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Das R, Sarma K, Hazarika G, Choudhury H, Sarma D. Identification and characterisation of emerging fish pathogens Aeromonas veronii and Aeromonas hydrophila isolated from naturally infected Channa punctata. Antonie Van Leeuwenhoek 2023; 117:4. [PMID: 38153571 DOI: 10.1007/s10482-023-01896-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 11/17/2023] [Indexed: 12/29/2023]
Abstract
Naturally infected Channa punctata exhibiting bacterial septicemic syndrome including ulcerations along with mortality records were collected from a fish farm in Assam during winter season (early November 2020 to early January 2021). The moribund fishes were subjected for bacterial isolation followed by identification of the bacteria. Two dominant emerging bacterial pathogens were identified as Aeromonas veronii (isolate ZooGURD-01) and Aeromonas hydrophila (isolate ZooGURD-05) by standard biochemical characterization and 16S rRNA and rpo B gene amplification. Re-infection experiments of both the bacterial isolates in healthy disease-free C. punctata showed similar symptoms to that of natural infection thus confirming their virulence. The LD50 calculated during challenge test for both the isolates ZooGURD-01 and ZooGURD-05 found to be pathogenic at 2.6 × 104 and 1.6 × 104 CFU/fish respectively. Further PCR amplification of specific virulent genes (aerolysin, hemolysin and enterotoxin) confirmed pathogenicity for both isolates. Histopathological examinations of liver and kidney in re-infection experiments showed prominent changes supporting bacterial septicaemia. Antibiotic sensitivity pattern showed that the isolates ZooGURD-01 and ZooGURD-05 were sensitive to 22 and 19 out of 25 antimicrobials respectively. The present study was the first report on the mortality of farmed C. punctata associated with natural infection caused by A. veronii and A. hydrophila with no record of pathogenicity of A. veronii in C. punctata.
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Affiliation(s)
- Rajdeep Das
- Department of Zoology, Gauhati University, Guwahati, Assam, 781014, India
| | - Kangkan Sarma
- Department of Zoology, Gauhati University, Guwahati, Assam, 781014, India
| | - Gayatree Hazarika
- Department of Zoology, Gauhati University, Guwahati, Assam, 781014, India
| | | | - Dandadhar Sarma
- Department of Zoology, Gauhati University, Guwahati, Assam, 781014, India.
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Guo M, Zhang L, Ye J, He X, Cao P, Zhou Z, Liu X. Characterization of the pathogenesis and immune response to a highly virulent Edwardsiella tarda strain responsible for mass mortality in the hybrid snakehead (Channa maculate ♀ × Channa argus ♂). Microb Pathog 2022; 170:105689. [PMID: 35917990 DOI: 10.1016/j.micpath.2022.105689] [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: 04/22/2022] [Revised: 07/11/2022] [Accepted: 07/19/2022] [Indexed: 11/28/2022]
Abstract
Edwardsiella tarda is reported as the causative agent of the systemic disease Edwardsiellosis in fish, which lead to huge economic losses in aquaculture. The pathogenicity and immune response to a highly virulent E. tarda isolate responsible for mass mortality in hybrid snakehead were performed. After species identification, morphology and virulence gene detection of Edwardsiella isolated from hybrid snakehead, the pathogenicity of the strain and histopathological changes in infected fish were analyzed. The infected fish exhibited typical acute hemorrhagic symptoms and enlarged internal organs. Histopathology revealed that the liver, spleen, kidney and intestinal tissues of diseased fish exhibited marked inflammatory with vacuolar degeneration and cell necrosis. Subsequently, humoral immune factors such as superoxide dismutase, lysozyme and acid phosphatase activities were detected as serum indicators, and real-time quantitative PCR was used to investigate immune-related genes (STAT1, HSP70, IgM, IL-6, IL-8, TRAF2, CD40, HLA-DMA and LCK) expression patterns in liver, spleen and head kidney. The results showed that these enzyme activity indicators and immune-related gene expression were significantly activated compared with healthy fish. These data provide insight into the pathogenic mechanisms and host immune responses of E. tarda, which could be useful for the future prevention and treatment of Edwardsiellosis in fish.
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Affiliation(s)
- Mengya Guo
- College of Animal Science and Technology, Yangzhou University, Yangzhou, 225009, China
| | - Liwen Zhang
- College of Animal Science and Technology, Yangzhou University, Yangzhou, 225009, China
| | - Jiaxin Ye
- College of Animal Science and Technology, Yangzhou University, Yangzhou, 225009, China
| | - Xiao He
- College of Animal Science and Technology, Yangzhou University, Yangzhou, 225009, China
| | - Pan Cao
- Institute of Surface Engineering, Yangzhou University, Yangzhou, 225127, China
| | - Zicheng Zhou
- College of Animal Science and Technology, Yangzhou University, Yangzhou, 225009, China
| | - Xiaodan Liu
- College of Animal Science and Technology, Yangzhou University, Yangzhou, 225009, China.
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3
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Li D, Cui Z, Zhao F, Zhu X, Tan A, Deng Y, Lai Y, Huang Z. Characterization of snakehead (Channa argus) interleukin-21: Involvement in immune defense against two pathogenic bacteria, in leukocyte proliferation, and in activation of JAK-STAT signaling pathway. FISH & SHELLFISH IMMUNOLOGY 2022; 123:207-217. [PMID: 35278639 DOI: 10.1016/j.fsi.2022.03.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 03/08/2022] [Accepted: 03/08/2022] [Indexed: 06/14/2023]
Abstract
Interleukin-21 (IL-21), a crucial immune regulatory molecule, belongs to the common γ-chain family of type I cytokines, and exerts pleiotropic effects on multiple immune cell types in mammals. However, the characteristics and functions of fish IL-21 remain unclear. To further investigate the molecular mechanism of IL-21 in teleosts, we first cloned and identified the IL-21 gene (designated shIL-21) of the snakehead (Channa argus). The full-length open reading frame of shIL-21 is 438 bp in length, and encodes a predicted protein of 145 amino acid residues. A sequence analysis showed that shIL-21 has the typical structural characteristics of other IL-21 proteins, containing four α-helices and four conserved cysteine residues. In a phylogenetic analysis, shIL-21 clustered within a subgroup of IL-21 proteins from other teleost species and shared its closest evolutionary relationship with that of Lates calcarifer. The expression analysis showed that shIL-21 was ubiquitously expressed in all the healthy snakehead tissues tested, albeit at different levels. After infection with Nocardia seriolae or Aeromonas schubertii, the relative expression of shIL-21 was mainly upregulated in the head kidney and spleen in vivo. Similarly, after stimulation with the three pathogen analogues lipoteichoic acid, lipopolysaccharides, and polyinosinic-polycytidylic acid, the expression of shIL-21 was also induced in head kidney leukocytes in vitro. A recombinant shIL-21 protein was expressed and purified, and promoted the proliferation of head kidney leukocytes, induced the expression of genes encoding critical signaling molecules in the Janus kinase (JAK) and signal transducer and activator of transcription (STAT) pathway, including JAK1, JAK3, STAT1, and STAT3, and induced the expression of endogenous shIL-21 and genes encoding several key proinflammatory cytokines (tumor necrosis factor-α, interferon-γ, and IL-1β). Taken together, these preliminary findings suggest that shIL-21 is involved in the immune defense against bacterial infection, in leukocyte proliferation, and in the activation of the JAK-STAT pathway. They thus extend the functional studies of IL-21 in teleosts.
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Affiliation(s)
- Dongqi Li
- Key Laboratory of Fishery Drug Development of Ministry of Agriculture and Rural Affairs, Key Laboratory of Aquatic Animal Immune Technology of Guangdong Province, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, 510380, China; National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai, 201306, China
| | - Zhengwei Cui
- Key Laboratory of Marine Biotechnology of Fujian Province, College of Marine Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Fei Zhao
- Key Laboratory of Fishery Drug Development of Ministry of Agriculture and Rural Affairs, Key Laboratory of Aquatic Animal Immune Technology of Guangdong Province, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, 510380, China.
| | - Xueqing Zhu
- Key Laboratory of Fishery Drug Development of Ministry of Agriculture and Rural Affairs, Key Laboratory of Aquatic Animal Immune Technology of Guangdong Province, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, 510380, China; National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai, 201306, China
| | - Aiping Tan
- Key Laboratory of Fishery Drug Development of Ministry of Agriculture and Rural Affairs, Key Laboratory of Aquatic Animal Immune Technology of Guangdong Province, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, 510380, China
| | - Yuting Deng
- Key Laboratory of Fishery Drug Development of Ministry of Agriculture and Rural Affairs, Key Laboratory of Aquatic Animal Immune Technology of Guangdong Province, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, 510380, China
| | - Yingtiao Lai
- Key Laboratory of Fishery Drug Development of Ministry of Agriculture and Rural Affairs, Key Laboratory of Aquatic Animal Immune Technology of Guangdong Province, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, 510380, China
| | - Zhibin Huang
- Key Laboratory of Fishery Drug Development of Ministry of Agriculture and Rural Affairs, Key Laboratory of Aquatic Animal Immune Technology of Guangdong Province, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, 510380, China
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Draft Genome Sequences of Aeromonas schubertii Strains Isolated from Asian Seabass from Thailand. Microbiol Resour Announc 2022; 11:e0100721. [PMID: 34989613 PMCID: PMC8759401 DOI: 10.1128/mra.01007-21] [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] [Indexed: 11/20/2022] Open
Abstract
Aeromonas schubertii is a Gram-negative, rod-shaped bacterium. It is a rare species that has been reported in humans and aquatic animals. Here, we report the genome sequences of A. schubertii strains isolated from two mass mortality events in central Thailand that were associated with aquaculture of Asian seabass.
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Immune Response and Apoptosis-Related Pathways Induced by Aeromonas schubertii Infection of Hybrid Snakehead ( Channa maculata♀ × Channa argus♂). Pathogens 2021; 10:pathogens10080997. [PMID: 34451461 PMCID: PMC8401259 DOI: 10.3390/pathogens10080997] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 07/27/2021] [Accepted: 08/04/2021] [Indexed: 11/17/2022] Open
Abstract
Aeromonas schubertii is the etiological pathogen of internal organ nodules in snakehead fish. Infections with A. schubertii produce a significant economic loss in aquaculture. Therefore, it is important to examine the immune mechanisms by which snakeheads defend against A. schubertii infection. In this study, we established a hybrid snakehead infection model by intraperitoneal injection of A. schubertii that produced internal organ nodules. The splenic immune response of infected fish was examined at the transcriptome level by Illumina-seq analysis. Results showed 14,796 differentially expressed genes (DEGs) following A. schubertii infection, including 4441 up-regulated unigenes and 10,355 down-regulated unigenes. KEGG analysis showed 2084 DEGs to be involved in 192 pathways, 14 of which were immune-related. Twelve DEGs were used to validate quantitative real-time PCR results with RNA-seq data. Time-course expression analysis of six genes demonstrated modulation of the snakehead immune response by A. schubertii. Furthermore, transcriptome analysis identified a substantial number of DEGs that were involved in the apoptosis signaling pathway. TUNEL analysis of infected spleens confirmed the presence of apoptotic cells. This study provided new information for a further understanding of the pathogenesis of A. schubertii in snakeheads, which can be used to prevent and possibly treat A. schubertii infections.
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Li D, Kong L, Cui Z, Zhao F, Deng Y, Tan A, Jiang L. MEKK3 in hybrid snakehead (Channa maculate ♀ ×Channa argus ♂): Molecular characterization and immune response to infection with Nocardia seriolae and Aeromonas schubertii. Comp Biochem Physiol B Biochem Mol Biol 2021; 256:110643. [PMID: 34186154 DOI: 10.1016/j.cbpb.2021.110643] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Revised: 06/19/2021] [Accepted: 06/25/2021] [Indexed: 12/30/2022]
Abstract
Mitogen-activated protein kinase/extracellular signal-regulated kinase kinase kinase 3 (MEKK3) is a serine/threonine protein kinase that acts as a key regulator and is widely involved in various innate and acquired immune signaling pathways. In this study, we first cloned the complete open reading frame (ORF) of the MEKK3 gene (named CcMEKK3) in a hybrid snakehead (Channa maculate ♀ × Channa argus ♂). The full-length ORF of CcMEKK3 is 1851 bp, and encodes a putative protein of 616 amino acids containing a serine/threonine kinase catalytic (S-TKc) domain and a Phox and Bem1p (PB1) domain. A sequence alignment and phylogenetic tree analysis showed that CcMEKK3 is highly conserved relative to the MEKK3 proteins of other teleost species. CcMEKK3 was constitutively expressed in all the healthy hybrid snakehead tissues tested, with greatest expression in the immune tissues, such as the head kidney and spleen. The expression of CcMEKK3 was usually upregulated in the head kidney, spleen, and liver at different time points after infection with Nocardia seriolae or Aeromonas schubertii. Similarly, the dynamic expression levels of CcMEKK3 in head kidney leukocytes after stimulation revealed that CcMEKK3 was induced by LTA, LPS, and poly(I:C). In the subcellular localization analysis, CcMEKK3 was evenly distributed in the cytoplasm of HEK293T cells, and its overexpression significantly promoted the activities of NF-κB and AP-1. These results suggest that CcMEKK3 is involved in the immune defense against these two pathogens, and plays a crucial role in activating the NF-κB and MAPK signaling pathways.
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Affiliation(s)
- Dongqi Li
- Key Laboratory of Fishery Drug Development of Ministry of Agriculture and Rural Affairs, Key Laboratory of Aquatic Animal Immune Technology of Guangdong Province, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, Guangdong 510380, China; College of Fisheries and Life Science, Shanghai Ocean University, Shanghai 201306, China
| | - Lulu Kong
- Key Laboratory of Fishery Drug Development of Ministry of Agriculture and Rural Affairs, Key Laboratory of Aquatic Animal Immune Technology of Guangdong Province, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, Guangdong 510380, China
| | - Zhengwei Cui
- Key Laboratory of Marine Biotechnology of Fujian Province, Institute of Oceanology, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
| | - Fei Zhao
- Key Laboratory of Fishery Drug Development of Ministry of Agriculture and Rural Affairs, Key Laboratory of Aquatic Animal Immune Technology of Guangdong Province, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, Guangdong 510380, China.
| | - Yuting Deng
- Key Laboratory of Fishery Drug Development of Ministry of Agriculture and Rural Affairs, Key Laboratory of Aquatic Animal Immune Technology of Guangdong Province, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, Guangdong 510380, China
| | - Aiping Tan
- Key Laboratory of Fishery Drug Development of Ministry of Agriculture and Rural Affairs, Key Laboratory of Aquatic Animal Immune Technology of Guangdong Province, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, Guangdong 510380, China
| | - Lan Jiang
- Key Laboratory of Fishery Drug Development of Ministry of Agriculture and Rural Affairs, Key Laboratory of Aquatic Animal Immune Technology of Guangdong Province, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, Guangdong 510380, China
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7
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Zhang DF, Xiong XL, Wang YJ, Gao YX, Ren Y, Wang Q, Shi CB. Bacillus velezensis WLYS23 strain possesses antagonistic activity against hybrid snakehead bacterial pathogens. J Appl Microbiol 2021; 131:3056-3068. [PMID: 34037300 DOI: 10.1111/jam.15162] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 05/06/2021] [Accepted: 05/19/2021] [Indexed: 11/30/2022]
Abstract
AIM The aims of this study were to screen an antagonistic probiotic for the prevention and control of bacterial diseases in snakehead fish and to evaluate the antimicrobial activities, biosafety and biocontrol effect of the antagonistic strain. METHODS AND RESULTS In this study, the WLYS23 strain exhibiting the most effective antagonistic properties against several fish pathogens was selected from the intestine of healthy snakehead fish. The strain was identified as Bacillus velezensis based on morphological, physiological and biochemical characteristics, and phylogenetic analysis. This strain showed amylase, cellulase, protease and lipase activities according to extracellular enzyme activity assays. Moreover, the cell-free extract of the WLYS23 strain exhibited strong antibacterial activity, with MICs of ≤64 μg ml-1 for most fish pathogens. Additionally, the cell-free extract was heat and pH stable, and resistant to protease, whereas their antimicrobial activities were significantly influenced by metal ions at high concentration. The WLYS23 strain and its cell-free extract were safe for snakehead and zebrafish. The disease resistance of snakehead fish was significantly increased following administration of the WLYS23 strain and its cell-free extract respectively. The complete genome of the WLYS23 strain was sequenced and found to harbour seven gene clusters encoding secondary metabolites with antimicrobial activity. CONCLUSION The WLYS23 strain possesses great potential as a biocontrol agent, which can be commercially developed to improve disease control in freshwater aquaculture. SIGNIFICANCE AND IMPACT OF THE STUDY Snakehead fish are important commercially farmed fish worldwide. However, the bacterial diseases caused by Aeromonas sp. and Nocardia seriolae in farmed snakehead fish lead to huge economic losses. Safe, economical and efficient probiotics are limited to prevent and control these diseases. Here, we provide a promising biocontrol agent with antagonistic activity against bacterial diseases of snakehead.
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Affiliation(s)
- D F Zhang
- Key Laboratory of Fishery Drug Development, Ministry of Agriculture and Rural Affairs, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China.,Key Laboratory of Aquatic Animal Immune Technology, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China
| | - X L Xiong
- Key Laboratory of Fishery Drug Development, Ministry of Agriculture and Rural Affairs, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China.,Key Laboratory of Aquatic Animal Immune Technology, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China
| | - Y J Wang
- Key Laboratory of Fishery Drug Development, Ministry of Agriculture and Rural Affairs, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China.,Key Laboratory of Aquatic Animal Immune Technology, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China
| | - Y X Gao
- Key Laboratory of Fishery Drug Development, Ministry of Agriculture and Rural Affairs, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China.,Key Laboratory of Aquatic Animal Immune Technology, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China
| | - Y Ren
- Key Laboratory of Fishery Drug Development, Ministry of Agriculture and Rural Affairs, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China.,Key Laboratory of Aquatic Animal Immune Technology, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China
| | - Q Wang
- Key Laboratory of Fishery Drug Development, Ministry of Agriculture and Rural Affairs, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China.,Key Laboratory of Aquatic Animal Immune Technology, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China
| | - C B Shi
- Key Laboratory of Fishery Drug Development, Ministry of Agriculture and Rural Affairs, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China.,Key Laboratory of Aquatic Animal Immune Technology, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China
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Liang J, Hu X, Lü A, Sun J. First report on the characterization of pathogenic Rahnella aquatilis KCL-5 from crucian carp: Revealed by genomic and proteomic analyses. JOURNAL OF FISH DISEASES 2020; 43:889-914. [PMID: 32608057 DOI: 10.1111/jfd.13200] [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: 02/25/2020] [Revised: 05/16/2020] [Accepted: 05/19/2020] [Indexed: 06/11/2023]
Abstract
Rahnella aquatilis is an important pathogen of several aquatic organisms and is found widely distributed in the freshwater, soil, fish and human clinical samples. Our previously published study reported a novel pathogenic R. aquatilis strain KCL-5 to crucian carp (Carassius auratus). To further investigate the characteristics and pathogenesis caused by R. aquatilis, we here report on the pathological changes, bacterial genomic and proteomic analyses of strain KCL-5. Significantly pathological changes in liver, intestine, spleen and gills were observed in infected fish. The genome consists of one circular chromosome 5,062,299 bp with 52.02% GC content and two plasmids (506,827 bp, 52.16%; 173,433 bp, 50.00%) and predicted 5,653 genes, 77 tRNAs and 22 rRNAs. Some virulence factors were characterized, including outer membrane protein, haemolysin, RTX toxin, chemotaxis and T3SS secretion system. Antimicrobial resistance genes such as EmrAB-TolC, MexABC-OpmB and RosAB efflux pump were found in strain KCL-5. KEGG analysis showed that mainly functional modules were ABC transporters, biosynthesis of amino acids, two-component system, quorum sensing, flagellum assembly and chemotaxis, in which most of them were identified by using 2-DE/MS analyses. To our knowledge, this was first report on the molecular characteristics of R. aquatilis by multi-omics approaches, which will provide insights into the pathogenic mechanism of R. aquatilis infection in fish.
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Affiliation(s)
- Jing Liang
- Tianjin Key Lab of Aqua-Ecology and Aquaculture, College of Fisheries, Tianjin Agricultural University, Tianjin, China
| | - Xiucai Hu
- Tianjin Key Lab of Aqua-Ecology and Aquaculture, College of Fisheries, Tianjin Agricultural University, Tianjin, China
| | - Aijun Lü
- Tianjin Key Lab of Aqua-Ecology and Aquaculture, College of Fisheries, Tianjin Agricultural University, Tianjin, China
| | - Jingfeng Sun
- Tianjin Key Lab of Aqua-Ecology and Aquaculture, College of Fisheries, Tianjin Agricultural University, Tianjin, China
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Fernández-Bravo A, Figueras MJ. An Update on the Genus Aeromonas: Taxonomy, Epidemiology, and Pathogenicity. Microorganisms 2020; 8:microorganisms8010129. [PMID: 31963469 PMCID: PMC7022790 DOI: 10.3390/microorganisms8010129] [Citation(s) in RCA: 228] [Impact Index Per Article: 57.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 01/10/2020] [Accepted: 01/14/2020] [Indexed: 02/07/2023] Open
Abstract
The genus Aeromonas belongs to the Aeromonadaceae family and comprises a group of Gram-negative bacteria widely distributed in aquatic environments, with some species able to cause disease in humans, fish, and other aquatic animals. However, bacteria of this genus are isolated from many other habitats, environments, and food products. The taxonomy of this genus is complex when phenotypic identification methods are used because such methods might not correctly identify all the species. On the other hand, molecular methods have proven very reliable, such as using the sequences of concatenated housekeeping genes like gyrB and rpoD or comparing the genomes with the type strains using a genomic index, such as the average nucleotide identity (ANI) or in silico DNA–DNA hybridization (isDDH). So far, 36 species have been described in the genus Aeromonas of which at least 19 are considered emerging pathogens to humans, causing a broad spectrum of infections. Having said that, when classifying 1852 strains that have been reported in various recent clinical cases, 95.4% were identified as only four species: Aeromonas caviae (37.26%), Aeromonas dhakensis (23.49%), Aeromonas veronii (21.54%), and Aeromonas hydrophila (13.07%). Since aeromonads were first associated with human disease, gastroenteritis, bacteremia, and wound infections have dominated. The literature shows that the pathogenic potential of Aeromonas is considered multifactorial and the presence of several virulence factors allows these bacteria to adhere, invade, and destroy the host cells, overcoming the immune host response. Based on current information about the ecology, epidemiology, and pathogenicity of the genus Aeromonas, we should assume that the infections these bacteria produce will remain a great health problem in the future. The ubiquitous distribution of these bacteria and the increasing elderly population, to whom these bacteria are an opportunistic pathogen, will facilitate this problem. In addition, using data from outbreak studies, it has been recognized that in cases of diarrhea, the infective dose of Aeromonas is relatively low. These poorly known bacteria should therefore be considered similarly as enteropathogens like Salmonella and Campylobacter.
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10
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Zhang DX, Kang YH, Song MF, Shu HP, Guo SN, Jia JP, Tao LT, Zhao ZL, Zhang L, Wang CF, Wang GQ, Qian AD, Shan XF. Identity and virulence properties of Aeromonas isolates from healthy Northern snakehead (Channa argus) in China. Lett Appl Microbiol 2019; 69:100-109. [PMID: 31107978 DOI: 10.1111/lam.13172] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 04/16/2019] [Accepted: 05/07/2019] [Indexed: 12/29/2022]
Abstract
Members of the genus Aeromonas are opportunistic pathogen of a variety of aquatic animals that exhibits multidrug resistance, phenotypes, virulence genes and virulence. The present study described the species distribution and the potential pathogenicity of Aeromonas isolated from healthy Northern snakehead (Channa argus) in China. Molecular identification revealed that A. veronii biovar veronii (69/167; 41·3%) and A. hydrophila (41/167; 24·6%) were the most common species found in Northern snakehead intestine based on sequencing of the 16S rRNA gene and DNA gyrase subunit B protein. The distribution of seven virulence factors including aer (84·4%), act (80·8%), ser (40·1%), Aha (27·5%), lip (23·4%), exu (15·0%) and LuxS (12·6%) were determined exclusively in Aeromonas isolates. All the seven virulence genes were present in 9·6% (16/167), among which 11 strains were identified as A. veronii biovar veronii. For the strains harbouring seven virulence genes, the 50% lethal doses (LD50 ) of isolates were lower compared to the isolates carrying two virulence genes. The challenge tests revealed that isolate W31 had the lowest lethal dose, causing 50% mortality at 4·5 × 103 colony-forming units (CFU) per ml. Furthermore, histopathology of Northern snakehead infected with Aeromonas strains showed necrosis and congestion in liver, spleen and kidney and also damage to the intestine. This study confirms that the Aeromonas strains isolated from healthy Northern snakehead may be a cause of concern for public health. SIGNIFICANCE AND IMPACT OF THE STUDY: Aeromonas species are widely distributed in aquatic environments and have considerable virulence potential. The aim of this study was to identify Aeromonas strains isolated from healthy Northern snakehead, and to investigate if Aeromonas species isolated from healthy fish potential pathogenicity with special reference to virulence and epidemiology studies.
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Affiliation(s)
- D-X Zhang
- College of Animal Science and Technology, Jilin Agricultural University, Changchun, China
| | - Y-H Kang
- College of Animal Science and Technology, Jilin Agricultural University, Changchun, China
| | - M-F Song
- College of Animal Science and Technology, Jilin Agricultural University, Changchun, China
| | - H-P Shu
- College of Animal Science and Technology, Jilin Agricultural University, Changchun, China
| | - S-N Guo
- College of Animal Science and Technology, Jilin Agricultural University, Changchun, China
| | - J-P Jia
- College of Animal Science and Technology, Jilin Agricultural University, Changchun, China
| | - L-T Tao
- College of Animal Science and Technology, Jilin Agricultural University, Changchun, China
| | - Z-L Zhao
- College of Animal Science and Technology, Jilin Agricultural University, Changchun, China
| | - L Zhang
- College of Animal Science and Technology, Jilin Agricultural University, Changchun, China
| | - C-F Wang
- College of Animal Science and Technology, Jilin Agricultural University, Changchun, China
| | - G-Q Wang
- College of Animal Science and Technology, Jilin Agricultural University, Changchun, China
| | - A-D Qian
- College of Animal Science and Technology, Jilin Agricultural University, Changchun, China
| | - X-F Shan
- College of Animal Science and Technology, Jilin Agricultural University, Changchun, China
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11
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Liu C, Guo YM, Cao JZ, Zhang DF, Chang OQ, Li K, Wang F, Shi CB, Jiang L, Wang Q, Lin L. Detection and quantification of Aeromonas schubertii in Channa maculata by TaqMan MGB probe fluorescence real-time quantitative PCR. JOURNAL OF FISH DISEASES 2019; 42:109-117. [PMID: 30474192 DOI: 10.1111/jfd.12911] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Revised: 09/22/2018] [Accepted: 09/23/2018] [Indexed: 06/09/2023]
Abstract
Aeromonas schubertii is a major epidemiological agent that threatens cultured snakeheads (Channidae) and has caused great economic losses in fish-farming industries in China in recent years. In present study, a specific TaqMan minor groove binder (MGB) probe fluorescence real-time quantitative PCR (qPCR) assay was developed to rapidly detect and quantify A. schubertii. A pair of qPCR primers and a TaqMan MGB probe were selected from the rpoD gene, which were shown to be specific for A. schubertii. A high correlation coefficient (R2 = 0.9998) in a standard curve with a 103% efficiency was obtained. Moreover, the qPCR method's detection limit was as low as 18 copies/μl, which was 100 times more sensitive than that of conventional PCR. The detection results for the A. schubertii in pond water and fish tissue were consistent with those of the viable counts. Bacterial load changes detected by qPCR in different tissues of snakeheads infected with A. schubertii showed that the gills and intestines may be the entry for A. schubertii, and the spleen and kidney are major sites for A. schubertii replication. The established method in present study should be a useful tool for the early surveillance and quantitation of A. schubertii.
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Affiliation(s)
- Chun Liu
- College of Fisheries, Huazhong Agricultural University, Wuhan, Hubei, China
- Key Laboratory of Fishery Drug Development of Ministry of Agriculture, Key Laboratory of Aquatic Animal Immune Technology of Guangdong Province, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, Guangdong, China
| | - Yanming M Guo
- College of Medical Science and Technology, Heze University, Heze, Shandong, China
| | - Jizhen Z Cao
- Key Laboratory of Fishery Drug Development of Ministry of Agriculture, Key Laboratory of Aquatic Animal Immune Technology of Guangdong Province, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, Guangdong, China
| | - De-Feng Zhang
- Key Laboratory of Fishery Drug Development of Ministry of Agriculture, Key Laboratory of Aquatic Animal Immune Technology of Guangdong Province, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, Guangdong, China
| | - Ou-Qin Chang
- Key Laboratory of Fishery Drug Development of Ministry of Agriculture, Key Laboratory of Aquatic Animal Immune Technology of Guangdong Province, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, Guangdong, China
| | - Kaibin Li
- Key Laboratory of Fishery Drug Development of Ministry of Agriculture, Key Laboratory of Aquatic Animal Immune Technology of Guangdong Province, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, Guangdong, China
| | - Fang Wang
- Key Laboratory of Fishery Drug Development of Ministry of Agriculture, Key Laboratory of Aquatic Animal Immune Technology of Guangdong Province, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, Guangdong, China
| | - Cun-Bin Shi
- Key Laboratory of Fishery Drug Development of Ministry of Agriculture, Key Laboratory of Aquatic Animal Immune Technology of Guangdong Province, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, Guangdong, China
| | - Lan Jiang
- Key Laboratory of Fishery Drug Development of Ministry of Agriculture, Key Laboratory of Aquatic Animal Immune Technology of Guangdong Province, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, Guangdong, China
| | - Qing Wang
- Key Laboratory of Fishery Drug Development of Ministry of Agriculture, Key Laboratory of Aquatic Animal Immune Technology of Guangdong Province, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, Guangdong, China
| | - Li Lin
- College of Fisheries, Huazhong Agricultural University, Wuhan, Hubei, China
- Guangzhou Key Laboratory of Aquatic Animal Diseases and Waterfowl Breeding, Guangdong Provincial Key Laboratory of Waterfowl Healthy Breeding, College of Animal Sciences and Technology, Zhongkai University of Agriculture and Engineering, Guangzhou, China
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12
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Liu C, Chang OQ, Zhang DF, Li KB, Wang F, Lin MH, Shi CB, Jiang L, Wang Q, Bergmann SM. Aeromonas shuberti as a cause of multi-organ necrosis in internal organs of Nile tilapia, Oreochromis niloticus. JOURNAL OF FISH DISEASES 2018; 41:1529-1538. [PMID: 30039866 DOI: 10.1111/jfd.12848] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 06/06/2018] [Accepted: 06/07/2018] [Indexed: 06/08/2023]
Abstract
A disease with white spots in internal organs of Nile tilapia occurred in Zhanjiang, southern China. Multiple, white nodules, 0.8-2.2 mm in diameter, were scattered throughout the liver, spleen and kidney of diseased fish. Signs of nodules reproduced after artificial infection with the isolated strain. Isolated bacteria were Gram-negative, facultative anaerobic, motile, short rod-shaped, with a length of 1.2-2.2 μm. Morphological and biochemical tests, as well as phylogenetic analysis, all strongly indicated that the isolate from tilapia is identical to Aeromonas schubertii (A. schubertii) which temporary named LF1708 strain. Antibiotic sensitivity assays showed the LF1708 is sensitive to 24 of 27 tested antibiotics. Pathogenicity test revealed that the isolate at the dose of 3.75 × 106 CFU/g killed 100% of experimental tilapia within 2 days and the dose of 1 × 107 CFU/g killed 100% of experimental zebrafish within 1 day. Histopathology of diseased tilapia infected with A. schubertii showed numerous necrotic lesions widely distributed in spleen, liver and kidney, and infiltration with a large number of bacteria. To our knowledge, this was the first report that associated A. schubertii with mortality in tilapia.
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Affiliation(s)
- C Liu
- Key Laboratory of Fishery Drug Development of Ministry of Agriculture, Key Laboratory of Aquatic Animal Immune Technology of Guangdong Province, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangdong, China
| | - O Q Chang
- Key Laboratory of Fishery Drug Development of Ministry of Agriculture, Key Laboratory of Aquatic Animal Immune Technology of Guangdong Province, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangdong, China
| | - D F Zhang
- Key Laboratory of Fishery Drug Development of Ministry of Agriculture, Key Laboratory of Aquatic Animal Immune Technology of Guangdong Province, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangdong, China
| | - K B Li
- Key Laboratory of Fishery Drug Development of Ministry of Agriculture, Key Laboratory of Aquatic Animal Immune Technology of Guangdong Province, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangdong, China
| | - F Wang
- Key Laboratory of Fishery Drug Development of Ministry of Agriculture, Key Laboratory of Aquatic Animal Immune Technology of Guangdong Province, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangdong, China
| | - M H Lin
- Key Laboratory of Fishery Drug Development of Ministry of Agriculture, Key Laboratory of Aquatic Animal Immune Technology of Guangdong Province, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangdong, China
| | - C B Shi
- Key Laboratory of Fishery Drug Development of Ministry of Agriculture, Key Laboratory of Aquatic Animal Immune Technology of Guangdong Province, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangdong, China
| | - L Jiang
- Key Laboratory of Fishery Drug Development of Ministry of Agriculture, Key Laboratory of Aquatic Animal Immune Technology of Guangdong Province, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangdong, China
| | - Q Wang
- Key Laboratory of Fishery Drug Development of Ministry of Agriculture, Key Laboratory of Aquatic Animal Immune Technology of Guangdong Province, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangdong, China
| | - S M Bergmann
- Institute of Infectology, Friedrich-Loffler-Institut (FLI), Federal Research Institute for Animal Health, Greifswald-Insel Riems, Germany
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13
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First record of the rare species Aeromonas schubertii from mussels: phenotypic and genetic reevaluation of the species and a review of the literature. Arch Microbiol 2016; 198:333-45. [DOI: 10.1007/s00203-016-1189-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Revised: 12/17/2015] [Accepted: 01/08/2016] [Indexed: 10/22/2022]
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14
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Complete Genome Sequence of the Highly Virulent Aeromonas schubertii Strain WL1483, Isolated from Diseased Snakehead Fish (Channa argus) in China. GENOME ANNOUNCEMENTS 2016; 4:4/1/e01567-15. [PMID: 26798095 PMCID: PMC4722262 DOI: 10.1128/genomea.01567-15] [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
We sequenced the complete genome of the highly virulent Aeromonas schubertii strain WL1483, which was isolated from diseased snakehead fish (Channa argus) in China. The full genome sequence of A. schubertii WL1483 is 4,400,034 bp, which encodes 4,376 proteins and contains 195 predicted RNA genes.
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15
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Latif-Eugenín F, Beaz-Hidalgo R, María José F. A Culture Independent Method for the Detection of Aeromonas sp. from Water Samples. Ital J Food Saf 2016; 5:5489. [PMID: 27800428 PMCID: PMC5076704 DOI: 10.4081/ijfs.2016.5489] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Revised: 09/27/2015] [Accepted: 09/28/2015] [Indexed: 01/09/2023] Open
Abstract
The genus Aeromonas is present in a wide variety of water environments and is recognised as potentially pathogenic to humans and animals. Members of this genus are often confused with Vibrio when using automated, commercial identification systems that are culture-dependent. This study describes a polymerase chain reaction (PCR) detection method for Aeromonas that is culture-independent and that targets the glycerophospholopid-cholesterol acyltransferase (gcat) gene, which is specific for this genus. The GCAT-PCR was 100% specific in artificially inoculated water samples, with a detection limit that ranged from 2.5 to 25 cfu/mL. The success at detecting this pathogen in 86 water samples using the GCAT-PCR method was identical to the conventional culturing method when a pre-enrichment step was carried out, yielding 83.7% positive samples. On the other hand, without a pre-enrichment step, only 77.9% of the samples were positive by culturing and only 15.1% with the GCAT-PCR. However, 83.7% positive samples were obtained for the GCAT-PCR when the water volume for the DNA extraction was increased from 400 µL to 4 mL. The proposed molecular method is much faster (5 or 29 h) than the culturing method (24 or 48 h) whether performed directly or after a pre-enrichment step and it will enable the fast detection of Aeromonas in water samples helping to prevent a possible transmission to humans.
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Affiliation(s)
- Fadua Latif-Eugenín
- Unit of Microbiology, Medicine and Health Science School, Rovira i Virgili University , Reus, Spain
| | - Roxana Beaz-Hidalgo
- Unit of Microbiology, Medicine and Health Science School, Rovira i Virgili University , Reus, Spain
| | - Figueras María José
- Unit of Microbiology, Medicine and Health Science School, Rovira i Virgili University , Reus, Spain
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