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Aquaculture International : Journal of... 2023This study aimed to develop and evaluate live and inactivated vaccines to pathogenicity in Nile tilapia. Therefore, five well-identified isolates, including A (HY1), A...
This study aimed to develop and evaluate live and inactivated vaccines to pathogenicity in Nile tilapia. Therefore, five well-identified isolates, including A (HY1), A (HY2), A (HY3), A (HY4), and A (HY6) isolated from diseased Nile tilapia (), were used for vaccine preparation. Virulence genes detected by a polymerase chain reaction (PCR) and lethal dose determination were conducted. Nile tilapia, each with a body weight of 25 ± 0.5 g were divided into six experimental groups (each of 20): T1 group (control), fish were injected with saline as a negative control, T2 group (formalin-killed vaccine) for the A (HY2) strain, T3 group ( formalized killed vaccine) for the A (HY4), T4 group (autoclaved vaccine) for the A (HY2), T5 group (autoclaved vaccine) for A (HY4), and T6 (live vaccine) for A (HY1), triplicate. At the end of the immunization period, all groups were challenged by , A (HY2). Blood samples were drawn 21 days post-immunization and 3 days after the challenge test for antibody titer assay. The results showed that the pathogenicity of strains A (HY2) and A (HY4) was the strongest, as the lethality rates (LR) were 100% and 90%, respectively, whereas the pathogenicity was moderate for strains A (HY3) and A (HY6) (LR 60% for each). A (AY1) was the weakest strain as no dead fish was found for this strain. The presence of , and genes as the main cause of the pathogenesis. The best protective efficacy was obtained from the live vaccine, A (HY1) with a protective rate of about 94.12% (relative percentage of survival, RPS), compared to autoclaved killed vaccines and formalin-killed vaccines. Based on immunoglobulin estimation (IgM) and RPS%, our data concluded that A (HY1) live vaccine had the best vaccine prophylactic effect against the highly pathogenic strain A(HY2).
PubMed: 36439703
DOI: 10.1007/s10499-022-01023-1 -
Microbial Pathogenesis Aug 2022Aeromonas veronii AvX005 is a pathogenic bacterium with high toxicity to grass carp (Ctenopharyngodon idellus). The expression levels of g-type (goose-type lysozyme,...
Aeromonas veronii infection remarkably increases expression of lysozymes in grass carp (Ctenopharyngodon idellus) and injection of lysozyme expression cassette along with QCDC adjuvant significantly upregulates immune factors and decreases cumulative mortality.
Aeromonas veronii AvX005 is a pathogenic bacterium with high toxicity to grass carp (Ctenopharyngodon idellus). The expression levels of g-type (goose-type lysozyme, Lys-g) and c-type lysozyme (chicken-type lysozyme, Lys-c) in the spleen of grass carp infected with AvX005 were significantly increased by approximately 4.5 times and 27 times, respectively. The recombinant proteins rLys-g and rLys-c produced in a recombinant expression system of Escherichia coli showed significant antibacterial activity against the pathogenic bacteria AvX005. A challenge test was conducted after rLys-g and rLys-c were expressed in grass carp L8824 liver cells, and compared with the survival rate of the control cells (46.3%), the survival rate of the experimental cells (77.6% for rLys-g and 68.6% for rLys-c) was significantly increased. Grass carp were infected with AvX005 on the second day after delivering pcDNA3.1-lys-g and pcDNA-lys-c with the Quil A/cholesterol/DDA/Carbopol (QCDC) adjuvant, and both pcDNA3.1-lys-g and pcDNA-lys-c provided 70% relative protection for grass carp. The activity of lysozyme and alkaline phosphatase in the serum of grass carp was significantly increased after injection of DNA. The expression of the immune factors IgM, C3 and IL8 in the kidney was upregulated to varying degrees for pcDNA3.1-lys-g and immune factors C3 and IgM was upregulated for pcDNA-lys-c. The results indicated that pcDNA3.1-lys-g and pcDNA-lys-c may be used as immunostimulants to protect grass carp from the pathogenic bacterium AvX005.
Topics: Acrylic Resins; Adjuvants, Immunologic; Aeromonas hydrophila; Aeromonas veronii; Animals; Carps; Cholesterol; Fish Diseases; Gram-Negative Bacterial Infections; Immunity, Innate; Immunoglobulin M; Muramidase; Quillaja Saponins
PubMed: 35716927
DOI: 10.1016/j.micpath.2022.105646 -
Fish & Shellfish Immunology Jul 2023Aeromonas veronii is a pathogenic bacterium associated with various diseases in aquaculture. However, few studies address the antibacterial activity using nanoparticles...
Hematological, immuno-antioxidant disruptions, and genes down-regulation induced by Aeromonas veronii challenge in Clarias gariepinus: The ameliorative role of silica nanoparticles.
Aeromonas veronii is a pathogenic bacterium associated with various diseases in aquaculture. However, few studies address the antibacterial activity using nanoparticles (NPs). Hence, the current study is innovative to evaluate the antibacterial efficacy of silica nanoparticles (SiNPs) against A. veronii infection in-vitro with a trial for treatment in-vivo. Primarily, we assessed the in-vitro antibacterial activity against A. veronii. Further, we investigated the hematological profile, immune-antioxidant response, and gene expression of African catfish (Clarias gariepinus) in response to SiNPs exposure and the A. veronii challenge. Fish (N = 120; weight: 90 ± 6.19 g) were distributed into four groups (30 fish/group) for a ten-days-treatment trial. The first (control) and second (SiNPs) groups were treated with 0 mg/L and 20 mg/L SiNPs in water, respectively. The third (A. veronii) and fourth (SiNPs + A. veronii) groups were treated with 0 mg/L and 20 mg/L SiNPs in water, respectively, and infected with A. veronii (1.5 × 10 CFU/mL). Results demonstrated that SiNPs displayed an in-vitro antibacterial activity against A. veronii with a 21 mm inhibitory zone. A. veronii infection caused a high mortality rate (56.67%) and substantial reductions in hematological indices and immune indicators [nitric oxide (NO) and immunoglobulin M (IgM)]. Additionally, marked decline in the level of antioxidants [superoxide dismutase (SOD), catalase (CAT), and reduced glutathione content (GSH)] as well as down-regulation in the immune-related genes [interleukins (IL-1β and IL-8) and tumor necrosis factor-alpha (TNF-α)] and antioxidant-related genes [SOD1, glutathione peroxidase (GPx), and glutathione-S-transferase (GST)] were the consequences of A. veronii infection. Surprisingly, treatment of A. veronii-infected fish with SiNPs lessened the mortality rate, enhanced the blood picture, modulated the immune-antioxidant parameters, and resulted in gene up-regulation. Overall, this study encompasses the significant role of SiNPs, a new versatile tool for combating hematological, immuno-antioxidant alterations, and gene down-regulation induced by A. veronii infection and sustainable aquaculture production.
Topics: Animals; Antioxidants; Aeromonas veronii; Down-Regulation; Gene Expression; Catfishes; Nanoparticles; Fish Diseases; Gram-Negative Bacterial Infections
PubMed: 37209754
DOI: 10.1016/j.fsi.2023.108842 -
Antibiotics (Basel, Switzerland) Jun 2023is a Gram-negative bacterial species that causes disease in fish and is nowadays increasingly recurrent in enteric infections of humans. This study was performed to...
is a Gram-negative bacterial species that causes disease in fish and is nowadays increasingly recurrent in enteric infections of humans. This study was performed to characterize newly sequenced isolates by comparing them with complete genomes deposited at the NCBI (National Center for Biotechnology Information). Nine isolates from fish, environments, and humans from the São Francisco Valley (Petrolina, Pernambuco, Brazil) were sequenced and compared with complete genomes available in public databases to gain insight into taxonomic assignment and to better understand virulence and resistance profiles of this species within the One Health context. One local genome and four NCBI genomes were misidentified as . A total of 239 virulence genes were identified in the local genomes, with most encoding adhesion, motility, and secretion systems. In total, 60 genes involved with resistance to 22 classes of antibiotics were identified in the genomes, including and . The results suggest that the use of methods such as ANI is essential to avoid misclassification of the genomes. The virulence content of from local isolates is similar to those complete genomes deposited at the NCBI. Genes encoding colistin resistance are widespread in the species, requiring greater attention for surveillance systems.
PubMed: 37370358
DOI: 10.3390/antibiotics12061039 -
Fish & Shellfish Immunology Feb 2023CD3γ/δ found in non-mammalian vertebrates is a CD3 homolog with structural characteristics similar to both mammalian CD3γ and CD3δ, and plays important roles in T...
CD3γ/δ found in non-mammalian vertebrates is a CD3 homolog with structural characteristics similar to both mammalian CD3γ and CD3δ, and plays important roles in T cell recognization and immune response in fish. In this study, the full-length of CD3γ/δ from Qihe crucian carp (named CaCD3γ/δ) was cloned and characterized, then the expression response profiles and potential immune functions was explored after Aeromonas veronii and Poly(I:C) challenge. The results showed that the full-length of CaCD3γ/δ was 819 bp including a 5'-UTR of 141 bp, a 3'-UTR of 168 bp, and an ORF of 510 bp encoding a putative 169-aa protein with an estimated MW of 18.71 kD and a theoretical pI of 8.77. The protein sequence of CaCD3γ/δ contained a Leu-Leu and a CXXXC motif in the extracellular domain, and an ITAM and a Leu-Ile motif in the cytoplasm, and a residue of Asn in the transmembrane. CaCD3γ/δ was constitutively expressed in the spleen, liver, gill, and blood of Qihe crucian carp. After the carp were challenged with Poly(I:C) and Aeromonas veronii, the mRNA expression levels of CaCD3γ/δ were significantly changed in the spleen, head kidney, intestine and gill, according to the results of qPCR. However, compared with A. veronii, Poly(I:C) challenge can rapidly induce the CaCD3γ/δ expression levels in head kidney, intestine and spleen, which suggested CaCD3γ/δ may be differentially modulated by different pathogens. Moreover, the results of immunohistochemical analysis showed that the CaCD3γ/δ secreted cells in the spleen and gills of Qihe crucian were increased after challenged with Poly(I:C), as well as the spleen challenged with A. veronii, but at different levels. Combined with the fact that vascular congestion, necrosis of parenchymal cells, and inflammatory cells including lymphocytes infiltration were also observed in the gill and spleen of Qihe crucian carp treated with A. veronii and Poly(I:C) revealed by pathological analysis, it was predicted that CaCD3γ/δ T lymphocytes may participated in the immune response against pathogens. This study will contribute to understand the important role of CaCD3γ/δ T lymphocytes in the immune response of Qihe crucian carp, and provide new insights for the prevention and treatment of the diseases of Qihe crucian carp.
Topics: Animals; Goldfish; Carps; Aeromonas veronii; Immunity, Innate; Sequence Alignment; Fish Proteins; Fish Diseases; Mammals
PubMed: 36646341
DOI: 10.1016/j.fsi.2023.108550 -
International Journal of Molecular... Feb 2020is a virulent fish pathogen that causes extensive economic losses in the aquaculture industry worldwide. In this study, a virulent strain of TH0426 was used to... (Comparative Study)
Comparative Study
is a virulent fish pathogen that causes extensive economic losses in the aquaculture industry worldwide. In this study, a virulent strain of TH0426 was used to establish an in vitro biofilm model. The results show that the biofilm-forming abilities of TH0426 were similar in different media, peaking under conditions of 20 °C and pH 6. Further, isobaric tags for relative and absolute quantitation (iTRAQ)-based quantitative proteomics methods were used to compare the differential expression of between the biofilm and planktonic cells. The results show alterations in 277 proteins, with 130 being upregulated and 147 downregulated. Pathway analysis and GO (Gene Ontology) annotations indicated that these proteins are mainly involved in metabolic pathways and the biosynthesis of secondary metabolites and antibiotics. These proteins are the main factors affecting the adaptability of to its external environment. MRM (multiple reaction 27 monitoring) and qPCR (qPCR) were used to verify the differential proteins of the selected . This is the first report on the biofilm and planktonic cells of , thus contributing to studying the infection and pathogenesis of
Topics: Aeromonas veronii; Bacterial Proteins; Biofilms; Gene Expression Regulation, Bacterial; Proteomics
PubMed: 32093365
DOI: 10.3390/ijms21041450 -
Probiotics and Antimicrobial Proteins Dec 2021This study investigates the effects of dietary Aeromonas veronii V03 supplementation on growth performances, innate immunity, and expression of immune-related genes in...
Dietary Administration of Probiotic Aeromonas veronii V03 on the Modulation of Innate Immunity, Expression of Immune-Related Genes and Disease Resistance Against Aeromonas hydrophila Infection in Common Carp (Cyprinus carpio).
This study investigates the effects of dietary Aeromonas veronii V03 supplementation on growth performances, innate immunity, and expression of immune-related genes in lymphoid organs of Cyprinus carpio and resistance to Aeromonas hydrophila infection. Fish were fed for 4 weeks with basal diet (BD; without probiotic), and experiment diet containing different doses of A. veronii V03 at 3.2 × 10 (DI) and 3.5 × 10 (DII) CFU g of diet. At the end of the probiotic feeding trial, fish were challenged with A. hydrophila, and the percentage of survival rates was recorded over 7 days. Results revealed that fish fed with A. veronii V03 demonstrated a significant improvement in growth and enhancement of innate immunity, including respiratory burst, myeloperoxidase, and lysozyme activities, and total immunoglobulin level compared with BD fed to fish. Relatively, expression of cytokines (MyD88, IL-1β1, IL-8, and IL-10) and c- and g-type lysozymes were significantly up- and downregulated in lymphoid organs of fish. Moreover, dietary supplementation of A. veronii V03 exhibited significantly (p < 0.001) higher survival rates of DI (90%) and DII (96.66%) compared with BD (53.33%) fed fish against A. hydrophila infection. These findings help to understand the effects of probiotic A. veronii V03 administrated feed influences on growth and ailment resistance to A. hydrophila infection by regulating innate and systemic immunity in common carp fish.
Topics: Aeromonas hydrophila; Aeromonas veronii; Animals; Carps; Disease Resistance; Gram-Negative Bacterial Infections; Immunity, Innate; Probiotics
PubMed: 33856639
DOI: 10.1007/s12602-021-09784-6 -
International Journal of Molecular... Sep 2022Yellow catfish () is an important aquaculture fish susceptible to infection, which causes acute death resulting in huge economic losses. Understanding the molecular...
Yellow catfish () is an important aquaculture fish susceptible to infection, which causes acute death resulting in huge economic losses. Understanding the molecular processes of host immune defense is indispensable to disease control. Here, we conducted the integrated and comparative analyses of the transcriptome and metabolome of yellow catfish in response to infection at the invaded stage and recovering stage. The crosstalk between -induced genes and metabolites uncovered the key biomarkers and pathways that strongest contribute to different response strategies used by yellow catfish at corresponding defense stages. We found that at the invading stage, the immune defense was strengthened by synthesizing lipids with energy consumption to repair the skin defense line and accumulate lipid droplets promoting intracellular defense line; triggering an inflammatory response by elevating cytokine IL-6, IL-10 and IL-1β following PAMP-elicited mitochondrial signaling, which was enhanced by ROS produced by impaired mitochondria; and activating apoptosis by up-regulating caspase 3, 7 and 8 and Prostaglandin F1α, meanwhile down-regulating FoxO3 and BCL6. Apoptosis was further potentiated via oxidative stress caused by mitochondrial dysfunction and exceeding inflammatory response. Additionally, cell cycle arrest was observed. At the fish recovering stage, survival strategies including sugar catabolism with D-mannose decreasing; energy generation through the TCA cycle and Oxidative phosphorylation pathways; antioxidant protection by enhancing Glutathione (oxidized), Anserine, and α-ketoglutarate; cell proliferation by inducing Cyclin G2 and CDKN1B; and autophagy initiated by FoxO3, ATG8 and ATP6V1A were highlighted. This study provides a comprehensive picture of yellow catfish coping with infection, which adds new insights for deciphering molecular mechanisms underlying fish immunity and developing stage-specific disease control techniques in aquaculture.
Topics: Aeromonas veronii; Animals; Catfishes; Fish Diseases; Fish Proteins; Metabolome; Transcriptome
PubMed: 36077519
DOI: 10.3390/ijms231710121 -
BMC Microbiology Jun 2021Aeromonas veronii is a bacterial pathogen in aquaculture, which produces virulence factors to enable it colonize and evade host immune defense. Given that experimental...
BACKGROUND
Aeromonas veronii is a bacterial pathogen in aquaculture, which produces virulence factors to enable it colonize and evade host immune defense. Given that experimental verification of virulence factors is time-consuming and laborious, few virulence factors have been characterized. Moreover, most studies have only focused on single virulence factors, resulting in biased interpretation of the pathogenesis of A. veronii.
RESULTS
In this study, a PPI network at genome-wide scale for A. veronii was first constructed followed by prediction and mapping of virulence factors on the network. When topological characteristics were analyzed, the virulence factors had higher degree and betweenness centrality than other proteins in the network. In particular, the virulence factors tended to interact with each other and were enriched in two network modules. One of the modules mainly consisted of histidine kinases, response regulators, diguanylate cyclases and phosphodiesterases, which play important roles in two-component regulatory systems and the synthesis and degradation of cyclic-diGMP. Construction of the interspecies PPI network between A. veronii and its host Oreochromis niloticus revealed that the virulence factors interacted with homologous proteins in the host. Finally, the structures and interacting sites of the virulence factors during interaction with host proteins were predicted.
CONCLUSIONS
The findings here indicate that the virulence factors probably regulate the virulence of A. veronii by involving in signal transduction pathway and manipulate host biological processes by mimicking and binding competitively to host proteins. Our results give more insight into the pathogenesis of A. veronii and provides important information for designing targeted antibacterial drugs.
Topics: Aeromonas veronii; Animals; Cichlids; Fish Diseases; Genome, Bacterial; Gram-Negative Bacterial Infections; Virulence Factors
PubMed: 34162325
DOI: 10.1186/s12866-021-02261-8 -
Journal of Fish Diseases Dec 2023Aeromonas hydrophila and A. veronii are widespread and important critical pathogenic bacteria in the aquaculture industry and cause severe economic damage. At present,...
Aeromonas hydrophila and A. veronii are widespread and important critical pathogenic bacteria in the aquaculture industry and cause severe economic damage. At present, magnolol has been proved to be a broad-spectrum antibacterial activity, such as A. hydrophila, Staphylococcus aureus and Streptococcus mutans. In order to explore the cause of in vivo disease resistance of magnolol and promote its safe application in aquaculture, the pathological detection and changes in immune indicators of fish after feeding with magnolol were conducted in this paper. Results showed that the diets supplemented with magnolol (3 g magnolol/kg commercial feed) significantly increase the expression level of anti-inflammatory cytokines (IL-10, TGF-β and IL-4) in the liver of goldfish (p < .05). Additionally, the expression levels of proinflammatory cytokines (IL-1β, IL-8 and IFN-γ) did not increase significantly. Subsequently, this study investigated the resistance of goldfish to A. hydrophila and A. veronii infection after feeding with magnolol. The results showed that the survival rates of treatment groups fed 3 g magnolol/kg commercial feed daily increased by 23.1% and 38.5% after 10 days post A. hydrophila and A. veronii (p = .0351) infection, respectively. Meanwhile, growth performance (body weight and length), major internal organs (liver, spleen, kidney and intestine) and the serum biochemistry indicators (ATL and AST) all exhibited no significant adverse effects after the goldfish fed with magnolol for 30 days. TP showed an increasing concentration in the treatment group (p < .05). Results of the mRNA expression of stress response indicated that the expression level of cyp1a and hsp70 was significantly down-regulated after a 30-day treatment (p < .05), and the two genes recovered to the similar level as the control group after a commercial feed diet. In brief, the diets supplemented with magnolol protected the host from the excessive immune response caused by A. hydrophila and A. veronii via enhancing its anti-inflammatory capacity and had no adverse effects with feeding.
Topics: Animals; Goldfish; Aeromonas hydrophila; Gram-Negative Bacterial Infections; Fish Diseases; Diet; Disease Resistance; Cytokines; Animal Feed; Aeromonas veronii
PubMed: 37705318
DOI: 10.1111/jfd.13859