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1.
Microb Pathog ; : 104638, 2020 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-33242647

RESUMO

The production of tambaqui Colossoma macropomum has recently reached a milestone, being considered the main native species produced in South American continental waters. Despite the importance of this fish, its immunity is not well understood. In this study we established some patterns of innate immunity for the species via two experiments. Both studies evaluated the fish in the absence (intraperitoneal saline) or presence (intraperitoneal, 3 x 107 CFU/mL of Aeromonas hydrophila at 0.1 mL/10 g of living weight) of infection at 5 points over time-course of 14 days (0 h, 6 h, 24 h, 7 d, 14 d). In the first experiment, the partial gene sequences and gene expression of IL-1ß, IRAK-1, C3, C4, lysozyme, IL-10, HSP70 and ß-actin were determined in the main secondary lymphoid organs of fish: the spleen and head kidney. The second study was performed to analyse the alternative complement pathway ACH50 in serum to support the elucidation of C3 gene expression. Results of the gene expression assays showed a tendency towards up-regulation of immune genes in infected fish in early phases of infection (mostly around 6 h and 24 h) and in the chronic phase (7 d and 14 d), with the exception of HSP70 which showed a down-regulation in infected fish. Our results also suggested that lysozyme was evolved in both pro- and anti-inflammatory activities. For genes of the complement system, it was demonstrated that C4 regulation followed the tendency of pro-inflammatory genes. However, the C3 gene was, surprisingly, not expressed in most fish and this corroborated with the results of the complement system activity in serum that also did not show activity in most fish. The possible reasons for the regulation of gene expression and association with fish disease are addressed in this paper.

2.
Vet Anim Sci ; 10: 100136, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32964167

RESUMO

Tildipirosin is a latest generation macrolide that is used to battle infection diseases caused by Gram-negative bacteria. Recent studies have shown the effectiveness of this antimicrobial agent against Actinobacillus pleuropneumoniae; however, little information is available about Glaesserella parasuis, the etiological agent of Glässer's disease. In this study, the Tildipirosin activity to 100 Brazilian clinical isolates of G. parasuis was assessed using a broth microdilution assay. A total of 90% of G. parasuis isolates were sensitive at concentrations ≤ 4 µg/mL Tildipirosin, thus showing to be efficiently controlled by the therapeutic concentration recommended for pigs. On the other hand, a total of ten isolates have shown resistance to this antibiotic, with a minimal inhibitory concentration (MIC) ≥ 8 and ≤ 16 µg/ml. Notably, our findings highly support the use of Tildipirosin for treating Glässer's disease outbreaks, and it also advises the using of MIC approach to monitor the evolution of sensitivity or resistance exhibited by G. parasuis to this molecule, as well as to adjust therapeutic doses when necessary.

3.
Front Vet Sci ; 7: 98, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32158772

RESUMO

Glaesserella parasuis is a Gram-negative bacterium that causes Glässer's disease, a common pathology found in young pigs characterized by polyarthritis, polyserositis, and meningitis. The bacterium has 15 known serovars that have been classified by virulence. Serovars 1, 4, 5, and 12 are considered highly virulent and used in most studies. Serovars 3, 6, 7, 9, and 11 are considered avirulent. Recent reports that serovar 7 is an emerging problem in the pig industry indicate that the association of virulence and serovar may not always be reliable. This led us to infect colostrum-deprived piglets with the reference serovar 7 strain (SV7 strain 174) that had been passaged through pigs and characterize the clinical and pathological signs. We observed that SV7 strain 174 caused clinical signs consistent with Glässer's disease in all infected piglets that succumbed to infection for up to day 5 post-infection. Macroscopic and microscopic lesions were consistent with those found in piglets infected with conventional virulent serovars. In addition, we describe novel microscopic lesions associated with Glässer's disease such as endophthalmitis and thymic depletion. Thus, our findings indicate that SV7 strain 174 causes classical signs of Glässer's disease in colostrum-deprived piglets and some caution should be used in employing vaccine strategies based on association between capsular serovar and virulence.

4.
Stress ; : 1-6, 2020 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-32013653

RESUMO

We report the effects of acute and chronic stress on the expression of selective immune-related genes and markers of neuronal function in the brain of the zebrafish (Danio rerio). Fish were distributed into three groups: the non-stressed control group; the acute stress (AS) group, submitted to a single stressing episode; and the unpredictable chronic stress (UCS) group, submitted to two daily stressing episodes of alternating times and types of stress. The stressing protocols were applied for a period of 14 days. The UCS protocol triggered the expression of the pro-inflammatory cytokine genes IL-1ß and TNF-α, the anti-inflammatory cytokine IL-10 (negative feedback from the immune system), reduction in cFOS gene expression, and caused neuro-inflammation. The AS protocol had no effect on gene expression. Altered expression of cytokine genes, as observed in our study, correlates with several pathologies associated with neuro-inflammation, and the reduction of cFOS gene expression may indicate the occurrence of reduced neuronal plasticity. Our study further extends our knowledge about the interaction of the immune system and the different forms of stress.

5.
Trop Anim Health Prod ; 52(2): 619-623, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31444664

RESUMO

Trichinellosis is a zoonotic disease exotic in Brazil but commonly found worldwide including South American countries like Argentina. International trading of swine meat needs an official Trichinella-free diagnosis commonly carried out by pepsin-HCl digestion of diaphragm tissue fragments followed by microscopic examination for the presence or absence of Trichinella larvae. The easiness of this diagnostic method allows it to be performed at slaughtering plants but, in contrast, it lacks sensitivity and does not allow species differentiation, which is fundamental for determining geographical and species distribution of different genotypes. In our study, we aimed to evaluate a highly sensitive diagnostic method based on the polymerase chain reaction (PCR) that would allow us to detect and classify different species of Trichinella. Thus, we designed a synthetic gene and selected five sets of primers targeting specific regions of the Trichinella genome. The synthetic gene was cloned into a plasmid and then used to optimize PCR conditions. Using our PCR, we were able to detect 0.001 pg of the synthetic gene, which corresponded to 0.01 larvae. Then, we collected 175 samples of Suidae (domestic and wild boars) diaphragm fragments that were pooled into groups, digested with pepsin-HCl, and had the DNA extracted for analysis by PCR. The clinical samples evaluated were negative by PCR. Our results indicate that the PCR-based method might be a useful diagnostic method complementary to the pepsin-HCl digestion method currently in use, mostly in non-endemic areas.


Assuntos
Genes Sintéticos , Carne/parasitologia , Reação em Cadeia da Polimerase/veterinária , Trichinella/isolamento & purificação , Triquinelose/veterinária , Animais , Argentina/epidemiologia , Brasil/epidemiologia , Primers do DNA , Larva , Sensibilidade e Especificidade , Suínos , Doenças dos Suínos/diagnóstico , Trichinella/genética , Triquinelose/diagnóstico , Triquinelose/epidemiologia , Zoonoses
6.
Fish Shellfish Immunol ; 93: 575-579, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31398396

RESUMO

The immune modulating activity of ß-glucan on aquatic species has been a matter of intense investigation. Here, we aimed to investigate the effect of ß-glucan on wound healing of silver catfish, a Neotropical South American scale-free fish. Small sections of skin and muscle (3 mm in diameter) were removed and fish were bathed daily with ß-glucan (0.1% and 0.5%) up to 28 days when cicatrization was complete. A group of fish similarly injured and non-exposed to ß-glucan was used as control. Wound closure and healing was monitored visually and by histopathological analysis. In fish bathed with 0.5% ß-glucan we found reduced blood cortisol levels at day one post-wounding and, by day 7 post wounding, the deposition of granulation tissue was higher compared to non-exposed fish. In addition, from day 7 forward, wound size was significantly lower in fish bathed with 0.5% ß-glucan. Histopathological analysis of the wounded site indicated a thin layer of immature epidermal cells at day one post wounding. A discrete inflammation with mixed inflammatory cell infiltrate was observed on wounded muscle and was lower by day 7 post wounding on fish bathed with 0.5% ß-glucan. By day 14 post wounding, the deposition of collagen fibers and the presence of fibroblast and new muscle fibers were higher in fish exposed to 0.5% ß-glucan, and dermis restoration was complete. Thus, our results indicate that in silver catfish wound healing occurs rapidly and improves greatly by daily bathing with ß-glucan.


Assuntos
Peixes-Gato/imunologia , Cicatrização/imunologia , beta-Glucanas/metabolismo , Animais , Feminino , Imersão , Masculino , beta-Glucanas/administração & dosagem
7.
PeerJ ; 7: e6817, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31198621

RESUMO

Glässer's disease (GD) is an important infectious disease of swine caused by Haemophilus (Glaesserella) parasuis. Vaccination with inactivated whole cell vaccines is the major approach for prevention of H. parasuis infection worldwide, but the immunity induced is predominantly against the specific polysaccharide capsule. As a consequence, the available vaccines may not induce adequate protection against the field strains, when the capsules present in the vaccine strains are different from those in strains isolated from the farms. Therefore, it is crucial to map H. parasuis serovars associated with regional outbreaks so that appropriate bacterin vaccines can be developed and distributed for prevention of infection. In this study, 459 H. parasuis field strains isolated from different Glässer's disease outbreaks that occurred in 10 different Brazilian States were analyzed for serotype using PCR-based approaches. Surprisingly, non-typeable (NT) strains were the second most prevalent group of field strains and along with serovars 4, 5 and 1 comprised more than 70% of the isolates. A PCR-based approach designed to amplify the entire polysaccharide capsule locus revealed 9 different band patterns in the NT strains, and 75% of the NT strains belonged to three clusters, suggesting that a number of new serovars are responsible for a substantial proportion of disease. These results indicate that commercially available vaccines in Brazil do not cover the most prevalent H. parasuis serovars associated with GD.

8.
Braz J Microbiol ; 49 Suppl 1: 68-75, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29866609

RESUMO

Serological testing and culling infected animals are key management practices aiming eradication of bovine leukemia virus infection. Here, we report the development of an indirect ELISA based on BLV recombinant capsid protein (BLVp24r) to detect anti-BLV antibodies in cattle serum. The BLVp24r was expressed in Escherichia coli and purified by affinity chromatography, and then used to set up the ELISA parameters. The Polysorp® plate coated with 50ng of antigen/well and bovine serum diluted 1:100 gave the best results during standardization. Using sera from infected and non-infected cattle we set up the cutoff point at 0.320 (OD450nm) with a sensitivity of 98.5% and specificity of 100.0%. Then, we tested 1.187 serum samples from dairy (736 samples) and beef cattle (451 samples) with unknown status to BLV. We found that 31.1% (229/736) and 9.5% (43/451) of samples amongst dairy and beef cattle, respectively, had IgGs to BLV. The rate of agreement with a commercial competitive ELISA was 84.3% with a κ value of 0.68. Thus, our BLVp24r iELISA is suitable to detect BLV infected animals and should be a useful tool to control BLV infection in cattle.


Assuntos
Anticorpos Antivirais/sangue , Proteínas do Capsídeo/imunologia , Leucose Enzoótica Bovina/diagnóstico , Ensaio de Imunoadsorção Enzimática/métodos , Vírus da Leucemia Bovina/imunologia , Testes Sorológicos/métodos , Animais , Proteínas do Capsídeo/análise , Proteínas do Capsídeo/genética , Bovinos , Leucose Enzoótica Bovina/sangue , Leucose Enzoótica Bovina/virologia , Ensaio de Imunoadsorção Enzimática/instrumentação , Vírus da Leucemia Bovina/genética , Vírus da Leucemia Bovina/isolamento & purificação , Proteínas Recombinantes/análise , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Sensibilidade e Especificidade
9.
Sci Rep ; 8(1): 7372, 2018 05 09.
Artigo em Inglês | MEDLINE | ID: mdl-29743502

RESUMO

Haemophilus parasuis is the causative agent of the Glässer's disease (GD), one of the most important bacterial diseases that affect young pigs worldwide. GD prevention based on vaccination is a major concern due to the limited cross-protection conferred by the inactivated whole cell vaccines used currently. In this study, vaccines based on two mutant recombinant proteins derived from transferrin binding protein B of H. parasuis (Y167A-TbpB and W176A-TbpB) were formulated and evaluated in terms of protection against lethal challenge using a serovar 7 (SV7) H. parasuis in a high susceptibility pig model. Our results showed that H. parasuis strain 174 (SV7) is highly virulent in conventional and colostrum-deprived pigs. The Y167A-TbpB and W176A-TbpB antigens were immunogenic in pigs, however, differences in terms of antigenicity and functional immune response were observed. In regard to protection, animals immunized with Y167A-TbpB antigen displayed 80% survival whereas the W176A-TbpB protein was not protective. In conjunction with previous studies, our results demonstrate, (a) the importance of testing engineered antigens in an in vivo pig challenge model, and, (b) that the Y167A-TbpB antigen is a promising antigen for developing a broad-spectrum vaccine against H. parasuis infection.


Assuntos
Vacinas Bacterianas/genética , Vacinas Bacterianas/metabolismo , Mutação , Engenharia de Proteínas , Proteína B de Ligação a Transferrina/genética , Proteína B de Ligação a Transferrina/metabolismo , Transferrina/metabolismo , Animais , Vacinas Bacterianas/química , Feminino , Haemophilus/imunologia , Haemophilus/fisiologia , Imunização , Camundongos , Ligação Proteica , Suínos , Proteína B de Ligação a Transferrina/química
10.
Sci Rep ; 8(1): 846, 2018 01 16.
Artigo em Inglês | MEDLINE | ID: mdl-29339805

RESUMO

Considering the intriguing relationship between immune system and behavior recently described in mammals, and the lack of information of this relationship in fish, here we describe for the first time the interaction between the immune system and social and exploratory behavior in zebrafish. Fish high responders to novelty (HRN) presented a proinflammatory profile, with increased IL-1ß and reduced IL-10 expression compared to fish low responders to novelty (LRN). Likewise, fish less responsive to social stimuli have a reduced expression of INF-γ. We show that fish with different behavior patterns have differences in the immune response. Our findings indicate that the interplay between immune system and behavior in zebrafish is similar to that found in mammalian models and that zebrafish should be considered as a potential model organism to study the relationship between immune system and behavior.


Assuntos
Comportamento Exploratório , Sistema Imunitário/metabolismo , Peixe-Zebra/metabolismo , Animais , Feminino , Interferon gama/genética , Interferon gama/metabolismo , Interleucina-10/genética , Interleucina-10/metabolismo , Interleucina-1beta/genética , Masculino , Transcriptoma
11.
Braz. j. microbiol ; 49(supl.1): 68-75, 2018. tab, graf
Artigo em Inglês | LILACS | ID: biblio-974318

RESUMO

Abstract Serological testing and culling infected animals are key management practices aiming eradication of bovine leukemia virus infection. Here, we report the development of an indirect ELISA based on BLV recombinant capsid protein (BLVp24r) to detect anti-BLV antibodies in cattle serum. The BLVp24r was expressed in Escherichia coli and purified by affinity chromatography, and then used to set up the ELISA parameters. The Polysorp ® plate coated with 50 ng of antigen/well and bovine serum diluted 1:100 gave the best results during standardization. Using sera from infected and non-infected cattle we set up the cutoff point at 0.320 (OD450 nm) with a sensitivity of 98.5% and specificity of 100.0%. Then, we tested 1.187 serum samples from dairy (736 samples) and beef cattle (451 samples) with unknown status to BLV. We found that 31.1% (229/736) and 9.5% (43/451) of samples amongst dairy and beef cattle, respectively, had IgGs to BLV. The rate of agreement with a commercial competitive ELISA was 84.3% with a κ value of 0.68. Thus, our BLVp24r iELISA is suitable to detect BLV infected animals and should be a useful tool to control BLV infection in cattle.


Assuntos
Animais , Bovinos , Ensaio de Imunoadsorção Enzimática/métodos , Testes Sorológicos/métodos , Leucose Enzoótica Bovina/diagnóstico , Vírus da Leucemia Bovina/imunologia , Proteínas do Capsídeo/imunologia , Anticorpos Antivirais/sangue , Proteínas Recombinantes/análise , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Ensaio de Imunoadsorção Enzimática/instrumentação , Sensibilidade e Especificidade , Leucose Enzoótica Bovina/sangue , Leucose Enzoótica Bovina/virologia , Vírus da Leucemia Bovina/isolamento & purificação , Vírus da Leucemia Bovina/genética , Proteínas do Capsídeo/análise , Proteínas do Capsídeo/genética
12.
Sci Rep ; 7(1): 10377, 2017 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-28871190

RESUMO

Vaccines have become fundamental in the control and elimination of Glässer Disease, a systemic disease of pigs caused by Haemophilus parasuis. The classic vaccines available for prevention of this infection were developed without a robust knowledge about host immunological mechanisms. In this study, we demonstrated the presence of cross-reactive epitopes on both the N-lobe and C-lobe of variants of transferrin binding protein B (TbpBs) expressed on the surface of 6 virulent serovars of H. parasuis. Antibodies against TbpB-derived antigens were capable of increasing the phagocytic capacity of neutrophils and were also capable of blocking porcine transferrin from binding to TbpB. Surprisingly, none of the pig or mice antisera from animals immunized with TbpB-derived antigens mixed with Montanide IMS 2215 VG PR adjuvant were able to activate the classical complement pathway (CCP). In contrast, antisera from mice immunized with TbpB-derived antigens adjuvanted with Freund's adjuvants or Montanide Gel 01 were able to activate the CCP and kill H. parasuis. Our results demonstrate that the type of adjuvant can modulate the functional response induced by TbpB-derived antigens. Based on these results, we propose that a properly formulated TbpB-based vaccine may elicit a functional protective antibody response with broad cross-reactivity against heterologous strains of H. parasuis.


Assuntos
Anticorpos Antibacterianos/metabolismo , Epitopos/imunologia , Vacinas Anti-Haemophilus/imunologia , Haemophilus parasuis/imunologia , Proteína B de Ligação a Transferrina/química , Adjuvantes Imunológicos/administração & dosagem , Animais , Reações Cruzadas , Infecções por Haemophilus/imunologia , Infecções por Haemophilus/prevenção & controle , Infecções por Haemophilus/veterinária , Vacinas Anti-Haemophilus/administração & dosagem , Haemophilus parasuis/patogenicidade , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Suínos , Doenças dos Suínos/imunologia , Doenças dos Suínos/prevenção & controle , Transferrina/metabolismo , Proteína B de Ligação a Transferrina/genética , Proteína B de Ligação a Transferrina/imunologia , Virulência
13.
PLoS One ; 12(5): e0176409, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28486512

RESUMO

Hepatitis E Virus (HEV) is a zoonotic pathogen responsible for causing acute hepatitis in human, especially in developing countries. Diagnosis of HEV usually relies on the detection of antibodies mostly by enzyme-linked immunosorbent assay (ELISA). In the present study, we designed a new indirect ELISA (iELISA) based on a short recombinant peptide derived from the capsid protein (ORF2p) and demonstrated its potential for detecting human IgG against HEV genotype 3. The best polystyrene plate (Maxisorp®), optimal ORF2p coating antigen concentration (0,67µg/well) and primary antibody dilution (1:100) were determined. This iELISA showed a sensitivity of 91.4% and specificity of 95.9%. The comparison of our in house iELISA with a commercial assay (RecomWell, Mikrogen®) showed 94.25% of agreement and a kappa index of 0.88. The ORF2 recombinant ELISA was used to screen 780 blood donors for anti-HEV IgG and we found that 314 (40,25%) of these donors were IgG positive. This high prevalence of antibodies suggests, for the first time, that the Southern Brazil region might be endemic to Hepatitis E Virus genotype 3.


Assuntos
Doadores de Sangue , Endonucleases/metabolismo , Ensaio de Imunoadsorção Enzimática/métodos , Vírus da Hepatite E/isolamento & purificação , Imunoglobulina G/imunologia , DNA Polimerase Dirigida por RNA/metabolismo , Brasil/epidemiologia , Vírus da Hepatite E/imunologia , Humanos , Proteínas Recombinantes/metabolismo , Estudos Soroepidemiológicos
14.
Fish Shellfish Immunol ; 64: 78-83, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28267632

RESUMO

The effect of atrazine (ATZ) and its metabolites on aquatic vertebrate species has been a matter of concern to researchers and environmentalist. In this study we exposed head kidney monocytes to sublethal concentrations of atrazine (1 and 10 µg/ml-1), corresponding to 1% and 10% of the LC50-96h, to evaluate the expression of immune-related genes central to immune stimulation. The mRNA levels of TNF-α, Mieloperoxidase and Mx genes were significantly reduced following 24 h exposure to both concentrations of ATZ. The mRNA levels of iRAK4 were reduced only at the higher ATZ concentration and the mRNA levels of IL-1ß were not affected. The results reported here support our previous findings on the immunosuppressive effect of ATZ indicating its potential to interfere with the expression of immune-related genes, and strengthen the need to regulate ATZ usage aiming to preserve animal and human health.


Assuntos
Atrazina/toxicidade , Peixes-Gato/genética , Proteínas de Peixes/genética , Expressão Gênica/efeitos dos fármacos , Herbicidas/toxicidade , Animais , Peixes-Gato/imunologia , Peixes-Gato/metabolismo , Proteínas de Peixes/metabolismo , Tolerância Imunológica , Poluentes Químicos da Água/toxicidade
15.
Pesqui. vet. bras ; 37(1): 73-78, jan. 2017. tab., graf.
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-846421

RESUMO

The immunomodulatory effects of dietary ß-glucan were evaluated in silver catfish. ß-glucan was added to the diet (0.01%, and 0.1%) and fed to the fish for 21 days, to evaluate effects on blood and some innate immune parameter, or fed for 42 days, to evaluate growth rate and resistance to challenge with pathogenic Aeromonas hydrophila. We found that adding ß-glucan to the diet had no effect on fish growth and no effect on blood cells, or serum bacterial agglutination and serum myeloperoxidase activity. However, fish that received ß-glucan in the diet had the natural hemolytic activity of complement significantly higher compared to control fish. Furthermore, fish fed with ß-glucan and challenged with A. hydrophila had fewer bacteria in blood and presented a significantly higher survival rate compared to control fish. Thus, we concluded that ß-glucan might be explored as feed additive aiming to improve silver catfish innate immunity and resistance to specific pathogen.(AU)


O uso da ß-glucana como suplemento alimentar foi avaliado em jundiás. A ß-glucana foi adicionada à ração na proporção de 0.01%, e 0.1% e fornecida aos peixes por 21, para avaliar dados hematológicos e parâmetros do sistema imune natural, ou 42 dias, para avaliar ganho de peso e resistência ao desafio com Aeromonas hydrophila. A adição da ß-glucana na dieta não afetou o ganho de peso e não induziu alterações hematológicas nem alterações nos níveis de aglutininas e mieloperoxidase sanguínea. No entanto, a atividade hemolítica natural do sistema do complemento foi significativamente maior nos peixes alimentados com ß-glucana. Além disso, nos peixes alimentados com ß-glucana e desafiados com A. hydrophila, o número de bactérias isoladas do sangue foi significativamente menor, e a sobrevivência ao desafio foi significativamente maior do que nos peixes que não receberam ß-glucana. Consequentemente, concluímos que a ß-glucana tem potencial imunomodulador quando adicionada à dieta, nas condições experimentais aqui indicadas, e contribui para aumentar imunidade natural e a resistência dos jundiás ao desafio com patógenos específicos.(AU)


Assuntos
Animais , Adjuvantes Imunológicos , beta-Glucanas/análise , Peixes-Gato/metabolismo , Aditivos Alimentares/análise , Fatores Imunológicos , Aeromonas hydrophila , Peixes/imunologia
16.
An Acad Bras Cienc ; 88(3): 1451-7, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27508996

RESUMO

Molecules with immune modulating activity are ubiquitously distributed in nature and their impact on aquaculture has been exploited in order to increase fish resistance to pathogens. Here, we investigated the effect of inactivated Parapoxvirus ovis (iPPVO) on blood cells and innate and acquired immune response of silver catfish (Rhamdia quelen). iPPVO inoculation had no effect on respiratory burst activity; however, following iPPVO inoculation, we observed a significant decrease on circulating monocytes concomitantly with an increased number of heterophilic granulocytes and thrombocytes, which are the main cells involved in innate immunity and provide connection with acquired immunity. Fish inoculated with a combination of bovine serum albumin (BSA) + iPPVO had significantly higher levels of antibodies to BSA compared to fish inoculated with BSA alone, but lower than fish inoculated with BSA + Freund's incomplete adjuvant (FIA). These findings points to the potential usefulness of iPPVO as immunomodulator in fish and instigate further research to identify its component that interact with immune cells and that could be exploited as adjuvants in fish.


Assuntos
Adjuvantes Imunológicos , Peixes-Gato/imunologia , Parapoxvirus/imunologia , Inativação de Vírus , Animais , Adjuvante de Freund/imunologia , Imunidade Celular , Imunidade Inata , Monócitos/imunologia , Neutrófilos/imunologia , Soroalbumina Bovina/imunologia
17.
Comp Immunol Microbiol Infect Dis ; 37(4): 259-65, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25159996

RESUMO

Hemoplasmas are ubiquitous pleomorphic and epicellular bacteria detected in erythrocytes in several species. In Brazil, studies on hemoplasmas have not included information on occurrence, clinical signs, and risk factors in dogs. This paper investigates the occurrence of hemoplasmas in dogs, focusing on risk factors and clinical status. Conventional PCR for the four types of canine hemoplasmas was performed in 331 blood samples collected from dogs clinically treated at a teaching veterinary hospital. Of all samples, 17/331 (5.1%) were positive for Mycoplasma haemocanis and 6/331 (1.8%) were positive for a 'Candidatus Mycoplasma haemominutum-like' organism. Risk factors included the presence of vectors, old age, dog bite wounds, and neoplastic diseases. In the multivariate analysis, a 4.40 odds ratio in dogs with vector-borne diseases indicated risk for hemoplasmosis. There was correlation between hemoplasma infection and neoplastic disease, suggesting that neoplastic conditions are a risk factor for hemoplasma infection in dogs.


Assuntos
Doenças do Cão/diagnóstico , Doenças do Cão/microbiologia , Infecções por Mycoplasma/veterinária , Mycoplasma/classificação , Animais , Brasil/epidemiologia , Doenças do Cão/epidemiologia , Cães , Feminino , Gliceraldeído-3-Fosfato Desidrogenase (Fosforiladora)/genética , Masculino , Mycoplasma/genética , RNA Ribossômico 16S/genética , Fatores de Risco
18.
Chemosphere ; 112: 85-91, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25048892

RESUMO

We studied the stress response of Rhamdia quelen fingerlings at 45, 90, 135 and 180 d following acute exposure to agrichemicals. Herein, we report the novel observation that acute exposure of fingerling-aged fish to a methyl parathion-based insecticide (MPBI) and to a tebuconazole-based fungicide (TBF) induced chronic inhibition of the stress response. In contrast, fish exposed to an atrazine-simazine-based herbicide (ASBH) recovered the stress response on day 45, and fish exposed to a glyphosate-based herbicide (GBH) did not present stress response inhibition. Additionally, fish exposed to MPBI, GBH and ASBH showed lower survival rates and attained lower final weights. In the case of TBF, the presence of the stressful stimulus more strongly influenced the changes in the performance parameters than did the agrichemical exposure itself. An impairment of the cortisol response may seriously hamper the adaptive response and the ability to promote the necessary metabolic and ionic adjustments to respond to environmental stress.


Assuntos
Peixes-Gato/fisiologia , Hidrocortisona/antagonistas & inibidores , Praguicidas/toxicidade , Estresse Fisiológico/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Metil Paration/toxicidade , Taxa de Sobrevida , Fatores de Tempo
19.
Vet Immunol Immunopathol ; 157(3-4): 142-8, 2014 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-24368084

RESUMO

The aim of this study was to evaluate the activity of eugenol against the fish pathogen Aeromonas hydrophila and eugenol's effect on hematological and natural immune parameters in silver catfish (Rhamdia quelen). In vitro, eugenol showed weak activity against A. hydrophila, but in vivo, at a subinhibitory concentration (10 mg L(-1)), it promoted survival in infected silver catfish. Eugenol (50 µg mL(-1)) reduced the hemolytic activity of A. hydrophila supernatant in vitro in fish erythrocytes. Subjecting catfish to eugenol baths (5 and 10 mg L(-1)) for five days did not alter the hematological and immunological parameters studied in this work. Based on these results, eugenol can be used to treat or prevent bacterial diseases in fish.


Assuntos
Aeromonas hydrophila/efeitos dos fármacos , Anti-Infecciosos/farmacologia , Peixes-Gato/imunologia , Eugenol/farmacologia , Animais , Peixes-Gato/sangue , Peixes-Gato/microbiologia
20.
BMC Vet Res ; 9: 207, 2013 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-24119995

RESUMO

BACKGROUND: The pathogenesis of Haemophilus parasuis depends on the bacterium's ability to interact with endothelial cells and invade adjacent tissues. In this study, we investigated the abilities of eight H. parasuis reference strains belonging to serovars 1, 2, 4, 5, 7, 9, 10 and 13 to adhere to and invade porcine aortic endothelial cells (AOC-45 cell line). RESULTS: The strains belonging to serovars 1, 2 and 5 were able to attach at high rates between 60 and 240 min of incubation, and serovars 4, 7 and 13 had moderate attachment rates; however, the strains belonging to serovars 9 and 10 had low adherence at all time points. Strong adherence was observed by scanning electron microscopy for the strains of serovars 5 and 4, which had high and moderate numbers, respectively, of H. parasuis cells attached to AOC-45 cells after 240 min of incubation. The highest invasiveness was reached at 180 min by the serovar 4 strain, followed by the serovar 5 strain at 240 min. The invasion results differed substantially depending on the strain. CONCLUSION: The reference strains of H. parasuis serovars 1, 2, 4 and 5 exhibited high adhesion and invasion levels to AOC-45 porcine aorta endothelial cells, and these findings could aid to better explain the pathogenesis of the disease caused by these serovars.


Assuntos
Aorta , Aderência Bacteriana/fisiologia , Células Endoteliais/microbiologia , Haemophilus parasuis/fisiologia , Animais , Linhagem Celular , Células Endoteliais/ultraestrutura , Haemophilus parasuis/ultraestrutura , Suínos
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