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Kanaan H, Chapalain A, Chokr A, Doublet P, Gilbert C. Legionella pneumophila cell surface RtxA release by LapD/LapG and its role in virulence. BMC Microbiol 2024; 24:266. [PMID: 39026145 PMCID: PMC11264772 DOI: 10.1186/s12866-024-03395-1] [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: 07/06/2023] [Accepted: 06/20/2024] [Indexed: 07/20/2024] Open
Abstract
BACKGROUND Legionella pneumophila is a Gram-negative intracellular bacillus and is the causative agent of a severe form of pneumonia called Legionnaires' disease which accounts for 2-9% of cases of community acquired pneumonia. It produces an extremely large protein belonging to the RTX (Repeats in ToXin) family, called RtxA, and we previously reported that RtxA is transported by a dedicated type 1 secretion system (T1SS) to the cell surface. RTX proteins have been shown to participate in the virulence or biofilm formation of various bacteria, the most studied models being the pore forming hemolysin A (HlyA) of Escherichia coli and the biofilm associated protein LapA of P. fluorescens. LapA localization depends on the enzymatic release by LapD/LapG complex activity. This study aimed to elucidate the dual localization (cell surface associated or released state) of L. pneumophila RTX protein (RtxA) and whether this released versus sequestered state of RtxA plays a role in L. pneumophila virulence. RESULTS The hereby work reveals that, in vitro, LapG periplasmic protease cleaves RtxA N-terminus in the middle of a di-alanine motif (position 108-109). Consistently, a strain lacking LapG protease maintains RtxA on the cell surface, whereas a strain lacking the c-di-GMP receptor LapD does not exhibit cell surface RtxA because of its continuous cleavage and release, as in the LapA-D-G model of Pseudomonas fluorescens. Interestingly, our data point out a key role of RtxA in enhancing the infection process of amoeba cells, regardless of its location (embedded or released); therefore, this may be the result of a secondary role of this surface protein. CONCLUSIONS This is the first experimental identification of the cleavage site within the RTX protein family. The primary role of RtxA in Legionella is still questionable as in many other bacterial species, hence it sounds reasonable to propose a major function in biofilm formation, promoting cell aggregation when RtxA is embedded in the outer membrane and facilitating biofilm dispersion in case of RtxA release. The role of RtxA in enhancing the infection process may be a result of its action on host cells (i.e., PDI interaction or pore-formation), and independently of its status (embedded or released).
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Affiliation(s)
- Hussein Kanaan
- Centre International de Recherche en Infectiologie (CIRI), Université Lyon 1, INSERM U1111, CNRS UMR5308, ENS, Lyon Bât. Rosalind Franklin, 50 avenue Tony Garnier, Lyon, 69007, France
- Research Laboratory of Microbiology (RLM), Department of Life and Earth Sciences, Faculty of Sciences I, Lebanese University, Hadat Campus, Beirut, Lebanon
| | - Annelise Chapalain
- Centre International de Recherche en Infectiologie (CIRI), Université Lyon 1, INSERM U1111, CNRS UMR5308, ENS, Lyon Bât. Rosalind Franklin, 50 avenue Tony Garnier, Lyon, 69007, France
| | - Ali Chokr
- Research Laboratory of Microbiology (RLM), Department of Life and Earth Sciences, Faculty of Sciences I, Lebanese University, Hadat Campus, Beirut, Lebanon
| | - Patricia Doublet
- Centre International de Recherche en Infectiologie (CIRI), Université Lyon 1, INSERM U1111, CNRS UMR5308, ENS, Lyon Bât. Rosalind Franklin, 50 avenue Tony Garnier, Lyon, 69007, France
| | - Christophe Gilbert
- Centre International de Recherche en Infectiologie (CIRI), Université Lyon 1, INSERM U1111, CNRS UMR5308, ENS, Lyon Bât. Rosalind Franklin, 50 avenue Tony Garnier, Lyon, 69007, France.
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2
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Chen T, Wang J, Peng S, Li L, An C, Li J, He W. Vibrio vulnificus infection from tilapia sting wounds in an inland city: A case report. Heliyon 2024; 10:e28012. [PMID: 38533013 PMCID: PMC10963329 DOI: 10.1016/j.heliyon.2024.e28012] [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: 12/12/2023] [Revised: 03/07/2024] [Accepted: 03/11/2024] [Indexed: 03/28/2024] Open
Abstract
Vibrio vulnificus is a pathogen that can cause serious and fatal infections, primarily associated with a history of contact with the sea or aquatic organisms or products. However, with global climate change and increased global seafood trade, V. vulnificus infections are also occurring in non-coastal areas. In this report, we present the successful diagnosis and treatment of a case of necrotizing wound caused by V. vulnificus infection in an inland city in southwest China. In addition, we review the epidemiology and distribution of V. vulnificus in China and related vaccine research, which may provide a reference for the clinical diagnosis and treatment of V. vulnificus infection.
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Affiliation(s)
- Taigui Chen
- Affiliated Hospital of Panzhihua University, Panzhihua, China
| | - Jun Wang
- Affiliated Hospital of Panzhihua University, Panzhihua, China
| | - Shijie Peng
- Affiliated Hospital of Panzhihua University, Panzhihua, China
| | - Lianbao Li
- Panzhihua Central Hospital, Panzhihua, China
| | - Changxue An
- Affiliated Hospital of Panzhihua University, Panzhihua, China
| | - Jun Li
- Affiliated Hospital of Panzhihua University, Panzhihua, China
| | - Wei He
- Affiliated Hospital of Panzhihua University, Panzhihua, China
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3
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Brehm TT, Berneking L, Sena Martins M, Dupke S, Jacob D, Drechsel O, Bohnert J, Becker K, Kramer A, Christner M, Aepfelbacher M, Schmiedel S, Rohde H. Heatwave-associated Vibrio infections in Germany, 2018 and 2019. ACTA ACUST UNITED AC 2021; 26. [PMID: 34651572 PMCID: PMC8518310 DOI: 10.2807/1560-7917.es.2021.26.41.2002041] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Background Vibrio spp. are aquatic bacteria that prefer warm seawater with moderate salinity. In humans, they can cause gastroenteritis, wound infections, and ear infections. During the summers of 2018 and 2019, unprecedented high sea surface temperatures were recorded in the German Baltic Sea. Aim We aimed to describe the clinical course and microbiological characteristics of Vibrio infections in Germany in 2018 and 2019. Methods We performed an observational retrospective multi-centre cohort study of patients diagnosed with domestically-acquired Vibrio infections in Germany in 2018 and 2019. Demographic, clinical, and microbiological data were assessed, and isolates were subjected to whole genome sequencing and antimicrobial susceptibility testing. Results Of the 63 patients with Vibrio infections, most contracted the virus between June and September, primarily in the Baltic Sea: 44 (70%) were male and the median age was 65 years (range: 2–93 years). Thirty-eight patients presented with wound infections, 16 with ear infections, six with gastroenteritis, two with pneumonia (after seawater aspiration) and one with primary septicaemia. The majority of infections were attributed to V. cholerae (non–O1/non-O139) (n = 30; 48%) or V. vulnificus (n = 22; 38%). Phylogenetic analyses of 12 available isolates showed clusters of three identical strains of V. vulnificus, which caused wound infections, suggesting that some clonal lines can spread across the Baltic Sea. Conclusions During the summers of 2018 and 2019, severe heatwaves facilitated increased numbers of Vibrio infections in Germany. Since climate change is likely to favour the proliferation of these bacteria, a further increase in Vibrio-associated diseases is expected.
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Affiliation(s)
- Thomas Theo Brehm
- Division of Infectious Diseases, I. Department of Internal Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,German Center for Infection Research (DZIF), Partner Site Hamburg-Lübeck-Borstel-Riems, Hamburg, Germany.,These authors contributed equally to this article and share first authorship
| | - Laura Berneking
- These authors contributed equally to this article and share first authorship.,Institute of Medical Microbiology, Virology and Hygiene, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Meike Sena Martins
- Institut für Meereskunde, Centrum für Erdsystemwissenschaften und Nachhaltigkeit, University Hamburg, Hamburg, Germany
| | - Susann Dupke
- Robert Koch Institute, ZBS 2: Centre for Biological Threats and Special Pathogens, Highly Pathogenic Microorganisms, Berlin, Germany
| | - Daniela Jacob
- Robert Koch Institute, ZBS 2: Centre for Biological Threats and Special Pathogens, Highly Pathogenic Microorganisms, Berlin, Germany
| | | | - Jürgen Bohnert
- Friedrich Loeffler-Institute of Medical Microbiology, University Medicine Greifswald, Greifswald, Germany
| | - Karsten Becker
- Friedrich Loeffler-Institute of Medical Microbiology, University Medicine Greifswald, Greifswald, Germany
| | - Axel Kramer
- Institute of Hygiene and Environmental Medicine, University Medicine Greifswald, Greifswald, Germany
| | - Martin Christner
- Institute of Medical Microbiology, Virology and Hygiene, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Martin Aepfelbacher
- German Center for Infection Research (DZIF), Partner Site Hamburg-Lübeck-Borstel-Riems, Hamburg, Germany.,Institute of Medical Microbiology, Virology and Hygiene, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Stefan Schmiedel
- Division of Infectious Diseases, I. Department of Internal Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,German Center for Infection Research (DZIF), Partner Site Hamburg-Lübeck-Borstel-Riems, Hamburg, Germany
| | - Holger Rohde
- German Center for Infection Research (DZIF), Partner Site Hamburg-Lübeck-Borstel-Riems, Hamburg, Germany.,Institute of Medical Microbiology, Virology and Hygiene, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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- The members of the Study Group are listed at the end of the article
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4
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Cai R, Liu N, Guo P, Liao K, Li M, Zhu J, Chen S, Chen L, Shu B, Qi S. Protective Effects of Chicken Egg Yolk Immunoglobulins (IgYs) against Vibrio vulnificus Infections. J Immunol Res 2021; 2021:6678513. [PMID: 33506061 PMCID: PMC7808826 DOI: 10.1155/2021/6678513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 12/20/2020] [Accepted: 12/28/2020] [Indexed: 11/30/2022] Open
Abstract
Vibrio (V.) vulnificus infection is a rare disease whose death rates exceed 50% despite aggressive antibiotic treatment and surgical debridement. The aim of this study was to assess the ability of specific anti-V. vulnificus immunoglobulins Y (IgYs) for preventing and treating V. vulnificus infections. IgYs were produced by immunizing egg laying hens with inactivated whole cell bacteria. Peritoneal cytokines, blood's bacterial load, and survival curves were obtained from both prophylactic and therapeutic mouse models. The results showed that the specific IgYs (i) inhibited the growth of V. vulnificus in vitro, (ii) dramatically reduced the inflammatory response and blood's bacterial load, and (iii) improved the survival rate of V. vulnificus-infected mice. These results prove that anti-V. vulnificus IgYs can be markedly effective means for the prophylaxis and the therapy of V. vulnificus infections.
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Affiliation(s)
- Ruizhao Cai
- Department of Burns, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510080 Guangdong Province, China
- Guangdong Engineering & Technology Research Center for Precise Diagnosis and Treatment of Burns and Wounds, Guangzhou, 510080 Guangdong Province, China
| | - Ning Liu
- Department of Burns, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510080 Guangdong Province, China
- Guangdong Engineering & Technology Research Center for Precise Diagnosis and Treatment of Burns and Wounds, Guangzhou, 510080 Guangdong Province, China
| | - Penghao Guo
- Department of Clinical Laboratory, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510080 Guangdong Province, China
| | - Kang Liao
- Department of Clinical Laboratory, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510080 Guangdong Province, China
| | - Mengzhi Li
- Department of Burns, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510080 Guangdong Province, China
- Guangdong Engineering & Technology Research Center for Precise Diagnosis and Treatment of Burns and Wounds, Guangzhou, 510080 Guangdong Province, China
| | - Junyou Zhu
- Department of Burns, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510080 Guangdong Province, China
- Guangdong Engineering & Technology Research Center for Precise Diagnosis and Treatment of Burns and Wounds, Guangzhou, 510080 Guangdong Province, China
| | - Shouyi Chen
- Guangzhou Center for Disease Control and Prevention, Guangzhou 510080, Guangdong Province, China
| | - Lei Chen
- Department of Burns, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510080 Guangdong Province, China
- Guangdong Engineering & Technology Research Center for Precise Diagnosis and Treatment of Burns and Wounds, Guangzhou, 510080 Guangdong Province, China
| | - Bin Shu
- Department of Burns, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510080 Guangdong Province, China
- Guangdong Engineering & Technology Research Center for Precise Diagnosis and Treatment of Burns and Wounds, Guangzhou, 510080 Guangdong Province, China
| | - Shaohai Qi
- Department of Burns, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510080 Guangdong Province, China
- Guangdong Engineering & Technology Research Center for Precise Diagnosis and Treatment of Burns and Wounds, Guangzhou, 510080 Guangdong Province, China
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5
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Guo S, Hu L, Feng J, Lin P, He L, Yan Q. Immunogenicity of a bivalent protein as a vaccine against Edwardsiella anguillarum and Vibrio vulnificus in Japanese eel (Anguilla japonica). Microbiologyopen 2018; 8:e00766. [PMID: 30444580 PMCID: PMC6562130 DOI: 10.1002/mbo3.766] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Revised: 10/13/2018] [Accepted: 10/16/2018] [Indexed: 02/03/2023] Open
Abstract
The OMPs A (OmpA)—of Edwardsiella anguillarum and OmpU of V. vulnificus have been proven to be good antigens. In this study, after construction of a vector, a new recombinant Omp (rOMP) containing both OmpA and OmpU was expressed and purified. Then, the Japanese eels (Anguilla japonica) were intraperitoneally (i.p.) injected with the phosphate‐buffered saline (PBS group), formalin‐killed‐cell (FKC group) or the recombinant Omp (rOMP group). The stimulation index of the whole blood cells in eels from FKC group was significantly higher than the eels from PBS and rOMP groups at 28 dpi; serum titers of anti‐E. anguillarum and anti‐V. vulnificus antibody of eels from FKC and rOMP group increased significantly at 21 and 28 dpi; in the rOMP group, eels serum titer stayed at a high level on 42 dpi. The activities of lysozyme in skin mucus, liver, kidney, and serum in three groups exhibited considerable changes. The relative percent survival (RPS) rate of eels from rOMP group were 100% and 83% when challenged with V. vulnificus or E. anguillarum. These results indicated that inoculation of rOMP would protect Japanese eels against the infection by E. anguillarum and V. vulnificus.
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Affiliation(s)
- Songlin Guo
- Fishery College of Jimei University/Engineering Research Center of Modern Eel Industrial Technology of the Ministry of Education, PRC, Xiamen, China.,Jimei University, Fujian, Xiamen, China
| | - Linlin Hu
- Fishery College of Jimei University/Engineering Research Center of Modern Eel Industrial Technology of the Ministry of Education, PRC, Xiamen, China.,Jimei University, Fujian, Xiamen, China
| | - Jianjun Feng
- Fishery College of Jimei University/Engineering Research Center of Modern Eel Industrial Technology of the Ministry of Education, PRC, Xiamen, China.,Jimei University, Fujian, Xiamen, China
| | - Peng Lin
- Fishery College of Jimei University/Engineering Research Center of Modern Eel Industrial Technology of the Ministry of Education, PRC, Xiamen, China.,Jimei University, Fujian, Xiamen, China
| | - Le He
- Fishery College of Jimei University/Engineering Research Center of Modern Eel Industrial Technology of the Ministry of Education, PRC, Xiamen, China.,Jimei University, Fujian, Xiamen, China
| | - Qingpi Yan
- Fishery College of Jimei University/Engineering Research Center of Modern Eel Industrial Technology of the Ministry of Education, PRC, Xiamen, China.,Jimei University, Fujian, Xiamen, China
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6
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Yamazaki K, Kashimoto T, Hashimoto Y, Kado T, Ueno S. Immunogenicity and protective efficacy of Vibrio vulnificus flagellin protein FlaB in a wound infection model. J Vet Med Sci 2018; 80:55-58. [PMID: 29142160 PMCID: PMC5797859 DOI: 10.1292/jvms.17-0395] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Vibrio vulnificus is known as an opportunistic bacterial pathogen that causes primary septicemia and wound infection in humans. Recently, the incidence of wound infection by V. vulnificus is increasing in warm countries. In this study, we examined a vaccine antigen against V. vulnificus in mice. FlaB, a component protein of the V. vulnificus flagellum, was expressed as a recombinant protein, named rFlaB. After immunization of mice with rFlaB, the mice were challenged by subcutaneous inoculation with V. vulnificus. Bacterial burdens in muscular tissue at the infection site in rFlaB-immunized mice were significantly decreased compared with those of control mice. We found that rFlaB immunization can partially suppress proliferation of V. vulnificus at the local infection site.
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Affiliation(s)
- Kohei Yamazaki
- Laboratory of Veterinary Public Health, School of Veterinary Medicine, Kitasato University, Higashi 23-35-1, Towada, Aomori 034-8628, Japan
| | - Takashige Kashimoto
- Laboratory of Veterinary Public Health, School of Veterinary Medicine, Kitasato University, Higashi 23-35-1, Towada, Aomori 034-8628, Japan
| | - Yuki Hashimoto
- Laboratory of Veterinary Public Health, School of Veterinary Medicine, Kitasato University, Higashi 23-35-1, Towada, Aomori 034-8628, Japan
| | - Takehiro Kado
- Laboratory of Veterinary Public Health, School of Veterinary Medicine, Kitasato University, Higashi 23-35-1, Towada, Aomori 034-8628, Japan
| | - Shunji Ueno
- Laboratory of Veterinary Public Health, School of Veterinary Medicine, Kitasato University, Higashi 23-35-1, Towada, Aomori 034-8628, Japan
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7
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Heng SP, Letchumanan V, Deng CY, Ab Mutalib NS, Khan TM, Chuah LH, Chan KG, Goh BH, Pusparajah P, Lee LH. Vibrio vulnificus: An Environmental and Clinical Burden. Front Microbiol 2017; 8:997. [PMID: 28620366 PMCID: PMC5449762 DOI: 10.3389/fmicb.2017.00997] [Citation(s) in RCA: 103] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 05/17/2017] [Indexed: 12/14/2022] Open
Abstract
Vibrio vulnificus is a Gram negative, rod shaped bacterium that belongs to the family Vibrionaceae. It is a deadly, opportunistic human pathogen which is responsible for the majority of seafood-associated deaths worldwide. V. vulnificus infection can be fatal as it may cause severe wound infections potentially requiring amputation or lead to sepsis in susceptible individuals. Treatment is increasingly challenging as V. vulnificus has begun to develop resistance against certain antibiotics due to their indiscriminate use. This article aims to provide insight into the antibiotic resistance of V. vulnificus in different parts of the world as well as an overall review of its clinical manifestations, treatment, and prevention. Understanding the organism's antibiotic resistance profile is vital in order to select appropriate treatment and initiate appropriate prevention measures to treat and control V. vulnificus infections, which should eventually help lower the mortality rate associated with this pathogen worldwide.
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Affiliation(s)
- Sing-Peng Heng
- Jeffrey Cheah School of Medicine and Health Sciences, Monash University MalaysiaBandar Sunway, Malaysia
| | - Vengadesh Letchumanan
- Division of Genetics and Molecular Biology, Faculty of Science, Institute of Biological Sciences, University of MalayaKuala Lumpur, Malaysia
- Novel Bacteria and Drug Discovery Research Group, School of Pharmacy, Monash University MalaysiaBandar Sunway, Malaysia
| | - Chuan-Yan Deng
- Zhanjiang Evergreen South Ocean Science and Technology CorporationGuangdong, China
| | - Nurul-Syakima Ab Mutalib
- UKM Medical Centre, UKM Medical Molecular Biology Institute, Universiti Kebangsaan MalaysiaKuala Lumpur, Malaysia
| | - Tahir M. Khan
- Novel Bacteria and Drug Discovery Research Group, School of Pharmacy, Monash University MalaysiaBandar Sunway, Malaysia
- Department of Pharmacy, Absyn University PeshawarPeshawar, Pakistan
| | - Lay-Hong Chuah
- Novel Bacteria and Drug Discovery Research Group, School of Pharmacy, Monash University MalaysiaBandar Sunway, Malaysia
| | - Kok-Gan Chan
- Division of Genetics and Molecular Biology, Faculty of Science, Institute of Biological Sciences, University of MalayaKuala Lumpur, Malaysia
| | - Bey-Hing Goh
- Novel Bacteria and Drug Discovery Research Group, School of Pharmacy, Monash University MalaysiaBandar Sunway, Malaysia
- Center of Health Outcomes Research and Therapeutic Safety (Cohorts), School of Pharmaceutical Sciences, University of PhayaoPhayao, Thailand
| | - Priyia Pusparajah
- Jeffrey Cheah School of Medicine and Health Sciences, Monash University MalaysiaBandar Sunway, Malaysia
| | - Learn-Han Lee
- Novel Bacteria and Drug Discovery Research Group, School of Pharmacy, Monash University MalaysiaBandar Sunway, Malaysia
- Center of Health Outcomes Research and Therapeutic Safety (Cohorts), School of Pharmaceutical Sciences, University of PhayaoPhayao, Thailand
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Lee TH, Cha SS, Lee CS, Rhee JH, Woo HR, Chung KM. Cross-protection against Vibrio cholerae infection by monoclonal antibodies against Vibrio vulnificus RtxA1/MARTX Vv. Microbiol Immunol 2016; 60:793-800. [PMID: 27921342 DOI: 10.1111/1348-0421.12449] [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: 06/18/2016] [Revised: 10/17/2016] [Accepted: 11/01/2016] [Indexed: 01/09/2023]
Abstract
Gram-negative Vibrio species secrete multifunctional autoprocessing repeats-in-toxin (MARTX) toxins associated with bacterial pathogenesis. Here, the cross-reactivity and cross-protectivity of mAbs against V. vulnificus RtxA1/MARTXVv was evaluated. Passive administration of any of these mAbs (21RA, 24RA, 46RA, 47RA and 50RA) provided strong protection against lethal V. cholerae infection. Interestingly, 24RA and 46RA, which map to the cysteine protease domain of V. cholerae MARTXVc , inhibited CPD autocleavage in vitro; this process is involved in V. cholerae pathogenesis. These results generate new insight into the development of broadly protective mAbs and/or vaccines against Vibrio species with MARTX toxins.
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Affiliation(s)
- Tae Hee Lee
- Department of Microbiology and Immunology, Chonbuk National University Medical School, Jeonju, Jeonbuk 54896, Republic of Korea.,Institute for Medical Science, Chonbuk National University Medical School, Jeonju, Jeonbuk 54896, Republic of Korea
| | - Sun-Shin Cha
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Chang-Seop Lee
- Department of Internal Medicine, Chonbuk National University Medical School, Jeonju, Jeonbuk 54896, Republic of Korea
| | - Joon Haeng Rhee
- Department of Microbiology and Clinical Vaccine R&D Center, Chonnam National University Medical School, Gwangju 61469, Republic of Korea
| | - Hye Ryun Woo
- Department of New Biology, DGIST, Daegu 42988, Republic of Korea
| | - Kyung Min Chung
- Department of Microbiology and Immunology, Chonbuk National University Medical School, Jeonju, Jeonbuk 54896, Republic of Korea.,Institute for Medical Science, Chonbuk National University Medical School, Jeonju, Jeonbuk 54896, Republic of Korea
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9
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Garrett SB, Garrison-Schilling KL, Cooke JT, Pettis GS. Capsular polysaccharide production and serum survival of Vibrio vulnificus are dependent on antitermination control by RfaH. FEBS Lett 2016; 590:4564-4572. [PMID: 27859050 DOI: 10.1002/1873-3468.12490] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Revised: 11/06/2016] [Accepted: 11/10/2016] [Indexed: 12/19/2022]
Abstract
The human pathogen Vibrio vulnificus undergoes phase variation among colonial morphotypes, including a virulent opaque form which produces capsular polysaccharide (CPS) and a translucent phenotype that produces little or no CPS and is attenuated. Here, we found that a V. vulnificus mutant defective for RfaH antitermination control showed a diminished capacity to undergo phase variation and displayed significantly reduced distal gene expression within the Group I CPS operon. Moreover, the rfaH mutant produced negligible CPS and was highly sensitive to killing by normal human serum, results which indicate that RfaH is likely essential for virulence in this bacterium.
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Affiliation(s)
- Shana B Garrett
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, USA
| | | | - Jeffrey T Cooke
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, USA
| | - Gregg S Pettis
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, USA
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10
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Abstract
Multifunctional-autoprocessing repeats-in-toxin (MARTX) toxins are a heterogeneous group of toxins found in a number of Vibrio species and other Gram-negative bacteria. The toxins are composed of conserved repeat regions and an autoprocessing protease domain that together function as a delivery platform for transfer of cytotoxic and cytopathic domains into target eukaryotic cell cytosol. Within the cells, the effectors can alter biological processes such as signaling or cytoskeletal structure, presumably to the benefit of the bacterium. Ten effector domains are found in the various Vibrio MARTX toxins, although any one toxin carries only two to five effector domains. The specific toxin variant expressed by a species can be modified by homologous recombination to acquire or lose effector domains, such that different strains within the same species can express distinct variants of the toxins. This review examines the conserved structural elements of the MARTX toxins and details the different toxin arrangements carried by Vibrio species and strains. The catalytic function of domains and how the toxins are linked to pathogenesis of human and animals is described.
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11
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Kim YR, Lee SE, Kim JR, Rhee JH. Safety and vaccine efficacy of an attenuated Vibrio vulnificus strain with deletions in major cytotoxin genes. FEMS Microbiol Lett 2015; 362:fnv169. [PMID: 26381905 DOI: 10.1093/femsle/fnv169] [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] [Accepted: 09/14/2015] [Indexed: 11/12/2022] Open
Abstract
Vibrio vulnificus is a human pathogen causing a rapidly progressing fatal septicemia. We have previously reported that a V. vulnificus large toxin RtxA1 causes programmed necrotic cell death through calcium-mediated mitochondrial dysfunction. Here we developed a live attenuated vaccine strain (CMM781) having deletions in three genes encoding major virulence factors: RTX cytotoxin (rtxA1), hemolysin/cytolysin (vvhA) and metalloprotease (vvpE) of a clinical isolate strain CMCP6. The CMM781 strain showed significant attenuation in cytotoxicity and mouse lethality. The safety of CMM781 was also confirmed by measuring the transepithelial electric resistance of Caco-2 cell monolayers. Intragastric immunization of mice with the live attenuated V. vulnificus strain resulted in induction of systemic and mucosal antibodies specific to the pathogen. Moreover, the vaccinated mice were protected from challenges with high doses of the virulent strain through various injection routes. These results suggest that CMM781 appears to be a safe and effective vaccine candidate that would provide significant protection against V. vulnificus infection.
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Affiliation(s)
- Young Ran Kim
- Clinical Vaccine R&D Center, Chonnam National University Hwasun Hospital, Chonnam National University Medical School, Hwasun 519-763, Korea College of Pharmacy, Chonnam National University, Gwangju 500-757, Korea
| | - Shee Eun Lee
- Clinical Vaccine R&D Center, Chonnam National University Hwasun Hospital, Chonnam National University Medical School, Hwasun 519-763, Korea Department of Pharmacology and Dental Therapeutics, Dental Research Institute, Chonnam National University, Gwangju 500-757, Korea
| | - Jong Ro Kim
- Busung Food and Business, Jangheung, Jeonnam 529-873, Korea
| | - Joon Haeng Rhee
- Clinical Vaccine R&D Center, Chonnam National University Hwasun Hospital, Chonnam National University Medical School, Hwasun 519-763, Korea Research Institute of Vibrio Infections and Genome Research Center for Enteropathogenic Bacteria, Chonnam National University Hwasun Hospital, Chonnam National University Medical School, Hwasun 519-763, Korea Department of Microbiology, Chonnam National University Hwasun Hospital, Chonnam National University Medical School, Hwasun 519-763, Korea
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Lee TH, Chung KM. Development and characterization of a catalytically inactive cysteine protease domain of RtxA1/MARTXVv as a potential vaccine for Vibrio vulnificus. Microbiol Immunol 2015; 59:555-61. [PMID: 26177798 DOI: 10.1111/1348-0421.12284] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Revised: 07/01/2015] [Accepted: 07/12/2015] [Indexed: 01/22/2023]
Abstract
Recent studies have defined several virulence factors as vaccine candidates against Vibrio vulnificus. However, most of these factors have the potential to cause pathogenic effects in the vaccinees or induce incomplete protection. To overcome these drawbacks, a catalytically inactive form, CPDVv (C3725S), of the well-conserved cysteine protease domain (CPD) of V. vulnificus multifunctional autoprocessing repeats-in-toxin (MARTXVv /RtxA1) was recombinantly generated and characterized. Notably, active and passive immunization with CPDVv (C3725S) conferred protective immunity against V. vulnificus strains. These results may provide a novel framework for developing safe and efficient subunit vaccines and/or therapeutics against V. vulnificus that target the CPD of MARTX toxins.
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Affiliation(s)
| | - Kyung Min Chung
- Department of Microbiology and Immunology.,Institute for Medical Science, Chonbuk National University Medical School, Jeonju, Jeonbuk, 561-756, Korea
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SongLin G, PanPan L, JianJun F, JinPing Z, Peng L, LiHua D. A novel recombinant bivalent outer membrane protein of Vibrio vulnificus and Aeromonas hydrophila as a vaccine antigen of American eel (Anguilla rostrata). FISH & SHELLFISH IMMUNOLOGY 2015; 43:477-484. [PMID: 25655329 DOI: 10.1016/j.fsi.2015.01.017] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Revised: 01/08/2015] [Accepted: 01/22/2015] [Indexed: 06/04/2023]
Abstract
The immogenicity of a novel vaccine antigen was evaluated after immunized American eels (Anguilla rostrata) with a recombinant bivalent expressed outer membrane protein (OMP) of Vibrio vulnificus and Aeromonas hydrophila. Three groups of eels were intraperitoneal (i.p) injected with phosphate-buffered saline (PBS group), formaline-killed-whole-cell (FKC) of A. hydrophila and V. vulnificus (FKC group) or the bivalent OMP (OMP group). On 14, 21, 28 and 42 days post-vaccination respectively, proliferation of the whole blood cells, titers of specific antibody and lysozyme activities of experimental eels were detected. On 28 day post-vaccination, eels from three groups were challenged by i.p injection of live A. hydrophila or V. vulnificus. The results showed that, compared with the PBS group, proliferation of whole blood cells in OMP group was significant enhanced on 28 days, and the serum titers of anti-A.hydrophila and anti-V. vulnificus antibody in eels of FKC and OMP group were significant increased on 14, 21 and 28d. Lysozyme Activities in serum, skin mucus, liver and kidney were significant changed between the three groups. Relative Percent Survival (RPS) after challenged A. hydrophila in KFC vs. PBS group and OMP vs. PBS group were 62.5% and 50% respectively, and the RPS challenged V. vulnificus in FKC and OMP vs. PBS group were 37.5% and 50% respectively. These results suggest that American eels immunized with the bivalent OMP would positively affect specific as well as non-specific immune parameters and protect against infection by the two pathogens in fresh water farming.
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Affiliation(s)
- Guo SongLin
- Fishery College of Jimei University/Engineering Research Center of Modern Eel Industrial Technology of the Ministry of Education, PRC. Jimei University, Xiamen, Fujian 361021, China.
| | - Lu PanPan
- Fishery College of Jimei University/Engineering Research Center of Modern Eel Industrial Technology of the Ministry of Education, PRC. Jimei University, Xiamen, Fujian 361021, China
| | - Feng JianJun
- Fishery College of Jimei University/Engineering Research Center of Modern Eel Industrial Technology of the Ministry of Education, PRC. Jimei University, Xiamen, Fujian 361021, China
| | - Zhao JinPing
- Fishery College of Jimei University/Engineering Research Center of Modern Eel Industrial Technology of the Ministry of Education, PRC. Jimei University, Xiamen, Fujian 361021, China
| | - Lin Peng
- Fishery College of Jimei University/Engineering Research Center of Modern Eel Industrial Technology of the Ministry of Education, PRC. Jimei University, Xiamen, Fujian 361021, China
| | - Duan LiHua
- Fishery College of Jimei University/Engineering Research Center of Modern Eel Industrial Technology of the Ministry of Education, PRC. Jimei University, Xiamen, Fujian 361021, China
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Distinct roles of the repeat-containing regions and effector domains of the Vibrio vulnificus multifunctional-autoprocessing repeats-in-toxin (MARTX) toxin. mBio 2015; 6:mBio.00324-15. [PMID: 25827415 PMCID: PMC4453568 DOI: 10.1128/mbio.00324-15] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Vibrio vulnificus is a seafood-borne pathogen that destroys the intestinal epithelium, leading to rapid bacterial dissemination and death. The most important virulence factor is the multifunctional-autoprocessing repeats-in-toxin (MARTX) toxin comprised of effector domains in the center region flanked by long repeat-containing regions which are well conserved among MARTX toxins and predicted to translocate effector domains. Here, we examined the role of the repeat-containing regions using a modified V. vulnificus MARTX (MARTXVv) toxin generated by replacing all the internal effector domains with β-lactamase (Bla). Bla activity was detected in secretions from the bacterium and also in the cytosol of intoxicated epithelial cells. The modified MARTXVv toxin without effector domains retained its necrotic activity but lost its cell-rounding activity. Further, deletion of the carboxyl-terminal repeat-containing region blocked toxin secretion from the bacterium. Deletion of the amino-terminal repeat-containing region had no effect on secretion but completely abolished translocation and necrosis. Neither secretion nor translocation was affected by enzymatically inactivating the cysteine protease domain of the toxin. These data demonstrate that the amino-terminal and carboxyl-terminal repeat-containing regions of the MARTXVv toxin are necessary and sufficient for the delivery of effector domains and epithelial cell lysis in vitro but that effector domains are required for other cytopathic functions. Furthermore, Ca2+-dependent secretion of the modified MARTXVv toxin suggests that nonclassical RTX-like repeats found in the carboxyl-terminal repeat-containing region are functionally similar to classical RTX repeats found in other RTX proteins. Up to 95% of deaths from seafood-borne infections in the United States are due solely to one pathogen, V. vulnificus. Among its various virulence factors, the MARTXVv toxin has been characterized as a critical exotoxin for successful pathogenesis of V. vulnificus in mouse infection models. Similarly to MARTX toxins of other pathogens, MARTXVv toxin is comprised of repeat-containing regions, central effector domains, and an autoprocessing cysteine protease domain. Yet how each of these regions contributes to essential activities of the toxins has not been fully identified for any of MARTX toxins. Using modified MARTXVv toxin fused with β-lactamase as a reporter enzyme, the portion(s) responsible for toxin secretion from bacteria, effector domain translocation into host cells, rapid host cell rounding, and necrotic host cell death was identified. The results are relevant for understanding how MARTXVv toxin serves as both a necrotic pore-forming toxin and an effector delivery platform.
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Monoclonal antibodies against Vibrio vulnificus RtxA1 elicit protective immunity through distinct mechanisms. Infect Immun 2014; 82:4813-23. [PMID: 25156730 DOI: 10.1128/iai.02130-14] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Vibrio vulnificus causes rapidly progressing septicemia with an extremely high mortality rate (≥50%), even with aggressive antibiotic treatment. The bacteria secrete multifunctional autoprocessing repeats-in-toxin (MARTX) toxins, which are involved in the pathogenesis of Gram-negative Vibrio species. Recently, we reported that immunization with the C-terminal region of V. vulnificus RtxA1/MARTXVv, RtxA1-C, elicits a protective immune response against V. vulnificus through a poorly defined mechanism. In this study, we generated a panel of new monoclonal antibodies (MAbs) against V. vulnificus RtxA1-C and investigated their protective efficacies and mechanisms in a mouse model of infection. Prophylactic administration of seven MAbs strongly protected mice against lethal V. vulnificus infection (more than 90% survival). Moreover, three of these MAbs (21RA, 24RA, and 47RA) demonstrated marked efficacy as postexposure therapy. Notably, 21RA was therapeutically effective against lethal V. vulnificus infection by a variety of routes. Using Fab fragments and a neutropenic mouse model, we showed that 21RA and 24RA mediate protection from V. vulnificus infection through an Fc-independent and/or neutrophil-independent pathway. In contrast, 47RA-mediated protection was dependent on its Fc region and was reduced to 50% in neutropenic mice compared with 21RA-mediated and 24RA-mediated protection. Bacteriological study indicated that 21RA appears to enhance the clearance of V. vulnificus from the blood. Overall, these studies suggest that humoral immunity controls V. vulnificus infection through at least two different mechanisms. Furthermore, our panel of MAbs could provide attractive candidates for the further development of immunoprophylaxis/therapeutics and other therapies against V. vulnificus that target the MARTX toxin.
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Vibrio vulnificus biotype 3 multifunctional autoprocessing RTX toxin is an adenylate cyclase toxin essential for virulence in mice. Infect Immun 2014; 82:2148-57. [PMID: 24614656 DOI: 10.1128/iai.00017-14] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Vibrio vulnificus is an environmental organism that causes both food-borne and wound infections with high morbidity and mortality in humans. The annual incidence and global distribution of infections associated with this pathogen are increasing with climate change. In the late 1990s, an outbreak of tilapia-associated wound infections in Israel was linked to a previously unrecognized variant of V. vulnificus designated biotype 3. The sudden emergence and clonality of the outbreak suggest that this strain may be a true newly emergent pathogen with novel virulence properties compared to those of other V. vulnificus strains. In a subcutaneous infection model to mimic wound infection, the multifunctional autoprocessing RTX (MARTX) toxin of biotype 3 strains was shown to be an essential virulence factor contributing to highly inflammatory skin wounds with severe damage affecting every tissue layer. We conducted a sequencing-based analysis of the MARTX toxin and found that biotype 3 MARTX toxin has an effector domain structure distinct from that of either biotype 1 or biotype 2. Of the two new domains identified, a domain similar to Pseudomonas aeruginosa ExoY was shown to confer adenylate cyclase activity on the MARTX toxin. This is the first demonstration that the biotype 3 MARTX toxin is essential for virulence and that the ExoY-like MARTX effector domain is a catalytically active adenylate cyclase.
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