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Avi Eldar - One of the best experts on this subject based on the ideXlab platform.
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A pivotal role for the Streptococcus Iniae extracellular polysaccharide in triggering proinflammatory cytokines transcription and inducing death in rainbow trout.
FEMS microbiology letters, 2010Co-Authors: Marina Eyngor, Amir Zlotkin, Roni Shapira, Avshalom Hurvitz, Avishay Lublin, Yoram Tekoah, Avi EldarAbstract:Streptococcus Iniae is a major pathogen of fish, causing considerable economic losses in Israel, the United States and the Far East. Containment of mortalities through vaccination was recently compromised due to the emergence of novel vaccine-escape strains that are distinguished from previous strains by their ability to produce large amounts of extracellular polysaccharide (EPS) that is released to the medium. In vitro and in vivo data now indicate that the EPS is a major virulence factor, capable of triggering the proinflammatory cytokine machinery and inducing mortality of fish. Streptococcus Iniae EPS might therefore be considered to be responsible for sepsis and death just as lipopolysaccharide is for Gram-negative pathogens.
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Emergence of Novel Streptococcus Iniae Exopolysaccharide-Producing Strains following Vaccination with Nonproducing Strains
Applied and environmental microbiology, 2008Co-Authors: Marina Eyngor, Amir Zlotkin, Roni Shapira, Avshalom Hurvitz, Avishay Lublin, Yoram Tekoah, Avi EldarAbstract:Streptococcus Iniae is a major pathogen of fish, producing fatal disease among fish species living in very diverse environments. Recently, reoccurrences of disease outbreaks were recorded in rainbow trout (Oncorhynchus mykiss, Walbaum) farms where the entire fish population was routinely vaccinated. New strains are distinguished from previous strains by their ability to produce large amounts of extracellular polysaccharide that is released into the medium. Present findings indicate that the extracellular polysaccharide is a major antigenic factor, suggesting an evolutionary selection of strains capable of extracellular polysaccharide production.
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Transcytosis of Streptococcus Iniae through skin epithelial barriers: an in vitro study
FEMS Microbiology Letters, 2007Co-Authors: Marina Eyngor, Stefan Chilmonczyk, Amir Zlotkin, Elisabetta Manuali, Dan Lahav, Claudio Ghittino, Roni Shapira, Avshalom Hurvitz, Avi EldarAbstract:By constructing a biological model based on in vitro culture of polarized rainbow trout primary skin epithelial cell monolayers, the series of early events that precede Streptococcus Iniae infection, particularly colonization and translocation through external barriers, were analyzed. Streptococcus Iniae promptly invades skin epithelial cells, but the rapid decline of viable intracellular bacteria points out the limited capability of intracellular survival for this bacterium. Translocation assays, supported by electron microscopy microphotographs, demonstrate that following successful in vitro invasion of skin epithelial cell, the bacterium exists free in the cytoplasm after release from the endosome, and translocates through the skin barrier. Bacterial invasion and transcytosis is not accompanied by apparent cellline damages or disruption of host cells’ tight junctions. It is hypothesized that the phenomenon of epithelial invasion coupled to the rapid translocation through the barrier plays a crucial role in Streptococcus Iniae infection.
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Streptococcus Iniae type II infections in rainbow trout Oncorhynchus mykiss
Diseases of aquatic organisms, 2004Co-Authors: D Lahav, Claudio Ghittino, M Eyngor, A Hurvitz, A Lublin, Avi EldarAbstract:Clinical and pathological findings (anorexia, hemorrhage, lethargy, loss of orientation and exophthalmia) indicated that Streptococcus Iniae type II is responsible for a fatal disease in rainbow trout. Histopathological findings revealed that S. Iniae type II produces a systemic disease, including a diffuse necrotizing myositis. The distribution of viable bacteria in infected tissues substantiated the pathological findings, confirming that S. Iniae type II is responsible for a generalized septic disease of rainbow trout.
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Recovery of Streptococcus Iniae from diseased fish previously vaccinated with a Streptococcus vaccine.
Applied and environmental microbiology, 2001Co-Authors: Gilad Bachrach, Amir Zlotkin, Avshalom Hurvitz, Donald L. Evans, Avi EldarAbstract:Streptococcus Iniae was recovered from diseased rainbow trout (Oncorhynchus mykiss, Walbaum) previously vaccinated against streptococcosis. PCR and serological methods indicate the presence of a new serotype in the diseased fish.
Amir Zlotkin - One of the best experts on this subject based on the ideXlab platform.
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A pivotal role for the Streptococcus Iniae extracellular polysaccharide in triggering proinflammatory cytokines transcription and inducing death in rainbow trout.
FEMS microbiology letters, 2010Co-Authors: Marina Eyngor, Amir Zlotkin, Roni Shapira, Avshalom Hurvitz, Avishay Lublin, Yoram Tekoah, Avi EldarAbstract:Streptococcus Iniae is a major pathogen of fish, causing considerable economic losses in Israel, the United States and the Far East. Containment of mortalities through vaccination was recently compromised due to the emergence of novel vaccine-escape strains that are distinguished from previous strains by their ability to produce large amounts of extracellular polysaccharide (EPS) that is released to the medium. In vitro and in vivo data now indicate that the EPS is a major virulence factor, capable of triggering the proinflammatory cytokine machinery and inducing mortality of fish. Streptococcus Iniae EPS might therefore be considered to be responsible for sepsis and death just as lipopolysaccharide is for Gram-negative pathogens.
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Emergence of Novel Streptococcus Iniae Exopolysaccharide-Producing Strains following Vaccination with Nonproducing Strains
Applied and environmental microbiology, 2008Co-Authors: Marina Eyngor, Amir Zlotkin, Roni Shapira, Avshalom Hurvitz, Avishay Lublin, Yoram Tekoah, Avi EldarAbstract:Streptococcus Iniae is a major pathogen of fish, producing fatal disease among fish species living in very diverse environments. Recently, reoccurrences of disease outbreaks were recorded in rainbow trout (Oncorhynchus mykiss, Walbaum) farms where the entire fish population was routinely vaccinated. New strains are distinguished from previous strains by their ability to produce large amounts of extracellular polysaccharide that is released into the medium. Present findings indicate that the extracellular polysaccharide is a major antigenic factor, suggesting an evolutionary selection of strains capable of extracellular polysaccharide production.
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Transcytosis of Streptococcus Iniae through skin epithelial barriers: an in vitro study
FEMS Microbiology Letters, 2007Co-Authors: Marina Eyngor, Stefan Chilmonczyk, Amir Zlotkin, Elisabetta Manuali, Dan Lahav, Claudio Ghittino, Roni Shapira, Avshalom Hurvitz, Avi EldarAbstract:By constructing a biological model based on in vitro culture of polarized rainbow trout primary skin epithelial cell monolayers, the series of early events that precede Streptococcus Iniae infection, particularly colonization and translocation through external barriers, were analyzed. Streptococcus Iniae promptly invades skin epithelial cells, but the rapid decline of viable intracellular bacteria points out the limited capability of intracellular survival for this bacterium. Translocation assays, supported by electron microscopy microphotographs, demonstrate that following successful in vitro invasion of skin epithelial cell, the bacterium exists free in the cytoplasm after release from the endosome, and translocates through the skin barrier. Bacterial invasion and transcytosis is not accompanied by apparent cellline damages or disruption of host cells’ tight junctions. It is hypothesized that the phenomenon of epithelial invasion coupled to the rapid translocation through the barrier plays a crucial role in Streptococcus Iniae infection.
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Streptococcus Iniae infections in Red Sea cage-cultured and wild fishes.
Diseases of aquatic organisms, 2002Co-Authors: A. Colorni, Ariel Diamant, A Eldar, H. Kvitt, Amir ZlotkinAbstract:Streptococcus Iniae was isolated from 2 moribund wild Red Sea fishes, Pomadasys stridens (Pomadasyidae) and Synodus variegatus (Synodontidae), both collected in shallow waters along the Israeli coast of the Gulf of Eilat. The site is approximately 2 km from a mariculture cage farm in which streptococcal infections were diagnosed in previous years in the red drum Sciaenops ocellatus. This is the first report of S. Iniae in Red Sea fishes. Biochemical and molecular similarities between the isolates from cultured fishes and those from the wild specimens suggest that a single strain is involved, and that 'amplification' and dispersal of this pathogen from captive to feral fishes have occurred. At the molecular level, the pathogen is different from the S. Iniae isolates that have been afflicting the Israeli freshwater aquaculture in recent years. Although S. Iniae prevalence in the wild fish populations of the area remains to be determined, the northernmost region of the Gulf of Eilat, virtually landlocked and with generally calm seas and weak currents, seems to be particularly vulnerable to the impact of diseases that develop in this mariculture system.
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Recovery of Streptococcus Iniae from diseased fish previously vaccinated with a Streptococcus vaccine.
Applied and environmental microbiology, 2001Co-Authors: Gilad Bachrach, Amir Zlotkin, Avshalom Hurvitz, Donald L. Evans, Avi EldarAbstract:Streptococcus Iniae was recovered from diseased rainbow trout (Oncorhynchus mykiss, Walbaum) previously vaccinated against streptococcosis. PCR and serological methods indicate the presence of a new serotype in the diseased fish.
Craig A. Shoemaker - One of the best experts on this subject based on the ideXlab platform.
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Antimicrobial activity of the biopolymer chitosan against Streptococcus Iniae.
Journal of fish diseases, 2019Co-Authors: Benjamin H. Beck, Craig A. Shoemaker, Mediha Yildirim-aksoy, Sidney Adam Fuller, Eric PeatmanAbstract:The antimicrobial activity and mode of action of chitosan were evaluated against Streptococcus Iniae, a pathogenic Gram-positive bacterium of fish worldwide. Cell proliferation kinetics were examined following exposure to varying concentrations of chitosan. The action of chitosan on S. Iniae was also investigated by measuring agglutination activity, conductivity, and extracellular and intracellular bacterial adenosine triphosphate (ATP) levels. Chitosan exhibited antibacterial activity against S. Iniae at concentrations of 0.1% and above and was lethal at a concentration of 0.4% and higher. The mechanism of antibacterial activity of chitosan at the inhibitory level of bacterial growth appears to hinge upon the interaction between chitosan and the oppositely charged bacterial surface. This interplay causes agglutination, which was readily observed grossly and microscopically. After interacting with the cell surface via adsorption, an efflux of intracellular ATP was documented, which suggests that chitosan disrupts the bacterial cell causing leakage of cytosolic contents and ultimately cell death. Results suggest chitosan may be worth evaluating as a natural alternative to antibiotic against S. Iniae infection of fish.
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The macrophage chemotactic activity of Streptococcus agalactiae and Streptococcus Iniae extracellular products (ECP).
Fish & shellfish immunology, 2006Co-Authors: Phillip H. Klesius, Joyce J. Evans, Craig A. ShoemakerAbstract:Abstract The ability of Streptococcus agalactiae and Streptococcus Iniae to attract macrophages of Nile tilapia ( Oreochromis niloticus ) was investigated. The extracellular products (ECP) from S. agalactiae and S. Iniae were tested in vitro for macrophage chemotaxis using blind-well chambers. The macrophages were obtained from the peritoneal cavity 4–5 days after intraperitoneal injection of squalene. Both macrophage chemotactic and chemokinetic activities were demonstrated using the S. agalactiae ECP. However, only chemotactic activity was shown for S. Iniae ECP. High-pressure liquid chromatography fractionation revealed that semi-purified S. agalactiae and S. Iniae ECPs had estimated molecular weights of 7.54 and 19.2 kDa, respectively. The prominent chemotactic activities of ECP from S. agalactiae and S. Iniae are likely to be involved in the proinflammatory responses of macrophages to S. agalactiae and S. Iniae infections.
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prevalence of Streptococcus Iniae in tilapia hybrid striped bass and channel catfish on commercial fish farms in the united states
American Journal of Veterinary Research, 2001Co-Authors: Craig A. Shoemaker, Phillip H. Klesius, Joyce J. EvansAbstract:Objective—To determine the prevalence of Streptococcus Iniae in tilapia (Oreochromis spp), hybrid striped bass (Morone chrysops × M saxatilis), and channel catfish (Ictalurus punctatus) on commercial fish farms in the United States. Animals—1,543 fish (970 tilapia, 415 hybrid striped bass, and 158 channel catfish). Procedures—The dry-swab technique was used for collection of specimens for streptococcal isolation. Specimens were shipped by overnight delivery and processed by use of standard bacteriologic techniques. Results—Streptococcus Iniae was not isolated from market-size channel catfish. Prevalence in tilapia and hybrid striped bass was 37 of 970 (3.81%) and 30 of 415 (7.23%), respectively. Prevalence by farm ranged from 0.0 to 27.4% for tilapia and 0.0 to 21.6% for hybrid striped bass. In tilapia, prevalence was lowest in market-size and nursery fish (4 of 239 [1.67%] and 3 of 339 [0.88%], respectively), with an increase in prevalence for fish in the grow-out stage (30 of 337 [7.96%]). For hybrid st...
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Efficacy of single and combined Streptococcus Iniae isolate vaccine administered by intraperitoneal and intramuscular routes in tilapia (Oreochromis niloticus).
Aquaculture, 2000Co-Authors: Phillip H. Klesius, Craig A. Shoemaker, Joyce J. EvansAbstract:We evaluated the effectiveness of Streptococcus Iniae vaccines prepared from formalin-killed .
Joyce J. Evans - One of the best experts on this subject based on the ideXlab platform.
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The macrophage chemotactic activity of Streptococcus agalactiae and Streptococcus Iniae extracellular products (ECP).
Fish & shellfish immunology, 2006Co-Authors: Phillip H. Klesius, Joyce J. Evans, Craig A. ShoemakerAbstract:Abstract The ability of Streptococcus agalactiae and Streptococcus Iniae to attract macrophages of Nile tilapia ( Oreochromis niloticus ) was investigated. The extracellular products (ECP) from S. agalactiae and S. Iniae were tested in vitro for macrophage chemotaxis using blind-well chambers. The macrophages were obtained from the peritoneal cavity 4–5 days after intraperitoneal injection of squalene. Both macrophage chemotactic and chemokinetic activities were demonstrated using the S. agalactiae ECP. However, only chemotactic activity was shown for S. Iniae ECP. High-pressure liquid chromatography fractionation revealed that semi-purified S. agalactiae and S. Iniae ECPs had estimated molecular weights of 7.54 and 19.2 kDa, respectively. The prominent chemotactic activities of ECP from S. agalactiae and S. Iniae are likely to be involved in the proinflammatory responses of macrophages to S. agalactiae and S. Iniae infections.
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prevalence of Streptococcus Iniae in tilapia hybrid striped bass and channel catfish on commercial fish farms in the united states
American Journal of Veterinary Research, 2001Co-Authors: Craig A. Shoemaker, Phillip H. Klesius, Joyce J. EvansAbstract:Objective—To determine the prevalence of Streptococcus Iniae in tilapia (Oreochromis spp), hybrid striped bass (Morone chrysops × M saxatilis), and channel catfish (Ictalurus punctatus) on commercial fish farms in the United States. Animals—1,543 fish (970 tilapia, 415 hybrid striped bass, and 158 channel catfish). Procedures—The dry-swab technique was used for collection of specimens for streptococcal isolation. Specimens were shipped by overnight delivery and processed by use of standard bacteriologic techniques. Results—Streptococcus Iniae was not isolated from market-size channel catfish. Prevalence in tilapia and hybrid striped bass was 37 of 970 (3.81%) and 30 of 415 (7.23%), respectively. Prevalence by farm ranged from 0.0 to 27.4% for tilapia and 0.0 to 21.6% for hybrid striped bass. In tilapia, prevalence was lowest in market-size and nursery fish (4 of 239 [1.67%] and 3 of 339 [0.88%], respectively), with an increase in prevalence for fish in the grow-out stage (30 of 337 [7.96%]). For hybrid st...
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Efficacy of single and combined Streptococcus Iniae isolate vaccine administered by intraperitoneal and intramuscular routes in tilapia (Oreochromis niloticus).
Aquaculture, 2000Co-Authors: Phillip H. Klesius, Craig A. Shoemaker, Joyce J. EvansAbstract:We evaluated the effectiveness of Streptococcus Iniae vaccines prepared from formalin-killed .
Avshalom Hurvitz - One of the best experts on this subject based on the ideXlab platform.
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A pivotal role for the Streptococcus Iniae extracellular polysaccharide in triggering proinflammatory cytokines transcription and inducing death in rainbow trout.
FEMS microbiology letters, 2010Co-Authors: Marina Eyngor, Amir Zlotkin, Roni Shapira, Avshalom Hurvitz, Avishay Lublin, Yoram Tekoah, Avi EldarAbstract:Streptococcus Iniae is a major pathogen of fish, causing considerable economic losses in Israel, the United States and the Far East. Containment of mortalities through vaccination was recently compromised due to the emergence of novel vaccine-escape strains that are distinguished from previous strains by their ability to produce large amounts of extracellular polysaccharide (EPS) that is released to the medium. In vitro and in vivo data now indicate that the EPS is a major virulence factor, capable of triggering the proinflammatory cytokine machinery and inducing mortality of fish. Streptococcus Iniae EPS might therefore be considered to be responsible for sepsis and death just as lipopolysaccharide is for Gram-negative pathogens.
-
Emergence of Novel Streptococcus Iniae Exopolysaccharide-Producing Strains following Vaccination with Nonproducing Strains
Applied and environmental microbiology, 2008Co-Authors: Marina Eyngor, Amir Zlotkin, Roni Shapira, Avshalom Hurvitz, Avishay Lublin, Yoram Tekoah, Avi EldarAbstract:Streptococcus Iniae is a major pathogen of fish, producing fatal disease among fish species living in very diverse environments. Recently, reoccurrences of disease outbreaks were recorded in rainbow trout (Oncorhynchus mykiss, Walbaum) farms where the entire fish population was routinely vaccinated. New strains are distinguished from previous strains by their ability to produce large amounts of extracellular polysaccharide that is released into the medium. Present findings indicate that the extracellular polysaccharide is a major antigenic factor, suggesting an evolutionary selection of strains capable of extracellular polysaccharide production.
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Transcytosis of Streptococcus Iniae through skin epithelial barriers: an in vitro study
FEMS Microbiology Letters, 2007Co-Authors: Marina Eyngor, Stefan Chilmonczyk, Amir Zlotkin, Elisabetta Manuali, Dan Lahav, Claudio Ghittino, Roni Shapira, Avshalom Hurvitz, Avi EldarAbstract:By constructing a biological model based on in vitro culture of polarized rainbow trout primary skin epithelial cell monolayers, the series of early events that precede Streptococcus Iniae infection, particularly colonization and translocation through external barriers, were analyzed. Streptococcus Iniae promptly invades skin epithelial cells, but the rapid decline of viable intracellular bacteria points out the limited capability of intracellular survival for this bacterium. Translocation assays, supported by electron microscopy microphotographs, demonstrate that following successful in vitro invasion of skin epithelial cell, the bacterium exists free in the cytoplasm after release from the endosome, and translocates through the skin barrier. Bacterial invasion and transcytosis is not accompanied by apparent cellline damages or disruption of host cells’ tight junctions. It is hypothesized that the phenomenon of epithelial invasion coupled to the rapid translocation through the barrier plays a crucial role in Streptococcus Iniae infection.
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Recovery of Streptococcus Iniae from diseased fish previously vaccinated with a Streptococcus vaccine.
Applied and environmental microbiology, 2001Co-Authors: Gilad Bachrach, Amir Zlotkin, Avshalom Hurvitz, Donald L. Evans, Avi EldarAbstract:Streptococcus Iniae was recovered from diseased rainbow trout (Oncorhynchus mykiss, Walbaum) previously vaccinated against streptococcosis. PCR and serological methods indicate the presence of a new serotype in the diseased fish.