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1.
Biomed Res Int ; 2019: 9617659, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31317044

RESUMO

The yellow catfish (Pelteobagrus fulvidraco) is an important economic freshwater aquaculture species in Asia. However, little is known about its immune response to bacterial pathogen infection. Here, two cytokines, the proinflammatory cytokine interleukin-8 (IL-8) and the anti-inflammatory cytokine interleukin-10 (IL-10), were identified and characterized in the yellow catfish for the first time. We found that the full length of the IL-8 cDNA was 784 bp and contained an open reading frame (ORF) of 336 bp, while the IL-10 gene was 973 bp in length with a 549 bp of ORF. In addition, both the IL-8 and the IL-10 had similar tissue-specific expression patterns. They were more abundant in the spleen and lowest expressed in the liver. Furthermore, IL-10 but not IL-8 was significantly upregulated in the intestine of yellow catfish by feed supplementation of Clostridium butyricum (CB). More importantly, the expression levels of intestinal IL-10 and IL-8 were up- and downregulated by pathogen Aeromonas punctata stimuli with the presence of CB, respectively. Collectively, these results suggest that IL-10 and IL-8 mediate important roles in the immunity of yellow catfish, and feed supplementation of CB may able to reduce the intestinal inflammation caused by bacteria infections through regulating the expression of IL-10 and IL-8.


Assuntos
Infecções Bacterianas/genética , Peixes-Gato/genética , Interleucina-10/genética , Interleucina-8/genética , Animais , Infecções Bacterianas/microbiologia , Infecções Bacterianas/patologia , Peixes-Gato/microbiologia , Clonagem Molecular , Doenças dos Peixes/genética , Doenças dos Peixes/microbiologia , Regulação da Expressão Gênica/genética , Fígado/microbiologia , Filogenia , Baço/microbiologia
2.
Wilderness Environ Med ; 30(3): 291-294, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31221600

RESUMO

Although catfish are found worldwide and commonly consumed in the southern United States, fatal infections from catfish are rare. Edwardsiella tarda is a bacterium known to cause gastrointestinal distress most commonly, but extraintestinal infections are a rarely considered danger for those acquiring, preparing, and consuming aquatic animals. Susceptible to all gram-negative active antibiotics, it is easily treated except in immunocompromised hosts, such as those with malignancy, diabetes, and hepatic dysfunction.


Assuntos
Mordeduras e Picadas/terapia , Peixes-Gato/microbiologia , Edwardsiella tarda/isolamento & purificação , Infecções por Enterobacteriaceae/diagnóstico , Animais , Mordeduras e Picadas/microbiologia , Infecções por Enterobacteriaceae/complicações , Infecções por Enterobacteriaceae/patologia , Infecções por Enterobacteriaceae/fisiopatologia , Evolução Fatal , Humanos , Masculino , Pessoa de Meia-Idade , Choque Séptico/microbiologia
3.
Microb Pathog ; 132: 261-265, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31078710

RESUMO

Aeromonosis is a fish disease that leads to haemorrhagic septicaemia and high mortality. The detection of early behavioural changes associated to this disease could be helpful in anticipating the initiation of treatment, increasing the probability of success. The influence of this disease on the hypothalamic-pituitary-interrenal (HPI) axis and on the brain expression of heat shock proteins (HSP) is little known. Therefore, the aim of this study was to evaluate the effect of Aeromonas hydrophila infection on individual behaviour and brain expression of genes related to stress (slc6a2, hsp90, hspa12a, hsd20b, hsd11b2, crh) in silver catfish (Rhamdia quelen). Thirty fish were divided into healthy and infected groups. The fish of the infected group were inoculated intramuscularly with 50 µL of bacterial suspension (6.4 × 108 CFU/mL), while control animals received 50 µL of saline. On day five post-infection, animals were submitted to the novel tank test, euthanized, and the brain was collected for molecular analysis. Infected fish swam more in the unknown aquarium and presented an increase in brain expression of genes related to HSP (hspa12a) and the route of cortisol synthesis (crh) when compared to uninfected fish. Therefore, this disease causes hyperlocomotion related to stress.


Assuntos
Aeromonas hydrophila/patogenicidade , Peixes-Gato/microbiologia , Doenças dos Peixes/microbiologia , Doenças dos Peixes/fisiopatologia , Infecções por Bactérias Gram-Negativas/microbiologia , Infecções por Bactérias Gram-Negativas/fisiopatologia , Infecções por Bactérias Gram-Negativas/veterinária , 11-beta-Hidroxiesteroide Desidrogenase Tipo 2/genética , Animais , Comportamento Animal , Encéfalo/metabolismo , Peixes-Gato/genética , Modelos Animais de Doenças , Feminino , Expressão Gênica , Proteínas de Choque Térmico HSP90/genética , Proteínas de Choque Térmico/genética , Locomoção , Masculino , Proteínas da Membrana Plasmática de Transporte de Norepinefrina/genética
4.
Dev Comp Immunol ; 98: 65-75, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31002844

RESUMO

Recombination-activating gene 2 (rag 2) allies with recombination-activating gene 1 (rag 1) and regulates the V(D)J recombination of immunoglobulin (Ig) and T-cell receptor (TCR) genes. Being a key player in the adaptive immune response of vertebrates, functional characterization of rag 2 from yellow catfish is beneficial for understanding the biological response towards the pathogens. In this report, we have cloned and characterized the rag 2 gene of yellow catfish, and a particular pattern of expression was analysed in the major tissues of yellow catfish. The results showed that the open reading frame (ORF) of yellow catfish rag 2 was 1596 bp in length, which encodes a peptide of 531 amino acids. The multiple sequence alignment and phylogenetic analysis of rag 2 of yellow catfish with other species showed the conserved regions and the classical taxonomic evolution among the different vertebrate species. The qRT-PCR and Western blot results revealed that rag 2 transcripts and proteins were present in various tissues of yellow catfish with relatively high expression in the tissues of the thymus, head-kidney, and spleen. The systematic distribution analysis of the rag 2 expression by immunohistochemistry (IHC) using the rabbit polyclonal antibody, exposed relatively high expression in head kidney, spleen and thymus tissues after infected with Edwardsiella ictaluri. Moreover, the temporal expression of rag 2 and pro-inflammatory cytokines (IL-1ß and TNF-α) were significantly upregulated at different time points in the specific lymphoid tissues of yellow catfish following E. ictaluri infection. Our findings suggest that rag 2 potentially exhibited the immunological response in primary lymphoid tissues of yellow catfish against bacterial infection. This study will provide an essential source about rag 2 gene and its relationship with the inflammatory cytokines during infection.


Assuntos
Peixes-Gato/imunologia , Proteínas de Ligação a DNA/imunologia , Edwardsiella ictaluri/imunologia , Infecções por Enterobacteriaceae/imunologia , Doenças dos Peixes/imunologia , Proteínas de Peixes/imunologia , Animais , Peixes-Gato/genética , Peixes-Gato/microbiologia , Clonagem Molecular , Citocinas/genética , Citocinas/imunologia , Proteínas de Ligação a DNA/classificação , Proteínas de Ligação a DNA/genética , Edwardsiella ictaluri/fisiologia , Infecções por Enterobacteriaceae/microbiologia , Doenças dos Peixes/microbiologia , Proteínas de Peixes/classificação , Proteínas de Peixes/genética , Perfilação da Expressão Gênica/métodos , Rim Cefálico/imunologia , Rim Cefálico/metabolismo , Interações Hospedeiro-Patógeno/imunologia , Mediadores da Inflamação/imunologia , Mediadores da Inflamação/metabolismo , Baço/imunologia , Baço/metabolismo , Timo/imunologia , Timo/metabolismo
6.
Biocontrol Sci ; 24(1): 1-11, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30880308

RESUMO

 The prevalence of antibiotic resistant bacteria in aquaculture has reached alarming proportions and intensified the search for microbe derived antimicrobial compounds. This study isolated bacteria from the intestine of Sagor catfish (Hexanematichthys sagor) and screened it for antagonistic properties. Five out of 334 bacterial isolates inhibited growth of fish pathogens. The 5 bacterial strains included relatives of Shewanella haliotis, Myroides odoratimimus, Vibrio harveyi, Vibrio alginolyticus and Alcaligenes faecalis. The growth profiles and probiotic properties of these bacteria were examined. The results showed that the isolate 9 (3) 7.5.2.1, whose closest relative was S. haliotis exhibited growth and probiotic advantage compared to the other bacterial strains, such as highest doubling time and the ability to survive at all experimental temperatures (18 to 60℃) , and bile concentrations (0.01 to 1.00%) and pH (pH2 to 9) . While the bacteria with probiotic properties were successfully isolated. Further study is necessary to examine the efficiency of the probiotic candidate bacteria in boosting fish immunity against pathogens.


Assuntos
Antibiose , Bactérias/crescimento & desenvolvimento , Peixes-Gato/microbiologia , Doenças dos Peixes , Mucosa Intestinal/microbiologia , Probióticos/isolamento & purificação , Animais , Bactérias/classificação , Bactérias/isolamento & purificação , Doenças dos Peixes/microbiologia , Doenças dos Peixes/prevenção & controle , Probióticos/classificação
7.
Biocontrol Sci ; 24(1): 23-28, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30880310

RESUMO

Striped catfish (Pangasianodon hypophthalmus) farming in the Mekong Delta Vietnam (MKDVN) importantly contributes to national aquaculture export. Currently, however, diseases occur more frequently across the entire MKDVN region. One of the most common types is hemorrhagic septicemia caused by Aeromonas hydrophila. In this study, isolation and selection of the phages for control in vitro Aeromonas hydrophila were conducted. 24 phages were isolated from 100 striped catfish pond water samples. Next, lytic activity of these phages was clarified. Four phages with short latent period (about 25 to 40 min) and/or high burst size (about 67 to 94 PFU/ cell) were selected to evaluate their infection activity to different phage-resistant A. hydrophila strains. Two phages termed as TG25P and CT45P were subjected to the phage cocktail to inactivate A. hydrophila. Re-growth of the host bacteria appeared about eight hours after treatment. Usage of the phage cocktail that attach different host bacterial receptors is not always much effective than usage of single phage. This is the first report about phage therapy to control A. hydrophila isolated from striped catfish. Some challenges in the phage cocktail were shown to achieve strategies in prospective studies in the context of high antibiotic resistance of A. hydrophila.


Assuntos
Aeromonas hydrophila/crescimento & desenvolvimento , Aquicultura/métodos , Bacteriófagos , Peixes-Gato/microbiologia , Doenças dos Peixes/prevenção & controle , Infecções por Bactérias Gram-Negativas/prevenção & controle , Aeromonas hydrophila/virologia , Animais , Doenças dos Peixes/microbiologia , Infecções por Bactérias Gram-Negativas/microbiologia , Infecções por Bactérias Gram-Negativas/veterinária , Vietnã
8.
J Fish Dis ; 42(4): 465-475, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30734315

RESUMO

Aerolysin (aer) is one of the most important and abundant virulence factors in the infection of fish by Aeromonas veronii. A comprehensive study on the molecular characterization and pathogenicity of the aer gene from 34 A. veronii isolates from diseased carp and catfish was carried out and its interactome was analysed to observe the functional correlations between aer and other proteins within the A. veronii network. The PCR-based amplification of aer from the 34 isolates of A. veronii showed more aer-positive isolates from catfish with a high pathogenic potential in the in vivo challenge test than the carp fish. The analysis of aer gene sequence from challenged fish revealed significant sequence divergence according to the types and geographical distribution of the fish. The networking analysis of aer from the model A. veronii B565 revealed histidine kinase (cheA) as the most functional interacting partner. The study of the interaction between aer from the experimental A. veronii and cheA demonstrated that the A chain of cheA plays a more important role than the corresponding B chain during contact, and a linker sequence of 15 residues controlled the entire interaction process. Therefore, cheA could be an excellent drug target for controlling A. veronii infection of fish.


Assuntos
Aeromonas veronii/genética , Aeromonas veronii/patogenicidade , Toxinas Bacterianas/genética , Histidina Quinase/genética , Proteínas Citotóxicas Formadoras de Poros/genética , Animais , Aquicultura , Carpas/microbiologia , Peixes-Gato/microbiologia , Doenças dos Peixes/microbiologia , Virulência/genética , Fatores de Virulência
9.
J Appl Microbiol ; 126(5): 1353-1361, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30735293

RESUMO

AIMS: This study investigated the in vitro antibacterial activity of Hesperozygis ringens (Benth.) Epling leaf extracts against fish pathogenic bacteria, as well as the in vivo activity of the most active extract in silver catfish (Rhamdia quelen) experimentally infected with Aeromonas hydrophila. Moreover, the chemical composition of the extract used in the survival assay was evaluated. METHODS AND RESULTS: Only hexane extract (HEHR) showed in vitro antibacterial activity (MIC and MBC ranging from 1600 to 3200 µg ml-1 ) against clinical isolates of A. hydrophila, Raoultella ornithinolytica and Citrobacter freundii, obtained from naturally infected silver catfish, and A. hydrophilaATCC 7966. The major compound of the volatile fraction of HEHR was determined as pulegone. HEHR promoted a 93·33% relative survival rate of silver catfish experimentally infected with A. hydrophila 7 days after a single therapeutic bath at 30 mg l-1 , while florfenicol at 4 mg l-1 , which promoted a 60% relative survival rate. CONCLUSIONS: The antibacterial activity of H. ringens (Benth.) Epling leaf extracts seems to be related to phytochemicals of apolar character, since HEHR promoted better survival rate of infected animals than florfenicol. SIGNIFICANCE AND IMPACT OF THE STUDY: The HEHR has potential to be used in the control and treatment of bacterial infections in organic aquaculture.


Assuntos
Aeromonas hydrophila , Antibacterianos/uso terapêutico , Peixes-Gato/microbiologia , Doenças dos Peixes/tratamento farmacológico , Infecções por Bactérias Gram-Negativas/veterinária , Lamiaceae/química , Animais , Doenças dos Peixes/microbiologia , Infecções por Bactérias Gram-Negativas/tratamento farmacológico , Infecções por Bactérias Gram-Negativas/microbiologia , Monoterpenos/análise , Extratos Vegetais/química , Extratos Vegetais/uso terapêutico
10.
Fish Shellfish Immunol ; 87: 87-95, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30615987

RESUMO

Edwardsiella ictaluri is a causative agent of enteric septicemia of catfish (ESC), a seriously lethal disease in Vietnamese catfish (Pangasius hypophthalmus). A safe and effective vaccine against ESC is currently an urgent demand due to antibiotic overuse in pangasius farms has led to an alarming antimicrobial resistance. In this study, two E. ictaluri wzzE mutants (WzM-L3, deficient in a 1038bp-entire wzzE gene and WzM-S3, a 245bp-partial deletion of wzzE) were developed and their protection efficiacy was evaluated in hatched pangasius against ESC by immersion vaccination. As comparing to the high virulent wild-type strain who caused 73.33% of death on pangasius fingerlings immersed at 7.1 × 106 CFU ml-1, both mutants showed extremely low mortality rates at 3.33% (WzM-S3) and 0% (WzM-L3) on pangasius fingerlings immersed at high concentration of 1.5 × 107 CFU mL-1 and 9.7 × 106 CFU ml-1, respectively. Interestingly, both WzM-S3 and WzM-L3 had a remarkably high protection against ESC, as RPS % were found at 89.29% and 90%, respectively. The mutant WzM-L3 is a potential live attenuated vaccine against ESC in Vietnamese catfish farms with good protection and simple practice.


Assuntos
Vacinas Bacterianas/imunologia , Peixes-Gato/imunologia , Edwardsiella ictaluri/imunologia , Infecções por Enterobacteriaceae/veterinária , Doenças dos Peixes/prevenção & controle , Animais , Vacinas Bacterianas/genética , Peixes-Gato/microbiologia , Edwardsiella ictaluri/genética , Infecções por Enterobacteriaceae/imunologia , Infecções por Enterobacteriaceae/prevenção & controle , Doenças dos Peixes/imunologia , Doenças dos Peixes/microbiologia , Deleção de Genes , Mutação , Vacinas Atenuadas/genética , Vacinas Atenuadas/imunologia
11.
J Food Sci ; 84(2): 370-380, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30640981

RESUMO

A rapid and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was validated and used to quantify crystal violet (CV), leucocrystal violet (LCV), malachite green (MG), leucomalachite green (LMG), and brilliant green (BG) residues in frozen fish (121 samples) from various countries, in order to detect the use of prohibited antibiotic dyes in fish for human consumption. The microbial quality of the fish was also assessed along with the effectiveness of a simple treatment with whole fat milk to reduce the levels of CV and LCV contamination. CV and LCV were the only two residues detected. They were found in farmed Pangasius (0.362 to 41.34 µg/kg and 0.178 to 10.58 µg/kg, respectively) and Tilapia (1.24 to 9.48 µg/kg and 1.29 to 2.81 µg/kg). Based on aerobic plate count (APC), 74%, 59%, and 55% of the samples of Tilapia fillets (from China) and Pangasius fillets (United Arab Emirates and Vietnam), and 100% and 50% of the skin samples of Hake (Argentina and U.S.A.) were of unacceptable microbial quality (APC > 107 cfu/g). Human pathogens, namely Escherichia coli, Staphylococcus aureus, and Vibrio spp., were detected in most fish. A significant reduction in CV and LCV concentrations by more than a third was achieved after immersing Pangasius and Tilapia fillets in whole fat milk for 120 minutes. These findings support the necessity of regular inspections and monitoring of CV and other antibiotic dye residues in fish, along with routine assessments of fish microbial quality, in order to protect public health. PRACTICAL APPLICATION: The described LC-MS/MS method can be used to rapidly and simultaneously quantify antibiotic dye residues in frozen fish. CV and LCV were detected in farmed Pangasius and Tilapia fillets and their concentrations was reduced by more than one third after immersing the fillets in whole milk for 120 min, a treatment which is not intended to replace safe fish farming practices upstream to artificially lower the level of banned dyes in fish. The findings support the necessity of regular inspections and monitoring of CV and other antibiotic dye residues in fish, along with assessments of fish microbial quality, to protect public health.


Assuntos
Corantes/análise , Leite/química , Alimentos Marinhos/análise , Compostos de Tritil/análise , Adsorção , Animais , Argentina , Peixes-Gato/microbiologia , China , Cromatografia Líquida/métodos , Corantes/isolamento & purificação , Contaminação de Alimentos/análise , Violeta Genciana/análise , Violeta Genciana/isolamento & purificação , Corantes de Rosanilina/análise , Corantes de Rosanilina/isolamento & purificação , Alimentos Marinhos/microbiologia , Espectrometria de Massas em Tandem/métodos , Tilápia/microbiologia , Compostos de Tritil/isolamento & purificação , Vietnã
12.
Fish Shellfish Immunol ; 86: 559-570, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30481557

RESUMO

Pituitary adenylate cyclase-activating polypeptide (PACAP) is a regulatory neuropeptide that belongs to the secretin/glucagon superfamily, of which some members have shown antimicrobial activities. Contrasting to mammals, published studies on the action of PACAP in non-mammalian vertebrate immune system remain scarce. Some of our recent studies added this peptide to the growing list of mediators that allow cross-talk between the nervous, endocrine and immune systems in teleost fish. Regulation of PACAP and expression of its receptor genes has been demonstrated during an immune response mounted against acute bacterial infection in fish, though the direct effect of PACAP against fish pathogenic bacteria has never been addressed. Current work provides evidence of antimicrobial activity of Clarias gariepinus PACAP against a wide spectrum of Gram-negative and Gram-positive bacteria and fungi of interest for human medicine and aquaculture, in which computational prediction studies supported the putative PACAP therapeutic activity. Results also indicated that catfish PACAP not only exhibits inhibitory effects on pathogen growth, but also affects the proliferation of human non-small cell lung cancer cell line H460 in a dose-dependent manner. The observed cytotoxic activity of catfish PACAP against human tumor cells and pathogenic microorganisms, but not healthy fish and mammalian erythrocytes support a potential physiological role of this neuropeptide in selective microbial and cancer cell killing. All together, our findings extend the mechanisms by which PACAP could contribute to immune responses, and open up new avenues for future therapeutic application of this bioactive neuropeptide.


Assuntos
Anti-Infecciosos/farmacologia , Peptídeos Catiônicos Antimicrobianos/farmacologia , Bactérias/efeitos dos fármacos , Peixes-Gato/imunologia , Polipeptídeo Hipofisário Ativador de Adenilato Ciclase/farmacologia , Aeromonas hydrophila/efeitos dos fármacos , Animais , Antineoplásicos/farmacologia , Bactérias/patogenicidade , Candida albicans/efeitos dos fármacos , Candida albicans/patogenicidade , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Peixes-Gato/microbiologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Peptídeos Penetradores de Células/farmacologia , Eritrócitos/efeitos dos fármacos , Hemólise , Humanos , Neoplasias Pulmonares/tratamento farmacológico
13.
Int J Syst Evol Microbiol ; 69(1): 255-260, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30489240

RESUMO

A novel Gram-stain-negative, rod-shaped, ivory-white, facultatively anaerobic and catalase-positive bacterium, designated H1304T, was isolated from the gut of sea catfish from Coast of Weihai, China. Optimal growth occurred at 30-33 °C (range, 4-37 °C) and pH 7.0-7.5 (range, pH 6.5-9.0) with 2.0-3.0 % (w/v) NaCl (range, 0.5-4.0 %). Phylogenetic analysis based on 16S rRNA gene sequences showed that H1304T belonged to the genus Cohaesibacter and was most closely related to Cohaesibactermarisflavi CGMCC 1.9157T (96.7 % 16S rRNA gene sequence similarity), Cohaesibactergelatinilyticus MCCC 1A02698T (96.3 %) and Cohaesibacterhaloalkalitolerans KCTC 32038T (96.0 %). The sole isoprenoid quinone was Q-10, the polar lipid profile consisted of phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylmonomethylethanolamine, phosphatidylcholine, glycolipid, an unidentified phospholipid and an unidentified aminolipid. The major fatty acids (>10 %) were C18 : 1ω7c and summed feature 3 (C16 : 1ω7c/C16 : 1ω6c). The DNA G+C content of strain H1304T is 50.8 mol%. Based on the combination of phylogenetic analysis, phenotypic data and chemotaxonomic data, strain H1304T is considered to represent a novel species within the genus Cohaesibacter in the family Cohaesibacteraceae, for which the name Cohaesibacter celericrescens sp. nov. is proposed. The type strain of the new species is H1304T (=KCTC 62075T=MCCC 1H00241T).


Assuntos
Alphaproteobacteria/classificação , Peixes-Gato/microbiologia , Trato Gastrointestinal/microbiologia , Filogenia , Alphaproteobacteria/isolamento & purificação , Animais , Técnicas de Tipagem Bacteriana , Composição de Bases , China , DNA Bacteriano/genética , Ácidos Graxos/química , Glicolipídeos/química , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Ubiquinona/análogos & derivados , Ubiquinona/química
14.
Fish Shellfish Immunol ; 84: 38-47, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30261297

RESUMO

The present investigation aims to study role of dietary selenium (Se) on growth performance, oxidative stress markers (catalase, superoxide dismutase and glutathione-s-transferase), stress biomarkers [blood glucose, cortisol and heat shock protein (HSP 70) and immunological status, Nitro blue tetrazolium (NBT), total protein, albumin, globulin, A/G ratio, total immunoglobulin and vitamin C] and survival of fish after Aeromonas veronii biovar sobria challenged. Pangasianodon hypophthalmus was treated with lead (Pb, 4 ppm), and high temperature (34 °C) for 60 days. The growth performance was reduced with declined in feed intake, growth rate and feed efficiency in case of group exposed with Pb alone and concurrent exposure to Pb high temperature (34 °C). The Se has immunomodulatory properties however, supplementation of the dietary Se @ 1 and 2 mg/kg diet has been realistically improved growth performance up to 240%, elevated antioxidative status in different tissues, and immunological status were also improved significantly in the P. hypophthalmus. The bacterial challenged with A. veronii biovar sobria in the P. hypophthalmus resulting in less cumulative mortality (%) and high relative (%) survival has been observed with supplementation of dietary Se @ 1 and 2 mg/kg diet. The bioaccumulation of Pb in muscle tissue has been also drastically reduced with supplementation of dietary Se in feed. Hence, overall results indicated that, dietary Se @ 1 and 2 mg/kg have ability to enhanced overall performance and alleviated multiple stresses in P hypophthalmus.


Assuntos
Aeromonas veronii , Peixes-Gato/fisiologia , Doenças dos Peixes/metabolismo , Infecções por Bactérias Gram-Negativas/metabolismo , Selênio/administração & dosagem , Acetilcolinesterase/metabolismo , Animais , Glicemia/análise , Peixes-Gato/microbiologia , Dieta , Infecções por Bactérias Gram-Negativas/veterinária , Proteínas de Choque Térmico HSP70/metabolismo , Hidrocortisona/sangue , Chumbo/administração & dosagem , Chumbo/farmacocinética , Músculos/metabolismo , Estresse Oxidativo , Estresse Fisiológico/fisiologia
15.
J Photochem Photobiol B ; 191: 59-64, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30583267

RESUMO

Recently, it has become widely recognized that ultraviolet A (UVA) exposure is harmful for both aquatic and terrestrial organisms. Many studies have reported the effects of UVA on aquatic animals, especially fish, but little is known about the antioxidant role of microalgae in ameliorating the negative effects of UVA exposure. Recently, there has been great interest in using Spirulina platensis (SP) as a dietary antioxidant agent. Therefore, this study aimed to investigate the protective role of SP against UVA-induced effects by analysing haemato-biochemical alterations and erythrocyte cytotoxic and genotoxic biomarkers in African catfish (Clarias gariepinus). Fish were exposed to UVA, UVA + 100 mg/L SP extract, UVA + 200 mg/L SP extract for 3 days (UVA exposure: 1 h/day), and were not subjected to treatment (control group). The results showed the presence of some morphological malformations in red blood cells (RBCs) after UVA exposure. Additionally, nuclear abnormalities, including micronuclei, were observed. UVA induced alterations in most of the haemato-biochemical indices. Adding SP to the fish aquaria restored the haemato-biochemical parameters to their control values. In addition, SP repaired cellular damage in a dose-dependent manner. We conclude that SP plays a modulatory role in preventing and/or repairing the haemotoxic effects induced by UVA.


Assuntos
Peixes-Gato/microbiologia , Spirulina/fisiologia , Raios Ultravioleta/efeitos adversos , Animais , Núcleo Celular/efeitos da radiação , Índices de Eritrócitos/efeitos da radiação , Eritrócitos/patologia , Eritrócitos/efeitos da radiação
16.
Microb Pathog ; 125: 276-280, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30266258

RESUMO

Citrobacter freundii is a fish pathogen known for its ability to cause injury and high mortality. There have been no studies reporting the effect of this bacterium on hematological parameters and internal organ histology in silver catfish (Rhamdia quelen). Therefore, the aim of this study is to evaluate the hematological and histopathological effects of an experimentally induced C. freundii infection in silver catfish. Twenty fish were divided into healthy and infected groups. The fish of the infected group were inoculated intramuscularly with 100 µL of bacterial suspension (6.4 × 108 CFU mL-1), while healthy control animals received 100 µL of sterile saline. On day 18 post-infection, blood and tissues (cephalic kidneys, livers, and spleens) were collected for histological analysis. The infected animals presented high mortality, as well as hematological and histological changes. In relation to hematology, the infected fish presented aregenerative anemia, protein loss, leukopenia with neutropenia, lymphocytosis, and leukoblastosis. Regarding histology, there was liver degeneration, decrease in the amount of renal hematopoietic tissue, and the presence of melanomacrophage centers (MMCs) in the spleen and cephalic kidney of infected fish. In summary, these alterations may contribute to disease pathophysiology, contributing to high mortality of affected fish.


Assuntos
Peixes-Gato/microbiologia , Citrobacter freundii/isolamento & purificação , Infecções por Enterobacteriaceae/veterinária , Doenças dos Peixes/patologia , Estruturas Animais/patologia , Animais , Células Sanguíneas/patologia , Infecções por Enterobacteriaceae/microbiologia , Infecções por Enterobacteriaceae/patologia , Doenças dos Peixes/microbiologia , Histocitoquímica , Análise de Sobrevida
17.
J Appl Microbiol ; 125(5): 1552-1568, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30066443

RESUMO

AIM: Control of operations of catfish farmers still lacks in Nigeria due to the absence of catfish inspection programmes by relevant regulatory agencies. Thus, this study aimed at performing comprehensive surveillance of Nigerian catfish pisciculture systems so as to provide empirical evidence on the extent of contamination with multidrug-resistant bacteria due to potential abuse of standard operational procedures by catfish farmers. METHODS AND RESULTS: One-way analysis of variance was performed on pond water and catfish samples which were randomized with the Wei's-Urn randomization modelling technique. Ceftriaxone-selected bacterial colonies isolated from catfish and pond water samples collected from nursery and grow-out pond systems were tested for multidrug resistance. Haemocytotoxigenic and Shiga toxigenic virulence traits in multidrug-resistant colonies, as well as detection of hyper-Ambler class C-(AmpC) beta-lactamase and carbapenemase production, were also performed using phenotypic/molecular methods. Of the 648 ceftriaxone-selected bacterial isolates examined in this study, 515 isolates were found to be multidrug-resistant bacteria, of which 366 isolates were characterized as pathogenic multidrug-resistant bacteria. Both nursery and grow-out ponds had high frequencies of bacterial resistance to ampicillin (86-93%), cotrimoxazole (47-87%) and chloramphenicol (95-100%). However, high frequencies of bacterial resistance to amoxicillin/clavulanic acid (75-83%) were only observed in the grow-out ponds. Also, hyper-AmpC beta-lactamase-producing multidrug-resistant bacteria were only seen in the grow-out ponds. Isolated multidrug-resistant bacteria were confirmed as Enterobacter cloacae, Citrobacter freundii, Bacillus cereus, Pseudomonas aeruginosa, Escherichia coli and Enterococcus faecalis. CONCLUSION: The findings in this study corroborate the urgent need for some form of international mediation to urge the Nigerian government and her regulatory agencies to commence monitoring of catfish pisciculture operations since multidrug-resistant bacteria could be transmitted to humans. SIGNIFICANCE AND IMPACT OF THE STUDY: Our study provided empirical evidence that revealed the misuse/abuse of antibiotics during pisciculture operations in Nigeria; thus, constituting these pisciculture systems into reservoirs of multidrug-resistant bacteria.


Assuntos
Aquicultura/normas , Bactérias/classificação , Peixes-Gato/microbiologia , Farmacorresistência Bacteriana Múltipla , Animais , Aquicultura/legislação & jurisprudência , Bactérias/efeitos dos fármacos , Bactérias/isolamento & purificação , Proteínas de Bactérias/metabolismo , Humanos , Testes de Sensibilidade Microbiana , Nigéria , beta-Lactamases/metabolismo
18.
Mol Genet Genomics ; 293(6): 1365-1378, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29967962

RESUMO

Disease resistance is one of the most important traits for aquaculture industry. For catfish industry, enteric septicemia of catfish (ESC), caused by the bacterial pathogen Edwardsiella ictaluri, is the most severe disease, causing enormous economic losses every year. In this study, we used three channel catfish families with 900 individuals (300 fish per family) and the 690K catfish SNP array, and conducted a genome-wide association study to detect the quantitative trait loci (QTL) associated with ESC resistance. Three significant QTL, with two of located on LG1 and one on LG26, and three suggestive QTL located on LG1, LG3, and LG21, respectively, were identified to be associated with ESC resistance. With a well-assembled- and -annotated reference genome sequence, genes around the involved QTL regions were identified. Among these genes, 37 genes had known functions in immunity, which may be involved in ESC resistance. Notably, nlrc3 and nlrp12 identified here were also found in QTL regions of ESC resistance in the channel catfish × blue catfish interspecific hybrid system, suggesting this QTL was operating within both intra-specific channel catfish populations and interspecific hybrid backcross populations. Many of the genes of the Class I MHC pathway, for mediated antigen processing and presentation, were found in the QTL regions. The positional correlation found in this study and the expressional correlation found in previous studies indicated that Class I MHC pathway was significantly associated with ESC resistance. This study validated one QTL previously identified using the second and fourth generation of the interspecific hybrid backcross progenies, and identified five additional QTL among channel catfish families. Taken together, it appears that there are only a few major QTL for ESC disease resistance, making marker-assisted selection an effective approach for genetic improvements of ESC resistance.


Assuntos
Peixes-Gato/genética , Resistência à Doença/genética , Edwardsiella ictaluri/imunologia , Infecções por Enterobacteriaceae/genética , Locos de Características Quantitativas , Sepse/genética , Animais , Peixes-Gato/imunologia , Peixes-Gato/microbiologia , Infecções por Enterobacteriaceae/imunologia , Doenças dos Peixes/genética , Doenças dos Peixes/imunologia , Ligação Genética , Estudo de Associação Genômica Ampla , Ictaluridae/genética , Ictaluridae/imunologia , Ictaluridae/microbiologia , Polimorfismo de Nucleotídeo Único , Sepse/imunologia , Sepse/veterinária
19.
Mar Biotechnol (NY) ; 20(6): 729-738, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30014301

RESUMO

Alternative splicing is the process of generating multiple transcripts from a single pre-mRNA used by eukaryotes to regulate gene expression and increase proteomic complexity. Although alternative splicing profiles have been well studied in mammalian species, they have not been well studied in aquatic species, especially after biotic stresses. In the present study, genomic information and RNA-Seq datasets were utilized to characterize alternative splicing profiles and their induced changes after bacterial infection with Edwardsiella ictaluri in channel catfish (Ictalurus punctatus). A total of 27,476 alternative splicing events, derived from 9694 genes, were identified in channel catfish. Exon skipping was the most abundant while mutually exclusive exon was the least abundant type of alternative splicing. Alternative splicing was greatly induced by E. ictaluri infection with 21.9% increase in alternative splicing events. Interestingly, genes involved in RNA binding and RNA splicing themselves were significantly enriched in differentially alternatively spliced genes after infection. Sequence analyses of splice variants of a representative alternatively spliced gene, splicing factor srsf2, revealed that certain spliced transcripts may undergo nonsense-mediated decay (NMD), suggesting functional significance of the induced alternative splicing. Although statistical analysis was not possible with such large datasets, results from quantitative real-time PCR from representative differential alternative splicing events provided general validation of the bacterial infection-induced alternative splicing. This is the first comprehensive study of alternative splicing and its changes in response to bacterial infection in fish species, providing insights into the molecular mechanisms of host responses to biotic stresses.


Assuntos
Peixes-Gato/metabolismo , Peixes-Gato/microbiologia , Edwardsiella ictaluri/patogenicidade , Processamento Alternativo/genética , Animais , Infecções por Enterobacteriaceae/genética , Infecções por Enterobacteriaceae/metabolismo , Perfilação da Expressão Gênica
20.
J Water Health ; 16(3): 460-471, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29952334

RESUMO

The prevalence of salmonellae in the intestines of the invasive suckermouth catfish Hypostomus plecostomus was assessed in the San Marcos River, just down-stream of its spring-fed headwaters. In 2014, H. plecostomus, sediment, and water samples were collected during 15 sampling events. A combination of semi-selective enrichment and quantitative polymerase chain reaction (qPCR) revealed the presence of salmonellae in 45% of the fish intestines across the entire year, with a prevalence range of 13-100% per sampling event. Repetitive element sequence-based PCR (rep-PCR) and multi-locus sequence typing (MLST) revealed a high diversity of salmonellae from fish intestine samples at individual sampling times, single or multiple presence of rep-PCR patterns and serotypes within individual fish, and identical rep-PCR patterns and serotypes for different fish within and across sampling events. Overall, 15 serotypes were identified by MLST, with a diversity range between one and seven serotypes per sampling event. Some serotypes were retrieved only once, while others were detected more frequently. A few serotypes were retrieved at several sampling times, nearly evenly distributed over the entire sampling period. Prevalence and diversity were independent of precipitation events, indicating the potential presence of environmental strains that are capable of long-term persistence in the environment.


Assuntos
Peixes-Gato/microbiologia , Doenças dos Peixes/parasitologia , Salmonelose Animal/microbiologia , Salmonella/isolamento & purificação , Animais , Doenças dos Peixes/epidemiologia , Intestinos/microbiologia , Salmonella/classificação , Salmonelose Animal/epidemiologia , Sorogrupo , Texas/epidemiologia
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