewage Promotes Vibrio vulnificus Growth and Alters Gene Transcription in Vibrio vulnificus CMCP6. Microbiol Spectr 2022; 10:e0191321. [PMID: 35171011 PMCID: PMC8849060 DOI: 10.1128/spectrum.01913-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 01/14/2022] [Indexed: 11/20/2022] Open
Abstract
Vibrio vulnificus is a naturally occurring, potentially lethal pathogen found in coastal waters, fish, and shellfish. Sewage spills in coastal waters occur when infrastructure fails due to severe storms or age, and may affect bacterial populations by altering nutrient levels. This study investigated effects of sewage on clonal and natural V. vulnificus populations in microcosms. Addition of 1% sewage to estuarine water caused the density of a pure culture of V. vulnificus CMCP6 and a natural V. vulnificus population to increase significantly, by two to three orders of magnitude, whether measured by quantitative PCR (qPCR) or culture and in batch and continuous cultures. Changes in the transcription of six virulence- and survival-associated genes in response to sewage were assessed using continuous culture. Exposure to sewage affected transcription of genes that may be associated with virulence, i.e., it modulated the oxidative stress response by altering superoxide dismutase transcription, significantly increasing sodB transcription while repressing sodA. Sewage also repressed transcription of nptA, which encodes a sodium-phosphate cotransporter. Sewage had no effect on sodC transcription or the putative virulence-associated genes hupA or wza. The effects of environmentally relevant levels of sewage on V. vulnificus populations and gene transcription suggest that sewage spills that impact warm coastal waters could lead to an increased risk of V. vulnificus infections. IMPORTANCE Vibrio vulnificus infections have profound impacts such as limb amputation and death for individuals with predisposing conditions. The warming climate is contributing to rising V. vulnificus prevalence in waters that were previously too cold to support high levels of the pathogen. Climate change is also expected to increase precipitation in many regions, which puts more pressure on wastewater infrastructure and will result in more frequent sewage spills. The finding that 1% wastewater in estuarine water leads to 100 to over 1,000-fold greater V. vulnificus concentrations suggests that human exposure to oysters and estuarine water could have greater health impacts in the future. Further, wastewater had a significant effect on gene transcription and has the potential to affect virulence during the initial environment-to-host transition.
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Affiliation(s)
- James W. Conrad
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
| | - Valerie J. Harwood
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
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6
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uvrY deletion and acetate reduce gut colonization of Crohn's disease-associated adherent-invasive Escherichia coli by decreasing expression of type 1 fimbriae. Infect Immun 2022; 90:e0066221. [PMID: 34978926 DOI: 10.1128/iai.00662-21] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Adherent-invasive Escherichia coli (AIEC) is involved in onset and/or exacerbation of Crohn's disease. AIEC adapts to the gut environment by altering gene-expression programs, leading to successful gut-lumen colonization. However, the underlying mechanism of gut colonization is still far from clarified. Here, we show the role of UvrY, a response regulator of bacterial two-component signal transduction systems, in AIEC gut colonization. An AIEC mutant lacking the uvrY gene exhibited impairment of competitive colonization in the murine intestinal tract. UvrY contributes to functional expression of type 1 fimbriae by activating expression of small RNA CsrB, which confers adherence and invasion into epithelial cells on AIEC. In contrast, acetate suppresses the UvrY-dependent expression of type 1 fimbriae, resulting in less efficient cell invasion and attenuated gut colonization. Our findings might lead to therapeutic interventions for CD, in which inhibitions of UvrY activation and acetate supplementation reduce the colonization levels of AIEC by decreasing type-1 fimbriae expression.
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7
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Chen YW, Yeh WH, Tang HJ, Chen JW, Shu HY, Su YC, Wang ST, Kuo CJ, Chuang YC, Chen CC, Ko WC, Chen CS, Chen PL. UvrY is required for the full virulence of Aeromonas dhakensis. Virulence 2021; 11:502-520. [PMID: 32434424 PMCID: PMC7250320 DOI: 10.1080/21505594.2020.1768339] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Aeromonas dhakensis is an emerging human pathogen which causes fast and severe infections worldwide. Under the gradual pressure of lacking useful antibiotics, finding a new strategy against A. dhakensis infection is urgent. To understand its pathogenesis, we created an A. dhakensis AAK1 mini-Tn10 transposon library to study the mechanism of A. dhakensis infection. By using a Caenorhabditis elegans model, we established a screening platform for the purpose of identifying attenuated mutants. The uvrY mutant, which conferred the most attenuated toxicity toward C. elegans, was identified. The uvrY mutant was also less virulent in C2C12 fibroblast and mice models, in line with in vitro results. To further elucidate the mechanism of UvrY in controlling the toxicity in A. dhakensis, we conducted a transcriptomic analysis. The RNAseq results showed that the expression of a unique hemolysin ahh1 and other virulence factors were regulated by UvrY. Complementation of Ahh1, one of the most important virulence factors, rescued the pore-formation phenotype of uvrY mutant in C. elegans; however, complementation of ahh1 endogenous promoter-driven ahh1 could not produce Ahh1 and rescue the virulence in the uvrY mutant. These findings suggest that UvrY is required for the expression of Ahh1 in A. dhakensis. Taken together, our results suggested that UvrY controls several different virulence factors and is required for the full virulence of A. dhakensis. The two-component regulator UvrY therefore a potential therapeutic target which is worthy of further study.
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Affiliation(s)
- Yi-Wei Chen
- Department of Biochemistry and Molecular Biology, College of Medicine, National Cheng Kung University, Tainan, Taiwan.,Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan.,Division of Oral Biology and Medicine, School of Dentistry, University of California, Los Angeles, CA, USA
| | - Wen-Hsuan Yeh
- Department of Biochemistry and Molecular Biology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Hung-Jen Tang
- Department of Medicine, Chi Mei Medical Center, Tainan, Taiwan
| | - Jenn-Wei Chen
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Hung-Yu Shu
- Department of Bioscience Technology, Chang Jung Christian University, Tainan, Taiwan
| | - Yu-Chen Su
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Sin-Tian Wang
- Department of Biochemistry and Molecular Biology, College of Medicine, National Cheng Kung University, Tainan, Taiwan.,Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Cheng-Ju Kuo
- Department of Biochemistry and Molecular Biology, College of Medicine, National Cheng Kung University, Tainan, Taiwan.,Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Yin-Ching Chuang
- Department of Medicine, Chi Mei Medical Center, Tainan, Taiwan.,Department of Medical Research, Chi Mei Medical Center, Tainan, Taiwan
| | - Chi-Chung Chen
- Department of Medical Research, Chi Mei Medical Center, Tainan, Taiwan.,Department of Food Science, National Chiayi University, Chiayi, Taiwan
| | - Wen-Chien Ko
- Department of Internal Medicine, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Chang-Shi Chen
- Department of Biochemistry and Molecular Biology, College of Medicine, National Cheng Kung University, Tainan, Taiwan.,Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Po-Lin Chen
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan.,Department of Internal Medicine, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan
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8
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Pettis GS, Mukerji AS. Structure, Function, and Regulation of the Essential Virulence Factor Capsular Polysaccharide of Vibrio vulnificus. Int J Mol Sci 2020; 21:ijms21093259. [PMID: 32380667 PMCID: PMC7247339 DOI: 10.3390/ijms21093259] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 05/01/2020] [Accepted: 05/03/2020] [Indexed: 12/23/2022] Open
Abstract
Vibrio vulnificus populates coastal waters around the world, where it exists freely or becomes concentrated in filter feeding mollusks. It also causes rapid and life-threatening sepsis and wound infections in humans. Of its many virulence factors, it is the V. vulnificus capsule, composed of capsular polysaccharide (CPS), that plays a critical role in evasion of the host innate immune system by conferring antiphagocytic ability and resistance to complement-mediated killing. CPS may also provoke a portion of the host inflammatory cytokine response to this bacterium. CPS production is biochemically and genetically diverse among strains of V. vulnificus, and the carbohydrate diversity of CPS is likely affected by horizontal gene transfer events that result in new combinations of biosynthetic genes. Phase variation between virulent encapsulated opaque colonial variants and attenuated translucent colonial variants, which have little or no CPS, is a common phenotype among strains of this species. One mechanism for generating acapsular variants likely involves homologous recombination between repeat sequences flanking the wzb phosphatase gene within the Group 1 CPS biosynthetic and transport operon. A considerable number of environmental, genetic, and regulatory factors have now been identified that affect CPS gene expression and CPS production in this pathogen.
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9
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Conrad JW, Harwood VJ. Comparison of DNA Methylation in Vibrio vulnificus Cells Grown in Human Serum with Those Grown in Seawater. Microbiol Resour Announc 2019; 8:e00419-19. [PMID: 31320429 PMCID: PMC6639608 DOI: 10.1128/mra.00419-19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 06/13/2019] [Indexed: 11/20/2022] Open
Abstract
The chromosomal methylation statuses of the highly virulent Vibrio vulnificus strain CMCP6 grown in human serum and in seawater are compared here. Growth in seawater resulted in ∼4 times as much methylation as that in human serum, primarily N4-methylcytosines.
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Affiliation(s)
- James W Conrad
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
| | - Valerie J Harwood
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
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10
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csrB Gene Duplication Drives the Evolution of Redundant Regulatory Pathways Controlling Expression of the Major Toxic Secreted Metalloproteases in Vibrio tasmaniensis LGP32. mSphere 2018; 3:3/6/e00582-18. [PMID: 30487156 PMCID: PMC6262261 DOI: 10.1128/msphere.00582-18] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The conserved CsrB sRNAs are an example of sibling sRNAs, i.e., sRNAs which are present in multiple copies in genomes. This report illustrates how new copies arise through gene duplication events and highlights two evolutionary advantages of having such multiple copies: differential regulation of the multiple copies allows integration of different input signals into the regulatory network of which they are parts, and the high redundancy that they provide confers a strong robustness to the system. CsrBs are bacterial highly conserved and multiple-copy noncoding small RNAs (sRNAs) that play major roles in cell physiology and virulence. In the Vibrio genus, they are known to be regulated by the two-component system VarS/VarA. They modulate the well-characterized quorum sensing pathway controlling virulence and luminescence in Vibrio cholerae and Vibrio harveyi, respectively. Remarkably, Vibrio tasmaniensis LGP32, an oyster pathogen that belongs to the Splendidus clade, was found to have four copies of csrB, named csrB1-4, compared to two to three copies in other Vibrio species. Here, we show that the extra csrB4 copy results from a csrB3 gene duplication, a characteristic of the Splendidus clade. Interestingly, csrB genes are regulated in different ways in V. tasmaniensis, with csrB1 expression being independent of the VarS/VarA system. We found that a complex regulatory network involving CsrBs, quorum sensing, and the stationary-phase sigma factor σS redundantly but differentially controls the production of two secreted metalloproteases, Vsm and PrtV, the former being a major determinant of the V. tasmaniensis extracellular product toxicity. In particular, we identified a novel VarS/VarA-dependent but CsrB-independent pathway that controls positively both Vsm production and PrtV production as well as rpoS expression. Altogether, our data show that a csrB gene duplication event in V. tasmaniensis supported the evolution of the regulatory network controlling the expression of major toxic secreted metalloproteases, thereby increasing redundancy and enabling the integration of additional input signals. IMPORTANCE The conserved CsrB sRNAs are an example of sibling sRNAs, i.e., sRNAs which are present in multiple copies in genomes. This report illustrates how new copies arise through gene duplication events and highlights two evolutionary advantages of having such multiple copies: differential regulation of the multiple copies allows integration of different input signals into the regulatory network of which they are parts, and the high redundancy that they provide confers a strong robustness to the system.
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11
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Abstract
Vibrio is a genus of ubiquitous bacteria found in a wide variety of aquatic and marine habitats; of the >100 described Vibrio spp., ~12 cause infections in humans. Vibrio cholerae can cause cholera, a severe diarrhoeal disease that can be quickly fatal if untreated and is typically transmitted via contaminated water and person-to-person contact. Non-cholera Vibrio spp. (for example, Vibrio parahaemolyticus, Vibrio alginolyticus and Vibrio vulnificus) cause vibriosis - infections normally acquired through exposure to sea water or through consumption of raw or undercooked contaminated seafood. Non-cholera bacteria can lead to several clinical manifestations, most commonly mild, self-limiting gastroenteritis, with the exception of V. vulnificus, an opportunistic pathogen with a high mortality that causes wound infections that can rapidly lead to septicaemia. Treatment for Vibrio spp. infection largely depends on the causative pathogen: for example, rehydration therapy for V. cholerae infection and debridement of infected tissues for V. vulnificus-associated wound infections, with antibiotic therapy for severe cholera and systemic infections. Although cholera is preventable and effective oral cholera vaccines are available, outbreaks can be triggered by natural or man-made events that contaminate drinking water or compromise access to safe water and sanitation. The incidence of vibriosis is rising, perhaps owing in part to the spread of Vibrio spp. favoured by climate change and rising sea water temperature.
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12
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Mima T, Gotoh K, Yamamoto Y, Maeda K, Shirakawa T, Matsui S, Murata Y, Koide T, Tokumitsu H, Matsushita O. Expression of Collagenase is Regulated by the VarS/VarA Two-Component Regulatory System in Vibrio alginolyticus. J Membr Biol 2017; 251:51-63. [PMID: 28993850 DOI: 10.1007/s00232-017-9991-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Accepted: 09/20/2017] [Indexed: 12/19/2022]
Abstract
Vibrio alginolyticus is an opportunistic pathogen in both humans and marine animals. Collagenase encoded by colA is considered to be one of the virulence factors. Expression of colA is regulated by multiple environmental factors, e.g., temperature, growth phase, and substrate. To elucidate the mechanism of regulation of colA expression, transposon mutagenesis was performed. VarS, a sensor histidine kinase of the two-component regulatory system, was demonstrated to regulate the expression of colA. VarA, a cognate response regulator of VarS, was also identified and shown to be involved in the regulation of colA expression. In vitro phosphorylation assays showed that phosphorylated VarS acted as a phosphoryl group donor to VarA. A site-directed mutagenesis study showed that the His300, Asp718 and His874 residues in VarS were essential for the phosphorylation of VarS, and the Asp54 residue in VarA was likely to receive the phosphoryl group from VarS. The results demonstrate that the VarS/VarA two-component regulatory system regulates the expression of collagenase in V. alginolyticus.
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Affiliation(s)
- Takehiko Mima
- Department of Bacteriology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan.
| | - Kazuyoshi Gotoh
- Department of Bacteriology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Yumiko Yamamoto
- Department of Bacteriology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Keiko Maeda
- Department of Bacteriology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | | | - Shunsuke Matsui
- Department of Chemistry and Biochemistry, School of Advanced Science and Engineering, Waseda University, Tokyo, Japan
| | - Yumi Murata
- Department of Chemistry and Biochemistry, School of Advanced Science and Engineering, Waseda University, Tokyo, Japan
| | - Takaki Koide
- Department of Chemistry and Biochemistry, School of Advanced Science and Engineering, Waseda University, Tokyo, Japan
| | - Hiroshi Tokumitsu
- Division of Medical Bioengineering, Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan
| | - Osamu Matsushita
- Department of Bacteriology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
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13
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Kim MJ, Kim J, Lee HY, Noh HJ, Lee KH, Park SJ. Role of AcsR in expression of the acetyl-CoA synthetase gene in Vibrio vulnificus. BMC Microbiol 2015; 15:86. [PMID: 25887971 PMCID: PMC4409781 DOI: 10.1186/s12866-015-0418-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Accepted: 03/25/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND VarS/VarA is one of the global factors regulating diverse aspects of the metabolism and virulence of bacteria including pathogenic Vibrio spp. An experiment to identify the VarS/VarA-regulon in V. vulnificus revealed that a putative LuxR-type transcriptional regulator was down-regulated in ΔvarA mutant. To investigate the roles of this regulatory cascade, the target gene regulated by a LuxR-regulator was identified and its expression was characterized. RESULTS Transcriptomic analysis of the mutant deficient in this LuxR-type regulator showed that the acsA gene encoding acetyl-CoA synthetase was down-regulated. Thus, this regulator was named AcsR for "regulator of acetyl-CoA synthetase". A putative histidine kinase gene, acsS, was located five ORFs downstream of the acsR gene. Expression of an acsA::luxAB transcriptional fusion was decreased in both ΔacsR and ΔacsS mutants. Similar to a ΔacsA mutant, strains carrying deletions either in acsR or acsS grew slowly than wild type in a minimal medium with acetate as a sole carbon source. Growth defect of the ΔacsR strain in acetate-minimal medium was restored by complementation. To investigate if AcsR directly regulates acsA expression, in vitro-gel shift assays were performed using the recombinant AcsR and the regulatory region of the acsA gene, showing that AcsR specifically bound the upstream region of the acsA ORF. CONCLUSION This study indicates that the VarS/VarA system plays a role in V. vulnificus metabolism via regulating AcsR, which in turn controls acetate metabolism by activating the transcription of the acetyl-CoA synthetase gene.
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Affiliation(s)
- Min Jung Kim
- Department of Environmental Medical Biology and Institute of Tropical Medicine, Brain Korea 21 PLUS Project for Medical Science, Yonsei University, Seoul, 120-752, South Korea.
| | - Juri Kim
- Department of Environmental Medical Biology and Institute of Tropical Medicine, Brain Korea 21 PLUS Project for Medical Science, Yonsei University, Seoul, 120-752, South Korea.
| | - Hye Yeon Lee
- Department of Environmental Medical Biology and Institute of Tropical Medicine, Brain Korea 21 PLUS Project for Medical Science, Yonsei University, Seoul, 120-752, South Korea.
| | - Hyeon Jin Noh
- Department of Environmental Medical Biology and Institute of Tropical Medicine, Brain Korea 21 PLUS Project for Medical Science, Yonsei University, Seoul, 120-752, South Korea.
| | - Kyu-Ho Lee
- Department of Life Science, Sogang University, Seoul, 121-742, South Korea.
| | - Soon-Jung Park
- Department of Environmental Medical Biology and Institute of Tropical Medicine, Brain Korea 21 PLUS Project for Medical Science, Yonsei University, Seoul, 120-752, South Korea.
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14
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Jacobs J, Rhodes M, Brown C, Hood R, Leight A, Long W, Wood R. Modeling and forecasting the distribution of Vibrio vulnificus
in Chesapeake Bay. J Appl Microbiol 2014; 117:1312-27. [DOI: 10.1111/jam.12624] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Revised: 08/08/2014] [Accepted: 08/14/2014] [Indexed: 12/13/2022]
Affiliation(s)
- J.M. Jacobs
- National Oceanic and Atmospheric Administration; National Centers for Coastal Ocean Science; Cooperative Oxford Lab; Oxford MD USA
| | - M. Rhodes
- JHT Inc.; Contractor to National Oceanic and Atmospheric Administration; National Centers for Coastal Ocean Science; Cooperative Oxford Lab; Oxford MD USA
| | - C.W. Brown
- National Oceanic and Atmospheric Administration; Center for Satellite Applications and Research; College Park MD USA
| | - R.R. Hood
- Center for Environmental Science; Horn Point Laboratory; University of Maryland; Cambridge MD USA
| | - A. Leight
- National Oceanic and Atmospheric Administration; National Centers for Coastal Ocean Science; Cooperative Oxford Lab; Oxford MD USA
| | - W. Long
- Center for Environmental Science; Horn Point Laboratory; University of Maryland; Cambridge MD USA
- Marine Sciences Laboratory; Pacific Northwest National Laboratory; Sequim WA USA
| | - R. Wood
- National Oceanic and Atmospheric Administration; National Centers for Coastal Ocean Science; Cooperative Oxford Lab; Oxford MD USA
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15
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Bisharat N, Bronstein M, Korner M, Schnitzer T, Koton Y. Transcriptome profiling analysis of Vibrio vulnificus during human infection. MICROBIOLOGY-SGM 2013; 159:1878-1887. [PMID: 23782800 DOI: 10.1099/mic.0.067900-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Vibrio vulnificus is a waterborne pathogen that was responsible for an outbreak of severe soft-tissue infections among fish farmers and fish consumers in Israel. Several factors have been shown to be associated with virulence. However, the transcriptome profile of the pathogen during human infection has not been determined yet. We compared the transcriptome profile, using RNA sequencing, of a human-pathogenic strain harvested directly from tissue of a patient suffering from severe soft-tissue infection with necrotizing fasciitis, with the same strain and three other environmental strains grown in vitro. The five sequenced libraries were aligned to the reference genomes of V. vulnificus strains CMCP6 and YJ016. Approximately 47.8 to 62.3 million paired-end raw reads were generated from the five runs. Nearly 84 % of the genome was covered by reads from at least one of the five runs, suggesting that nearly 16 % of the genome is not transcribed or is transcribed at low levels. We identified 123 genes that were differentially expressed during the acute phase of infection. Sixty-three genes were mapped to the large chromosome, 47 genes mapped to the small chromosome and 13 genes mapped to the YJ016 plasmid. The 123 genes fell into a variety of functional categories including transcription, signal transduction, cell motility, carbohydrate metabolism, intracellular trafficking and cell envelope biogenesis. Among the genes differentially expressed during human infection we identified genes encoding bacterial toxin (RtxA1) and genes involved in flagellar components, Flp-coding region, GGDEF family protein, iron acquisition system and sialic acid metabolism.
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Affiliation(s)
- Naiel Bisharat
- Bruce Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel.,Department of Medicine D, Emek Medical Center, Afula, Israel
| | - Michal Bronstein
- Center for Genomic Technologies, Alexander Silberman Institute of Life Sciences, Hebrew University, Jerusalem, Israel
| | - Mira Korner
- Center for Genomic Technologies, Alexander Silberman Institute of Life Sciences, Hebrew University, Jerusalem, Israel
| | - Temima Schnitzer
- Goldyne Savad Institute of Gene Therapy, Hadassah Medical Center, Hebrew University, Jerusalem, Israel
| | - Yael Koton
- Department of Medicine D, Emek Medical Center, Afula, Israel
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16
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Johnson CN. Fitness factors in vibrios: a mini-review. MICROBIAL ECOLOGY 2013; 65:826-851. [PMID: 23306394 DOI: 10.1007/s00248-012-0168-x] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Accepted: 12/13/2012] [Indexed: 06/01/2023]
Abstract
Vibrios are Gram-negative curved bacilli that occur naturally in marine, estuarine, and freshwater systems. Some species include human and animal pathogens, and some vibrios are necessary for natural systems, including the carbon cycle and osmoregulation. Countless in vivo and in vitro studies have examined the interactions between vibrios and their environment, including molecules, cells, whole animals, and abiotic substrates. Many studies have characterized virulence factors, attachment factors, regulatory factors, and antimicrobial resistance factors, and most of these factors impact the organism's fitness regardless of its external environment. This review aims to identify common attributes among factors that increase fitness in various environments, regardless of whether the environment is an oyster, a rabbit, a flask of immortalized mammalian cells, or a planktonic chitin particle. This review aims to summarize findings published thus far to encapsulate some of the basic similarities among the many vibrio fitness factors and how they frame our understanding of vibrio ecology. Factors representing these similarities include hemolysins, capsular polysaccharides, flagella, proteases, attachment factors, type III secretion systems, chitin binding proteins, iron acquisition systems, and colonization factors.
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Affiliation(s)
- Crystal N Johnson
- Department of Environmental Sciences, Louisiana State University, Baton Rouge, LA, USA.
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17
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Krediet CJ, Carpinone EM, Ritchie KB, Teplitski M. Characterization of the gacA-dependent surface and coral mucus colonization by an opportunistic coral pathogen Serratia marcescens PDL100. FEMS Microbiol Ecol 2013; 84:290-301. [PMID: 23278392 DOI: 10.1111/1574-6941.12064] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Revised: 11/05/2012] [Accepted: 12/11/2012] [Indexed: 12/22/2022] Open
Abstract
Opportunistic pathogens rely on global regulatory systems to assess the environment and to control virulence and metabolism to overcome host defenses and outcompete host-associated microbiota. In Gammaproteobacteria, GacS/GacA is one such regulatory system. GacA orthologs direct the expression of the csr (rsm) small regulatory RNAs, which through their interaction with the RNA-binding protein CsrA (RsmA), control genes with functions in carbon metabolism, motility, biofilm formation, and virulence. The csrB gene was controlled by gacA in Serratia marcescens PDL100. A disruption of the S. marcescens gacA gene resulted in an increased fitness of the mutant on mucus of the host coral Acropora palmata and its high molecular weight fraction, whereas the mutant was as competitive as the wild type on the low molecular weight fraction of the mucus. Swarming motility and biofilm formation were reduced in the gacA mutant. This indicates a critical role for gacA in the efficient utilization of specific components of coral mucus and establishment within the surface mucopolysaccharide layer. While significantly affecting early colonization behaviors (coral mucus utilization, swarming motility, and biofilm formation), gacA was not required for virulence of S. marcescens PDL100 in either a model polyp Aiptasia pallida or in brine shrimp Artemia nauplii.
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Affiliation(s)
- Cory J Krediet
- Interdisciplinary Ecology, University of Florida-IFAS, Gainesville, FL 32610-3610, USA
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18
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Utsumi R, Igarashi M. [Two-component signal transduction as attractive drug targets in pathogenic bacteria]. YAKUGAKU ZASSHI 2012; 132:51-8. [PMID: 22214580 DOI: 10.1248/yakushi.132.51] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Gene clusters contributing to processes such as cell growth and pathogenicity are often controlled by two-component signal transduction systems (TCSs). TCS consists of a histidine kinase (HK) and a response regulator (RR). TCSs are attractive as drug targets for antimicrobials because many HK and RR genes are coded on the bacterial genome though few are found in lower eukaryotes. The HK/RR signal transduction system is distinct from serine/threonine and tyrosine phosphorylation in higher eukaryotes. Specific inhibitors against TCS systems work differently from conventional antibiotics, and developing them into new drugs that are effective against various drug-resistant bacteria may be possible. Furthermore, inhibitors of TCSs that control virulence factors may reduce virulence without killing the pathogenic bacteria. Previous TCS inhibitors targeting the kinase domain of the histidine kinase sensor suffered from poor selectivity. Recent TCS inhibitors, however, target the sensory domains of the sensors blocking the quorum sensing system, or target the essential response regulator. These new targets are introduced, together with several specific TCSs that have the potential to serve as effective drug targets.
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Affiliation(s)
- Ryutaro Utsumi
- Department of Bioscience, Graduate School of Agriculture, Kinki University, 3327-204 Nakamachi, Nara 631-8505, Japan.
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Gopalan S, Ausubel FM. A high throughput amenable Arabidopsis-P. aeruginosa system reveals a rewired regulatory module and the utility to identify potent anti-infectives. PLoS One 2011; 6:e16381. [PMID: 21283656 PMCID: PMC3025032 DOI: 10.1371/journal.pone.0016381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2010] [Accepted: 12/14/2010] [Indexed: 11/18/2022] Open
Abstract
We previously demonstrated that in a metasystem consisting of Arabidopsis seedlings growing in liquid medium (in 96 well plates) even microbes considered to be innocuous such as laboratory strains of E. coli and B. subtilis can cause potent damage to the host. We further posited that such environment-induced adaptations are brought about by 'system status changes' (rewiring of pre-existing cellular signaling networks and components) of the host and the microbe, and that prolongation of such a situation could lead to the emergence of pathogenic states in real-life. Here, using this infection model, we show that the master regulator GacA of the human opportunistic pathogen P. aeruginosa (strain PA14) is dispensable for pathogenesis, as evidenced by three independent read-outs. The gene expression profile of the host after infection with wild type PA14 or the gacA mutant are also identical. GacA normally acts upstream of the quorum sensing regulatory circuit (that includes the regulator LasR) that controls a subset of virulence factors. Double mutants in gacA and lasR behave similar to the lasR mutant, as seen by abrogation of a characteristic cell type specific host cell damage caused by PA14 or the gacA mutant. This indicates that a previously unrecognized regulatory mechanism is operative under these conditions upstream of LasR. In addition, the detrimental effect of PA14 on Arabidopsis seedlings is resistant to high concentrations of the aminoglycoside antibiotic gentamicin. These data suggest that the Arabidopsis seedling infection system could be used to identify anti-infectives with potentially novel modes of action.
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Affiliation(s)
- Suresh Gopalan
- Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts, United States of America.
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