Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 4.439
Filtrar
1.
Res Vet Sci ; 138: 109-115, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34126449

RESUMO

Streptococcus agalactiae (GBS) is an important pathogen that has increasingly received attention for its role in invasive infections and its broad host range. Research on the regulation of gene expression could illuminate GBS pathogenesis. We previously identified a novel transcriptional regulator XtgS, which is a negative regulator of GBS pathogenicity. Here, we demonstrate that XtgS overexpression significantly attenuated GBS virulence in zebrafish infection tests, and XtgS indirectly downregulated the transcription of two iron transport systems based on the results of transcriptomic analysis, electrophoretic mobility shift assays (EMSAs) and lacZ fusion assays. Subsequent studies verified that the inactivation of iron transport system 1 resulted in GBS excessive iron accumulation and attenuated virulence. Thus, we infer that the downregulation of iron transport system 1 caused by XtgS overexpression probably attenuates bacterial virulence, which partially clarifies the mechanism by which XtgS alleviates the pathogenesis. These findings provide new insights into the relationship between exogenous transcriptional regulation and bacterial virulence.


Assuntos
Proteínas de Bactérias/genética , Doenças dos Peixes/microbiologia , Ferro/metabolismo , Infecções Estreptocócicas/veterinária , Streptococcus agalactiae/genética , Streptococcus agalactiae/patogenicidade , Fatores de Transcrição/genética , Peixe-Zebra , Animais , Proteínas de Bactérias/metabolismo , Infecções Estreptocócicas/microbiologia , Fatores de Transcrição/metabolismo , Virulência/genética
2.
Fish Shellfish Immunol ; 115: 70-74, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34089887

RESUMO

The polymerization of monomeric antigens can be a strategy to overcome the low immunogenicity of subunit vaccines. IMX313 is a hybrid oligomerization domain of chicken C4bp, and has been demonstrated to have potent activity as adjuvants for the fused antigens in mammals. In the present study, we investigated whether the oligomerization of α-enolase of Streptococcus iniae by fusion with IMX313 affected on antibody induction and on protection against S. iniae infection in olive flounder (Paralichthys olivaceus). The oligomerization of S. iniae enolase by fusion with IMX313 (enolase-IMX313) was verified by non-reducing PAGE, and the antibody titer against enolase in olive flounder immunized with enolase-IMX313 was significantly higher than that in fish immunized with enolase alone. Furthermore, although the survival of olive flounder immunized with enolase alone was low, fish immunized with enolase-IMX313 showed much higher survival (RPS 50%) in accordance with higher serum antibody titer, suggesting that fusion of antigens with IMX313 can be an effective way to enhance protective efficacy of subunit vaccines in olive flounder.


Assuntos
Formação de Anticorpos , Proteínas de Bactérias/genética , Doenças dos Peixes/imunologia , Linguados , Fosfopiruvato Hidratase/genética , Infecções Estreptocócicas/veterinária , Streptococcus iniae/genética , Animais , Anisóis , Proteínas Aviárias/genética , Proteínas de Bactérias/metabolismo , Doenças dos Peixes/microbiologia , Longevidade , Proteínas Adaptadoras de Sinalização NOD/genética , Fosfopiruvato Hidratase/metabolismo , Infecções Estreptocócicas/imunologia , Infecções Estreptocócicas/microbiologia , Streptococcus iniae/enzimologia , Triazinas , Triazóis
3.
Fish Shellfish Immunol ; 115: 189-197, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34147613

RESUMO

The present study examines the effectiveness of DNA vaccine against Aeromonas hydrophila through oral route using chitosan-tripolyphosphate (Cs-TPP) nanoparticles encapsulation. The virulent gene of outer membrane protein (OMP) and hemolysin (hly) related to pathogenicity of A. hydrophila was used to construct a DNA vaccine using pVAX1, and the construct was named as pVAX-OMP and pVAX-hly DNA vaccines. The pVAX-OMP and pVAX-hly DNA vaccines were encapsulated by Cs-TPP nanoparticles and size measured by field emission scanning electron microscopy (FE-SEM). The encapsulation efficiency of Cs-TPP nanoparticles was found to be 79.6% for pVAX-OMP DNA and 82.3% for pVAX-hly DNA binding with Cs-TPP nanoparticles. The stability and invitro release profile of plasmid DNA was also determined after encapsulation using DNase and chitosanase. DNA vaccines distribution in tissues was investigated in fish fed with the pVAX-OMP, pVAX-hly and pVAX-OMP+pVAX-hly encapsulated in Cs-TPP nanoparticles and confirmed by PCR and multiplex PCR. The results suggest that Cs-TPP nanoparticles encapsulated DNA vaccine delivered into fish by feeding. After oral vaccination of Labeo rohita were challenged with A. hydrophila by intraperitoneal injection. Relatively, gene expression of c- and g-type lysozyme followed by pro- and anti-inflammatory cytokines (Interlukin-10 and Tumor Growth Factor ß) was up-regulated in heart and kidney for pVAX-OMP+pVAX-hly vaccinated group. Moreover, fish fed with pVAX-OMP+pVAX-hly encapsulated in Cs-TPP nanoparticles had a significantly higher survival rate (76.2%) against A. hydrophila. This study concludes that pVAX-OMP and pVAX-hly DNA vaccines can be delivered orally using Cs-TPP nanoparticles for protection against A. hydrophilainfection.


Assuntos
Vacinas Bacterianas/administração & dosagem , Quitosana/análogos & derivados , Cyprinidae , Doenças dos Peixes/prevenção & controle , Infecções por Bactérias Gram-Negativas/veterinária , Vacinação/veterinária , Vacinas de DNA/administração & dosagem , Administração Oral , Aeromonas hydrophila/fisiologia , Animais , Proteínas da Membrana Bacteriana Externa/imunologia , Quitosana/administração & dosagem , Quitosana/imunologia , Doenças dos Peixes/microbiologia , Infecções por Bactérias Gram-Negativas/microbiologia , Infecções por Bactérias Gram-Negativas/prevenção & controle , Proteínas Hemolisinas/imunologia , Nanopartículas/administração & dosagem
4.
Fish Shellfish Immunol ; 114: 132-141, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33932598

RESUMO

Biofilm vaccine has been recognised as one of the successful strategy to reduce the Aeromonas hydrophila infection in fish. But, the vaccine contains the protective and non-protective proteins, which may lead to show altered heterologous adaptive immunity response. Moreover, cross protection and effectiveness of previously developed biofilm vaccine was not tested against different geographical A. hydrophila isolates. Therefore, in the present study, whole-cell A. hydrophila biofilm vaccine was evaluated in rohu, vaccinated group showed increased antibody titer and protection against the different geographical A. hydrophila isolates namely KAH1 and AAH2 with 78.9% and 84.2% relative percentage survival, respectively. In addition, by using the immune sera of biofilm vaccinated group, a total of six protective proteins were detected using western blot assay. Further, the same proteins were identified by nano LC-MS/MS method, a total of fourteen candidate proteins showing the immunogenic property including highly expressed OMP's tolC, bamA, lamb, AH4AK4_2542, AHGSH82_029580 were identified as potential vaccine candidates. The STRING analysis revealed that, top candidate proteins identified may potentially interact with other intracellular proteins; involved in ribosomal and (tricarboxylic acid) TCA pathway. Importantly, all the selected vaccine candidate proteins contain the B-cell epitope region. Finally, the present study concludes that, whole-cell A. hydrophila biofilm vaccine able to protect the fish against the different geographical A. hydrophila isolates. Further, through reverse vaccinology approach, a total of fourteen proteins were identified as potential vaccine candidates against A. hydrophila pathogen.


Assuntos
Aeromonas hydrophila/fisiologia , Biofilmes/crescimento & desenvolvimento , Cyprinidae , Doenças dos Peixes/prevenção & controle , Aeromonas hydrophila/imunologia , Animais , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Vacinas Bacterianas , Cromatografia Líquida/métodos , Epitopos de Linfócito B , Doenças dos Peixes/microbiologia , Nanotecnologia , Espectrometria de Massas em Tandem , Vacinologia/métodos
5.
Fish Shellfish Immunol ; 114: 207-217, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33965522

RESUMO

We previously identified a novel acidic polysaccharide, silkrose-AY, from the Japanese oak silkmoth (Antheraea yamamai), which can activate an innate immune response in mouse macrophage cells. However, innate immune responses stimulated by silkrose-AY in teleosts remain unclear. Here, we show the influence of dietary silkrose-AY in medaka (Oryzias latipes), a teleost model, in response to Edwardsiella tarda infection. Dietary silkrose-AY significantly improved the survival of fish and decreased the number of bacteria in their kidneys after the fish were artificially infected with E. tarda by immersion. We also performed a microarray analysis of the intestine, which serves as a primary barrier against microbial infection, to understand the profiles of differentially expressed genes (DEGs) evoked by silkrose-AY. The dietary silkrose-AY group showed differential expression of 2930 genes when compared with the control group prior to E. tarda infection. Gene ontology and pathway analysis of the DEGs highlighted several putative genes involved in pathogen attachment/recognition, the complement and coagulation cascade, antimicrobial peptides/enzymes, opsonization/phagocytosis, and epithelial junctional modification. Our findings thus provide fundamental information to help understand the molecular mechanism of bacterial protection offered by insect-derived immunostimulatory polysaccharides in teleosts.


Assuntos
Edwardsiella tarda , Infecções por Enterobacteriaceae/veterinária , Doenças dos Peixes/microbiologia , Mariposas/metabolismo , Oryzias , Polissacarídeos/farmacologia , Animais , Infecções por Enterobacteriaceae/tratamento farmacológico , Infecções por Enterobacteriaceae/microbiologia , Doenças dos Peixes/tratamento farmacológico , Regulação da Expressão Gênica/efeitos dos fármacos , Polissacarídeos/metabolismo
6.
Fish Shellfish Immunol ; 114: 253-262, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33979691

RESUMO

Vibriosis, an illness caused by the Vibrio bacteria species, results in significant economic loss in olive flounder farms. Here we present a novel anti-Vibrio feed vaccine protecting multiple strains of Vibrio pathogens, a universal vaccine effect. The vaccine was generated by engineering Lactococcus lactis BFE920 to express the fusion antigens of Vibrio outer membrane protein K (OmpK) and flagellin B subunit (FlaB). These antigen genes are highly conserved among Vibrio species. Olive flounder (7.1 ± 0.8 g and 140 ± 10 g) were fed the vaccine adsorbed to a regular feed (1 × 107 CFU/g) for one week with a 1-week interval, repeating three times (a triple boost). The vaccinated fish increased the significant levels of antigen-specific antibodies, T cell numbers (CD4-1, CD4-2, and CD8α), cytokine production (T-bet and IFN-γ), and innate immune responses (TLR5M, IL-1ß, and IL-12p40). Also, the survival rates of adult and juvenile fish fed the vaccine were significantly elevated when challenged with V. anguillarum, V. alginolyticus, and V. harveyi. In addition, weight gain rate and feed conversion ratio were improved in vaccinated fish. The feed vaccine protected multiple Vibrio pathogens, a universal vaccine effect, by activating innate and adaptive immune responses. This oral vaccine may be developed as an anti-Vibrio vaccine to protect against a broad spectrum of Vibrio pathogens.


Assuntos
Proteínas de Bactérias/imunologia , Vacinas Bacterianas/imunologia , Linguado , Lactococcus lactis/metabolismo , Vibrioses/veterinária , Vibrio/metabolismo , Imunidade Adaptativa , Animais , Vacinas Bacterianas/administração & dosagem , Doenças dos Peixes/microbiologia , Doenças dos Peixes/prevenção & controle , Imunidade Inata , Probióticos , Vibrio/imunologia , Vibrioses/prevenção & controle
7.
Fish Shellfish Immunol ; 114: 293-300, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34004271

RESUMO

Functional additives of natural origin included as dietary supplements have become an alternative to synthetic antibiotics to improve health and resistance to ecologically correct pathogenic diseases in fish farming. We tested whether incorporating a mixture of phytobiotics such as volatile oils of thyme, red thyme and pepper rosemary into the diet improves growth performance, oxidative stress, immune and hematological responses and resistance of juvenile Nile tilapia when subjected to a challenge with Aeromonas hydrophila compared to a synthetic antibiotic (enrofloxacin). The experimental design was completely randomized with three experimental groups: control diet, diets containing a mixture of thyme phytobiotic essential oils, red thyme and pepper rosemary (FTB) and the synthetic antibiotic enrofloxacin (ATB), with four replicates (14 fish per repetition/experimental unit). Plasma glucose levels, leukocyte respiratory activity, serum lysozyme levels, number of circulating erythrocytes and leukocytes, levels of lipid peroxidation (LPO), catalase (CAT) and glutathione S-transferase (GST) activity at the end of 20 days of feeding (phase) were evaluated and 24 h after exposure to bacteria (phase II). The supplementation of FTB and ATB did not change the performance parameters, but it was sufficient to increase lysozyme, leukocytes, neutrophils and monocytes after the bacterial challenge, reduction of CAT and LPO activity and the highest GST activity (P < 0.05). The results of the present study suggest that FTB as a dietary supplement has benefits and can replace synthetic ATB, including supplementation with FTB for 20 days to provide greater antioxidant protection in Nile tilapia, mitigate the impacts of stressors and modulate immunity, providing to fish greater resistance and protection against diseases.


Assuntos
Aeromonas hydrophila , Ração Animal/análise , Ciclídeos , Dieta/veterinária , Suplementos Nutricionais , Doenças dos Peixes/microbiologia , Fenômenos Fisiológicos da Nutrição Animal , Animais , Antibacterianos/uso terapêutico , Enrofloxacina/uso terapêutico , Doenças dos Peixes/prevenção & controle , Infecções por Bactérias Gram-Negativas/prevenção & controle , Infecções por Bactérias Gram-Negativas/veterinária , Lippia/química , Fitoterapia , Óleos Vegetais/administração & dosagem , Óleos Vegetais/farmacologia , Thymus (Planta)/química
8.
Fish Shellfish Immunol ; 114: 330-339, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34015481

RESUMO

The external mucus layer that covers fish skin contains numerous immune substances scarcely studied that act as the first line of defence against a broad spectrum of pathogens. This study aimed to characterize and describe for the first time several humoral immune defence parameters in the skin mucus of the European eel (Anguilla anguilla) after intraperitoneal injection with Vibrio anguillarum or Tenacibaculum soleae. This study evaluated several immune-related enzymes and bactericidal activity against fish pathogenic bacteria in the skin mucus of European eels at 24, 48, and 72 h post-challenge. The results demonstrated that European eel skin mucus showed significant increments in peroxidase and lysozyme activity at 48 and 72 h after V. anguillarum challenge, compared to other experimental groups. In the case of antiprotease activity, an increase was observed at 24 h in the skin mucus of fish challenged with V. anguillarum compared to unchallenged fish, while this activity was undetected at 48 and 72 h. In contrast, protease activity had decreased at 48 and 72 h in the skin mucus of fish challenged with V. anguillarum compared to the unchallenged group. Regarding bactericidal activity, a high growth capacity of T. soleae was observed in the skin mucus of all experimental groups. Interestingly, the skin mucus from fish challenged with V. anguillarum exhibited increased bactericidal activity against this bacterium at 48 h, compared to unchallenged fish. Finally, severe histopathological alterations were observed in the gills and liver at the end of the trial (72 h), whereas the skin showed only an overspread presence of goblet cells in the challenged fish compared to unchallenged fish. The present results may give new insights into the mucosal immune system of this primitive species with potential applications in aquaculture.


Assuntos
Anguilla , Doenças dos Peixes/microbiologia , Infecções por Flavobacteriaceae/veterinária , Imunidade nas Mucosas/fisiologia , Tenacibaculum , Vibrio , Animais , Infecções por Flavobacteriaceae/tratamento farmacológico , Infecções por Flavobacteriaceae/microbiologia , Pele/imunologia , Vibrioses/imunologia , Vibrioses/microbiologia , Vibrioses/veterinária
9.
J Fish Dis ; 44(8): 1201-1214, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33960425

RESUMO

The use of cleaner fish as a delousing method in Norwegian salmonid aquaculture has increased tremendously over the last few years. This has led to the emergence of a new large industry of farming lumpsuckers (Cyclopterus lumpus L.). The use of lumpsuckers as cleaner fish has, however, not been problem-free. Bacterial diseases cause high mortalities with pasteurellosis as one of the major emerging diseases. During the past few years, outbreaks of pasteurellosis in farmed Atlantic salmon (Salmo salar L.) have become more frequent. This has led to an increasing concern that this disease will become common in salmon farming as well. The purpose of this study was to investigate the susceptibility of Atlantic salmon to Pasteurella spp. infection and the possibility of lumpsuckers transmitting pasteurellosis to Atlantic salmon. Atlantic salmon were experimentally challenged, either by bath or by cohabitation with challenged lumpsuckers, using two different strains of Pasteurella spp. (originating from lumpsucker and Atlantic salmon, respectively). No clinical signs of pasteurellosis were observed on any of the Atlantic salmon. The lumpsuckers were, however, equally susceptible to both isolates. In addition, clear differences in histopathological changes were observed between individuals challenged with the two isolates.


Assuntos
Doenças dos Peixes/microbiologia , Infecções por Pasteurella/veterinária , Pasteurella/fisiologia , Perciformes , Salmo salar , Animais , Aquicultura , Noruega , Infecções por Pasteurella/microbiologia
10.
Fish Shellfish Immunol ; 113: 106-117, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33826938

RESUMO

Catalase, a key enzyme in the antioxidant defense grid of organisms, scavenges free radicals to curtail their harmful effects on the host, supporting proper immune function. Herein, we report the identification and characterization of a catalase homolog from Amphiprion clarkii (ClCat), followed by its functional characterization. An open reading frame was identified in the cDNA sequence of ClCat at 1581 bp, which encodes a protein of 527 amino acids (aa) with a molecular mass of 60 kDa. In silico analyses of ClCat revealed characteristic features of the catalase family and a lack of a signal peptide. Multiple sequence alignment of ClCat indicated the conservation of functionally important residues among its homologs. According to phylogenetic analysis, ClCat was of vertebrate origin, positioned within the teleost clade. During native conditions, ClCat mRNA was highly expressed in blood, followed by the liver and kidney. Moreover, significant changes in ClCat transcription were observed after stimulation with LPS, poly I:C, and Vibrio harveyi, in a time-dependent manner. Recombinant ClCat (rClCat) was characterized, and its peroxidase activity was determined. Furthermore, the optimum temperature and pH for rClCat were determined to be 30-40 °C and pH 7, respectively. Oxidative stress tolerance and chromatin condensation assays indicated enhanced cell survival and reduced apoptosis, resulting from reactive oxygen species scavenging by rClCat. The DNA-protective function of rClCat was further confirmed via a metal-catalyzed oxidation assay. Taken together, our findings propose that rClCat plays an essential role in maintaining cellular oxidative homeostasis and host immune protection.


Assuntos
Catalase/imunologia , Doenças dos Peixes/imunologia , Peixes/imunologia , Regulação da Expressão Gênica/genética , Imunidade Inata/genética , Animais , Antioxidantes/fisiologia , DNA/imunologia , Doenças dos Peixes/microbiologia , Regulação da Expressão Gênica/fisiologia , Lipopolissacarídeos/administração & dosagem , Estresse Oxidativo/imunologia , Poli I-C/administração & dosagem , Vibrio/fisiologia , Vibrioses/imunologia , Vibrioses/microbiologia , Vibrioses/veterinária
11.
Fish Shellfish Immunol ; 113: 148-153, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33838222

RESUMO

The mechanism of extracellular traps (ETs) is important in the cellular response against bacteria. Thus, in the present study, we describe for the first time the capacity of the Nile tilapia (Oreochromis niloticus) microglia in the formation of ETs in Weissella cibaria in vitro infection. Thus, we evaluated the ultrastructure of the microglia culture and observed the formation of ETs 6 h after stimulation with lipopolysaccharide (LPS) and during the course of infection. Our results shed light on the mechanism of formation of ETs in the microglia of teleost fish and the ability of W. cibaria to infect these cells.


Assuntos
Ciclídeos/imunologia , Armadilhas Extracelulares/microbiologia , Doenças dos Peixes/imunologia , Infecções por Bactérias Gram-Positivas/veterinária , Lipopolissacarídeos/farmacologia , Microglia/ultraestrutura , Weissella/fisiologia , Animais , Doenças dos Peixes/microbiologia , Infecções por Bactérias Gram-Positivas/imunologia , Infecções por Bactérias Gram-Positivas/microbiologia , Microscopia Eletrônica de Varredura/veterinária
12.
Fish Shellfish Immunol ; 113: 185-195, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33857623

RESUMO

Immunoglobulin (IgM) is the primary immunoglobulin essential for defense mechanisms in fish. It is difficult to reliably quantify IgM because a lack of standardization in methodology and limited availability of commercially reagents. In the present study, a polyclonal antibody was developed for the specific detection and quantification of IgM in Labeo rohita. Recombinant bicistronic NanoDNA plasmid (RBND Vac) encoding the glyceraldehyde-3-phosphate dehydrogenase gene of Edwarsiella tarda conjugated with poly (lactic-co-glycolic acid) - Chitosan (PLGA-Chit) was developed and its potential as a DNA vaccine, to prevent the infection of E. tarda in L. rohita was investigated. Two treatment groups [T1 - (PLGA-Chit-NPs-pDNA), T2 - (PLGA-NPs-pDNA) and one control group (T0 - 1 × PBS)] were utilized. Polyclonal antibody was developed to estimate IgM titers in the serum and mucosal associated tissues (MAT) using Enzyme-linked Immunosorbent Assay (ELISA) technique. Additionally, immune gene expression was studied using qRT-PCR. Vaccinated groups also exhibited a significant increase in the total serum protein, globulin concentration and relatively less mortality was observed in T1 group. IgM level in serum and mucosal tissues (skin, gill and gut) increased significantly days post vaccination compared to control group, also non-specific immune parameters (myeloperoxidase and lysozyme levels) showed significant improvement in vaccinated fish. Furthermore, histopathological examination confirmed minor damage in physiological structure of kidney and liver tissues in vaccinated fish. Knowledge of the immunoglobulin in L. rohita primed with RBND Vac complex provides the better protection against E. tarda. The normal physiology findings of this study will aid in monitoring changes in the health status of fish, when the animals undergo vaccination by immersion method.


Assuntos
Anticorpos Antibacterianos/imunologia , Vacinas Bacterianas/administração & dosagem , Cyprinidae , Edwardsiella tarda/imunologia , Doenças dos Peixes/imunologia , Imunidade nas Mucosas , Imunoglobulina M/imunologia , Animais , Infecções por Enterobacteriaceae/imunologia , Infecções por Enterobacteriaceae/microbiologia , Infecções por Enterobacteriaceae/veterinária , Doenças dos Peixes/microbiologia , Especificidade da Espécie , Vacinas de DNA/administração & dosagem
13.
Int J Mol Sci ; 22(8)2021 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-33924078

RESUMO

In the present work, we performed immunochemical studies of LPS, especially the O-specific polysaccharide (O-PS) of Aeromonas veronii bv. sobria strain K133, which was isolated from the kidney of carp (Cyprinus carpio L.) during an outbreak of motile aeromonad infection/motile aeromonad septicemia (MAI/MAS) on a Polish fish farm. The structural characterization of the O-PS, which was obtained by mild acid degradation of the LPS, was performed with chemical methods, MALDI-TOF mass spectrometry, and 1H and 13C NMR spectroscopy. It was revealed that the O-PS has a unique composition of a linear tetrasaccharide repeating unit and contains a rarely occurring sugar 2,4-diamino-2,4,6-trideoxy-D-glucose (bacillosamine), which may determine the specificity of the serogroup. Western blotting and ELISA confirmed that A. veronii bv. sobria strain K133 belongs to the new serogroup PGO1, which is one of the most commonly represented immunotypes among carp and trout isolates of Aeromonas sp. in Polish aquacultures. Considering the increase in the MAI/MAS incidences and their impact on freshwater species, also with economic importance, and in the absence of an effective immunoprophylaxis, studies of the Aeromonas O-antigens are relevant in the light of epidemiological data and monitoring emergent pathogens representing unknown antigenic variants and serotypes.


Assuntos
Aeromonas veronii/química , Carpas/microbiologia , Doenças dos Peixes/microbiologia , Infecções por Bactérias Gram-Negativas/veterinária , Lipopolissacarídeos/química , Aeromonas veronii/classificação , Aeromonas veronii/isolamento & purificação , Animais , Animais Domésticos , Doenças dos Peixes/imunologia , Lipopolissacarídeos/imunologia , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Polônia , Sorogrupo , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
14.
Fish Shellfish Immunol ; 113: 51-60, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33798718

RESUMO

Killer cell lectin-like receptor G subfamily 1 (KLRG1) is a receptor generally expressed on effector CD8+ T cells or NK cells at terminal differentiation stage, and it will be highly induced for lymphocyte cytotoxicity upon pathogen infection or lymphocyte activation. However, little is known about the character or function of KLRG1 in lower vertebrates. In present study, we reappraised a molecule that previously defined as KLRG1 in the genomic sequence of Nile tilapia Oreochromis niloticus, and identified it as an atypical KLRG1-like molecule (defined as On-KLRG1-L), and illustrated its potential function serving as a marker representing effector T lymphocytes of fish species. On-KLRG1-L consists of two C-type lectin-like domains (CTLDs) without transmembrane region, and the tertiary structure of the CTLD is highly alike to that in mouse KLRG1. As a CTLD-containing protein, the recombinant On-KLRG1-L could bind PGN and several microbes in vitro. On-KLRG1-L was widely expressed in immune-associated tissues, with the highest expression level in the gill. Once Nile tilapia is infected by Aeromonas hydrophila, mRNA level of On-KLRG1-L in spleen lymphocytes were significantly up-regulated on 5 days after infection. Meanwhile, On-KLRG1-L protein was also induced on 5 or 8 days after A. hydrophila infection. Furthermore, we found both mRNA and protein levels of On-KLRG1-L were dramatically enhanced within several hours after spleen lymphocytes were activated by T cell-specific mitogen PHA in vitro. More importantly, the ratio of On-KLRG1-L+ T cells was also augmented after PHA stimulation. The observations suggested that the KLRG1-like molecule from Nile tilapia participated in lymphocyte activation and anti-bacterial adaptive immune response, and could serve as an activation marker of T lymphocytes. Our study thus provided new evidences to understand lymphocyte-mediated adaptive immunity of teleost.


Assuntos
Imunidade Adaptativa/genética , Ciclídeos/imunologia , Doenças dos Peixes/imunologia , Lectinas Tipo C/imunologia , Ativação Linfocitária/imunologia , Receptores Imunológicos/imunologia , Aeromonas hydrophila/fisiologia , Sequência de Aminoácidos , Animais , Biomarcadores/metabolismo , Doenças dos Peixes/microbiologia , Proteínas de Peixes/genética , Proteínas de Peixes/imunologia , Infecções por Bactérias Gram-Negativas/imunologia , Infecções por Bactérias Gram-Negativas/microbiologia , Infecções por Bactérias Gram-Negativas/veterinária , Lectinas Tipo C/genética , Estrutura Terciária de Proteína , Receptores Imunológicos/genética , Alinhamento de Sequência/veterinária
15.
Int J Mol Sci ; 22(9)2021 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-33922312

RESUMO

Pattern recognition receptors (PRRs) play a crucial role in inducing inflammatory responses; they recognize pathogen-associated molecular patterns, damage-associated molecular patterns, and environmental factors. Nucleotide-binding oligomerization domain-leucine-rich repeat-containing receptors (NLRs) are part of the PRR family; they form a large multiple-protein complex called the inflammasome in the cytosol. In mammals, the inflammasome consists of an NLR, used as a sensor molecule, apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) as an adaptor protein, and pro-caspase1 (Casp1). Inflammasome activation induces Casp1 activation, promoting the maturation of proinflammatory cytokines, such as interleukin (IL)-1ß and IL-18, and the induction of inflammatory cell death called pyroptosis via gasdermin D cleavage in mammals. Inflammasome activation and pyroptosis in mammals play important roles in protecting the host from pathogen infection. Recently, numerous inflammasome-related genes in teleosts have been identified, and their conservation and/or differentiation between their expression in mammals and teleosts have also been elucidated. In this review, we summarize the current knowledge of the molecular structure and machinery of the inflammasomes and the ASC-spec to induce pyroptosis; moreover, we explore the protective role of the inflammasome against pathogenic infection in teleosts.


Assuntos
Infecções Bacterianas/imunologia , Doenças dos Peixes/imunologia , Proteínas de Peixes/metabolismo , Inflamassomos/imunologia , Piroptose , Animais , Infecções Bacterianas/metabolismo , Infecções Bacterianas/microbiologia , Infecções Bacterianas/patologia , Caspase 1/metabolismo , Citocinas/metabolismo , Doenças dos Peixes/metabolismo , Doenças dos Peixes/microbiologia , Doenças dos Peixes/patologia , Peixes
16.
Fish Shellfish Immunol ; 114: 90-101, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33838221

RESUMO

This investigation describes the impacts of dietary provisioning with astaxanthin on hemato-biochemistry, non-specific immunity, and disease resistance of the Asian seabass, Lates calcarifer, against the virulent Vibrio alginolyticus; with specific reference to dose-response associations and variations over different post-infection periods (0-, 7-, and 14-day). Triplicate groups of fish weighing 28 g, on average, were fed various diets (C, the control or astaxanthin-free; AXT50, 50 mg astaxanthin kg-1 diet; AXT100, 100 mg astaxanthin kg-1 diet; and AXT150, 150 mg astaxanthin kg-1 diet) for 90 days and subsequently challenged with V. alginolyticus at the end of the feeding period. Experimental infection unveiled that supplemented fish demonstrated significant improvements (P < 0.05) of hematological parameters (white blood cell [WBC] and red blood cell [RBC] counts, and hemoglobin and hematocrit levels) when fed diets with elevating supplemental doses of astaxanthin through distinct post-infection periods (0-, 7-, and 14-day). Furthermore, the administration of dietary astaxanthin at escalating levels markedly enhanced (P < 0.05) the serum biochemical profile (aspartate aminotransferase [AST], alanine aminotransferase [ALT], glucose, cortisol, cholesterol, and triglyceride contents) of challenged fish, resulting in better welfare. Significantly higher (P < 0.05) contents of serum total protein were observed in supplemented fish, as opposed to the control. Additionally, immunological defense mechanisms (lysozyme activity, phagocytic activity, respiratory burst activity, and total serum immunoglobulin) of challenged fish were pronouncedly elicited (P < 0.05) following the ingestion of astaxanthin. Besides, the supplementation with dietary astaxanthin significantly augmented (P < 0.05) the post-challenge survival rate of fish. Collectively, the results manifest that supplementary feeding of astaxanthin is effective in reinforcing fish immunocompetence and disease resistance against V. alginolyticus infection.


Assuntos
Dieta/veterinária , Doenças dos Peixes/microbiologia , Perciformes , Vibrio alginolyticus , Ração Animal , Animais , Relação Dose-Resposta a Droga , Doenças dos Peixes/imunologia , Doenças dos Peixes/prevenção & controle , Explosão Respiratória , Xantofilas/administração & dosagem , Xantofilas/uso terapêutico
17.
Fish Shellfish Immunol ; 114: 119-131, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33930548

RESUMO

As complex components of innate immune system, members of complement system play crucial roles during the process of defensing against pathogens. Black rockfish (Sebastes schlegelii) is one of the important aquaculture species in East Asian. However, studies of complement genes in black rockfish and its related immune activities are still lacking. Therefore, a total of 112 members of the complement genes were identified from the genome of black rockfish and were classified into five subgroups. According to their functional annotations, 30 genes belonged to pattern recognition, 6 genes belonged to proteases, 14 genes belonged to complement components, 36 genes belonged to receptors, and 26 genes belonged to regulators. It can be found that many complement genes evolved into multi-copies, especially in teleost, which may be influenced by whole-genome duplication or tandem duplication events. Complement genes were randomly distributed on 22 chromosomes. The number of introns of complement genes varied from 1 to 70. Results of the expression patterns of 10 randomly selected genes from 5 subtypes response to Vibrio anguillarum infection revealed that most of the members of the complement genes were induced in gill and skin. In contrast, most genes in intestine showed downregulation. This study systematically characterized and analyzed the complement genes in black rockfish and provided new insights into their functions responding to bacterial infection.


Assuntos
Evolução Biológica , Proteínas do Sistema Complemento/metabolismo , Doenças dos Peixes/microbiologia , Proteínas de Peixes/metabolismo , Vibrio , Animais , Cromossomos , Proteínas do Sistema Complemento/genética , Doenças dos Peixes/metabolismo , Proteínas de Peixes/genética , Regulação da Expressão Gênica/imunologia , Estudo de Associação Genômica Ampla , Perciformes
18.
J Fish Dis ; 44(8): 1117-1130, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33848372

RESUMO

Between August and December 2013, the offshore cages of a commercial marine farm culturing red drum Sciaenops ocellatus in Campeche Bay Mexico were affected by an outbreak of an ulcerative granulomatous disease with up to 70% cumulative mortality. Thirty-one adults displaying open ulcers on the skin were submitted for diagnosis. At necropsy, multiple white-yellowish nodules (0.1-0.5 cm in diameter) were present in all internal organs, where the kidney and the spleen were the most severely affected. Histopathology evinced typical systemic granulomatous formations. Gram and Ziehl-Neelsen stains on tissue imprints, bacterial swabs and tissue sections revealed Gram-positive, acid-fast, branching beaded long rod filamentous bacteria. Tissue samples resulted positive for nocardiosis with a Nocardia genus-specific nested PCR. Definite identification at the species level and taxonomic positioning of the fastidious pathogen were achieved through a specific Nocardia seriolae PCR and by sequencing the gyrB gene of pure isolates. After administration of antibiotics during fry production, a posterior follow-up monitoring (from 2014 to 2017) detected mild but recurrent outbreaks of the bacteria with no seasonality pattern. To the extent of our knowledge, this is the first report of piscine nocardiosis in Mexico and the first time this disease is detected in red drum.


Assuntos
Doenças dos Peixes/diagnóstico , Peixes , Nocardiose/veterinária , Nocardia/isolamento & purificação , Animais , Doenças dos Peixes/microbiologia , México , Nocardia/classificação , Nocardia/genética , Nocardiose/diagnóstico , Nocardiose/microbiologia
19.
J Fish Dis ; 44(8): 1255-1263, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33913522

RESUMO

Haemorrhagic septicaemia caused by Aeromonas hydrophila in striped catfish (Pangasianodon hypophthalmus) is one of the most important aquatic diseases in the Mekong Delta, Vietnam. However, antibiotic-resistant A. hydrophila strains have become popular and resulted in inadequate control of the disease in striped catfish farms. This study investigates the protective efficacy of bacteriophage PVN02 against haemorrhagic septicaemia in striped catfish via oral administration. The phage-containing pellets were prepared by spraying the phage solution on food pellets at 20 ml/kg. The rate of phage desorption from the food pellets into the water was very low; the phage titres in the water were approximately log 1.0 PFU/ml or undetectable. The in vivo experiment evaluating the protective efficacy of PVN02 against haemorrhagic septicaemia in striped catfish was conducted using 21 groups of 1,260 fish in 50-L plastic tanks in triplicate. The catfish were fed twice daily with phage-sprayed pellets. Different densities of bacterial suspensions were added into the tanks for 24 hr. Without the existence of the phage, the highest mortality rate was 68.3 ± 2.9% at the highest density of bacterial suspension. In contrast, the mortality rate at the highest density of bacterial suspension was significantly reduced to 8.33 ± 2.9% or 16.67 ± 2.9% at the phage dose of log 6.2 ± 0.09 or log 4.2 ± 0.09 PFU/g. This study provides a very practical manner of applying phage therapy to prevent disease in large-scale striped catfish farms.


Assuntos
Aeromonas hydrophila/fisiologia , Anti-Infecciosos/administração & dosagem , Bacteriófagos/química , Peixes-Gato , Doenças dos Peixes/prevenção & controle , Septicemia Hemorrágica/veterinária , Administração Oral , Aeromonas hydrophila/efeitos dos fármacos , Animais , Anti-Infecciosos/química , Resistência Microbiana a Medicamentos , Doenças dos Peixes/microbiologia , Septicemia Hemorrágica/microbiologia , Septicemia Hemorrágica/prevenção & controle , Vietnã
20.
Fish Shellfish Immunol ; 113: 79-85, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33812989

RESUMO

Bacterial infections cause huge losses to aquaculture globally, and increased antibiotic resistance means that alternative methods of reducing mortality from bacterial diseases are required. We compared the resistance of Juvenile olive flounders, Paralichthys olivaceus, to Streptococcus iniae between those reared in biofloc and seawater conditions for ten months. Experimental fish were challenged with S. iniae at concentrations of 0, 3.36 × 106, 3.36 × 107, 3.36 × 108, and 3.36 × 109 colony forming units (CFU)/g fish for 96 h to evaluate the difference in S. iniae susceptibility of flounders reared in biofloc and seawater. The 96 h lethal concentration 50% (LC50) of fish injected with S. iniae was 2.41 × 109 CFU/g fish in biofloc and 1.51 × 108 CFU/g fish in seawater. Hematological parameters such as hemoglobin and hematocrit significantly decreased when fish were challenged by S. iniae. Plasma components such as calcium, glucose, cholesterol, total protein, GOT, GPT, and ALP were significantly altered by S. iniae infection and acetylcholinesterase activity was significantly inhibited. These results indicate that S. iniae infection affects the survival rates, hematological parameters, and neurotransmitter levels of flounders reared in biofloc and seawater, and that S. iniae susceptibility was higher in flounders reared in seawater than those reared in biofloc.


Assuntos
Aquicultura/instrumentação , Doenças dos Peixes/mortalidade , Linguados , Testes Hematológicos/veterinária , Neurotransmissores/metabolismo , Água do Mar/química , Infecções Estreptocócicas/veterinária , Animais , Doenças dos Peixes/microbiologia , Infecções Estreptocócicas/microbiologia , Infecções Estreptocócicas/mortalidade , Streptococcus iniae/fisiologia , Taxa de Sobrevida
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...