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Chakraborty S, Gnanagobal H, Hossain A, Cao T, Vasquez I, Boyce D, Santander J. Inactivated Aeromonas salmonicida impairs adaptive immunity in lumpfish (Cyclopterus lumpus). JOURNAL OF FISH DISEASES 2024; 47:e13944. [PMID: 38523320 DOI: 10.1111/jfd.13944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Revised: 02/25/2024] [Accepted: 03/01/2024] [Indexed: 03/26/2024]
Abstract
Aeromonas salmonicida, a widely distributed aquatic pathogen causing furunculosis in fish, exhibits varied virulence, posing challenges in infectious disease and immunity studies, notably in vaccine efficacy assessment. Lumpfish (Cyclopterus lumpus) has become a valuable model for marine pathogenesis studies. This study evaluated several antigen preparations against A. salmonicida J223, a hypervirulent strain of teleost fish, including lumpfish. The potential immune protective effect of A. salmonicida bacterins in the presence and absence of the A-layer and extracellular products was tested in lumpfish. Also, we evaluated the impact of A. salmonicida outer membrane proteins (OMPs) and iron-regulated outer membrane proteins (IROMPs) on lumpfish immunity. The immunized lumpfish were intraperitoneally (i.p.) challenged with 104 A. salmonicida cells/dose at 8 weeks-post immunization (wpi). Immunized and non-immunized fish died within 2 weeks post-challenge. Our analyses showed that immunization with A. salmonicida J223 bacterins and antigen preparations did not increase IgM titres. In addition, adaptive immunity biomarker genes (e.g., igm, mhc-ii and cd4) were down-regulated. These findings suggest that A. salmonicida J223 antigen preparations hinder lumpfish immunity. Notably, many fish vaccines are bacterin-based, often lacking efficacy evaluation. This study offers crucial insights for finfish vaccine approval and regulations.
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Affiliation(s)
- Setu Chakraborty
- Marine Microbial Pathogenesis and Vaccinology Laboratory, Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada
| | - Hajarooba Gnanagobal
- Marine Microbial Pathogenesis and Vaccinology Laboratory, Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada
| | - Ahmed Hossain
- Marine Microbial Pathogenesis and Vaccinology Laboratory, Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada
| | - Trung Cao
- Marine Microbial Pathogenesis and Vaccinology Laboratory, Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada
| | - Ignacio Vasquez
- Marine Microbial Pathogenesis and Vaccinology Laboratory, Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada
| | - Danny Boyce
- Department of Ocean Sciences, Dr. Joe Brown Aquatic Research Building, Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada
| | - Javier Santander
- Marine Microbial Pathogenesis and Vaccinology Laboratory, Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada
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Pradhan SK, Devi R, Khan MIR, Kamilya D, Gon Choudhury T, Parhi J. Isolation of Aeromonas salmonicida subspecies salmonicida from aquaculture environment in India: Polyphasic identification, virulence characterization, and antibiotic susceptibility. Microb Pathog 2023; 179:106100. [PMID: 37028687 DOI: 10.1016/j.micpath.2023.106100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 04/05/2023] [Accepted: 04/05/2023] [Indexed: 04/09/2023]
Abstract
This study reports the polyphasic identification, characterization of virulence potential, and antibiotic susceptibility of Aeromonas salmonicida subspecies salmonicida COFCAU_AS, isolated from an aquaculture system in India. The physiological, biochemical, 16s rRNA gene sequencing and PAAS PCR test identified the strain as Aeromonas salmonicida. The MIY PCR tests established the subspecies as 'salmonicida'. The in vitro tests showed the isolated bacterium as haemolytic with casein, lipid, starch, and gelatin hydrolysis activity, indicating its pathogenic attributes. It also showed the ability to produce slime and biofilm, and additionally, it possessed an A-layer surface protein. In vivo pathogenicity test was performed to determine the LD50 dose of the bacterium in Labeo rohita fingerlings (14.42 ± 1.01 g), which was found to be 106.9 cells fish-1. The bacteria-challenged fingerlings showed skin lesions, erythema at the base of the fins, dropsy, and ulcer. Almost identical clinical signs and mortalities were observed when the same LD50 dose was injected into other Indian major carp species, L. catla and Cirrhinus mrigala. Out of the twelve virulent genes screened, the presence of nine genes viz., aerA, act, ast, alt, hlyA, vapA, exsA, fstA, and lip were detected, whereas ascV, ascC, and ela genes were absent. The A. salmonicida subsp. salmonicida COFCAU_AS was resistant to antibiotics such as penicillin G, rifampicin, ampicillin, and vancomycin while highly sensitive to amoxiclav, nalidixic acid, chloramphenicol, ciprofloxacin, and tetracycline. In summary, we have isolated a virulent A. salmonicida subsp. salmonicida from a tropical aquaculture pond which can cause significant mortality and morbidity in Indian major carp species.
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Affiliation(s)
- Subham Kumar Pradhan
- Dept. of Aquatic Health & Environment, College of Fisheries, CAU, Lembucherra, Tripura, 799210, India
| | - Rajashree Devi
- Dept. of Aquatic Health & Environment, College of Fisheries, CAU, Lembucherra, Tripura, 799210, India
| | - Md Idrish Raja Khan
- Dept. of Aquatic Health & Environment, College of Fisheries, CAU, Lembucherra, Tripura, 799210, India; Late Shri Punaram Nishad College of Fisheries, DSVCKU, Kawardha, 491995, Chhattisgarh, India
| | - Dibyendu Kamilya
- Dept. of Aquatic Health & Environment, College of Fisheries, CAU, Lembucherra, Tripura, 799210, India; Agricultural and Food Engineering Department, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal, 721302, India
| | - Tanmoy Gon Choudhury
- Dept. of Aquatic Health & Environment, College of Fisheries, CAU, Lembucherra, Tripura, 799210, India.
| | - Janmejay Parhi
- Dept. of Fish Genetics & Reproduction, College of Fisheries, CAU, Lembucherra, Tripura, 799210, India
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Cai H, Yu J, Qiao Y, Ma Y, Zheng J, Lin M, Yan Q, Huang L. Effect of the Type VI Secretion System Secreted Protein Hcp on the Virulence of Aeromonas salmonicida. Microorganisms 2022; 10:microorganisms10122307. [PMID: 36557560 PMCID: PMC9784854 DOI: 10.3390/microorganisms10122307] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 11/16/2022] [Accepted: 11/19/2022] [Indexed: 11/23/2022] Open
Abstract
Aeromonas salmonicida, a psychrophilic bacterial pathogen, is widely distributed in marine freshwater, causing serious economic losses to major salmon farming areas in the world. At present, it is still one of the most important pathogens threatening salmon farming. Hcp (haemolysin-coregulated protein) is an effector protein in the type-VI secretion system (T6SS), which is secreted by T6SS and functions as its structural component. The results of our previous genomic sequencing showed that hcp existed in the mesophilic A. salmonicida SRW-OG1 isolated from naturally infected Epinephelus coioides. To further explore the role of Hcp in A. salmonicida SRW-OG1, we constructed an hcp-RNAi strain and verified its effect on the virulence of A. salmonicida. The results showed that compared with the wild strain, the hcp-RNAi strain suffered from different degrees of decreased adhesion, growth, biofilm formation, extracellular product secretion, and virulence. It was suggested that hcp may be an important virulence gene of A. salmonicida SRW-OG1.
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Affiliation(s)
- Hongyan Cai
- Key Laboratory of Healthy Mariculture for the East China Sea, Fisheries College, Ministry of Agriculture, Jimei University, Xiamen 361021, China
| | - Jiaying Yu
- Key Laboratory of Healthy Mariculture for the East China Sea, Fisheries College, Ministry of Agriculture, Jimei University, Xiamen 361021, China
| | - Ying Qiao
- Fourth Institute of Oceanography, Ministry of Natural Resources, No. 26, New Century Avenue, Beihai 536000, China
| | - Ying Ma
- Key Laboratory of Healthy Mariculture for the East China Sea, Fisheries College, Ministry of Agriculture, Jimei University, Xiamen 361021, China
| | - Jiang Zheng
- Key Laboratory of Healthy Mariculture for the East China Sea, Fisheries College, Ministry of Agriculture, Jimei University, Xiamen 361021, China
| | - Mao Lin
- Key Laboratory of Healthy Mariculture for the East China Sea, Fisheries College, Ministry of Agriculture, Jimei University, Xiamen 361021, China
| | - Qingpi Yan
- Key Laboratory of Healthy Mariculture for the East China Sea, Fisheries College, Ministry of Agriculture, Jimei University, Xiamen 361021, China
- Correspondence: (Q.Y.); (L.H.)
| | - Lixing Huang
- Key Laboratory of Healthy Mariculture for the East China Sea, Fisheries College, Ministry of Agriculture, Jimei University, Xiamen 361021, China
- Correspondence: (Q.Y.); (L.H.)
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Kroniger T, Mehanny M, Schlüter R, Trautwein-Schult A, Köllner B, Becher D. Effect of Iron Limitation, Elevated Temperature, and Florfenicol on the Proteome and Vesiculation of the Fish Pathogen Aeromonas salmonicida. Microorganisms 2022; 10:microorganisms10091735. [PMID: 36144337 PMCID: PMC9503180 DOI: 10.3390/microorganisms10091735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 08/19/2022] [Accepted: 08/24/2022] [Indexed: 11/16/2022] Open
Abstract
We analyzed the proteomic response of the Gram-negative fish pathogen A. salmonicida to iron limitation, an elevated incubation temperature, and the antibiotic florfenicol. Proteins from different subcellular fractions (cytosol, inner membrane, outer membrane, extracellular and outer membrane vesicles) were enriched and analyzed. We identified several iron-regulated proteins that were not reported in the literature for A. salmonicida before. We could also show that hemolysin, an oxidative-stress-resistance chaperone, a putative hemin receptor, an M36 peptidase, and an uncharacterized protein were significantly higher in abundance not only under iron limitation but also with an elevated incubation temperature. This may indicate that these proteins involved in the infection process of A. salmonicida are induced by both factors. The analysis of the outer membrane vesicles (OMVs) with and without applied stresses revealed significant differences in the proteomes. OMVs were smaller and contained more cytoplasmic proteins after antibiotic treatment. After cultivation with low iron availability, several iron-regulated proteins were found in the OMVs, indicating that A. salmonicida OMVs potentially have a function in iron acquisition, as reported for other bacteria. The presence of iron-regulated transporters further indicates that OMVs obtained from ‘stressed’ bacteria might be suitable vaccine candidates that induce a protective anti-virulence immune response.
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Affiliation(s)
- Tobias Kroniger
- Institute of Microbiology, Department of Microbial Proteomics, Center for Functional Genomics of Microbes, University of Greifswald, 17489 Greifswald, Germany
| | - Mina Mehanny
- Helmholtz Institute for Pharmaceutical Research Saarland, 66123 Saarbrücken, Germany
- Department of Pharmacy, Saarland University, 66123 Saarbrücken, Germany
- Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Ain Shams University, Cairo 11566, Egypt
| | - Rabea Schlüter
- Imaging Center of the Department of Biology, University of Greifswald, 17489 Greifswald, Germany
| | - Anke Trautwein-Schult
- Institute of Microbiology, Department of Microbial Proteomics, Center for Functional Genomics of Microbes, University of Greifswald, 17489 Greifswald, Germany
| | - Bernd Köllner
- Institute of Immunology, Friedrich-Loeffler-Institute, Federal Research Institute for Animal Health, 17493 Greifswald-Insel Riems, Germany
| | - Dörte Becher
- Institute of Microbiology, Department of Microbial Proteomics, Center for Functional Genomics of Microbes, University of Greifswald, 17489 Greifswald, Germany
- Correspondence: ; Tel.: +49-3834-420-5903
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5
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Fu Q, Li Y, Zhang H, Cao M, Zhang L, Gao C, Cai X, Chen D, Yang Z, Li J, Yang N, Li C. Comparative Transcriptome Analysis of Spleen Reveals Potential Regulation of Genes and Immune Pathways Following Administration of Aeromonas salmonicida subsp. masoucida Vaccine in Atlantic Salmon (Salmo salar). MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2022; 24:97-115. [PMID: 35084599 PMCID: PMC8792528 DOI: 10.1007/s10126-021-10089-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Accepted: 12/17/2021] [Indexed: 06/14/2023]
Abstract
Aeromonas salmonicida is a global fish pathogen. Aeromonas salmonicida subsp. masoucida (ASM) is classified as atypical A. salmonicida and caused huge losses to salmonid industry in China. Hence, it is of great significance to develop ASM vaccine and explore its protection mechanism in salmonids. In this regard, we conducted RNA-seq analysis with spleen tissue of Atlantic salmon after ASM vaccination to reveal genes, their expression patterns, and pathways involved in immune protections. In our results, a total of 441.63 million clean reads were obtained, and 389.37 million reads were mapped onto the Atlantic salmon reference genome. In addition, 1125, 2126, 1098, 820, and 1351 genes were significantly up-regulated, and 747, 2626, 818, 254, and 908 genes were significantly down-regulated post-ASM vaccination at 12 h, 24 h, 1 month, 2 months, and 3 months, respectively. Subsequent pathway analysis revealed that many differentially expressed genes (DEGs) following ASM vaccination were involved in cytokine-cytokine receptor interaction (TNFRSF11b, IL-17RA, CCR9, and CXCL11), HTLV-I infection (MR1 and HTLV-1), MAPK signaling pathway (MAPK, IL8, and TNF-α-1), PI3K-Akt signaling pathway (PIK3R3, THBS4, and COL2A1), and TNF signaling pathway (PTGS2, TNFRSF21-l, and CXCL10). Finally, the results of qRT-PCR showed a significant correlation with RNA-seq results, suggesting the reliability of RNA-seq for gene expression analysis. This study provided insights into regulation of gene expression and their involved pathways in Atlantic salmon spleen in responses to vaccine, and set the foundation for further study on the vaccine protective mechanism in Atlantic salmon as well as other teleost species.
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Affiliation(s)
- Qiang Fu
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, 266109, China
| | - Yuqing Li
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, 266109, China
| | - Hao Zhang
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, 266109, China
| | - Min Cao
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, 266109, China
| | - Lu Zhang
- Shandong Sinder Technology Co., Ltd, Zhucheng, 262200, China
| | - Chengbin Gao
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, 266109, China
| | - Xin Cai
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, 266109, China
| | - Defeng Chen
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, 266109, China
| | - Ziying Yang
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, 266109, China
| | - Jie Li
- Key Laboratory of Maricultural Organism Disease Control, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, China
| | - Ning Yang
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, 266109, China
| | - Chao Li
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, 266109, China.
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6
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Girard SB, Paquet VE, Charette SJ. Improvements of virulence factor phenotypic tests for Aeromonas salmonicida subsp. salmonicida, a major fish pathogen. JOURNAL OF FISH DISEASES 2022; 45:177-184. [PMID: 34748248 DOI: 10.1111/jfd.13547] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 10/20/2021] [Accepted: 10/22/2021] [Indexed: 06/13/2023]
Abstract
Aeromonas salmonicida subspecies salmonicida, a fish pathogen, expresses various virulence factors such as an A-layer, lipases and proteases during the infection process. Not all strains of this bacterium express the same virulence factors. It is important to be able to evaluate which factors are present when characterizing strains. The A-layer and secreted lipases and proteases are usually detected by agar-based tests that require long incubation (24 h and more) and may provide ambiguous results. In the present study, protocols have been optimized to determine the presence of these virulence factors using liquid tests. For A-layer detection, the optimized method stains the positive bacteria with Coomassie Brilliant Blue. The lipases are detected by a colorimetric biochemical reaction triggered by the degradation of p-nitrophenyl dodecanoate into a yellow product detectable by spectrophotometry, if the result is positive. Both of these tests show results in less than an hour. Finally, the protease activity is measured by clarification of a medium containing milk during an overnight bacterial growth. These new protocols provide opportunities for quicker characterization of A. salmonicida subsp. salmonicida strains and, particularly, provide more precise results.
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Affiliation(s)
- Sarah B Girard
- Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Quebec City, Quebec, Canada
- Département de Biochimie, de Microbiologie et de Bio-Informatique, Faculté des Sciences et de Génie, Université Laval, Quebec City, Quebec, Canada
| | - Valérie E Paquet
- Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Quebec City, Quebec, Canada
- Département de Biochimie, de Microbiologie et de Bio-Informatique, Faculté des Sciences et de Génie, Université Laval, Quebec City, Quebec, Canada
- Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec (IUCPQ), Quebec City, Quebec, Canada
| | - Steve J Charette
- Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Quebec City, Quebec, Canada
- Département de Biochimie, de Microbiologie et de Bio-Informatique, Faculté des Sciences et de Génie, Université Laval, Quebec City, Quebec, Canada
- Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec (IUCPQ), Quebec City, Quebec, Canada
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Ramirez-Paredes JG, Verner-Jeffreys DW, Papadopoulou A, Monaghan SJ, Smith L, Haydon D, Wallis TS, Davie A, Adams A, Migaud H. A commercial autogenous injection vaccine protects ballan wrasse (Labrus bergylta, Ascanius) against Aeromonas salmonicida vapA type V. FISH & SHELLFISH IMMUNOLOGY 2020; 107:43-53. [PMID: 33011432 DOI: 10.1016/j.fsi.2020.09.040] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 09/22/2020] [Accepted: 09/28/2020] [Indexed: 06/11/2023]
Abstract
Atypical Aeromonas salmonicida (aAs) and Vibrionaceae related species are bacteria routinely recovered from diseased ballan wrasse used as cleaner fish in the Atlantic salmon farming industry. Autogenous (i.e. farm specific inactivated) multivalent vaccines formulated from these microorganisms are widely used to protect farmed wrasse despite limited experimental proof that they are primary pathogens. In this study, the components of a commercial multivalent injection vaccine containing four strains of Aeromonas salmonicida and one strain of Vibrio splendidus previously isolated from ballan wrasse in Scotland, were tested for infectivity, pathogenicity and virulence via intra peritoneal injection at pre-deployment size (25-50 g) and the efficacy of the vaccine for protection against aAs assessed. Injection with 3.5 × 109, 8 × 109 1.8 × 109 and 5 × 109 cfu/fish of Vibrio splendidus, V. ichthyoenteri, Aliivibrio logeii and A. salmonicida, respectively, did not cause significant mortalities, lesions or clinical signs after a period of 14 days. IP injection with both aAs and Photobacterium indicum successfully reproduced the clinical signs and internal lesions observed during natural outbreaks of the disease. Differences in virulence (LD50 at day 8-post infection of 3.6 × 106 cfu/fish and 1.6 × 107 cfu/fish) were observed for two aAs vapA type V isolates. In addition, the LD50 for Photobacterium indicum was 2.2 × 107 cfu/fish. The autogenous vaccine was highly protective against the two aAs vapA type V isolates after 700-degree days of immunisation. The RPSFINAL values for the first isolate were 95 and 91% at 1 × 106 cfu/fish and 1 × 107 cfu/fish, respectively, and 79% at 1 × 107 cfu/fish for the second isolate tested. In addition, significantly higher anti aAs seral antibodies (IgM), were detected by ELISA in vaccinated fish in contrast with control (mock vaccinated) fish. These results suggest wrasse can be effectively immunised and protected against aAs infection by injection with oil adjuvanted vaccines prepared with inactivated homologous isolates.
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Affiliation(s)
- J G Ramirez-Paredes
- Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling, Scotland, FK9 4LA, UK; Ridgeway Biologicals Ltd. a Ceva Santé Animale Company, Units 1-3 Old Station Business Park, Compton, Berkshire, England, RG20 6NE, UK
| | - D W Verner-Jeffreys
- Centre for Environment, Fisheries and Aquaculture Science, Barrack Road - the Nothe, Weymouth, Dorset, England, DT4 8UB, UK
| | - A Papadopoulou
- Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling, Scotland, FK9 4LA, UK
| | - S J Monaghan
- Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling, Scotland, FK9 4LA, UK
| | - L Smith
- Centre for Environment, Fisheries and Aquaculture Science, Barrack Road - the Nothe, Weymouth, Dorset, England, DT4 8UB, UK
| | - D Haydon
- Ridgeway Biologicals Ltd. a Ceva Santé Animale Company, Units 1-3 Old Station Business Park, Compton, Berkshire, England, RG20 6NE, UK
| | - T S Wallis
- Ridgeway Biologicals Ltd. a Ceva Santé Animale Company, Units 1-3 Old Station Business Park, Compton, Berkshire, England, RG20 6NE, UK
| | - A Davie
- Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling, Scotland, FK9 4LA, UK
| | - A Adams
- Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling, Scotland, FK9 4LA, UK
| | - H Migaud
- Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling, Scotland, FK9 4LA, UK.
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Attaya A, Secombes CJ, Wang T. Effective isolation of GALT cells: Insights into the intestine immune response of rainbow trout (Oncorhynchus mykiss) to different bacterin vaccine preparations. FISH & SHELLFISH IMMUNOLOGY 2020; 105:378-392. [PMID: 32615166 DOI: 10.1016/j.fsi.2020.06.051] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 06/24/2020] [Accepted: 06/25/2020] [Indexed: 06/11/2023]
Abstract
The teleost gut is a multifunction complex structure that plays a pivotal immunological role in homeostasis and the maintenance of health, in addition to digestion of food and/or nutrient absorption. In vitro examination of the intestine leucocyte repertoire has the potential to aid our understanding of gut immune competence and allows a rapid screen of host-microorganism interactions in different immunological contexts. To explore this possibility, in the present study we investigated the response of isolated gut leucocytes to 4 bacterins of Aeromonas salmonicida, prepared from different strains, combinations and strains grown in different environments, in comparison to a Yersinia ruckeri bacterin for which a commercial/effective oral booster vaccine has been developed. To aid this study we also optimized further our method of GALT cell isolation from rainbow trout, so as to avoid mechanical clearance of the intestine contents. This drastically increased the cell yield from ~12 × 106 to ~210 × 106/fish with no change in the percent cell viability over time or presence of transcripts typical of the key leucocyte types needed for the study of immune modulation (i.e. T- and B-cells, dendritic cells and macrophages). A wide array of immune transcripts were modulated by the bacterins, demonstrating the diversity of GALT cell responses to bacterial stimulation. Indeed, the GALT leucocyte responses were sensitive enough to distinguish the different bacterial species, strains and membrane proteins, as seen by distinct kinetics of immune gene expression. However, the response of the GALT cells was often relatively slow and of a low magnitude compared to those of PBL. These results enhance our knowledge of the gut biocapacity and help validate the use of this model for screening of oral vaccine candidates.
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Affiliation(s)
- Ahmed Attaya
- Scottish Fish Immunology Research Centre, School of Biological Sciences, University of Aberdeen, AB24 2TZ, UK.
| | - Christopher J Secombes
- Scottish Fish Immunology Research Centre, School of Biological Sciences, University of Aberdeen, AB24 2TZ, UK.
| | - Tiehui Wang
- Scottish Fish Immunology Research Centre, School of Biological Sciences, University of Aberdeen, AB24 2TZ, UK.
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Wang P, Li J, He TT, Li N, Mo ZL, Nie P, Xie HX. Pathogenic characterization of Aeromonas salmonicida subsp. masoucida turbot isolate from China. JOURNAL OF FISH DISEASES 2020; 43:1145-1154. [PMID: 32720397 DOI: 10.1111/jfd.13224] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 07/01/2020] [Accepted: 07/02/2020] [Indexed: 06/11/2023]
Abstract
Aeromonas salmonicida is a gram-negative bacterium that is the causative agent of furunculosis. An A. salmonicida strain was isolated from diseased turbot (Scophthalmus maximus) with the sign of furunculosis from North China. Based on vapA gene, the strain was further classified as A. salmonicida subsp. masoucida RZ6S-1. Culturing RZ6S-1 strain at high temperature (28°C) obtained the virulence attenuated strain RZ6S. Genome sequence comparison between the two strains revealed the loss of the type IV secretion system (T4SS) and type III secretion system (T3SS) from the native plasmid pAsmB-1 and pAsmC-1 of wild-type strain RZ6S-1, respectively. Further study demonstrated that the wild-type strain RZ6S-1, but not its derivative mutant RZ6S, can stimulate apoptosis. Elevated protein level of cleaved caspase-3 was detected from epithelioma papulosum cyprinid (EPC) cells infected with wild-type strain RZ6S-1 as compared with that infected with RZ6S strain. Meanwhile, the invasion of the mutant strain RZ6S was about 17-fold higher than the wild-type strain RZ6S-1, suggesting that some protein(s) from A. salmonicida subsp. masoucida RZ6S-1 suppress its invasion. The RZ6S mutant strain was attenuated, since its LD50 is over 10,000 times higher compared to the wild-type strain as revealed in the turbot infection model.
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Affiliation(s)
- Ping Wang
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, China
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Jie Li
- Key Laboratory of Maricultural Organism Disease Control, Ministry of Agriculture and Rural Affairs, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, China
| | - Tian Tian He
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Nan Li
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Zhao Lan Mo
- Key Laboratory of Maricultural Organism Disease Control, Ministry of Agriculture and Rural Affairs, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, China
| | - Pin Nie
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, China
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
- Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao, China
| | - Hai Xia Xie
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
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Valderrama K, Soto-Dávila M, Segovia C, Vásquez I, Dang M, Santander J. Aeromonas salmonicida infects Atlantic salmon (Salmo salar) erythrocytes. JOURNAL OF FISH DISEASES 2019; 42:1601-1608. [PMID: 31456227 DOI: 10.1111/jfd.13077] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 08/05/2019] [Accepted: 08/06/2019] [Indexed: 06/10/2023]
Abstract
Aeromonas salmonicida subsp. salmonicida (hereafter A. salmonicida) is the aetiological agent of furunculosis in marine and freshwater fish. Once A. salmonicida invade the fish host through skin, gut or gills, it spreads and colonizes the head kidney, liver, spleen and brain. A. salmonicida infects leucocytes and exhibits an extracellular phase in the blood of the host; however, it is unknown whether A. salmonicida have an intraerythrocytic phase. Here, we evaluate whether A. salmonicida infects Atlantic salmon (Salmo salar) erythrocytes in vitro and in vivo. A. salmonicida did not kill primary S. salar erythrocytes, even in the presence of high bacterial loads, but A. salmonicida invaded the S. salar erythrocytes in the absence of evident haemolysis. Naïve Atlantic salmon smolts intraperitoneally infected with A. salmonicida showed bacteraemia 5 days post-infection and the presence of intraerythrocytic A. salmonicida. Our results reveal a novel intraerythrocytic phase during A. salmonicida infection.
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Affiliation(s)
- Katherinne Valderrama
- Marine Microbial Pathogenesis and Vaccinology Laboratory, Department of Ocean Sciences, Ocean Science Centre, Memorial University of Newfoundland, Saint John's, Canada
| | - Manuel Soto-Dávila
- Marine Microbial Pathogenesis and Vaccinology Laboratory, Department of Ocean Sciences, Ocean Science Centre, Memorial University of Newfoundland, Saint John's, Canada
| | - Cristopher Segovia
- Marine Microbial Pathogenesis and Vaccinology Laboratory, Department of Ocean Sciences, Ocean Science Centre, Memorial University of Newfoundland, Saint John's, Canada
| | - Ignacio Vásquez
- Marine Microbial Pathogenesis and Vaccinology Laboratory, Department of Ocean Sciences, Ocean Science Centre, Memorial University of Newfoundland, Saint John's, Canada
| | - My Dang
- Marine Microbial Pathogenesis and Vaccinology Laboratory, Department of Ocean Sciences, Ocean Science Centre, Memorial University of Newfoundland, Saint John's, Canada
| | - Javier Santander
- Marine Microbial Pathogenesis and Vaccinology Laboratory, Department of Ocean Sciences, Ocean Science Centre, Memorial University of Newfoundland, Saint John's, Canada
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11
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Structural and Serological Studies of the O6-Related Antigen of Aeromonas veronii bv. sobria Strain K557 Isolated from Cyprinus carpio on a Polish Fish Farm, which Contains L-perosamine (4-amino-4,6-dideoxy-L-mannose), a Unique Sugar Characteristic for Aeromonas Serogroup O6. Mar Drugs 2019; 17:md17070399. [PMID: 31284525 PMCID: PMC6669630 DOI: 10.3390/md17070399] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 06/27/2019] [Accepted: 07/03/2019] [Indexed: 12/25/2022] Open
Abstract
Amongst Aeromonas spp. strains that are pathogenic to fish in Polish aquacultures, serogroup O6 was one of the five most commonly identified immunotypes especially among carp isolates. Here, we report immunochemical studies of the lipopolysaccharide (LPS) including the O-specific polysaccharide (O-antigen) of A. veronii bv. sobria strain K557, serogroup O6, isolated from a common carp during an outbreak of motile aeromonad septicemia (MAS) on a Polish fish farm. The O-polysaccharide was obtained by mild acid degradation of the LPS and studied by chemical analyses, mass spectrometry, and 1H and 13C NMR spectroscopy. It was revealed that the O-antigen was composed of two O-polysaccharides, both containing a unique sugar 4-amino-4,6-dideoxy-l-mannose (N-acetyl-l-perosamine, l-Rhap4NAc). The following structures of the O-polysaccharides (O-PS 1 and O-PS 2) were established: O-PS 1: →2)-α-l-Rhap4NAc-(1→; O-PS 2: →2)-α-l-Rhap4NAc-(1→3)-α-l-Rhap4NAc-(1→3)-α-l-Rhap4NAc-(1→. Western blotting and an enzyme-linked immunosorbent assay (ELISA) showed that the cross-reactivity between the LPS of A. veronii bv. sobria K557 and the A. hydrophila JCM 3968 O6 antiserum, and vice versa, is caused by the occurrence of common α-l-Rhap4NAc-(1→2)-α-l-Rhap4NAc and α-l-Rhap4NAc-(1→3)-α-l-Rhap4NAc disaccharides, whereas an additional →4)-α-d-GalpNAc-associated epitope defines the specificity of the O6 reference antiserum. Investigations of the serological and structural similarities and differences in the O-antigens provide knowledge of the immunospecificity of Aeromonas bacteria and are relevant in epidemiological studies and for the elucidation of the routes of transmission and relationships with pathogenicity.
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12
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Topologically-guided continuous protein crystallization controls bacterial surface layer self-assembly. Nat Commun 2019; 10:2731. [PMID: 31227690 PMCID: PMC6588578 DOI: 10.1038/s41467-019-10650-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Accepted: 05/16/2019] [Indexed: 12/22/2022] Open
Abstract
Many bacteria and most archaea possess a crystalline protein surface layer (S-layer), which surrounds their growing and topologically complicated outer surface. Constructing a macromolecular structure of this scale generally requires localized enzymatic machinery, but a regulatory framework for S-layer assembly has not been identified. By labeling, superresolution imaging, and tracking the S-layer protein (SLP) from C. crescentus, we show that 2D protein self-assembly is sufficient to build and maintain the S-layer in living cells by efficient protein crystal nucleation and growth. We propose a model supported by single-molecule tracking whereby randomly secreted SLP monomers diffuse on the lipopolysaccharide (LPS) outer membrane until incorporated at the edges of growing 2D S-layer crystals. Surface topology creates crystal defects and boundaries, thereby guiding S-layer assembly. Unsupervised assembly poses challenges for therapeutics targeting S-layers. However, protein crystallization as an evolutionary driver rationalizes S-layer diversity and raises the potential for biologically inspired self-assembling macromolecular nanomaterials. Bacteria assemble the surface layer (S-layer), a crystalline protein coat surrounding the curved surface, using protein self-assembly. Here authors image native and purified RsaA, the S-layer protein from C. crescentus, and show that protein crystallization alone is sufficient to assemble and maintain the S-layer in vivo.
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13
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A Unique Sugar l-Perosamine (4-Amino-4,6-dideoxy-l-mannose) Is a Compound Building Two O-Chain Polysaccharides in the Lipopolysaccharide of Aeromonas hydrophila Strain JCM 3968, Serogroup O6. Mar Drugs 2019; 17:md17050254. [PMID: 31035397 PMCID: PMC6562859 DOI: 10.3390/md17050254] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 04/20/2019] [Accepted: 04/23/2019] [Indexed: 02/07/2023] Open
Abstract
Lipopolysaccharide (LPS) is the major glycolipid and virulence factor of Gram-negative bacteria, including Aeromonas spp. The O-specific polysaccharide (O-PS, O-chain, O-antigen), i.e., the surface-exposed part of LPS, which is a hetero- or homopolysaccharide, determines the serospecificity of bacterial strains. Here, chemical analyses, mass spectrometry, and 1H and 13C NMR spectroscopy techniques were employed to study the O-PS of Aeromonas hydrophila strain JCM 3968, serogroup O6. MALDI-TOF mass spectrometry revealed that the LPS of A. hydrophila JCM 3968 has a hexaacylated lipid A with conserved architecture of the backbone and a core oligosaccharide composed of Hep6Hex1HexN1HexNAc1Kdo1P1. To liberate the O-antigen, LPS was subjected to mild acid hydrolysis followed by gel-permeation-chromatography and revealed two O-polysaccharides that were found to contain a unique sugar 4-amino-4,6-dideoxy-l-mannose (N-acetyl-l-perosamine, l-Rhap4NAc), which may further determine the specificity of the serogroup. The first O-polysaccharide (O-PS1) was built up of trisaccharide repeating units composed of one α-d-GalpNAc and two α-l-Rhap4NAc residues, whereas the other one, O-PS2, is an α1→2 linked homopolymer of l-Rhap4NAc. The following structures of the O-polysaccharides were established:
→3)-α-l-Rhap4NAc-(1→4)-α-d-GalpNAc-(1→3)-α-l-Rhap4NAc-(1→ →2)-α-l-Rhap4NAc-(1→
The present paper is the first work that reveals the occurrence of perosamine in the l-configuration as a component of bacterial O-chain polysaccharides.
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14
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Ben Hamed S, Tavares Ranzani-Paiva MJ, Tachibana L, de Carla Dias D, Ishikawa CM, Esteban MA. Fish pathogen bacteria: Adhesion, parameters influencing virulence and interaction with host cells. FISH & SHELLFISH IMMUNOLOGY 2018; 80:550-562. [PMID: 29966687 DOI: 10.1016/j.fsi.2018.06.053] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 06/04/2018] [Accepted: 06/29/2018] [Indexed: 06/08/2023]
Abstract
Wild fisheries are declining due to over-fishing, climate change, pollution and marine habitat destructions among other factors, and, concomitantly, aquaculture is increasing significantly around the world. Fish infections caused by pathogenic bacteria are quite common in aquaculture, although their seriousness depends on the season. Drug-supplemented feeds are often used to keep farmed fish free from the diseases caused by such bacteria. However, given that bacteria can survive well in aquatic environments independently of their hosts, bacterial diseases have become major impediments to aquaculture development. On the other hand, the indiscriminate uses of antimicrobial agents has led to resistant strains and the need to switch to other antibiotics, although it seems that an integrated approach that considers not only the pathogen but also the host and the environment will be the most effective method in the long-term to improve aquatic animal health. This review covers the mechanisms of bacterial pathogenicity and details the foundations underlying the interactions occurring between pathogenic bacteria and the fish host in the aquatic environment, as well as the factors that influence virulence. Understanding and linking the different phenomena that occur from adhesion to colonization of the host will offer novel and useful means to help design suitable therapeutic strategies for disease prevention and treatment.
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Affiliation(s)
- Said Ben Hamed
- Fishery Institute-APTA - SAA, Research Center of Aquaculture, Av. Francisco Matarazzo, 455, CEP. 05001-900, Sao Paulo, SP, Brazil
| | - Maria José Tavares Ranzani-Paiva
- Fishery Institute-APTA - SAA, Research Center of Aquaculture, Av. Francisco Matarazzo, 455, CEP. 05001-900, Sao Paulo, SP, Brazil
| | - Leonardo Tachibana
- Fishery Institute-APTA - SAA, Research Center of Aquaculture, Av. Francisco Matarazzo, 455, CEP. 05001-900, Sao Paulo, SP, Brazil
| | - Danielle de Carla Dias
- Fishery Institute-APTA - SAA, Research Center of Aquaculture, Av. Francisco Matarazzo, 455, CEP. 05001-900, Sao Paulo, SP, Brazil
| | - Carlos Massatoshi Ishikawa
- Fishery Institute-APTA - SAA, Research Center of Aquaculture, Av. Francisco Matarazzo, 455, CEP. 05001-900, Sao Paulo, SP, Brazil
| | - María Angeles Esteban
- Fish Innate Immune System Group, Department of Cell Biology & Histology, Faculty of Biology, Regional Campus of International Excellence, ''Campus Mare Nostrum'', University of Murcia, 30100, Murcia, Spain.
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15
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Complete Genome Sequence of the Virulent Aeromonas salmonicida subsp. masoucida Strain RFAS1. GENOME ANNOUNCEMENTS 2018; 6:6/22/e00470-18. [PMID: 29853510 PMCID: PMC5981031 DOI: 10.1128/genomea.00470-18] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Here, we report the complete genome sequence of the pathogenic Aeromonas salmonicida subsp. masoucida strain RFAS1, isolated from black rockfish and showing signs of furunculosis. Sequencing with the PacBio platform yielded a circular chromosome of 4,783,004 bp and two plasmids (70,968 bp and 63,563 bp) harboring 4,411, 67, and 71 protein-coding genes, respectively.
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16
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Valderrama K, Saravia M, Santander J. Phenotype of Aeromonas salmonicida sp. salmonicida cyclic adenosine 3',5'-monophosphate receptor protein (Crp) mutants and its virulence in rainbow trout (Oncorhynchus mykiss). JOURNAL OF FISH DISEASES 2017; 40:1849-1856. [PMID: 28548689 DOI: 10.1111/jfd.12658] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 04/15/2017] [Accepted: 04/17/2017] [Indexed: 06/07/2023]
Abstract
Precise deletion of genes related to virulence can be used as a strategy to produce attenuated bacterial vaccines. Here, we study the deletion of the cyclic-3',5'-adenosine monophosphate (cAMP) receptor protein (Crp) in Aeromonas salmonicida, the aetiologic agent of furunculosis in marine and freshwater fish. The Crp protein is a conserved global regulator, controlling physiology processes, like sugar utilization. Deletion of the crp gene has been utilized in live attenuated vaccines for mammals, birds and warm water fish. Here, we characterized the crp gene and reported the effect of a crp deletion in A. salmonicida virulent and non-virulent isolates. We found that A. salmonicida Δcrp was not able to utilize maltose and other sugars, and its generation time was similar to the wild type. A. salmonicida ∆crp showed a higher ability of cell invasion compared to the wild type. Fish challenges showed that A. salmonicida ∆crp is ~6 times attenuated in Oncorhynchus mykiss and conferred protective immunity against the intraperitoneal challenge with A. salmonicida wild type. We concluded that deletion of A. salmonicida crp influences sugar utilization, cell invasion and virulence. Deletion of crp in A. salmonicida could be considered as part of an effective strategy to develop immersion live attenuated vaccines against furunculosis.
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Affiliation(s)
- K Valderrama
- Marine Microbial Pathogenesis and Vaccinology Laboratory, Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, NL, Canada
- PhD Program in Aquaculture, Universidad Católica del Norte, Coquimbo, Chile
| | - M Saravia
- Faculty of Sciences, Universidad Mayor, Huechuraba, Chile
| | - J Santander
- Marine Microbial Pathogenesis and Vaccinology Laboratory, Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, NL, Canada
- Faculty of Sciences, Universidad Mayor, Huechuraba, Chile
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17
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Draft Genome Sequence of the Type Strain Aeromonas salmonicida subsp. salmonicida ATCC 33658. GENOME ANNOUNCEMENTS 2017; 5:5/40/e01064-17. [PMID: 28982999 PMCID: PMC5629056 DOI: 10.1128/genomea.01064-17] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Here, we report the draft genome sequence of the type strain Aeromonas salmonicida subsp. salmonicida ATCC 33658 isolated from Salmo salar The size of the genome is 4,728,143 bp with a G+C content of 58.5%. The A. salmonicida subsp. salmonicida ATCC 33658 genome lacks essential virulence genes that were likely lost during genomic rearrangements.
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18
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Ebersole JL, Dawson D, Emecen-Huja P, Nagarajan R, Howard K, Grady ME, Thompson K, Peyyala R, Al-Attar A, Lethbridge K, Kirakodu S, Gonzalez OA. The periodontal war: microbes and immunity. Periodontol 2000 2017; 75:52-115. [DOI: 10.1111/prd.12222] [Citation(s) in RCA: 95] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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19
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Herrmann J, Jabbarpour F, Bargar PG, Nomellini JF, Li PN, Lane TJ, Weiss TM, Smit J, Shapiro L, Wakatsuki S. Environmental Calcium Controls Alternate Physical States of the Caulobacter Surface Layer. Biophys J 2017; 112:1841-1851. [PMID: 28494955 PMCID: PMC5425405 DOI: 10.1016/j.bpj.2017.04.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 03/28/2017] [Accepted: 04/06/2017] [Indexed: 11/23/2022] Open
Abstract
Surface layers (S-layers) are paracrystalline, proteinaceous structures found in most archaea and many bacteria. Often the outermost cell envelope component, S-layers serve diverse functions including aiding pathogenicity and protecting against predators. We report that the S-layer of Caulobacter crescentus exhibits calcium-mediated structural plasticity, switching irreversibly between an amorphous aggregate state and the crystalline state. This finding invalidates the common assumption that S-layers serve only as static wall-like structures. In vitro, the Caulobacter S-layer protein, RsaA, enters the aggregate state at physiological temperatures and low divalent calcium ion concentrations. At higher concentrations, calcium ions stabilize monomeric RsaA, which can then transition to the two-dimensional crystalline state. Caulobacter requires micromolar concentrations of calcium for normal growth and development. Without an S-layer, Caulobacter is even more sensitive to changes in environmental calcium concentration. Therefore, this structurally dynamic S-layer responds to environmental conditions as an ion sensor and protects Caulobacter from calcium deficiency stress, a unique mechanism of bacterial adaptation. These findings provide a biochemical and physiological basis for RsaA's calcium-binding behavior, which extends far beyond calcium's commonly accepted role in aiding S-layer biogenesis or oligomerization and demonstrates a connection to cellular fitness.
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Affiliation(s)
- Jonathan Herrmann
- Department of Structural Biology, Stanford University, Stanford, California; Bioscience Division, SLAC National Accelerator Laboratory, Menlo Park, California.
| | - Fatemeh Jabbarpour
- Department of Structural Biology, Stanford University, Stanford, California
| | | | - John F Nomellini
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Po-Nan Li
- Department of Electrical Engineering, Stanford University, Stanford, California
| | - Thomas J Lane
- Bioscience Division, SLAC National Accelerator Laboratory, Menlo Park, California
| | - Thomas M Weiss
- Bioscience Division, SLAC National Accelerator Laboratory, Menlo Park, California
| | - John Smit
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Lucy Shapiro
- Department of Developmental Biology, Stanford University, Stanford, California.
| | - Soichi Wakatsuki
- Department of Structural Biology, Stanford University, Stanford, California; Bioscience Division, SLAC National Accelerator Laboratory, Menlo Park, California.
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20
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Marana MH, Jørgensen LVG, Skov J, Chettri JK, Holm Mattsson A, Dalsgaard I, Kania PW, Buchmann K. Subunit vaccine candidates against Aeromonas salmonicida in rainbow trout Oncorhynchus mykiss. PLoS One 2017; 12:e0171944. [PMID: 28182704 PMCID: PMC5300222 DOI: 10.1371/journal.pone.0171944] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Accepted: 01/29/2017] [Indexed: 12/12/2022] Open
Abstract
Aeromonas salmonicida subsp. salmonicida is the etiological agent of furunculosis and a major fish health problem in salmonid aquaculture worldwide. Injection vaccination with commercial mineral oil-adjuvanted bacterin vaccines has been partly successful in preventing the disease but in Danish rainbow trout (Oncorhynchus mykiss, Walbaum) aquaculture furunculosis outbreaks still occur. In this study we tested the efficacy of experimental subunit vaccines against A. salmonicida infection in rainbow trout. We utilized in silico screening of the proteome of A. salmonicida subsp. salmonicida strain A449 and identified potential protective protein antigens that were tested by in vivo challenge trial. A total of 14 proteins were recombinantly expressed in Escherichia coli and prepared in 3 different subunit vaccine combinations to immunize 3 groups of rainbow trout by intraperitoneal (i.p.) injection. The fish were exposed to virulent A. salmonicida 7 weeks after immunization. To assess the efficacy of the subunit vaccines we evaluated the immune response in fish after immunization and challenge infection by measuring the antibody levels and monitoring the survival of fish in different groups. The survival of fish at 3 weeks after challenge infection showed that all 3 groups of fish immunized with 3 different protein combinations exhibited significantly lower mortalities (17–30%) compared to the control groups (48% and 56%). The ELISA results revealed significantly elevated antibody levels in fish against several protein antigens, which in some cases were positively correlated to the survival.
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Affiliation(s)
- Moonika Haahr Marana
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
- * E-mail:
| | | | - Jakob Skov
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | | | | | - Inger Dalsgaard
- National Veterinary Institute, Technical University of Denmark, Denmark
| | - Per Walter Kania
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - Kurt Buchmann
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
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21
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Menanteau-Ledouble S, Kumar G, Saleh M, El-Matbouli M. Aeromonas salmonicida: updates on an old acquaintance. DISEASES OF AQUATIC ORGANISMS 2016; 120:49-68. [PMID: 27304870 DOI: 10.3354/dao03006] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Aeromonas salmonicida is the oldest known infectious agent to be linked to fish disease and constitutes a major bacterial pathogen of fish, in particular of salmonids. This bacterium can be found almost worldwide in both marine and freshwater environments and has been divided into several sub-species. In this review, we present the most recent developments concerning our understanding of this pathogen, including how the characterization of new isolates from non-salmonid hosts suggests a more nuanced picture of the importance of the so‑called 'atypical isolates'. We also describe the clinical presentation regarding the infection across several fish species and discuss what is known about the virulence of A. salmonicida and, in particular, the role that the type 3 secretion system might play in suppressing the immune response of its hosts. Finally, isolates have displayed varied levels of antibiotic resistance. Hence, we review a number of solutions that have been developed both to prevent outbreaks and to treat them once they occur, including the application of pre- and probiotic supplements.
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Affiliation(s)
- Simon Menanteau-Ledouble
- Clinical Division of Fish Medicine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine, Vienna, Austria
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22
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Rebl A, Korytář T, Köbis JM, Verleih M, Krasnov A, Jaros J, Kühn C, Köllner B, Goldammer T. Transcriptome profiling reveals insight into distinct immune responses to Aeromonas salmonicida in gill of two rainbow trout strains. MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2014; 16:333-348. [PMID: 24122123 DOI: 10.1007/s10126-013-9552-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2013] [Accepted: 09/22/2013] [Indexed: 06/02/2023]
Abstract
The fish gills represent a crucial organ for the communication with the aquatic environment. Transcriptional changes in gills of two hatchery rainbow trout strains in response to injection with the potent pathogen Aeromonas salmonicida were detected by global gene expression profiling using a 4×44K oligonucleotide microarray. Emphasis was placed on "day 3 postinfection" representing a decisive time point for the resolution of inflammation. The comparison of features and pathways differentially regulated in branchial tissues revealed that the local breeding strain BORN and imported American rainbow trout apply common and specific immune strategies. In gills of infected BORN trout, we observed a dynamic regulation of genes controlling NF-κB pathways and the induction of factors promoting the development of myeloid cells, whereas an increased expression of lysozyme and immunoglobulin genes was obvious in gills of infected import trout. In order to prove the relevance of the array-predicted candidates as well as well-known immune genes for gill immunity, a subsequent in vitro experiment was conducted. Altogether, we uncovered dynamic but moderate changes in the expression of a broad range of immune-relevant features implying the gill's involvement in pathogen defense strategies.
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23
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Structural studies of the lipopolysaccharide from the fish pathogen Aeromonas veronii strain Bs19, serotype O16. Mar Drugs 2014; 12:1298-316. [PMID: 24608968 PMCID: PMC3967211 DOI: 10.3390/md12031298] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2013] [Revised: 01/27/2014] [Accepted: 02/08/2014] [Indexed: 01/17/2023] Open
Abstract
Chemical analyses, mass spectrometry, and NMR spectroscopy were applied to study the structure of the lipopolysaccharide (LPS) isolated from Aeromonas veronii strain Bs19, serotype O16. ESI-MS revealed that the most abundant LPS glycoforms have tetra-acylated or hexa-acylated lipid A species, consisting of a bisphosphorylated GlcN disaccharide with an AraN residue as a non-stoichiometric substituent, and a core oligosaccharide composed of Hep5Hex3HexN1Kdo1P1. Sugar and methylation analysis together with 1D and 2D 1H and 13C NMR spectroscopy were the main methods used, and revealed that the O-specific polysaccharide (OPS) of A. veronii Bs19 was built up of tetrasaccharide repeating units with the structure: →4)-α-d-Quip3NAc-(1→3)-α-l-Rhap-(1→4)-β-d-Galp-(1→3)-α-d-GalpNAc-(1→. This composition was confirmed by mass spectrometry. The charge-deconvoluted ESI FT-ICR MS recorded for the LPS preparations identified mass peaks of SR- and R-form LPS species, that differed by Δm = 698.27 u, a value corresponding to the calculated molecular mass of one OPS repeating unit (6dHexNAc6dHexHexHexNAc-H2O). Moreover, unspecific fragmentation spectra confirmed the sequence of the sugar residues in the OPS and allowed to assume that the elucidated structure also represented the biological repeating unit.
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24
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Diamanka A, Loch TP, Cipriano RC, Faisal M. Polyphasic characterization of Aeromonas salmonicida isolates recovered from salmonid and non-salmonid fish. JOURNAL OF FISH DISEASES 2013; 36:949-963. [PMID: 23444966 DOI: 10.1111/jfd.12092] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Revised: 01/07/2013] [Accepted: 01/08/2013] [Indexed: 06/01/2023]
Abstract
Michigan's fisheries rely primarily upon the hatchery propagation of salmonid fish for release in public waters. One limitation on the success of these efforts is the presence of bacterial pathogens, including Aeromonas salmonicida, the causative agent of furunculosis. This study was undertaken to determine the prevalence of A. salmonicida in Michigan fish, as well as to determine whether biochemical or gene sequence variability exists among Michigan isolates. A total of 2202 wild, feral and hatchery-propagated fish from Michigan were examined for the presence of A. salmonicida. The examined fish included Chinook salmon, Oncorhynchus tshawytscha (Walbaum), coho salmon, O. kisutcha (Walbaum), steelhead trout, O. mykiss (Walbaum), Atlantic salmon, Salmo salar L., brook trout, Salvelinus fontinalis (Mitchill), and yellow perch, Perca flavescens (Mitchill). Among these, 234 fish yielded a brown pigment-producing bacterium that was presumptively identified as A. salmonicida. Further phenotypic and phylogenetic analyses identified representative isolates as Aeromonas salmonicida subsp. salmonicida and revealed some genetic and biochemical variability. Logistic regression analyses showed that infection prevalence varied according to fish species/strain, year and gender, whereby Chinook salmon and females had the highest infection prevalence. Moreover, this pathogen was found in six fish species from eight sites, demonstrating its widespread nature within Michigan.
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Affiliation(s)
- A Diamanka
- Department of Pathobiology and Diagnostic Investigation, College of Veterinary Medicine, Michigan State University, East Lansing, MI, USA
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Vanden Bergh P, Frey J. Aeromonas salmonicida subsp. salmonicida in the light of its type-three secretion system. Microb Biotechnol 2013; 7:381-400. [PMID: 24119189 PMCID: PMC4229320 DOI: 10.1111/1751-7915.12091] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Revised: 08/27/2013] [Accepted: 08/28/2013] [Indexed: 11/30/2022] Open
Abstract
Aeromonas salmonicida subsp. salmonicida is an important pathogen in salmonid aquaculture and is responsible for the typical furunculosis. The type-three secretion system (T3SS) is a major virulence system. In this work, we review structure and function of this highly sophisticated nanosyringe in A. salmonicida. Based on the literature as well as personal experimental observations, we document the genetic (re)organization, expression regulation, anatomy, putative functional origin and roles in the infectious process of this T3SS. We propose a model of pathogenesis where A. salmonicida induces a temporary immunosuppression state in fish in order to acquire free access to host tissues. Finally, we highlight putative important therapeutic and vaccine strategies to prevent furunculosis of salmonid fish.
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Affiliation(s)
- Philippe Vanden Bergh
- Institute of Veterinary Bacteriology, University of Bern, Länggassstrasse 122, Bern, Switzerland
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Dallaire-Dufresne S, Tanaka KH, Trudel MV, Lafaille A, Charette SJ. Virulence, genomic features, and plasticity of Aeromonas salmonicida subsp. salmonicida, the causative agent of fish furunculosis. Vet Microbiol 2013; 169:1-7. [PMID: 23890675 DOI: 10.1016/j.vetmic.2013.06.025] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2013] [Revised: 06/13/2013] [Accepted: 06/22/2013] [Indexed: 11/24/2022]
Abstract
The bacterium Aeromonas salmonicida subsp. salmonicida is the causative agent of furunculosis, a systemic disease of fish in the salmonid family. Furunculosis is a ubiquitous disease that affects aquaculture operations worldwide and is characterized by high mortality and morbidity. A better understanding of the bacterium is required to find a cure. Thereby, this review centers on A. salmonicida subsp. salmonicida, its major virulence factors, and its genome. The classification and characteristics of A. salmonicida subsp. salmonicida, the virulence factors, such as the A-layer, extracellular molecules, and type three secretion system as well as the characteristics and plasticity of its genome are described.
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Affiliation(s)
- Stéphanie Dallaire-Dufresne
- Institut de biologie intégrative et des systèmes, Pavillon Charles-Eugène-Marchand, Université Laval, 1030 avenue de la Médecine, Quebec City, QC, Canada G1V 0A6; Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec (Hôpital Laval), 2725 Chemin Sainte-Foy, Quebec City, QC, Canada G1V 4G5
| | - Katherine H Tanaka
- Institut de biologie intégrative et des systèmes, Pavillon Charles-Eugène-Marchand, Université Laval, 1030 avenue de la Médecine, Quebec City, QC, Canada G1V 0A6; Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec (Hôpital Laval), 2725 Chemin Sainte-Foy, Quebec City, QC, Canada G1V 4G5
| | - Mélanie V Trudel
- Institut de biologie intégrative et des systèmes, Pavillon Charles-Eugène-Marchand, Université Laval, 1030 avenue de la Médecine, Quebec City, QC, Canada G1V 0A6; Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec (Hôpital Laval), 2725 Chemin Sainte-Foy, Quebec City, QC, Canada G1V 4G5
| | - Andrée Lafaille
- Faculté de Médecine Vétérinaire, Université de Montréal, 3200 rue Sicotte, St-Hyacinthe, QC, Canada J2S 7C6
| | - Steve J Charette
- Institut de biologie intégrative et des systèmes, Pavillon Charles-Eugène-Marchand, Université Laval, 1030 avenue de la Médecine, Quebec City, QC, Canada G1V 0A6; Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec (Hôpital Laval), 2725 Chemin Sainte-Foy, Quebec City, QC, Canada G1V 4G5; Département de biochimie, de microbiologie et de bio-informatique, Faculté des sciences et de génie, Université Laval, 1045 avenue de la Médecine, Quebec City, QC, Canada G1V 0A6.
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27
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Turska-Szewczuk A, Lindner B, Komaniecka I, Kozinska A, Pekala A, Choma A, Holst O. Structural and immunochemical studies of the lipopolysaccharide from the fish pathogen, Aeromonas bestiarum strain K296, serotype O18. Mar Drugs 2013; 11:1235-55. [PMID: 23595053 PMCID: PMC3705401 DOI: 10.3390/md11041235] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Revised: 03/08/2013] [Accepted: 03/18/2013] [Indexed: 11/16/2022] Open
Abstract
Chemical analyses and mass spectrometry were used to study the structure of the lipopolysaccharide (LPS) isolated from Aeromonas bestiarum strain K296, serotype O18. ESI-MS revealed that the most abundant A. bestiarum LPS glycoforms have a hexa-acylated or tetra-acylated lipid A with conserved architecture of the backbone, consisting of a 1,4′-bisphosphorylated β-(1→6)-linked d-GlcN disaccharide with an AraN residue as a non-stoichiometric substituent and a core oligosaccharide composed of Kdo1Hep6Hex1HexN1P1. 1D and 2D NMR spectroscopy revealed that the O-specific polysaccharide (OPS) of A. bestiarum K296 consists of a branched tetrasaccharide repeating unit containing two 6-deoxy-l-talose (6dTalp), one Manp and one GalpNAc residues; thus, it is similar to that of the OPS of A. hydrophila AH-3 (serotype O34) in both the sugar composition and the glycosylation pattern. Moreover, 3-substituted 6dTalp was 2-O-acetylated and additional O-acetyl groups were identified at O-2 and O-4 (or O-3) positions of the terminal 6dTalp. Western blots with polyclonal rabbit sera showed that serotypes O18 and O34 share some epitopes in the LPS. The very weak reaction of the anti-O34 serum with the O-deacylated LPS of A. bestiarum K296 might have been due to the different O-acetylation pattern of the terminal 6dTalp. The latter suggestion was further confirmed by NMR.
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Affiliation(s)
- Anna Turska-Szewczuk
- Department of Genetics and Microbiology, Maria Curie-Sklodowska University, Akademicka 19, Lublin 20-033, Poland; E-Mails: (I.K.); (A.C.)
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +48-81-537-50-18; Fax: +48-81-537-59-59
| | - Buko Lindner
- Division of Immunochemistry, Research Center Borstel, Leibniz-Center for Medicine and Biosciences, Parkallee 10, D-23845 Borstel, Germany; E-Mail:
| | - Iwona Komaniecka
- Department of Genetics and Microbiology, Maria Curie-Sklodowska University, Akademicka 19, Lublin 20-033, Poland; E-Mails: (I.K.); (A.C.)
| | - Alicja Kozinska
- Department of Fish Diseases, National Veterinary Research Institute, Partyzantow 57, Pulawy 24-100, Poland; E-Mails: (A.K.); (A.P.)
| | - Agnieszka Pekala
- Department of Fish Diseases, National Veterinary Research Institute, Partyzantow 57, Pulawy 24-100, Poland; E-Mails: (A.K.); (A.P.)
| | - Adam Choma
- Department of Genetics and Microbiology, Maria Curie-Sklodowska University, Akademicka 19, Lublin 20-033, Poland; E-Mails: (I.K.); (A.C.)
| | - Otto Holst
- Division of Structural Biochemistry, Research Center Borstel, Leibniz-Center for Medicine and Biosciences, Airway Research Center North (ARCN), Member of the German Center for Lung Research (DZL), Parkallee 4a/c, D-23845 Borstel, Germany; E-Mail:
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Posch G, Sekot G, Friedrich V, Megson ZA, Koerdt A, Messner P, Schäffer C. Glycobiology Aspects of the Periodontal Pathogen Tannerella forsythia. Biomolecules 2012; 2:467-82. [PMID: 24970146 PMCID: PMC4030854 DOI: 10.3390/biom2040467] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2012] [Revised: 09/27/2012] [Accepted: 09/29/2012] [Indexed: 12/22/2022] Open
Abstract
Glycobiology is important for the periodontal pathogen Tannerella forsythia, affecting the bacterium's cellular integrity, its life-style, and virulence potential. The bacterium possesses a unique Gram-negative cell envelope with a glycosylated surface (S-) layer as outermost decoration that is proposed to be anchored via a rough lipopolysaccharide. The S-layer glycan has the structure 4‑MeO-b-ManpNAcCONH2-(1→3)-[Pse5Am7Gc-(2→4)-]-b-ManpNAcA-(1→4)-[4-MeO-a-Galp-(1→2)-]-a-Fucp-(1→4)-[-a-Xylp-(1→3)-]-b-GlcpA-(1→3)-[-b-Digp-(1→2)-]-a-Galp and is linked to distinct serine and threonine residues within the D(S/T)(A/I/L/M/T/V) amino acid motif. Also several other Tannerella proteins are modified with the S‑layer oligosaccharide, indicating the presence of a general O‑glycosylation system. Protein O‑glycosylation impacts the life-style of T. forsythia since truncated S-layer glycans present in a defined mutant favor biofilm formation. While the S‑layer has also been shown to be a virulence factor and to delay the bacterium's recognition by the innate immune system of the host, the contribution of glycosylation to modulating host immunity is currently unraveling. Recently, it was shown that Tannerella surface glycosylation has a role in restraining the Th17-mediated neutrophil infiltration in the gingival tissues. Related to its asaccharolytic physiology, T. forsythia expresses a robust enzymatic repertoire, including several glycosidases, such as sialidases, which are linked to specific growth requirements and are involved in triggering host tissue destruction. This review compiles the current knowledge on the glycobiology of T. forsythia.
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Affiliation(s)
- Gerald Posch
- Department of NanoBiotechnology, NanoGlycobiology Unit, Universität für Bodenkultur Wien, Muthgasse 11, A-1190 Vienna, Austria.
| | - Gerhard Sekot
- Department of NanoBiotechnology, NanoGlycobiology Unit, Universität für Bodenkultur Wien, Muthgasse 11, A-1190 Vienna, Austria.
| | - Valentin Friedrich
- Department of NanoBiotechnology, NanoGlycobiology Unit, Universität für Bodenkultur Wien, Muthgasse 11, A-1190 Vienna, Austria.
| | - Zoë A Megson
- Department of NanoBiotechnology, NanoGlycobiology Unit, Universität für Bodenkultur Wien, Muthgasse 11, A-1190 Vienna, Austria.
| | - Andrea Koerdt
- Department of NanoBiotechnology, NanoGlycobiology Unit, Universität für Bodenkultur Wien, Muthgasse 11, A-1190 Vienna, Austria.
| | - Paul Messner
- Department of NanoBiotechnology, NanoGlycobiology Unit, Universität für Bodenkultur Wien, Muthgasse 11, A-1190 Vienna, Austria.
| | - Christina Schäffer
- Department of NanoBiotechnology, NanoGlycobiology Unit, Universität für Bodenkultur Wien, Muthgasse 11, A-1190 Vienna, Austria.
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Impact of reattaching various Aeromonas salmonicida A-layer proteins on vaccine efficacy in Atlantic cod (Gadus morhua). Vaccine 2010; 28:4703-8. [DOI: 10.1016/j.vaccine.2010.04.100] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2010] [Revised: 04/27/2010] [Accepted: 04/28/2010] [Indexed: 11/17/2022]
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30
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Croisetière S, Tarte PD, Bernatchez L, Belhumeur P. Identification of MHC class IIβ resistance/susceptibility alleles to Aeromonas salmonicida in brook charr (Salvelinus fontinalis). Mol Immunol 2008; 45:3107-16. [PMID: 18455800 DOI: 10.1016/j.molimm.2008.03.007] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2008] [Revised: 03/07/2008] [Accepted: 03/10/2008] [Indexed: 10/22/2022]
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Jutfelt F, Sundh H, Glette J, Mellander L, Thrandur Björnsson B, Sundell K. The involvement of Aeromonas salmonicida virulence factors in bacterial translocation across the rainbow trout, Oncorhynchus mykiss (Walbaum), intestine. JOURNAL OF FISH DISEASES 2008; 31:141-151. [PMID: 18234022 DOI: 10.1111/j.1365-2761.2007.00879.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The pathogenic bacterium Aeromonas salmonicida is the causative agent of furunculosis, a lethal disease in salmonids. The mode of lateral transmission has not been conclusively defined, but A. salmonicida is able to translocate across the intestinal epithelium of salmonids, making the intestinal route a probable candidate. This study investigated some of the virulence mechanisms used by the bacteria to promote translocation. Intestinal segments were placed in modified Ussing chambers to investigate epithelial functions during exposure to bacterial factors. The factors were: extracellular products (ECP), lipopolysaccharide (LPS) or live or heat-inactivated A. salmonicida. Fluorescein isothiocynate (FITC)-labelling enabled detection of translocated bacteria by fluorometry. Live A. salmonicida translocated to a greater degree than heat-inactivated bacteria, suggesting that the bacteria utilize a heat sensitive surface-bound virulence factor which promotes translocation. The epithelium was negatively affected by ECP, manifested as decreased net ion transport, indicating a disturbance in ion channels or cell metabolism. LPS did not affect the epithelium in vitro when administered on the luminal side of the intestinal segment, but significantly increased epithelial translocation of fluorescent bacterial-sized microspheres when administered on the serosal side. This is suggested to be caused by increased transcellular transport, as the paracellular permeability was unaffected indicating maintained epithelial integrity.
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Affiliation(s)
- F Jutfelt
- Department of Zoology/Zoophysiology, Göteborg University, Göteborg, Sweden.
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32
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Kjøglum S, Larsen S, Bakke HG, Grimholt U. The Effect of Specific MHC Class I and Class II Combinations on Resistance to Furunculosis in Atlantic Salmon (Salmo salar). Scand J Immunol 2008; 67:160-8. [DOI: 10.1111/j.1365-3083.2007.02052.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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33
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Vanya Ewart K, Williams J, Richards RC, Gallant JW, Melville K, Douglas SE. The early response of Atlantic salmon (Salmo salar) macrophages exposed in vitro to Aeromonas salmonicida cultured in broth and in fish. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2008; 32:380-90. [PMID: 17825909 DOI: 10.1016/j.dci.2007.07.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2007] [Revised: 07/27/2007] [Accepted: 07/29/2007] [Indexed: 05/17/2023]
Abstract
Aeromonas salmonicida is a fish pathogen that causes furunculosis. Virulent strains of this bacterium are able to infect salmonid macrophages and survive within them, although mechanisms favouring intracellular survival are not completely understood. It is known that A. salmonicida cultured in vivo in the peritoneal cavity of the host undergoes changes in gene expression and surface architecture compared with cultures grown in vitro in broth. Therefore, in this study, the early macrophage responses to A. salmonicida grown in vivo and in vitro were compared. Macrophage-enriched cell preparations from head kidney of Atlantic salmon (Salmo salar) were infected in vitro in 96-well microtitre dishes and changes in gene expression during the infection process were monitored using a custom Atlantic salmon cDNA microarray. A. salmonicida cultures grown in tryptic soy broth and in peritoneal implants were used to infect the macrophages. The macrophages were harvested at 0.5, 1.0 and 2.0h after addition of the bacteria to the medium. Significant changes in gene expression were evident by microarray analysis at 2.0h post-infection in macrophages infected with broth-grown and implant-grown bacteria; however, qPCR analysis revealed earlier up-regulation of JunB and TNF-alpha in macrophages exposed to the implant-grown bacteria. Up-regulation of those genes and others is consistent with the effects of extracellular products of aeromonad bacteria on macrophages and also suggests initiation of the innate immune response.
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Affiliation(s)
- K Vanya Ewart
- Institute for Marine Biosciences, 1411 Oxford Street, Halifax, NS, Canada B3H 3Z1
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34
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Davis ML, Thoden JB, Holden HM. The x-ray structure of dTDP-4-keto-6-deoxy-D-glucose-3,4-ketoisomerase. J Biol Chem 2007; 282:19227-36. [PMID: 17459872 DOI: 10.1074/jbc.m702529200] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The repeating unit of the glycan chain in the S-layer of the bacterium Aneurinibacillus thermoaerophilus L420-91(T) is composed of four alpha-d-rhamnose molecules and two 3-acetamido-3,6-dideoxy-alpha-d-galactose moieties (abbreviated as Fucp3NAc). Formation of the glycan layer requires nucleotide-activated sugars as the donor molecules. Whereas the enzymes involved in the synthesis of GDP-rhamnose have been well characterized, less is known regarding the structures and enzymatic mechanisms of the enzymes required for the production of dTDP-Fucp3NAc. One of the enzymes involved in the biosynthesis of dTDP-Fucp3NAc is a 3,4-ketoisomerase, hereafter referred to as FdtA. Here we describe the first three-dimensional structure of this sugar isomerase complexed with dTDP and solved to 1.5 A resolution. The FdtA dimer assumes an almost jellyfish-like appearance with the sole alpha-helices representing the tentacles. Formation of the FdtA dimer represents a classical example of domain swapping whereby beta-strands 2 and 3 from one subunit form part of a beta-sheet in the second subunit. The active site architecture of FdtA is characterized by a cluster of three histidine residues, two of which, His(49) and His(51), appear to be strictly conserved in the amino acid sequences deposited to date. Site-directed mutagenesis experiments, enzymatic assays, and x-ray crystallographic analyses suggest that His(49) functions as an active site base.
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Affiliation(s)
- Melissa L Davis
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin 53706-1544, USA
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Sabet M, Lee SW, Nauman RK, Sims T, Um HS. The surface (S-) layer is a virulence factor of Bacteroides forsythus. MICROBIOLOGY-SGM 2004; 149:3617-3627. [PMID: 14663093 DOI: 10.1099/mic.0.26535-0] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Bacteroides forsythus has emerged as a crucial periodontal pathogen with possible implications for systemic disease. The aim of this study was to isolate the S-layer from B. forsythus and examine its virulence potential as a part of efforts to characterize virulence factors of B. forsythus. The role of the S-layer in the haemagglutinating and adherent/invasive activities was evaluated. It was observed that the S-layer alone was able to mediate haemagglutination. In adherent and invasive studies, transmission electron microscopy clearly revealed that B. forsythus cells were able to attach to and invade KB cells, showing the formation of a microvillus-like extension around adherent and intracellular bacteria. The quantitative analysis showed that five different B. forsythus strains exhibited attachment (1.9-2.3 %) and invasion (0.4-0.7 %) capabilities. It was also observed through antibody inhibition assays that adherent/invasive activities of B. forsythus are mediated by the S-layer. Furthermore, an in vivo immunization study adopting a murine abscess model was used to prove that the S-layer is involved in the infectious process of abscess formation. While mice immunized with purified S-layer and B. forsythus whole cells did not develop any abscesses when challenged with viable B. forsythus cells, unimmunized mice developed abscesses. Collectively, the data obtained from these studies indicate that the S-layer of B. forsythus is a virulence factor.
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Affiliation(s)
- M Sabet
- Department of Biomedical Sciences, University of Maryland, Baltimore, Dental School, 666 W. Baltimore Street, Baltimore, MD 21201, USA
| | - S-W Lee
- Department of Periodontics, University of Maryland, Baltimore, Dental School, 666 W. Baltimore Street, Baltimore, MD 21201, USA
| | - R K Nauman
- Department of Biomedical Sciences, University of Maryland, Baltimore, Dental School, 666 W. Baltimore Street, Baltimore, MD 21201, USA
| | - T Sims
- Oral Health Research Center, University of Washington, Seattle, WA, USA
| | - H-S Um
- Department of Periodontics, University of Maryland, Baltimore, Dental School, 666 W. Baltimore Street, Baltimore, MD 21201, USA
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Dacanay A, Johnson SC, Bjornsdottir R, Ebanks RO, Ross NW, Reith M, Singh RK, Hiu J, Brown LL. Molecular characterization and quantitative analysis of superoxide dismutases in virulent and avirulent strains of Aeromonas salmonicida subsp. salmonicida. J Bacteriol 2003; 185:4336-44. [PMID: 12867441 PMCID: PMC165764 DOI: 10.1128/jb.185.15.4336-4344.2003] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Aeromonas salmonicida subsp. salmonicida is a facultatively intracellular gram-negative bacterium that is the etiological agent of furunculosis, a bacterial septicemia of salmonids that causes significant economic loss to the salmon farming industry. The mechanisms by which A. salmonicida evades intracellular killing may be relevant in understanding virulence and the eventual design of appropriate treatment strategies for furunculosis. We have identified two open reading frames (ORFs) and related upstream sequences that code for two putative superoxide dismutases (SODs), sodA and sodB. The sodA gene encoded a protein of 204 amino acids with a molecular mass of approximately 23.0 kDa (SodA) that had high similarity to other prokaryotic Mn-SODs. The sodB gene encoded a protein of 194 amino acids with a molecular mass of approximately 22.3 kDa that had high similarity to other prokaryotic Fe-SODs. Two enzymes with activities consistent with both these ORFs were identified by inhibition of O(2)(-)-catalyzed tetrazolium salt reduction in both gels and microtiter plate assays. The two enzymes differed in their expression patterns in in vivo- and in vitro-cultured bacteria. The regulatory sequences upstream of putative sodA were consistent with these differences. We could not identify other SOD isozymes such as sodC either functionally or through data mining. Levels of SOD were significantly higher in virulent than in avirulent strains of A. salmonicida subsp. salmonicida strain A449 when cultured in vitro and in vivo.
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Affiliation(s)
- A Dacanay
- Institute for Marine Biosciences, National Research Council, Halifax, Nova Scotia, Canada.
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37
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Castro-Escarpulli G, Figueras MJ, Aguilera-Arreola G, Soler L, Fernández-Rendón E, Aparicio GO, Guarro J, Chacón MR. Characterisation of Aeromonas spp. isolated from frozen fish intended for human consumption in Mexico. Int J Food Microbiol 2003; 84:41-9. [PMID: 12781953 DOI: 10.1016/s0168-1605(02)00393-8] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
A total of 82 strains of presumptive Aeromonas spp. were identified biochemically and genetically (16S rDNA-RFLP). The strains were isolated from 250 samples of frozen fish (Tilapia, Oreochromis niloticus niloticus) purchased in local markets in Mexico City. In the present study, we detected the presence of several genes encoding for putative virulence factors and phenotypic activities that may play an important role in bacterial infection. In addition, we studied the antimicrobial patterns of those strains. Molecular identification demonstrated that the prevalent species in frozen fish were Aeromonas salmonicida (67.5%) and Aeromonas bestiarum (20.9%), accounting for 88.3% of the isolates, while the other strains belonged to the species Aeromonas veronii (5.2%), Aeromonas encheleia (3.9%) and Aeromonas hydrophila (2.6%). Detection by polymerase chain reaction (PCR) of genes encoding putative virulence factors common in Aeromonas, such as aerolysin/hemolysin, lipases including the glycerophospholipid-cholesterol acyltransferase (GCAT), serine protease and DNases, revealed that they were all common in these strains. Our results showed that first generation quinolones and second and third generation cephalosporins were the drugs with the best antimicrobial effect against Aeromonas spp. In Mexico, there have been few studies on Aeromonas and its putative virulence factors. The present work therefore highlights an important incidence of Aeromonas spp., with virulence potential and antimicrobial resistance, isolated from frozen fish intended for human consumption in Mexico City.
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Affiliation(s)
- G Castro-Escarpulli
- Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, 11340 México Distrito Federal, México
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38
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Grimholt U, Larsen S, Nordmo R, Midtlyng P, Kjoeglum S, Storset A, Saebø S, Stet RJM. MHC polymorphism and disease resistance in Atlantic salmon (Salmo salar); facing pathogens with single expressed major histocompatibility class I and class II loci. Immunogenetics 2003; 55:210-9. [PMID: 12811427 DOI: 10.1007/s00251-003-0567-8] [Citation(s) in RCA: 251] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2003] [Revised: 03/18/2003] [Indexed: 11/25/2022]
Abstract
Few studies have yet addressed the functional aspects of MHC molecules in fish. To lay the foundation for this, we evaluated the association between disease resistance and MHC class I and class II polymorphism in Atlantic salmon. Standardized disease challenge trials were performed on a semi-wild Atlantic salmon population with subsequent MHC typing and statistical analysis. The pathogens employed were infectious salmon anaemia virus (ISAV) causing infectious salmon anaemia and the Aeromonas salmonicida bacteria causing furunculosis. The material consisted of 1,182 Atlantic salmon from 33 families challenged with A. salmonicida and 1,031 Atlantic salmon from 25 families challenged with ISAV. We found highly significant associations between resistance towards infectious diseases caused by both pathogens and MH class I and class II polymorphism in Atlantic salmon. The observed associations were detected due to independently segregating MH class I and class II single loci, and inclusion of a large number of fish allowing an extensive statistical analysis.
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Affiliation(s)
- Unni Grimholt
- Department of Morphology, Genetics and Aquatic Biology, Section of Genetics, Norwegian School of Veterinary Science, Ullevaalsveien 72, P.O. Box 8146 Dep., 0033 Oslo, Norway.
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39
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Affiliation(s)
- Paul B Eckburg
- Department of Microbiology & Immunology, Stanford University School of Medicine, California 94305, USA
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40
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Abstract
Campylobacter fetus is a Gram-negative bacterial pathogen of humans and ungulates and is normally transmitted via ingestion of contaminated food or water with infection resulting in mild to severe enteritis. However, despite clinical evidence that C. fetus infection often involves transient bacteremic states from which systemic infection may develop and the frequent isolation of C. fetus from extra-intestinal sites, this organism displays very poor invasiveness in in vitro models of infection. In this study, immunofluorescence microscopy and gentamicin protection assays were used to investigate the ability of six clinical isolates and one reference strain of C. fetus to adhere to and invade the human intestinal epithelial cell line, INT 407. During an initial 4-h infection period, all C. fetus strains were detected intracellularly using both techniques, though adherence and internalization levels were very low when determined from gentamicin protection assays. Microscopy results indicated that during a 4-h infection period, four of the five clinical strains tested were adherent to 41.3-87.3% of INT 407 cells observed and that 25.2-34.6% of INT 407 cells contained intracellular C. fetus. The C. fetus reference strain displayed the lowest levels of adherence and internalization. A modified infection assay revealed that C. fetus adherence did not necessarily culminate in internalization. Despite the large percentage of INT 407 cells with adherent bacteria, the percentage of INT 407 cells with intracellular bacteria remained unchanged when incubation was extended from 4 h to 20 h. However, microscopy of INT 407 cells 24 h postinfection (p.i.) revealed that infected host cells contained clusters of densely packed C. fetus cells. Gentamicin protection assays revealed that intracellular C. fetus cells were not only viable 24 h p.i. but also that C. fetus had increased in number approximately three- to fourfold between 4 and 24 h p.i., indicative of intracellular replication. Investigation of the role of the host cell cytoskeleton revealed that pretreatment of host cells with cytochalasin D, colchicine, vinblastine, taxol, or dimethyl sulfoxide (DMSO) did not impact upon C. fetus adherence or internalization of INT 407 cells. Microscopy indicated neither rearrangement nor colocalization of either microtubules or microfilaments in INT 407 cells in response to C. fetus adherence or internalization. Together, these data indicate that clinical isolates of C. fetus are capable of adhering, entering, and surviving within the nonphagocytic epithelial cell line, INT 407.
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Affiliation(s)
- Lori L Graham
- Department of Biology, St. Francis Xavier University, Antigonish, NS B2G 2W5, Canada.
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41
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Braun M, Stuber K, Schlatter Y, Wahli T, Kuhnert P, Frey J. Characterization of an ADP-ribosyltransferase toxin (AexT) from Aeromonas salmonicida subsp. salmonicida. J Bacteriol 2002; 184:1851-8. [PMID: 11889090 PMCID: PMC134929 DOI: 10.1128/jb.184.7.1851-1858.2002] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
An ADP-ribosylating toxin named Aeromonas salmonicida exoenzyme T (AexT) in A. salmonicida subsp. salmonicida, the etiological agent of furunculosis in fish, was characterized. Gene aexT, encoding toxin AexT, was cloned and characterized by sequence analysis. AexT shows significant sequence similarity to the ExoS and ExoT exotoxins of Pseudomonas aeruginosa and to the YopE cytotoxin of different Yersinia species. The aexT gene was detected in all of the 12 A. salmonicida subsp. salmonicida strains tested but was absent from all other Aeromonas species. Recombinant AexT produced in Escherichia coli possesses enzymatic ADP-ribosyltransferase activity. Monospecific polyclonal antibodies directed against purified recombinant AexT detected the toxin produced by A. salmonicida subsp. salmonicida and cross-reacted with ExoS and ExoT of P. aeruginosa. AexT toxin could be detected in a wild type (wt) strain of A. salmonicida subsp. salmonicida freshly isolated from a fish with furunculosis; however, its expression required contact with RTG-2 rainbow trout gonad cells. Under these conditions, the AexT protein was found to be intracellular or tightly cell associated. No AexT was found when A. salmonicida subsp. salmonicida was incubated in cell culture medium in the absence of RTG-2 cells. Upon infection with wt A. salmonicida subsp. salmonicida, the fish gonad RTG-2 cells rapidly underwent significant morphological changes. These changes were demonstrated to constitute cell rounding, which accompanied induction of production of AexT and which led to cell lysis after extended incubation. An aexT mutant which was constructed from the wt strain with an insertionally inactivated aexT gene by allelic exchange had no toxic effect on RTG-2 cells and was devoid of AexT production. Hence AexT is directly involved in the toxicity of A. salmonicida subsp. salmonicida for RTG-2 fish cells.
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Affiliation(s)
- Martin Braun
- Institute for Veterinary Bacteriology, Center for Fish and Wildlife Health, University of Bern, CH-3012 Bern, Switzerland
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