The Experts below are selected from a list of 276 Experts worldwide ranked by ideXlab platform
Brian Austin - One of the best experts on this subject based on the ideXlab platform.
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Lack of uptake of Renibacterium salmoninarum by gill epithelia of rainbow trout
Journal of Fish Biology, 2000Co-Authors: D. Mcintosh, Brian Austin, E. Fla, Alberto J. Villena, J. A. Matinez-pereda, J. TarazonaAbstract:The role of rainbow trout (Oncorhynchus mykiss, Walbaum) gill cells in uptake of the salmonid pathogen Renibacterium salmoninarum was examined using in vitro, whole animal and isolated perfused head models. Uptake of the pathogen was observed only when dissected gill tissue was exposed to the live pathogen. In contrast, live cells of Yersinia ruckeri interacted with the gill epithelia in the isolated perfused head model, confirming the findings of previous studies with whole animal and in vitro systems. These results are discussed in relation to the role of gill tissue in bacterial kidney disease (BKD) pathogenesis and in antigen trapping
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A simplified PCR-based method for the detection of Renibacterium salmoninarum utilizing preparations of rainbow trout (Oncorhynchus mykiss, walbaum) lymphocytes
Applied and environmental microbiology, 1996Co-Authors: D. Mcintosh, Philip G. Meaden, Brian AustinAbstract:A method for the detection of Renibacterium salmoninarum by PCR is described. A rapid, reliable procedure was developed for the extraction of DNA, which could be applied to infected kidney homogenates and head kidney lymphocyte preparations. The target for DNA amplification was a 376-bp region of the gene encoding the 57-kDa major surface antigen (MSA). The PCR was specific for R. salmoninarum and allowed the detection of 10 to 100 cells of the pathogen. Use of the PCR for the examination of experimentally infected rainbow trout showed it to be as reliable as plate culture methods for the detection of R. salmoninarum in infected kidneys.
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The validity of Western blotting for the diagnosis of bacterial kidney disease based on the detection of the p57 antigen of Renibacterium salmoninarum
Journal of Microbiological Methods, 1996Co-Authors: D. Mcintosh, Brian AustinAbstract:Six strains of Renibacterium salmoninarum were examined by Western blotting, which incorporated polyclonal and monoclonal antisera produced against the 57 kDa surface protein (=p57 antigen). An enhanced chemiluminescence (ECL) detection system increased the sensitivity of the reaction when compared to the use of chromogenic substrates. However, Western blotting was not as sensitive as culturing methods for the detection of R. salmoninarum during early stages of infection in salmonids. Yet, Western blotting was determined to be specific to R. salmoninarum, insofar as cross-reactions did not occur with Corynebacterium aquaticum or Carnobacterium piscicola.
Sigridur Gudmundsdottir - One of the best experts on this subject based on the ideXlab platform.
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Renibacterium salmoninarum, the causative agent of bacterial kidney disease in salmonid fish, detected by nested reverse transcription-PCR of 16S rRNA sequences.
Applied and environmental microbiology, 1994Co-Authors: H. B. Magnússon, Sigridur Gudmundsdottir, E. Benediktsdóttir, Olafur H. Fridjonsson, Ólafur S. Andrésson, Valgerdur AndrésdóttirAbstract:An assay based on reverse transcription and nested PCR amplification of hypervariable regions within the 16S rRNA sequence was used to specifically detect Renibacterium salmoninarum, the slowly growing causative agent of bacterial kidney disease in salmonid fish. This assay detected 1 to 10 bacteria per sample and took 1 to 2 days to perform. The assay was used to detect R. salmoninarum in ovarian fluid obtained from naturally infected fish. The assay was unreliable when it was used to examine kidney tissue.
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detection of Renibacterium salmoninarum in salmonid kidney samples a comparison of results using double sandwich elisa and isolation on selective medium
Journal of Fish Diseases, 1993Co-Authors: Sigridur Gudmundsdottir, E. Benediktsdóttir, S. HelgasonAbstract:A total of 1239 kidney samples from four species of salmonid fish, Atlantic salmon, Salmo salar L., brown trout, Salmo trutta L., Arctic charr, Salvelinus alpinus (L.), and rainbow trout, Oncorhynchus mykiss (Walbaum), were screened for Renibacterium salmoninarum using double-sandwich ELISA and bacterial isolation. For bacterial isolation, samples were homogenized, washed, plated onto S-KDM and incubated for 12 weeks. Samples for ELISA were kept frozen until tested. After thawing, 25% homogenates in PBS were heated at 100°C for 15 min in the presence (2.5% v/v) of HemoDe solvent (terpene and butylated hydroxyanisole) and then centrifuged. The supernatant was tested with polyclonal antibodies against whole bacterium in a double-sandwich ELISA. In seven out of 12 groups tested, all samples were negative in both tests. Positive ELISA results occurred in five groups. Renibacterium salmoninarum was isolated on SKDM from samples in four out of these five groups. The ELISA test gave significantly higher numbers of positive samples in three out of the four groups showing positive results in both tests.
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Detection of Renibacterium salmoninarum in salmonid kidney samples: a comparison of results using double‐sandwich ELISA and isolation on selective medium
Journal of Fish Diseases, 1993Co-Authors: Sigridur Gudmundsdottir, E. Benediktsdóttir, S. HelgasonAbstract:A total of 1239 kidney samples from four species of salmonid fish, Atlantic salmon, Salmo salar L., brown trout, Salmo trutta L., Arctic charr, Salvelinus alpinus (L.), and rainbow trout, Oncorhynchus mykiss (Walbaum), were screened for Renibacterium salmoninarum using double-sandwich ELISA and bacterial isolation. For bacterial isolation, samples were homogenized, washed, plated onto S-KDM and incubated for 12 weeks. Samples for ELISA were kept frozen until tested. After thawing, 25% homogenates in PBS were heated at 100°C for 15 min in the presence (2.5% v/v) of HemoDe solvent (terpene and butylated hydroxyanisole) and then centrifuged. The supernatant was tested with polyclonal antibodies against whole bacterium in a double-sandwich ELISA. In seven out of 12 groups tested, all samples were negative in both tests. Positive ELISA results occurred in five groups. Renibacterium salmoninarum was isolated on SKDM from samples in four out of these five groups. The ELISA test gave significantly higher numbers of positive samples in three out of the four groups showing positive results in both tests.
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Incubation time for the cultivation of Renibacterium salmoninarum from Atlantic salmon, Salmo salar L., broodfish
Journal of Fish Diseases, 1991Co-Authors: E. Benediktsdóttir, S. Helgason, Sigridur GudmundsdottirAbstract:. Cultivation plates for the primary isolation of Renibacterium salmoninarum were incubated for 12 or more weeks over 3.5 years. The incubation time for sample of two groups of Atlantic salmon, Salmo solar L., broodfish on a selective agar medium is reported. Samples turned positive over a long time-span. but the longest incubation time recorded for growth of the bacterium was 19 week. In one group, 79% of all positive samples form fish with macroscopic signs of bacterial kidney disease were positive after 6 weeks of incubation and the highest incidence of positive samples occured during the sixth week. From covertly infected fish within the same group.42% of sample were positive after 6 weeks of incubation, and the highest incidence of positive sample occured during the sixth and the ninth weeks of incubation. The growth pattern of the bacterium at primary isolation was characterized by a prolonged lag phase followed by a relatively growth in one week from microscopic to macroscopic size of the colonies.
S. Helgason - One of the best experts on this subject based on the ideXlab platform.
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detection of Renibacterium salmoninarum in salmonid kidney samples a comparison of results using double sandwich elisa and isolation on selective medium
Journal of Fish Diseases, 1993Co-Authors: Sigridur Gudmundsdottir, E. Benediktsdóttir, S. HelgasonAbstract:A total of 1239 kidney samples from four species of salmonid fish, Atlantic salmon, Salmo salar L., brown trout, Salmo trutta L., Arctic charr, Salvelinus alpinus (L.), and rainbow trout, Oncorhynchus mykiss (Walbaum), were screened for Renibacterium salmoninarum using double-sandwich ELISA and bacterial isolation. For bacterial isolation, samples were homogenized, washed, plated onto S-KDM and incubated for 12 weeks. Samples for ELISA were kept frozen until tested. After thawing, 25% homogenates in PBS were heated at 100°C for 15 min in the presence (2.5% v/v) of HemoDe solvent (terpene and butylated hydroxyanisole) and then centrifuged. The supernatant was tested with polyclonal antibodies against whole bacterium in a double-sandwich ELISA. In seven out of 12 groups tested, all samples were negative in both tests. Positive ELISA results occurred in five groups. Renibacterium salmoninarum was isolated on SKDM from samples in four out of these five groups. The ELISA test gave significantly higher numbers of positive samples in three out of the four groups showing positive results in both tests.
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Detection of Renibacterium salmoninarum in salmonid kidney samples: a comparison of results using double‐sandwich ELISA and isolation on selective medium
Journal of Fish Diseases, 1993Co-Authors: Sigridur Gudmundsdottir, E. Benediktsdóttir, S. HelgasonAbstract:A total of 1239 kidney samples from four species of salmonid fish, Atlantic salmon, Salmo salar L., brown trout, Salmo trutta L., Arctic charr, Salvelinus alpinus (L.), and rainbow trout, Oncorhynchus mykiss (Walbaum), were screened for Renibacterium salmoninarum using double-sandwich ELISA and bacterial isolation. For bacterial isolation, samples were homogenized, washed, plated onto S-KDM and incubated for 12 weeks. Samples for ELISA were kept frozen until tested. After thawing, 25% homogenates in PBS were heated at 100°C for 15 min in the presence (2.5% v/v) of HemoDe solvent (terpene and butylated hydroxyanisole) and then centrifuged. The supernatant was tested with polyclonal antibodies against whole bacterium in a double-sandwich ELISA. In seven out of 12 groups tested, all samples were negative in both tests. Positive ELISA results occurred in five groups. Renibacterium salmoninarum was isolated on SKDM from samples in four out of these five groups. The ELISA test gave significantly higher numbers of positive samples in three out of the four groups showing positive results in both tests.
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Incubation time for the cultivation of Renibacterium salmoninarum from Atlantic salmon, Salmo salar L., broodfish
Journal of Fish Diseases, 1991Co-Authors: E. Benediktsdóttir, S. Helgason, Sigridur GudmundsdottirAbstract:. Cultivation plates for the primary isolation of Renibacterium salmoninarum were incubated for 12 or more weeks over 3.5 years. The incubation time for sample of two groups of Atlantic salmon, Salmo solar L., broodfish on a selective agar medium is reported. Samples turned positive over a long time-span. but the longest incubation time recorded for growth of the bacterium was 19 week. In one group, 79% of all positive samples form fish with macroscopic signs of bacterial kidney disease were positive after 6 weeks of incubation and the highest incidence of positive samples occured during the sixth week. From covertly infected fish within the same group.42% of sample were positive after 6 weeks of incubation, and the highest incidence of positive sample occured during the sixth and the ninth weeks of incubation. The growth pattern of the bacterium at primary isolation was characterized by a prolonged lag phase followed by a relatively growth in one week from microscopic to macroscopic size of the colonies.
D. Mcintosh - One of the best experts on this subject based on the ideXlab platform.
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Lack of uptake of Renibacterium salmoninarum by gill epithelia of rainbow trout
Journal of Fish Biology, 2000Co-Authors: D. Mcintosh, Brian Austin, E. Fla, Alberto J. Villena, J. A. Matinez-pereda, J. TarazonaAbstract:The role of rainbow trout (Oncorhynchus mykiss, Walbaum) gill cells in uptake of the salmonid pathogen Renibacterium salmoninarum was examined using in vitro, whole animal and isolated perfused head models. Uptake of the pathogen was observed only when dissected gill tissue was exposed to the live pathogen. In contrast, live cells of Yersinia ruckeri interacted with the gill epithelia in the isolated perfused head model, confirming the findings of previous studies with whole animal and in vitro systems. These results are discussed in relation to the role of gill tissue in bacterial kidney disease (BKD) pathogenesis and in antigen trapping
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Production of putative virulence factors by Renibacterium salmoninarum grown in cell culture.
Microbiology (Reading England), 1997Co-Authors: D. Mcintosh, T. H. Grayson, E Flaño, M L Gilpin, B Austin, A J VillenaAbstract:A cell culture system, employing the fish cell line Epithelioma papillosum cyprini (EPC), was developed to study the synthesis of intracellular antigen and the expression of putative virulence factors by Renibacterium salmoninarum. EPC cultures infected with R. salmoninarum could be maintained for 7 weeks, during which the pathogen multiplied intracellularly. Immunohistochemical examination of infected cultures revealed the production of the p57 antigen, haemolysin and cytolysin. The intracellular nature of the infection was confirmed by transmission electron microscopic examination of EPC monolayers. A comparison of the relative virulence of bacterial cells cultured in EPC cells and on agar plates revealed that the former were markedly more virulent in challenge experiments with juvenile rainbow trout (Oncorhynchus mykiss Walbaum). The EPC cell culture model provided a system for the study of R. salmoninarum under more natural conditions than those achieved with plate culture techniques.
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A simplified PCR-based method for the detection of Renibacterium salmoninarum utilizing preparations of rainbow trout (Oncorhynchus mykiss, walbaum) lymphocytes
Applied and environmental microbiology, 1996Co-Authors: D. Mcintosh, Philip G. Meaden, Brian AustinAbstract:A method for the detection of Renibacterium salmoninarum by PCR is described. A rapid, reliable procedure was developed for the extraction of DNA, which could be applied to infected kidney homogenates and head kidney lymphocyte preparations. The target for DNA amplification was a 376-bp region of the gene encoding the 57-kDa major surface antigen (MSA). The PCR was specific for R. salmoninarum and allowed the detection of 10 to 100 cells of the pathogen. Use of the PCR for the examination of experimentally infected rainbow trout showed it to be as reliable as plate culture methods for the detection of R. salmoninarum in infected kidneys.
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The validity of Western blotting for the diagnosis of bacterial kidney disease based on the detection of the p57 antigen of Renibacterium salmoninarum
Journal of Microbiological Methods, 1996Co-Authors: D. Mcintosh, Brian AustinAbstract:Six strains of Renibacterium salmoninarum were examined by Western blotting, which incorporated polyclonal and monoclonal antisera produced against the 57 kDa surface protein (=p57 antigen). An enhanced chemiluminescence (ECL) detection system increased the sensitivity of the reaction when compared to the use of chromogenic substrates. However, Western blotting was not as sensitive as culturing methods for the detection of R. salmoninarum during early stages of infection in salmonids. Yet, Western blotting was determined to be specific to R. salmoninarum, insofar as cross-reactions did not occur with Corynebacterium aquaticum or Carnobacterium piscicola.
E. Benediktsdóttir - One of the best experts on this subject based on the ideXlab platform.
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Renibacterium salmoninarum, the causative agent of bacterial kidney disease in salmonid fish, detected by nested reverse transcription-PCR of 16S rRNA sequences.
Applied and environmental microbiology, 1994Co-Authors: H. B. Magnússon, Sigridur Gudmundsdottir, E. Benediktsdóttir, Olafur H. Fridjonsson, Ólafur S. Andrésson, Valgerdur AndrésdóttirAbstract:An assay based on reverse transcription and nested PCR amplification of hypervariable regions within the 16S rRNA sequence was used to specifically detect Renibacterium salmoninarum, the slowly growing causative agent of bacterial kidney disease in salmonid fish. This assay detected 1 to 10 bacteria per sample and took 1 to 2 days to perform. The assay was used to detect R. salmoninarum in ovarian fluid obtained from naturally infected fish. The assay was unreliable when it was used to examine kidney tissue.
-
detection of Renibacterium salmoninarum in salmonid kidney samples a comparison of results using double sandwich elisa and isolation on selective medium
Journal of Fish Diseases, 1993Co-Authors: Sigridur Gudmundsdottir, E. Benediktsdóttir, S. HelgasonAbstract:A total of 1239 kidney samples from four species of salmonid fish, Atlantic salmon, Salmo salar L., brown trout, Salmo trutta L., Arctic charr, Salvelinus alpinus (L.), and rainbow trout, Oncorhynchus mykiss (Walbaum), were screened for Renibacterium salmoninarum using double-sandwich ELISA and bacterial isolation. For bacterial isolation, samples were homogenized, washed, plated onto S-KDM and incubated for 12 weeks. Samples for ELISA were kept frozen until tested. After thawing, 25% homogenates in PBS were heated at 100°C for 15 min in the presence (2.5% v/v) of HemoDe solvent (terpene and butylated hydroxyanisole) and then centrifuged. The supernatant was tested with polyclonal antibodies against whole bacterium in a double-sandwich ELISA. In seven out of 12 groups tested, all samples were negative in both tests. Positive ELISA results occurred in five groups. Renibacterium salmoninarum was isolated on SKDM from samples in four out of these five groups. The ELISA test gave significantly higher numbers of positive samples in three out of the four groups showing positive results in both tests.
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Detection of Renibacterium salmoninarum in salmonid kidney samples: a comparison of results using double‐sandwich ELISA and isolation on selective medium
Journal of Fish Diseases, 1993Co-Authors: Sigridur Gudmundsdottir, E. Benediktsdóttir, S. HelgasonAbstract:A total of 1239 kidney samples from four species of salmonid fish, Atlantic salmon, Salmo salar L., brown trout, Salmo trutta L., Arctic charr, Salvelinus alpinus (L.), and rainbow trout, Oncorhynchus mykiss (Walbaum), were screened for Renibacterium salmoninarum using double-sandwich ELISA and bacterial isolation. For bacterial isolation, samples were homogenized, washed, plated onto S-KDM and incubated for 12 weeks. Samples for ELISA were kept frozen until tested. After thawing, 25% homogenates in PBS were heated at 100°C for 15 min in the presence (2.5% v/v) of HemoDe solvent (terpene and butylated hydroxyanisole) and then centrifuged. The supernatant was tested with polyclonal antibodies against whole bacterium in a double-sandwich ELISA. In seven out of 12 groups tested, all samples were negative in both tests. Positive ELISA results occurred in five groups. Renibacterium salmoninarum was isolated on SKDM from samples in four out of these five groups. The ELISA test gave significantly higher numbers of positive samples in three out of the four groups showing positive results in both tests.
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Incubation time for the cultivation of Renibacterium salmoninarum from Atlantic salmon, Salmo salar L., broodfish
Journal of Fish Diseases, 1991Co-Authors: E. Benediktsdóttir, S. Helgason, Sigridur GudmundsdottirAbstract:. Cultivation plates for the primary isolation of Renibacterium salmoninarum were incubated for 12 or more weeks over 3.5 years. The incubation time for sample of two groups of Atlantic salmon, Salmo solar L., broodfish on a selective agar medium is reported. Samples turned positive over a long time-span. but the longest incubation time recorded for growth of the bacterium was 19 week. In one group, 79% of all positive samples form fish with macroscopic signs of bacterial kidney disease were positive after 6 weeks of incubation and the highest incidence of positive samples occured during the sixth week. From covertly infected fish within the same group.42% of sample were positive after 6 weeks of incubation, and the highest incidence of positive sample occured during the sixth and the ninth weeks of incubation. The growth pattern of the bacterium at primary isolation was characterized by a prolonged lag phase followed by a relatively growth in one week from microscopic to macroscopic size of the colonies.