RESUMO
Nocardiosis has caused high mortalities among fish cultures; however, the effects of Nocardia infections in the fish gastrointestinal microbiota are unknown. In this research, tilapia was infected with Nocardia sp., to analyze the effect of infection on the gastrointestinal microbiota. Tilapia infected with Nocardia sp. reported a 46 % survival (100 % in non-infected). Moreover, the infection caused severe damage to the stomach microbiota, with a loss of diversity and a significant increase of Proteobacteria (94.8 %), resulting in a negative correlation network between Proteobacteria and other important phyla. Nocardia sp. is an emerging pathogen capable of inducing dysbiosis and causing significant mortalities.
Assuntos
Microbioma Gastrointestinal , Nocardiose , Nocardia , Tilápia , Animais , Disbiose , Nocardiose/veterinária , Nocardiose/microbiologiaRESUMO
This work aimed to determine the presence of bacterial pathogens in fish with a clinical picture suggestive of infectious disease in Nile tilapia reared in Chiapas, Mexico. Blood and viscera samples were taken from healthy and diseased animals from commercial farms. Clinical and pathological examinations of each individual were performed and samples were collected for bacteriological studies. The bacterial isolates were identified and characterized by culture, biochemical tests, antibiogram, challenge tests and 16S rRNA sequencing. Staphylococcus haemolyticus and Providencia vermicola were isolated from various diseased organisms. The clinical picture caused by Staphylococcus haemolyticus was characterized by appetite disorders, neurological signs, nodulation or ulceration in different areas and congestion or enlargement of internal organs. Providenciosis in juvenile specimens caused a characteristic picture of hemorrhagic septicemia. Challenge tests performed in healthy organisms revealed that both infections caused higher mortality rates in fish (p < 0.05) compared with non-infected specimens, with 100% survival. There was 100% mortality for animals infected with P. vermicola after three days post infection and 45% for those infected with S. haemolyticus. The isolation and identification of two pathogens involved in an infection process were achieved and cataloged as potential causal agents of disease outbreaks in tilapia farming in Mexico. This is the first report of possible bacterial infection caused by S. haemolyticus and P. vermicola in tilapia farms, which are two uncommon but potentially emerging pathogens for the species.
RESUMO
Assessment of fish health is one of the efforts of farmers in minimizing losses due to disease. Rapid tests on fish health can be done through blood observations. This study aimed to determine the blood glucose profile of koi carp due to ectoparasite infestation from the level of blood glucose. The results showed that reported parasites from Blitar's koi carp were Trichodina, Dactylogyrus, Gyrodactylus, Myxobolus, Thelohanellus, Ichthyophthirius, and Argulus. Trichodina showed the highest prevalence (100%) in this case while Thelohanellus was the highest intensity level (93.8±16.3). The results of blood glucose level measurement based on parasite infestation levels showed no significant difference (p>0.05) though the health problems caused by parasites in light, medium or heavy infestation. This research also indicated that the blood glucose profile could be used as a rapid method to detect fish health caused by parasites. We suggest that other variables such as nutritional status, life stage or feeding must be conducted to ensure the glucose role in parasite identification as a rapid method for the future work.(AU)
A avaliação da saúde dos peixes é um dos esforços dos produtores para minimizar as perdas por doenças. Testes rápidos de saúde de peixes podem ser feitos por meio de observações de sangue. Este estudo teve como objetivo determinar o perfil glicêmico de peixes "koi", devido à infestação de ectoparasitos a partir do nível de glicemia. Os resultados mostraram que os parasitas relatados de peixes "koi" de Blitar foram Trichodina, Dactylogyrus, Gyrodactylus, Myxobolus, Thelohanellus, Ichthyophthirius e Argulus. Trichodina apresentou a maior prevalência (100%) neste caso, enquanto Thelohanellus foi o maior em nível de intensidade (93,8±16,3). Os resultados da medição do nível de glicose no sangue, com base nos níveis de infestação parasitária, não mostraram diferença significativa (p>0,05), apesar dos problemas de saúde causados ââpor parasitas em infestação leve, média ou pesada. Esta pesquisa também indicou que o perfil de glicose no sangue pode ser usado como um método rápido, para detectar a saúde dos peixes causada por parasitas. Este estudo também sugere que outras variáveis, como estado nutricional, estágio de vida ou alimentação, devem ser conduzidas para garantir o papel da glicose na identificação do parasita como um método rápido para trabalhos futuros.(AU)
Assuntos
Glicemia/análise , Carpas/fisiologia , Ectoparasitoses/veterinária , IndonésiaRESUMO
Epitheliocystis is a fish disease with recorded in increasing numbers globally. Here we show that (a) pollution-exposed wild marine fishes have higher infection prevalence than nonexposed individuals from reference sites, suggesting that anthropogenic pollution predisposes individuals to this disease in natural systems, (b) the effect of pollution on infection status did not vary significantly between two sympatric fish species, and (c) infected and noninfected individuals from both species did not differ significantly in selected immune and general-health parameters, a result that deserves further study with increased sample sizes.
Assuntos
Doenças dos Peixes , Peixes , Animais , Poluição Ambiental , Doenças dos Peixes/epidemiologiaRESUMO
Bacterial diseases are common in ornamental fish, more frequently associated with ubiquitous bacteria from the aquarium environment. The disease can lead to fish mortality and cause high economic losses if not rapidly controlled. The aim of this study was to identify the main causative bacterial agents of infection in ornamental fish with different clinical signs. A total of 126 freshwater fish, from 12 families and 38 species, with clinical signs were collected in a wholesaler in São Paulo, SP, Brazil. Samples were taken from the eye, skin ulcers, kidneys, and gills, plated on MacConkey, CHROMagar Orientation, and blood agar and incubated under aerobic and anaerobic conditions. Bacterial identification was performed by MALDI-TOF mass spectrometry. From the 126 studied animals, 112 were positive for bacterial isolation. Among the positive animals, 32.1% presented infection caused by a single bacterial species, while in the remaining 67.9%, two to six different bacterial species were identified. A total of 259 bacterial strains were obtained and classified among 46 bacterial species. The species of higher frequency were Aeromonas veronii (26.3%), Aeromonas hydrophilla (16.2%), Shewanella putrefaciens (7.3%), Citrobacter freundii (8.1%), Vibrio albensis (5.8%), and Klebsiella pneumoniae (4.2%). MALDI-TOF MS showed to be a rapid method for diagnosis of bacterial disease outbreaks in ornamental fish establishments.
Assuntos
Aeromonas , Doenças dos Peixes , Animais , Brasil , Peixes , Água Doce , HumanosRESUMO
Streptococcus agalactiae is an invasive multi-host pathogen that causes invasive diseases mainly in newborns, elderly, and individuals with underlying health complications. In fish, S. agalactiae causes streptococcosis, which is characterized by septicemia and neurological signs, and leads to great economic losses to the fish farming industry worldwide. These bacteria can be classified into different serotypes based on capsular antigens, and into different sequence types (ST) based on multilocus sequence typing (MLST). In 2015, serotype III ST283 was identified to be associated with a foodborne invasive disease in non-pregnant immunocompetent humans in Singapore, and the infection was related to raw fish consumption. In addition, a serotype III strain isolated from tilapia in Brazil has been reported to be resistant to five antibiotic classes. This specific serotype can serve as a reservoir of resistance genes and pose a serious threat to public health. Thus, new approaches for the control and treatment of S. agalactiae infections are needed. In the present study, 24 S. agalactiae serotype III complete genomes, isolated from human and fish hosts, were compared. The core genome was identified, and, using bioinformatics tools and subtractive criteria, five proteins were identified as potential drug targets. Furthermore, 5,008 drug-like natural compounds were virtually screened against the identified targets. The ligands with the best binding properties are suggested for further in vitro and in vivo analysis.
RESUMO
We determined whether thymol supplementation of would minimize the negative effects of Aeromonas hydrophila infection on branchial energy metabolism, weight loss and mortality in grass carp (Ctenopharyngodon idella). We found that the infected fish all died, while 62.5% of those supplemented with 100 mg/kg thymol survived. Cytosolic and mitochondrial creatine kinase (CK) activities, as well as adenylate kinase (AK) and pyruvate kinase (PK) activities were significant lower in gills of A. hydrophila-infected fish than those of the control group, and adenosine triphosphate (ATP) levels were significant lower in the infected group. Finally, branchial reactive oxygen species (ROS) were significant higher in A. hydrophila-infected fish than in the control group. Supplementation with 100 and 300 mg thymol/kg diet prevented inhibition of branchial cytosolic and mitochondrial CK activities caused by infection, and also inhibited the reduction of branchial ATP levels. Supplementation with 100, 200 and 300 mg thymol/kg prevented the inhibition of branchial AK and PK activities induced by aeromonosis. Supplementation of 100 mg thymol/kg prevented weight loss after A. hydrophila infection. These data suggest that supplementation with 100 mg thymol/kg exerts potent bactericidal properties and augments longevity. Supplementation at all concentrations of thymol prevented A. hydrophila-induced branchial bioenergetics; nevertheless, higher concentrations were associated with side-effects.
Assuntos
Aeromonas hydrophila/fisiologia , Doenças dos Peixes/microbiologia , Infecções por Bactérias Gram-Negativas/veterinária , Timol/administração & dosagem , Trifosfato de Adenosina/metabolismo , Ração Animal/análise , Animais , Carpas/crescimento & desenvolvimento , Carpas/metabolismo , Carpas/microbiologia , Suplementos Nutricionais/análise , Metabolismo Energético/efeitos dos fármacos , Doenças dos Peixes/metabolismo , Doenças dos Peixes/mortalidade , Doenças dos Peixes/fisiopatologia , Infecções por Bactérias Gram-Negativas/metabolismo , Infecções por Bactérias Gram-Negativas/microbiologia , Infecções por Bactérias Gram-Negativas/mortalidade , Espécies Reativas de Oxigênio/metabolismoRESUMO
The aim of this study is to report the occurrence of Lymphocystivirus in Brazilian ornamental fish. From 25 ornamental fish species submitted for molecular diagnosis, only one sample (Pomacanthus imperator) was positive, and its viral nucleotide sequence obtained clustered with sequences of genotype VII. To our knowledge, this is the first report on the genetic characterization of Lymphocystivirus in Brazil.
Assuntos
Infecções por Vírus de DNA/veterinária , Doenças dos Peixes/virologia , Peixes/virologia , Iridoviridae/genética , Animais , Brasil , Comércio , Pesqueiros , Genótipo , Iridoviridae/isolamento & purificação , FilogeniaRESUMO
Bacterial diseases are one of the major problems in freshwater fish culture and have been linked to significant losses and high mortality rate. In this study, Nile tilapia Oreochromis niloticus was infected by Providencia rettgeri to evaluate the oxidative stress and antioxidant responses in the fish tissues. Juvenile Nile tilapia was divided into two groups, as follow: control (uninfected) and experimentally infected with 100⯵L of P. rettgeri suspension containing 2.4â¯×â¯107 viable cells/fish, and the liver and kidney tissues were collected on days 7 and 14 post-infection (PI). Liver and kidney ROS and lipid peroxidation levels were high in infected fish on day 14 PI compared to control group, while superoxide dismutase activity was lower in liver (days 7 and 14 PI) and kidney (day 14 PI) compared to their respective control groups. Liver and kidney antioxidant capacity against peroxyl radicals, non-proteic, and proteic thiols levels was lower in infected tilapia on day 14 PI compared to control group. Based on these results, P. rettgeri infection may elicit oxidative damage via increased ROS production, decreased ROS elimination and inhibits enzymatic and non-enzymatic antioxidant defense systems; which may contribute directly to disease pathophysiology of infected animals.
Assuntos
Antioxidantes/metabolismo , Ciclídeos/metabolismo , Doenças dos Peixes/metabolismo , Estresse Oxidativo , Providencia/patogenicidade , Animais , Brasil , Ciclídeos/imunologia , Ciclídeos/microbiologia , Modelos Animais de Doenças , Infecções por Enterobacteriaceae/imunologia , Infecções por Enterobacteriaceae/microbiologia , Infecções por Enterobacteriaceae/veterinária , Doenças dos Peixes/imunologia , Doenças dos Peixes/microbiologia , Interações Hospedeiro-Patógeno/fisiologia , Rim/metabolismo , Peroxidação de Lipídeos , Fígado/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Tilápia/microbiologiaRESUMO
Pseudomonas aeruginosa is a Gram-negative opportunistic bacterial pathogen in aquaculture systems being associated to extensive liver damage caused by oxidative stress in both marine and freshwater fish. Dietary supplementation with natural antioxidants is considered a rational strategy to prevent hepatic diseases involved with oxidative stress. Bio-residues resulting from the wine industry, such as grape pomace, are potential sources of bioactive phenolic compounds that can be applied as supplement for animal production. Thus, the aim of this study was to evaluate whether dietary supplementation with grape pomace flour (GPF) was able to prevent or reduce the hepatic oxidative damage of grass carp, Ctenopharyngodon idella, experimentally infected by P. aeruginosa. Hepatic reactive oxygen species (ROS), metabolites of nitric oxide (NOx), thiobarbituric acid reactive substances, and protein carbonylation levels were higher in fish experimentally infected by P. aeruginosa compared to the control group. Hepatic superoxide dismutase and catalase activities and antioxidant capacity against peroxyl radical levels were also higher in fish experimentally infected by P. aeruginosa compared to the control group. Dietary supplementation with 300â¯mg/kg GPF prevented all alterations elicited by P. aeruginosa, with the exception of protein carbonylation levels. The dietary supplementation with 150â¯mg/kg GPF was not able to avoid alteration of the analyzed variables, being results similar to those infected (positive control). Based on these results, dietary supplementation with 300â¯mg/kg GPF prevented P. aeruginosa-induced liver damage in grass carp, and this protective effect occurred through prevention on excessive ROS and NOx production, as well as via prevention of lipid damage. Moreover, 300â¯mg/kg GPF exerted its hepatoprotective effects by improving enzymatic and non-enzymatic antioxidant defense system. In summary, this supplementation can be an interesting approach to prevent P. aeruginosa-induced liver damage.
Assuntos
Antioxidantes/administração & dosagem , Dietoterapia/métodos , Doenças dos Peixes/terapia , Hepatopatias/veterinária , Estresse Oxidativo , Infecções por Pseudomonas/veterinária , Vitis/química , Animais , Carpas , Catalase/análise , Doenças dos Peixes/patologia , Farinha , Hepatopatias/patologia , Hepatopatias/terapia , Óxido Nítrico/análise , Carbonilação Proteica , Infecções por Pseudomonas/patologia , Infecções por Pseudomonas/terapia , Espécies Reativas de Oxigênio/análise , Superóxido Dismutase/análise , Substâncias Reativas com Ácido Tiobarbitúrico/análise , Resultado do TratamentoRESUMO
Aquarium ornamental pet fish constitute a major segment in the pet industry, with the United States, Europe, and Japan dominating the market. There are approximately 1,500 marine fish species and over 4,500 freshwater fish species commercialized as aquarium ornamental pet fish. Fish are the fourth most common pet present in Brazilian homes. In Brazil, aquarium ornamental pet fish can be marketed and distributed from different parts of the Brazilian territory and the world. Commercialization and circulation of living animals without the use of adequate prophylactic management procedures enables dissemination of a number of agents responsible for infectious diseases. Aquarium pet fish can also carry pathogenic agents, of bacterial, viral, fungal, or parasitic etiology, that may have a zoonotic feature endangering the persons handling the animals. This review presents the main pathogenic infectious agents of bacterial, viral, and fungal etiology that affect aquarium pet fish, as well as the prevention and control measures to ensure sanitary excellence in this segment.(AU)
Peixes ornamentais de aquário representam um grande segmento no mercado de animais de estimação, no qual Estados Unidos, Europa e Japão dominam. São aproximadamente 1.500 espécies de peixes marinhos e em torno de 4.500 de espécies de água doce comercializados com fins ornamentais. O peixe é a quarta espécie mais comum nos domicílios brasileiros. Peixes ornamentais de aquário são comercializados e distribuídos em diferentes partes do território nacional e do mundo. O comércio e circulação de animais vivos sem o uso de procedimentos de manejo profilático adequados possibilita a disseminação de inúmeros agentes patogênicos. Peixes ornamentais de aquário carreiam consigo agentes patogênicos de etiologia bacteriana, viral, fúngica e parasitária, sendo alguns de caráter zoonótico colocando em risco pessoas que os manipulam. O objetivo desta revisão é apresentar os principais agentes infeciosos patogênicos - de natureza bacteriana, viral e fúngica - que acometem peixes ornamentais de aquário, bem como os métodos de prevenção e controle que permitam excelência no segmento.(AU)
Assuntos
Animais , Doenças Transmissíveis/reabilitação , Peixes/microbiologia , Peixes/virologiaRESUMO
Aquarium ornamental pet fish constitute a major segment in the pet industry, with the United States, Europe, and Japan dominating the market. There are approximately 1,500 marine fish species and over 4,500 freshwater fish species commercialized as aquarium ornamental pet fish. Fish are the fourth most common pet present in Brazilian homes. In Brazil, aquarium ornamental pet fish can be marketed and distributed from different parts of the Brazilian territory and the world. Commercialization and circulation of living animals without the use of adequate prophylactic management procedures enables dissemination of a number of agents responsible for infectious diseases. Aquarium pet fish can also carry pathogenic agents, of bacterial, viral, fungal, or parasitic etiology, that may have a zoonotic feature endangering the persons handling the animals. This review presents the main pathogenic infectious agents of bacterial, viral, andfungal etiology that affect aquarium pet fish, as well as the prevention and control measures to ensure sanitary excellence in this segment.
Peixes ornamentais de aquário representam um grande segmento no mercado de animais de estimação, no qual Estados Unidos, Europa e Japão dominam. São aproximadamente 1.500 espécies de peixes marinhos e em torno de 4.500 de espécies de água doce comercializados com fins ornamentais. O peixe é a quarta espécie mais comum nos domicílios brasileiros. Peixes ornamentais de aquário são comercializados e distribuídos em diferentes partes do território nacional e do mundo. O comércio e circulação de animais vivos sem o uso de procedimentos de manejo profilático adequados possibilita a disseminação de inúmeros agentes patogênicos. Peixes ornamentais de aquário carreiam consigo agentes patogênicos de etiologia bacteriana, viral, fúngica e parasitária, sendo alguns de caráter zoonótico colocando em riscopessoas que os manipulam. O objetivo desta revisão é apresentar os principais agentes infeciosos patogênicos - de natureza bacteriana, viral e fúngica - que acometem peixes ornamentais de aquário, bem como os métodos de prevenção e controle que permitam excelência no segmento.
RESUMO
Aquarium ornamental pet fish constitute a major segment in the pet industry, with the United States, Europe, and Japan dominating the market. There are approximately 1,500 marine fish species and over 4,500 freshwater fish species commercialized as aquarium ornamental pet fish. Fish are the fourth most common pet present in Brazilian homes. In Brazil, aquarium ornamental pet fish can be marketed and distributed from different parts of the Brazilian territory and the world. Commercialization and circulation of living animals without the use of adequate prophylactic management procedures enables dissemination of a number of agents responsible for infectious diseases. Aquarium pet fish can also carry pathogenic agents, of bacterial, viral, fungal, or parasitic etiology, that may have a zoonotic feature endangering the persons handling the animals. This review presents the main pathogenic infectious agents of bacterial, viral, andfungal etiology that affect aquarium pet fish, as well as the prevention and control measures to ensure sanitary excellence in this segment.
Peixes ornamentais de aquário representam um grande segmento no mercado de animais de estimação, no qual Estados Unidos, Europa e Japão dominam. São aproximadamente 1.500 espécies de peixes marinhos e em torno de 4.500 de espécies de água doce comercializados com fins ornamentais. O peixe é a quarta espécie mais comum nos domicílios brasileiros. Peixes ornamentais de aquário são comercializados e distribuídos em diferentes partes do território nacional e do mundo. O comércio e circulação de animais vivos sem o uso de procedimentos de manejo profilático adequados possibilita a disseminação de inúmeros agentes patogênicos. Peixes ornamentais de aquário carreiam consigo agentes patogênicos de etiologia bacteriana, viral, fúngica e parasitária, sendo alguns de caráter zoonótico colocando em riscopessoas que os manipulam. O objetivo desta revisão é apresentar os principais agentes infeciosos patogênicos - de natureza bacteriana, viral e fúngica - que acometem peixes ornamentais de aquário, bem como os métodos de prevenção e controle que permitam excelência no segmento.
RESUMO
Aquarium ornamental pet fish constitute a major segment in the pet industry, with the United States, Europe, and Japan dominating the market. There are approximately 1,500 marine fish species and over 4,500 freshwater fish species commercialized as aquarium ornamental pet fish. Fish are the fourth most common pet present in Brazilian homes. In Brazil, aquarium ornamental pet fish can be marketed and distributed from different parts of the Brazilian territory and the world. Commercialization and circulation of living animals without the use of adequate prophylactic management procedures enables dissemination of a number of agents responsible for infectious diseases. Aquarium pet fish can also carry pathogenic agents, of bacterial, viral, fungal, or parasitic etiology, that may have a zoonotic feature endangering the persons handling the animals. This review presents the main pathogenic infectious agents of bacterial, viral, andfungal etiology that affect aquarium pet fish, as well as the prevention and control measures to ensure sanitary excellence in this segment.
Peixes ornamentais de aquário representam um grande segmento no mercado de animais de estimação, no qual Estados Unidos, Europa e Japão dominam. São aproximadamente 1.500 espécies de peixes marinhos e em torno de 4.500 de espécies de água doce comercializados com fins ornamentais. O peixe é a quarta espécie mais comum nos domicílios brasileiros. Peixes ornamentais de aquário são comercializados e distribuídos em diferentes partes do território nacional e do mundo. O comércio e circulação de animais vivos sem o uso de procedimentos de manejo profilático adequados possibilita a disseminação de inúmeros agentes patogênicos. Peixes ornamentais de aquário carreiam consigo agentes patogênicos de etiologia bacteriana, viral, fúngica e parasitária, sendo alguns de caráter zoonótico colocando em riscopessoas que os manipulam. O objetivo desta revisão é apresentar os principais agentes infeciosos patogênicos - de natureza bacteriana, viral e fúngica - que acometem peixes ornamentais de aquário, bem como os métodos de prevenção e controle que permitam excelência no segmento.
RESUMO
Aquarium ornamental pet fish constitute a major segment in the pet industry, with the United States, Europe, and Japan dominating the market. There are approximately 1,500 marine fish species and over 4,500 freshwater fish species commercialized as aquarium ornamental pet fish. Fish are the fourth most common pet present in Brazilian homes. In Brazil, aquarium ornamental pet fish can be marketed and distributed from different parts of the Brazilian territory and the world. Commercialization and circulation of living animals without the use of adequate prophylactic management procedures enables dissemination of a number of agents responsible for infectious diseases. Aquarium pet fish can also carry pathogenic agents, of bacterial, viral, fungal, or parasitic etiology, that may have a zoonotic feature endangering the persons handling the animals. This review presents the main pathogenic infectious agents of bacterial, viral, andfungal etiology that affect aquarium pet fish, as well as the prevention and control measures to ensure sanitary excellence in this segment.
Peixes ornamentais de aquário representam um grande segmento no mercado de animais de estimação, no qual Estados Unidos, Europa e Japão dominam. São aproximadamente 1.500 espécies de peixes marinhos e em torno de 4.500 de espécies de água doce comercializados com fins ornamentais. O peixe é a quarta espécie mais comum nos domicílios brasileiros. Peixes ornamentais de aquário são comercializados e distribuídos em diferentes partes do território nacional e do mundo. O comércio e circulação de animais vivos sem o uso de procedimentos de manejo profilático adequados possibilita a disseminação de inúmeros agentes patogênicos. Peixes ornamentais de aquário carreiam consigo agentes patogênicos de etiologia bacteriana, viral, fúngica e parasitária, sendo alguns de caráter zoonótico colocando em riscopessoas que os manipulam. O objetivo desta revisão é apresentar os principais agentes infeciosos patogênicos - de natureza bacteriana, viral e fúngica - que acometem peixes ornamentais de aquário, bem como os métodos de prevenção e controle que permitam excelência no segmento.
RESUMO
Dawestrema cycloancistrium is the main ectoparasite causing mortality in fingerlings of pirarucu (Arapaima gigas) in Amazonian aquaculture. Very little is known about the D. cycloancistrium reproductive index and appropriate methods of collecting eggs for investigation. This study aimed to determine the oviposition rate of D. cycloancistrium. To achieve this aim, two egg quantification methods were tested: the estimative method (ME) and the total counting method (MT). Compared with the MT, the ME overestimated the number of eggs counted, which were 2943.5 ± 2840.6 and 1041.5 ± 533 eggs, and the oviposition rate, which was 80.1 ± 58.7 and 31.4 ± 16.4 eggs/parasite/day, for ME and MT, respectively. These results show that for studies quantifying D. cycloancistrium eggs, the total eggs in the sample must be counted, as the estimates made using subsamples are not representative. Using the MT, the oviposition rate for D. cycloancistrium was determined to be 31.4 ± 16.4 eggs per adult parasite per day. The present study demonstrates the egg production capacity of a monogenean species parasite of A. gigas, providing basic biological data for D. cycloancistrium.
Assuntos
Contagem de Células/métodos , Doenças dos Peixes/parasitologia , Oviposição , Óvulo/citologia , Trematódeos/fisiologia , Infecções por Trematódeos/veterinária , Animais , Peixes , Cinética , Reprodução , Trematódeos/química , Infecções por Trematódeos/parasitologiaRESUMO
Nanoencapsulated Melaleuca alternifolia essential oil (tea tree oil, TTO) is a natural alternative treatment, with 100% therapeutic efficacy in fish experimentally infected with Pseudomonas aeruginosa, and has also potent protective effects linked with antioxidant properties. However, the pathways responsible for the antioxidant capacity remain unknown. Thus, this study evaluated whether the inhibition of seric xanthine oxidase (XO) activity can be considered a pathway involved in the antioxidant capacity of nanoencapsulated TTO in fish experimentally infected with P. aeruginosa. Seric samples from fish infected with P. aeruginosa showed increased XO activity, as well as increased uric acid and reactive oxygen species (ROS) levels. In contrast, the prophylactic treatment with nanoencapsulated TTO prevented these infection-induced alterations. Based on the evidence obtained, the upregulation of seric XO activity induced pro-oxidative effects in the serum of fish experimentally infected with P. aeruginosa, due to excessive formation of uric acid, which stimulates the release of ROS. This treatment was able to prevent the upregulated seric XO activity and, consequently, the excessive formation of uric acid and ROS. In summary, inhibition of seric XO activity can be considered a pathway involved in the antioxidant capacity of nanoencapsulated TTO in fish experimentally infected with P. aeruginosa.
Assuntos
Antibacterianos/farmacologia , Peixes-Gato , Doenças dos Peixes/tratamento farmacológico , Infecções por Pseudomonas/veterinária , Pseudomonas aeruginosa/efeitos dos fármacos , Óleo de Melaleuca/farmacologia , Animais , Antioxidantes/metabolismo , Doenças dos Peixes/microbiologia , Proteínas de Peixes/antagonistas & inibidores , Proteínas de Peixes/sangue , Nanocápsulas , Infecções por Pseudomonas/tratamento farmacológico , Infecções por Pseudomonas/microbiologia , Xantina Oxidase/antagonistas & inibidores , Xantina Oxidase/sangueRESUMO
It has been recognized that the cholinergic and adenosinergic systems have an essential role in immune and inflammatory responses during bacterial fish pathogens, such as the enzymes acetylcholinesterase (AChE) and adenosine deaminase (ADA), which are responsible for catalysis of the anti-inflammatory molecules acetylcholine (ACh) and adenosine (Ado) respectively. Thus, the aim of this study was to investigate the involvement of the cholinergic and adenosinergic systems on the immune response and inflammatory process in gills of experimentally infected Rhamdia quelen with Streptococcus agalactiae. Acetylcholinesterase activity decreased, while ACh levels increased in gills of infected animals compared to uninfected animals. On the other hand, a significant increase in ADA activity with a concomitant decrease in Ado levels was observed in infected animals compared to uninfected animals. Based on this evidence, we concluded that infection by S. agalactiae in silver catfish alters the cholinergic and adenosinergic systems, suggesting the involvement of AChE and ADA activities on immune and inflammatory responses, regulating the ACh and Ado levels. In summary, the downregulation of AChE activity exerts an anti-inflammatory profile in an attempt to reduce or prevent the tissue damage, while the upregulation of ADA activity exerts a pro-inflammatory profile, contributing to disease pathophysiology.
Assuntos
Doenças dos Peixes/microbiologia , Brânquias/imunologia , Infecções Estreptocócicas/veterinária , Streptococcus agalactiae/imunologia , Acetilcolinesterase/análise , Adenosina Desaminase/análise , Animais , Peixes-Gato , Doenças dos Peixes/imunologia , Brânquias/enzimologia , Brânquias/microbiologia , Inflamação/imunologia , Inflamação/microbiologia , Infecções Estreptocócicas/imunologiaRESUMO
Cytosolic and mitochondrial creatine kinases (CK), through the creatine kinase-phosphocreatine (CK/PCr) system, provide a temporal and spatial energy buffer to maintain cellular energy homeostasis. However, the effects of bacterial infections on the kidney remain poorly understood and are limited only to histopathological analyses. Thus, the aim of this study was to investigate the involvement of cytosolic and mitochondrial CK activities in renal energetic homeostasis in silver catfish experimentally infected with Aeromonas caviae. Cytosolic CK activity decreased in infected animals, while mitochondrial CK activity increased compared to uninfected animals. Moreover, the activity of the sodium-potassium pump (Na+, K+-ATPase) decreased in infected animals compared to uninfected animals. Based on this evidence, it can be concluded that the inhibition of cytosolic CK activity by A. caviae causes an impairment on renal energy homeostasis through the depletion of adenosine triphosphate (ATP) levels. This contributes to the inhibition of Na+, K+-ATPase activity, although the mitochondrial CK activity acted in an attempt to restore the cytosolic ATP levels through a feedback mechanism. In summary, A. caviae infection causes a severe energetic imbalance in infected silver catfish, which may contribute to disease pathogenesis.
Assuntos
Aeromonas caviae/patogenicidade , Peixes-Gato/microbiologia , Creatina Quinase Mitocondrial/metabolismo , Citosol/metabolismo , Metabolismo Energético/fisiologia , Doenças dos Peixes/microbiologia , Infecções por Bactérias Gram-Negativas/veterinária , Rim/metabolismo , Adenosina Trifosfatases/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Brasil , Creatina Quinase/metabolismo , Citosol/enzimologia , Modelos Animais de Doenças , Doenças dos Peixes/patologia , Infecções por Bactérias Gram-Negativas/microbiologia , Infecções por Bactérias Gram-Negativas/patologia , Homeostase , Rim/microbiologia , Rim/patologia , Mitocôndrias/enzimologia , Mitocôndrias/metabolismo , Fosfocreatina/metabolismo , Fosforilação , ATPase Trocadora de Sódio-Potássio/metabolismoRESUMO
This study provides a detailed description and characterization of a strain of Aeromonas dhakensis isolated from a diseased juvenile Piaractus mesopotamicus obtained from the fish farm of the National Center for Continental Fish Research and Conservation (CEPTA/ICMBio), in the state of São Paul, Brazil. Biochemical tests using the VITEK 2 automated bacterial identification system identified the isolate to genus level; however, further molecular analysis of the 16S rRNA, gyrB and rpoD genes showed that the strain belonged to the species A. dhakensis. As expected, the isolated A. dhakensis strain was resistant to ampicillin and ampicillin/sulbactam, as resistance to ampicillin is a typical characteristic of the genus Aeromonas. Resistance to cefoxitin and meropenem was also observed, but the strain was susceptible to most of the tested antibiotics. The isolated strain of A. dhakensis caused acute haemorrhagic septicaemia in experimentally infected P. mesopotamicus, with a fifty per cent lethal dose of 1.14 × 105 CFU/fish. This is the first report of the occurrence of an A. dhakensis strain causing an infection in a fish species of South America, providing important epidemiologic data relating to this important pathogenic species.