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Christopher J Secombes - One of the best experts on this subject based on the ideXlab platform.
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sequential development of the immune response in rainbow trout oncorhynchus mykiss walbaum 1792 to experimental plerocercoid infections of diphyllobothrium dendriticum nitzsch 1824
Parasitology, 1992Co-Authors: Gregory J E Sharp, A W Pike, Christopher J SecombesAbstract:Development of the inflammatory response of rainbow trout to experimental infections with Diphyllobothrium dendriticum Plerocercoids is described using light and electron microscopy. The cellular response to Plerocercoids occurred within 2 weeks post-infection (p.i.). This was followed by an increase in leucocyte numbers during weeks 3-6 p.i., with full encapsulation of Plerocercoids by week 6 p.i. Neutrophils were the first leucocytes to engage the developing plerocercoid, followed by large influxes of macrophages which transformed into epithelioid cells. With longer times p.i. the accumulation of different leucocyte types increased, and a blood vascular network developed. Full development of the composite cyst was characterized by fibroplasia, particularly at the periphery of the cyst, and the subsequent deposition of a collagenous tissue matrix. Enzyme-linked immunosorbent assay (ELISA) examination of serum samples taken over the 20 week period showed that specific anti-D. dendriticum antibody titres were first detected at 5 weeks p.i. and increased to a maximum by 11 weeks p.i.
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leucocyte migration in rainbow trout oncorhynchus mykiss walbaum optimization of migration conditions and responses to host and pathogen diphyllobothrium dendriticum nitzsch derived chemoattractants
Developmental and Comparative Immunology, 1991Co-Authors: Gregory J E Sharp, A W Pike, Christopher J SecombesAbstract:A rainbow trout leucocyte-derived chemoattractant(s) was prepared and tested as a stimulant of leucocyte migration. It was used to optimize an in vitro leucocyte migration assay using a 48-well micro chemotaxis chamber. This assay has subsequently been used to test the chemoattractant activity of antigen extracts from the tegument of Diphyllobothrium dendriticum Plerocercoids and conditioned medium obtained after in vitro maintenance of live Plerocercoids. Leucocytes were found to have an increased directional motility (chemotactic response) to the host-derived chemoattractant(s) but a random increased motility (chemokinetic response) following stimulation/contact with parasite-derived antigens.
Gregory J E Sharp - One of the best experts on this subject based on the ideXlab platform.
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sequential development of the immune response in rainbow trout oncorhynchus mykiss walbaum 1792 to experimental plerocercoid infections of diphyllobothrium dendriticum nitzsch 1824
Parasitology, 1992Co-Authors: Gregory J E Sharp, A W Pike, Christopher J SecombesAbstract:Development of the inflammatory response of rainbow trout to experimental infections with Diphyllobothrium dendriticum Plerocercoids is described using light and electron microscopy. The cellular response to Plerocercoids occurred within 2 weeks post-infection (p.i.). This was followed by an increase in leucocyte numbers during weeks 3-6 p.i., with full encapsulation of Plerocercoids by week 6 p.i. Neutrophils were the first leucocytes to engage the developing plerocercoid, followed by large influxes of macrophages which transformed into epithelioid cells. With longer times p.i. the accumulation of different leucocyte types increased, and a blood vascular network developed. Full development of the composite cyst was characterized by fibroplasia, particularly at the periphery of the cyst, and the subsequent deposition of a collagenous tissue matrix. Enzyme-linked immunosorbent assay (ELISA) examination of serum samples taken over the 20 week period showed that specific anti-D. dendriticum antibody titres were first detected at 5 weeks p.i. and increased to a maximum by 11 weeks p.i.
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leucocyte migration in rainbow trout oncorhynchus mykiss walbaum optimization of migration conditions and responses to host and pathogen diphyllobothrium dendriticum nitzsch derived chemoattractants
Developmental and Comparative Immunology, 1991Co-Authors: Gregory J E Sharp, A W Pike, Christopher J SecombesAbstract:A rainbow trout leucocyte-derived chemoattractant(s) was prepared and tested as a stimulant of leucocyte migration. It was used to optimize an in vitro leucocyte migration assay using a 48-well micro chemotaxis chamber. This assay has subsequently been used to test the chemoattractant activity of antigen extracts from the tegument of Diphyllobothrium dendriticum Plerocercoids and conditioned medium obtained after in vitro maintenance of live Plerocercoids. Leucocytes were found to have an increased directional motility (chemotactic response) to the host-derived chemoattractant(s) but a random increased motility (chemokinetic response) following stimulation/contact with parasite-derived antigens.
Iain Barber - One of the best experts on this subject based on the ideXlab platform.
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transcriptome sequences spanning key developmental states as a resource for the study of the cestode schistocephalus solidus a threespine stickleback parasite
GigaScience, 2016Co-Authors: François Olivier Hébert, Stephan Grambauer, Iain Barber, Christian R. Landry, Nadia AubinhorthAbstract:Background Schistocephalus solidus is a well-established model organism for studying the complex life cycle of cestodes and the mechanisms underlying host-parasite interactions. However, very few large-scale genetic resources for this species are available. We have sequenced and de novo-assembled the transcriptome of S. solidus using tissues from whole worms at three key developmental states - non-infective plerocercoid, infective plerocercoid and adult plerocercoid - to provide a resource for studying the evolution of complex life cycles and, more specifically, how parasites modulate their interactions with their hosts during development.
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The Effect of Salinity on Egg Development and Viability of Schistocephalus solidus (Cestoda: Diphyllobothriidea)
The Journal of parasitology, 2015Co-Authors: Natalie E. Simmonds, Iain BarberAbstract:Schistocephalus solidus Plerocercoids commonly infect three-spined stickleback Gasterosteus aculeatus populations in brackish and freshwaters, but infections are typically absent from marine populations. Here we provide an experimental test of the salinity tolerance of S. solidus eggs, to determine the role of salinity in limiting the distribution of infection in coastal zones. We find that S. solidus eggs, derived from the in vitro culture of 3 different Plerocercoids, developed normally in salinities of up to 12.5‰, but above this egg viability dropped rapidly, and no egg hatching was observed at salinities above 20‰. Our results are consistent with the distribution of infections in natural stickleback populations and add resolution to previous descriptive observations on salinity tolerance in S. solidus. They also demonstrate that S. solidus presents a novel disease challenge to marine populations of three-spined sticklebacks entering brackish and freshwater environments.
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some worms like it hot fish parasites grow faster in warmer water and alter host thermal preferences
Global Change Biology, 2012Co-Authors: Vicki Macnab, Iain BarberAbstract:Elevated environmental temperatures associated with anthropogenic warming have the potential to impact host-parasite interactions, with consequences for population health and ecosystem functioning. One way that elevated temperatures might influence parasite prevalence and intensity is by increasing life cycle completion rates. Here, we investigate how elevated temperatures impact a critical phase of the life cycle of the bird tapeworm Schistocephalus solidus – the growth of plerocercoid larvae in host fish (three-spined sticklebacks Gasterosteus aculeatus). By 8 weeks post-infection, Plerocercoids recovered from experimentally infected sticklebacks held at 20 °C weighed on average 104.9 mg, with all exceeding 50 mg, the mass considered consistently infective to definitive hosts. In contrast, Plerocercoids from sticklebacks held at 15 °C weighed on average 26.5 mg, with none exceeding 50 mg. As small increases in plerocercoid mass affect adult fecundity disproportionately in this species, enhanced plerocercoid growth at higher temperatures predicts dramatically increased output of infective parasite stages. Subsequent screening of thermal preferences of sticklebacks from a population with endemic S. solidus infection demonstrated that fish harbouring infective Plerocercoids show significant preferences for warmer temperatures. Our results therefore indicate that parasite transmission might be affected in at least two ways under anthropogenic warming; by enhancing rates of parasite growth and development, and by increasing the likelihood of hosts being able to seek out proliferating warmer microhabitats. Furthermore, our results suggest the potential for positive feedback between parasite growth and host thermal preferences, which could dramatically increase the effects of even small temperature increases. We discuss the possible mechanisms underpinning our results, their likely ecological consequences and highlight key areas for further research.
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differences in adult egg output of schistocephalus solidus from singly and multiply infected sticklebacks
Journal of Parasitology, 2007Co-Authors: Mustafa Dorucu, Iain Barber, D WilsonAbstract:In this study, we recovered Schistocephalus solidus Plerocercoids from singly and multiply infected three-spine sticklebacks, Gasterosteus aculeatus, transferred them individually to in vitro culture conditions, and quantified their lifetime egg output. We found a significant difference in the relationships between plerocercoid mass and lifetime egg output for parasites recovered from singly and multiply infected sticklebacks. Although egg output was strongly and positively related to plerocercoid mass amongst worms from singly infected fish, for those recovered from multiply infected sticklebacks the relationship was marginally nonsignificant and negative, with small worms achieving high levels of egg production. We suggest 2 hypotheses that may explain differences in the egg production of Plerocercoids from singly and multiply infected fish. One possibility is that smaller Plerocercoids in asymmetric multiple infections develop precocially, in response to host manipulation strategies of larger worms that decrease survival prospects of the host. Alternatively, small worms in singly infected sticklebacks may be prevented from becoming sexually mature because they face energetic constraints associated with having to overcome the host's immune response alone. We discuss our results in terms of recent studies examining strategic egg production in helminths.
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nesting courtship and kidney hypertrophy in schistocephalus infected male three spined stickleback from an upland lake
Journal of Fish Biology, 2006Co-Authors: B J Rushbrook, Iain BarberAbstract:The effect of Schistocephalus solidus infection on reproductive development and behaviour of male three-spined stickleback Gasterosteus aculeatus from an upland lake (Llyn Frongoch, Wales, U.K.) was investigated. Uninfected and infected males were collected on two separate occasions during the 2005 breeding season and encouraged to build nests under favourable laboratory conditions. Male nuptial colouration, courtship levels and nesting activity were recorded daily over two separate 21 day studies. Completed nests were removed, encouraging males to build multiple nests. On termination of each study, males were dissected and the kidney and any S. solidus Plerocercoids were removed and weighed. In contrast to uninfected males, which readily built multiple nests, no infected males completed a nest during either study. Infected males also exhibited significantly reduced courtship levels, nesting activity, nuptial colouration, kidney development and body condition, compared with uninfected fish. Among infected three-spined stickleback, courtship and nesting behaviours tended to be more severely impacted in fish harbouring heavier plerocercoid burdens. In contrast to other populations, male three-spined stickleback from Llyn Frongoch appear to be unable to overcome the negative impacts of infections on reproductive development and behaviour when provided with short-term favourable conditions. Discrepancies between populations might have been related to the trophic status at the site of capture, emphasizing the importance of studying the biological effects of infections under different environmental conditions.
A W Pike - One of the best experts on this subject based on the ideXlab platform.
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sequential development of the immune response in rainbow trout oncorhynchus mykiss walbaum 1792 to experimental plerocercoid infections of diphyllobothrium dendriticum nitzsch 1824
Parasitology, 1992Co-Authors: Gregory J E Sharp, A W Pike, Christopher J SecombesAbstract:Development of the inflammatory response of rainbow trout to experimental infections with Diphyllobothrium dendriticum Plerocercoids is described using light and electron microscopy. The cellular response to Plerocercoids occurred within 2 weeks post-infection (p.i.). This was followed by an increase in leucocyte numbers during weeks 3-6 p.i., with full encapsulation of Plerocercoids by week 6 p.i. Neutrophils were the first leucocytes to engage the developing plerocercoid, followed by large influxes of macrophages which transformed into epithelioid cells. With longer times p.i. the accumulation of different leucocyte types increased, and a blood vascular network developed. Full development of the composite cyst was characterized by fibroplasia, particularly at the periphery of the cyst, and the subsequent deposition of a collagenous tissue matrix. Enzyme-linked immunosorbent assay (ELISA) examination of serum samples taken over the 20 week period showed that specific anti-D. dendriticum antibody titres were first detected at 5 weeks p.i. and increased to a maximum by 11 weeks p.i.
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leucocyte migration in rainbow trout oncorhynchus mykiss walbaum optimization of migration conditions and responses to host and pathogen diphyllobothrium dendriticum nitzsch derived chemoattractants
Developmental and Comparative Immunology, 1991Co-Authors: Gregory J E Sharp, A W Pike, Christopher J SecombesAbstract:A rainbow trout leucocyte-derived chemoattractant(s) was prepared and tested as a stimulant of leucocyte migration. It was used to optimize an in vitro leucocyte migration assay using a 48-well micro chemotaxis chamber. This assay has subsequently been used to test the chemoattractant activity of antigen extracts from the tegument of Diphyllobothrium dendriticum Plerocercoids and conditioned medium obtained after in vitro maintenance of live Plerocercoids. Leucocytes were found to have an increased directional motility (chemotactic response) to the host-derived chemoattractant(s) but a random increased motility (chemokinetic response) following stimulation/contact with parasite-derived antigens.
Motomi Torii - One of the best experts on this subject based on the ideXlab platform.
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the fatty acids of each lipid fraction and their use in providing energy source of the plerocercoid of spirometra erinacei
International Journal for Parasitology, 1995Co-Authors: Tetsuhito Fukushima, Yosuke Yamane, Akio Isobe, Nobumasa Hojo, Kuninori Shiwaku, Motomi ToriiAbstract:Abstract The fatty acid concentration of each lipid fraction of Plerocercoids of Spirometra erinacei and the host snake serum was investigated. The major fatty acids of phospholipid of the Plerocercoids were C18:1, C18:0 and C16:0, and those of the host snake serum were C16:0, C18:1 and C18:0, in order of amount in both cases. The changes of the fatty acid composition of phospholipid of the Plerocercoids when theywere incubated in physiological saline at 18°C and at 37°C for 24 h were investigated in both cases. Polyunsaturated fatty acids increased at 18°C, and saturated fatty acids increased at 37°C. Michaelis constants ( K m) of beta-hydroxyacyl-CoA dehydrogenase (HAD), NADH: ubiquinone oxidoreductase (complex I) (NADH: ferricyanide reaction) and complex I (NADH: ubiquinone reaction) for NADH were 20.6, 50 and 13.3 μM, respectively. The ATP production in mitochondria of the Plerocercoids was accelerated by adding ADP and inhibited by adding such electron transport system inhibitors as rotenone, antimycin A and sodium cyanide. These results suggested that the fatty acids in the Plerocercoids played an important role in regulating the fluidity of membrane by changing the composition in membrane lipid corresponding with the change of temperature circumstance. The NADH reduced by HAD might be accepted by the complex I in the electron transport system, and thus the parasites were capable of ATP production in a classical pathway of the oxidative phosphorylation system.
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the metabolism of arachidonic acid to prostaglandin e2 in Plerocercoids of spirometra erinacei
Parasitology Research, 1993Co-Authors: Tetsuhito Fukushima, Yosuke Yamane, Akio Isobe, Nobumasa Hojo, K Shiwaku, Motomi ToriiAbstract:With a simplified method of extracting and purifying prostaglandins, trace prostaglandins (nanogram order) were detected by gas chromatography-mass spectrometry. Arachidonic acid was metabolized to prostaglandin E2 (PGE2) by Plerocercoids ofSpirometra erinacei, the PGE2 was detected in the medium after incubation with arachidonic acid, and the role of albumin in the absorption of free arachidonic acid by Plerocercoids and in the release of its metabolite was investigated. Plerocercoids absorbed arachidonic acid-binding albumin and released PGE2 efficiently. PGE2 is known to suppress the functions of mononuclear cells of the host. The selective release of PGE2 may be related to the escape mechanism of Plerocercoids ofS. erinacei from the host immune system to become established larva migrans, i.e., sparganosis.