RESUMO
BACKGROUND: Bacterial infections are responsible of high economic losses in aquaculture. Mexican golden trout (Oncorhynchus chrysogaster) is a threatened native trout species that has been introduced in aquaculture both for species conservation and breeding for production and for which no studies of bacterial infections have been reported. CASE PRESENTATION: Fish from juvenile stages of Mexican golden trout showed an infectious outbreak in a farm in co-culture with rainbow trout (Oncorhynchus mykiss), showing external puntiform red lesions around the mouth and caudal pedunculus resembling furuncles by Aeromonas spp. and causing an accumulated mortality of 91%. Isolation and molecular identification of bacteria from lesions and internal organs showed the presence of Aeromonas bestiarum, Aeromonas sobria, Plesiomonas shigelloides and Ichthyobodo necator isolated from a single individual. All bacterial isolates were resistant to amoxicillin-clavulanic acid and cefazoline. P. shigelloides was resistant to third generation ß-lactamics. CONCLUSIONS: This is the first report of coinfection by Aeromonas bestiarum, Aeromonas sobria, Plesiomonas shigelloides and Ichthyobodo necator in an individual of Mexican golden trout in co-culture with rainbow trout. Resistance to ß-lactams suggests the acquisition of genetic determinants from water contamination by human- or livestock-associated activities.
Assuntos
Aeromonas , Coinfecção , Doenças dos Peixes , Infecções por Bactérias Gram-Negativas , Oncorhynchus mykiss , Oncorhynchus , Parasitos , Plesiomonas , Aeromonas/genética , Animais , Coinfecção/veterinária , Doenças dos Peixes/microbiologia , Infecções por Bactérias Gram-Negativas/microbiologia , Infecções por Bactérias Gram-Negativas/veterinária , Necator , Plesiomonas/genéticaRESUMO
Early reports accounted for two main genotypes of Piscirickettsia salmonis, a fish pathogen and causative agent of piscirickettsiosis, placing the single isolate EM-90 apart from the prototypic LF-89 and related isolates. In this study, we provide evidence that, contrary to what has been supposed, the EM-90-like isolates are highly prevalent and disseminated across Chilean marine farms. Molecular analysis of 507 P. salmonis field isolates derived from main rearing areas, diverse hosts and collected over 6 years, revealed that nearly 50% of the entire collection were indeed typed as EM-90-like. Interestingly, these isolates showed a marked host preference, being recovered exclusively from Atlantic salmon (Salmo salar) samples. Although both strains produce undistinguishable pathological outcomes, differences regarding growth kinetics and susceptibility to the antibiotics and bactericidal action of serum could be identified. In sum, our results allow to conclude that the EM-90-like isolates represent an epidemiologically relevant group in the current situation of piscirickettsiosis. Based on the consistency between genotype and phenotype exhibited by this strain, we point out the need for genotypic studies that may be as important for the Chilean salmon industry as the continuous surveillance of antimicrobial susceptibility patterns.
Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana , Doenças dos Peixes/epidemiologia , Oncorhynchus , Piscirickettsia/fisiologia , Infecções por Piscirickettsiaceae/veterinária , Salmo salar , Animais , Chile/epidemiologia , Doenças dos Peixes/microbiologia , Genótipo , Piscirickettsia/efeitos dos fármacos , Piscirickettsia/genética , Infecções por Piscirickettsiaceae/epidemiologia , Infecções por Piscirickettsiaceae/microbiologia , Prevalência , Análise de Sequência de DNARESUMO
The influence of weight (W) category of the rainbow trout on processing yield and chemical composition of the entire eviscerated fish and fish fillet was analyzed. A completely randomized design was employed for processing variables (W1 = 300 to 370 g and W2 = 371 to 440) coupled to a 2 x 2 factorial scheme for the chemical composition (W1 and W2 and forms of presentation: fillet and whole eviscerated fish). W1 showed higher yield for entire eviscerated fish (83.00%) and head (13.27%), but a lower yield for the viscera (17.00%), when compared to W2. We did not affect abdominal muscle yield, fillet with or without skin, skin percentage and residues. There were significant differences between W for moisture (W1 = 72.30% and W2 = 71.15%) and lipids (CP1 = 7.96% and CP2 = 9.04%) rates. Fillet moisture contents (73.74%) and crude protein (19.05%) were higher (p 0.01) than for entire eviscerated fish (69.71% and 17.81%, respectively). Ash (2.15%) and lipid (10.48%) rates were higher (p 0.01) for entire fish when compared to those of fillets (1.16% and 6.52%, respectively). The slaughter of fish weighing between 300 and 370 g and their fillets are more adequate for the market.(AU)
O objetivo deste trabalho foi analisar a influência da categoria de peso (CP) da truta arco-íris sobre o rendimento do processamento e a composição centesimal do peixe inteiro eviscerado e do filé. O delineamento foi inteiramente casualizado para as variáveis do processamento (CP1 = 300 a 370 g e CP2 = 371 a 440 g) e em esquema fatorial 2 x 2 para composição centesimal (CP1 e CP2 e formas de apresentação (filé e peixe inteiro eviscerado). CP1 apresentou superior rendimento do peixe inteiro eviscerado (83,00%) e cabeça (13,27%), porém inferior para vísceras (17,00%), quando comparados à CP2. A CP não influenciou no rendimento dos músculos abdominais, filé com pele e sem pele, porcentagem de pele e resíduos. Houve diferenças significativas entre as CP para os teores de umidade (CP1 = 72,30% e CP2 = 71,15%) e lipídios (CP1 = 7,96% e CP2 = 9,04%). A umidade (73,74%) e a proteína bruta (19,05%) dos filés foram superiores (p 0,01) do que para peixes inteiros eviscerados (69,71% e 17,81%, respectivamente). Teores de cinzas (2,15%) e lipídios (10,48%) foram superiores (p 0,01) para peixes inteiros em relação aos filés (1,16% e 6,52%, respectivamente). Sugere-se o abate dos peixes com peso entre 300 a 370 g e a apresentação em filé como mais adequada para o consumo.(AU)
Assuntos
Animais , Oncorhynchus/anatomia & histologia , Oncorhynchus/crescimento & desenvolvimento , Oncorhynchus/fisiologia , Peso Corporal/fisiologiaRESUMO
The influence of weight (W) category of the rainbow trout on processing yield and chemical composition of the entire eviscerated fish and fish fillet was analyzed. A completely randomized design was employed for processing variables (W1 = 300 to 370 g and W2 = 371 to 440) coupled to a 2 x 2 factorial scheme for the chemical composition (W1 and W2 and forms of presentation: fillet and whole eviscerated fish). W1 showed higher yield for entire eviscerated fish (83.00%) and head (13.27%), but a lower yield for the viscera (17.00%), when compared to W2. We did not affect abdominal muscle yield, fillet with or without skin, skin percentage and residues. There were significant differences between W for moisture (W1 = 72.30% and W2 = 71.15%) and lipids (CP1 = 7.96% and CP2 = 9.04%) rates. Fillet moisture contents (73.74%) and crude protein (19.05%) were higher (p 0.01) than for entire eviscerated fish (69.71% and 17.81%, respectively). Ash (2.15%) and lipid (10.48%) rates were higher (p 0.01) for entire fish when compared to those of fillets (1.16% and 6.52%, respectively). The slaughter of fish weighing between 300 and 370 g and their fillets are more adequate for the market.
O objetivo deste trabalho foi analisar a influência da categoria de peso (CP) da truta arco-íris sobre o rendimento do processamento e a composição centesimal do peixe inteiro eviscerado e do filé. O delineamento foi inteiramente casualizado para as variáveis do processamento (CP1 = 300 a 370 g e CP2 = 371 a 440 g) e em esquema fatorial 2 x 2 para composição centesimal (CP1 e CP2 e formas de apresentação (filé e peixe inteiro eviscerado). CP1 apresentou superior rendimento do peixe inteiro eviscerado (83,00%) e cabeça (13,27%), porém inferior para vísceras (17,00%), quando comparados à CP2. A CP não influenciou no rendimento dos músculos abdominais, filé com pele e sem pele, porcentagem de pele e resíduos. Houve diferenças significativas entre as CP para os teores de umidade (CP1 = 72,30% e CP2 = 71,15%) e lipídios (CP1 = 7,96% e CP2 = 9,04%). A umidade (73,74%) e a proteína bruta (19,05%) dos filés foram superiores (p 0,01) do que para peixes inteiros eviscerados (69,71% e 17,81%, respectivamente). Teores de cinzas (2,15%) e lipídios (10,48%) foram superiores (p 0,01) para peixes inteiros em relação aos filés (1,16% e 6,52%, respectivamente). Sugere-se o abate dos peixes com peso entre 300 a 370 g e a apresentação em filé como mais adequada para o consumo.
Assuntos
Animais , Oncorhynchus/anatomia & histologia , Oncorhynchus/crescimento & desenvolvimento , Oncorhynchus/fisiologia , Peso Corporal/fisiologiaRESUMO
Loma salmonae, an obligate intracellular microsporidian parasite, is the causal agent of microsporidial gill disease of salmon (MGDS), characterized by the production, growth and eventual rupture of spore-filled xenomas. MGDS in farmed chinook salmon remains occult until xenoma rupture, at which time the infected fish respond with intense branchitis and high rates of mortality. The present study showed that in experimentally infected fish the rate of change of xenoma diameter could be modelled through regression analysis, particularly through the period of 4-9 weeks post-infection, yielding the predictive equation: xenoma diameter=-42.9 microns +15.3 microns x (number of weeks post-infection). This provides a tool for diagnosticians to predict the time to xenoma rupture and hence to the initiation of the clinical phase of MGDS.
Assuntos
Doenças dos Peixes/parasitologia , Brânquias/parasitologia , Microsporídios/crescimento & desenvolvimento , Microsporidiose/veterinária , Oncorhynchus/parasitologia , Infecções Protozoárias em Animais/parasitologia , Animais , Doenças dos Peixes/patologia , Doenças dos Peixes/transmissão , Brânquias/patologia , Microsporidiose/parasitologia , Microsporidiose/patologia , Infecções Protozoárias em Animais/patologia , Organismos Livres de Patógenos EspecíficosRESUMO
The annual global production of farmed salmon has increased by a factor of 40 during the past two decades. Salmon from farms in northern Europe, North America, and Chile are now available widely year-round at relatively low prices. Salmon farms have been criticized for their ecological effects, but the potential human health risks of farmed salmon consumption have not been examined rigorously. Having analyzed over 2 metric tons of farmed and wild salmon from around the world for organochlorine contaminants, we show that concentrations of these contaminants are significantly higher in farmed salmon than in wild. European-raised salmon have significantly greater contaminant loads than those raised in North and South America, indicating the need for further investigation into the sources of contamination. Risk analysis indicates that consumption of farmed Atlantic salmon may pose health risks that detract from the beneficial effects of fish consumption.
Assuntos
Ração Animal , Poluentes Ambientais/análise , Pesqueiros , Contaminação de Alimentos , Hidrocarbonetos Clorados/análise , Oncorhynchus , Salmo salar , Análise de Variância , Ração Animal/análise , Ração Animal/toxicidade , Animais , Dieldrin/análise , Dieldrin/toxicidade , Dieta , Dioxinas/análise , Dioxinas/toxicidade , Poluentes Ambientais/toxicidade , Europa (Continente) , Produtos Pesqueiros/análise , Produtos Pesqueiros/toxicidade , Rotulagem de Alimentos , Humanos , Hidrocarbonetos Clorados/toxicidade , América do Norte , Política Nutricional , Oncorhynchus keta , Oncorhynchus kisutch , Bifenilos Policlorados/análise , Bifenilos Policlorados/toxicidade , Medição de Risco , América do Sul , Toxafeno/análise , Toxafeno/toxicidade , Estados Unidos , United States Environmental Protection Agency , United States Food and Drug AdministrationRESUMO
The complete sequence of the mitochondrial genome of Chinook salmon, Oncorhynchus tshawytscha, has been determined. The circular genome consisting of 16,644 base pairs encodes thirteen proteins, the 12S and 16S ribosomal RNAs, and 22 transfer RNAs. These genes are ordered in the same way as most other vertebrates. The nucleotide and amino acid sequences of the ribosomal RNAs and the thirteen protein-coding genes were compared with those of other salmonids such as Oncorhynchus mykiss, Salmo salar, Salvelinus fontinalis, Salvelinus alpinus and Coregonus lavaretus. The sequence features of the control region (D-loop), the origin of L-strand replication and a putative peptide codified by the 16S mitochondrial RNA are described and discussed.
Assuntos
DNA Mitocondrial/genética , Genoma , Oncorhynchus/genética , Animais , Código Genético/genética , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , RNA Ribossômico/genética , RNA Ribossômico 16S/genética , RNA de Transferência/análise , Análise de Sequência de DNA , Análise de Sequência de ProteínaRESUMO
The complete sequence of the mitochondrial genome of Chinook salmon, Oncorhynchus tshawytscha, has been determined. The circular genome consisting of 16,644 base pairs encodes thirteen proteins, the 12S and 16S ribosomal RNAs, and 22 transfer RNAs. These genes are ordered in the same way as most other vertebrates. The nucleotide and amino acid sequences of the ribosomal RNAs and the thirteen protein-coding genes were compared with those of other salmonids such as Oncorhynchus mykiss, Salmo salar, Salvelinus fontinalis, Salvelinus alpinus and Coregonus lavaretus. The sequence features of the control region (D-loop), the origin of L-strand replication and a putative peptide codified by the 16S mitochondrial RNA are described and discussed
Assuntos
Animais , DNA Mitocondrial , Genoma , Oncorhynchus , Código Genético , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , RNA Ribossômico 16S , RNA de Transferência , Análise de Sequência de DNARESUMO
Located along the ventral midline of the neural tube, the floor plate (FP) performs an essential role in central nervous system development, especially in the patterning of the ventral region of the neural tube and axonal guidance. Several studies have been directed to the identification of molecules mediating some of the functions of the FP. Most of the models proposed for floor plate actions involve contact-mediated- and/or gradients of diffusible-signals acting throughout the nervous tissue. This report presents and discusses findings showing that the FP cells secrete a novel compound, which is recognized by antisera raised against secretory products of the subcommissural organ (SCO). This immunoreactive compound appears to be very similar to one of the glycoproteins secreted by the SCO. This immunoreactivity is expressed transiently during central nervous system development, and its rostro-caudal extension along the anterior-posterior axis of the FP displays some species variations. However, a constant feature in all species investigated is that this immunoreactive compound is highly expressed in the FP located in the mesencephalic-metencephalic boundary. The distribution of this compound is compatible with basal and apical pathways of release from FP cells. The former might participate in the formation of some brain commissures. The latter might involve the use of the cerebrospinal fluid as a route for performing actions on distant targets, a pathway somehow disregarded by most models accounting for morphogen actions.
Assuntos
Anticorpos/imunologia , Glicoproteínas/imunologia , Glicoproteínas/metabolismo , Medula Espinal/embriologia , Órgão Subcomissural/metabolismo , Animais , Imuno-Histoquímica , Oncorhynchus/embriologia , Oncorhynchus/metabolismo , Ratos , Medula Espinal/crescimento & desenvolvimento , Medula Espinal/metabolismo , Vertebrados/embriologia , Vertebrados/crescimento & desenvolvimento , Vertebrados/metabolismoRESUMO
During 1991, in one of three specimens of Oncorhynchus mykiss cultured in Puyehue Lake (40 degrees 36'S, 72 degrees 26'W) was registered for first time the infection by Camallanus corderoi. Comments on the morphological and geographic distribution of the three species of Camallanus described in South America are also given.