| 1. |
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| 2. |
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| 3. |
- Bangyeekhun, E, et al.
(författare)
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Sequence analysis of the ribosomal internal transcribed spacer DNA of the crayfish parasite Psorospermium haeckeli.
- 2001
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Ingår i: Diseases of Aquatic Organisms. - 0177-5103 .- 1616-1580. ; 46:3, s. 217-22
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Tidskriftsartikel (refereegranskat)abstract
- Two morphotypes of the crayfish parasite Psorospermium haeckeli were isolated from 2 crayfish species of different geographical origin. The oval-shaped sporocysts were obtained from the epidermal and connective tissue beneath the carapace of the noble crayfish Astacus astacus fromSweden and Finland. Elongated spores were isolated from the abdominal muscle tissue of the red swamp crayfish Procambarus clarkii from USA. To compare genetic divergence of 2 morphotypes of the parasite, the ribosomal internal transcribed spacer (ITS) DNA (ITS 1 and ITS 2) and the 5.8S rRNAgene were cloned and sequenced. The analysed region is variable in length, with the ribosomal ITS sequence of the European morphotype longer than the North American one. Sequence diversity is found mainly in ITS 1 and ITS 2 regions, and there is 66% and 58% similarity between the 2 morphotypes,respectively. Thus, analysis of the ribosomal ITS DNA suggests that P. haeckeli forms obtained from Europe and North America are genetically diverse, which supports the previously reported morphological characteristics.
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| 4. |
- Bogwald, Mats, et al.
(författare)
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Infection cycle of Marteilia pararefringens in blue mussels Mytilus edulis in a heliothermic marine oyster lagoon in Norway
- 2022
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Ingår i: Diseases of Aquatic Organisms. - : Inter-Research Science Center. - 0177-5103 .- 1616-1580. ; 148, s. 153-166
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Tidskriftsartikel (refereegranskat)abstract
- Agapollen is a traditional heliothermic marine oyster lagoon in western Norway, representing the northernmost site of any Marteilia sp. protists detected in Europe. The semi-closed lagoon is a unique site to study the life cycle and development of M. pararefringens in naive mussels. Two baskets with uninfected mussels were deployed in the lagoon outlet in May and October 2018, respectively, and sampled every 6 wk. The parasite was first detected in the mussels by PCR in early July and by histology in late August. By then, M. pararefringens had developed into mature stages, indicating a rapid development during mid-summer. Sporulation occurred during autumn. Mussels deployed in October never became infected, indicating that transmission was restricted to the warmest period of the year. Pronounced pathology was observed in infected mussels, including degenerated digestive tubules and infiltration of haemocytes. Mussel mortality was observed in the baskets, but whether this was due to infections of M. pararefringens or other environmental factors could not be determined. Plankton samples from the lagoon were also collected for PCR analysis. These samples, dominated by copepods, were positive for M. pararefringens in summer. In sorted samples, M pararefringens was detected in the Acartia spp. and Paracartia grani fractions between July and October. These plankton copepods are therefore potentially involved in the life cycle of M. pararefringens.
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| 5. |
- Edsman, Lennart, et al.
(författare)
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Eroded swimmeret syndrome in female crayfish Pacifastacus leniusculus associated with Aphanomyces astaci and Fusarium spp. infections
- 2015
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Ingår i: Diseases of Aquatic Organisms. - : Inter-Research Science Center. - 0177-5103 .- 1616-1580. ; 112, s. 219-228
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Tidskriftsartikel (refereegranskat)abstract
- We describe a novel syndrome in crayfish, eroded swimmeret syndrome (ESS), affecting wild female signal crayfish Pacifastacus leniusculus. ESS causes partial or total swimmeret erosion. We observed ESS only in female signal crayfish larger than 40 mm carapace length, i.e. sexually mature and probably having carried eggs at least once. The eroded swimmerets were melanised, indicating a crayfish immune system response. We isolated Fusarium tricinctum species complex (SC), F. sambucinum SC, Saprolegnia parasitica and S. australis from the melanised tissue of the eroded swimmerets. ESS includes chronic Aphanomyces astaci infection and a secondary infection by Fusarium sp. In Sweden, we found female signal crayfish with ESS in 6 out of 11 populations with a prevalence below 1% in lakes with commercially productive signal crayfish populations and higher than 29% in lakes with documented signal crayfish population crashes. In Finland, the ESS prevalence was from 3.4 to 6.2% in a commercially productive population. None of the sampled male signal crayfish showed signs of ESS. A caging experiment indicated that females with at least 1 lost swimmeret carried on average 25% fewer fertilized eggs compared to females with intact swimmerets. ESS could significantly reduce individual female fecundity and thus could also affect fecundity at the population level. The decline in reproductive success due to ESS could be among the factors contributing to fluctuations in wild signal crayfish populations.
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| 6. |
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| 7. |
- Farto, R, et al.
(författare)
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Colonization of turbot tissues by virulent and avirulent Aeromonas salmonicida subsp. salmonicida strains during infection
- 2011
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Ingår i: Diseases of Aquatic Organisms. - : Inter Research. - 0177-5103 .- 1616-1580. ; 95, s. 167-173
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Tidskriftsartikel (refereegranskat)abstract
- Preventing disease outbreaks in cultured turbot Psetta maxima L. caused by Aeromonas salmonicida subsp. salmonicida (ASS) requires a better understanding of how this pathogen colonizes its host. Distribution of 1 virulent and 2 avirulent ASS strains in turbot tissues was investigated during early and late stages of infection following an immersion challenge. To track bacteria within the turbot, the ASS strains were tagged with green fluorescent protein (GFP). Both virulent and avirulent strains colonized the epidermal mucus, gills, and intestine within the first 12 h post challenge, suggesting that these sites may serve as points of entry into turbot. Although the avirulent strains colonized these initial sites in the turbot tissues, they were rarely found in the internal organs and were cleared from the host 4 d post challenge. In contrast, the virulent ASS strain was found in the liver and kidney as early as 12 h post challenge and was found in the muscle tissue at very late stages of infection. The virulent strain persisted in all tested host tissues until death occurred 7 d post challenge, suggesting that ASS must colonize and survive within the turbot tissues for an infection to result in death of the fish. Comparisons of the distribution profiles of both virulent and avirulent strains during early and late stages of an infection in turbot has provided important information on the route and persistence of an ASS infection in this host.
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| 8. |
- Grund, Stefanie, et al.
(författare)
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Assessment of fish health status in the Upper Danube River by investigation of ultrastructural alterations in the liver of barbel Barbus barbus
- 2010
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Ingår i: Diseases of Aquatic Organisms. - Luhe, Germany : Inter-Research. - 0177-5103 .- 1616-1580. ; 23, s. 235-248
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Tidskriftsartikel (refereegranskat)abstract
- Despite intensive efforts and tightened guidelines for improvement of water quality over the last 2 decades, declines of fish populations have been reported for several rivers around the world. The present study forms part of a comprehensive weight-of-evidence approach, which aims to identify potential causes for the decline in fish catches observed in the Upper Danube River. The major focus of the present study is the investigation of the health status of wild barbel Barbus barbus L. collected from 3 locations along the Danube River, which experienced different levels of contamination. Whereas the comparison of the condition factor (CF) of field fish with that of control fish revealed no differences, ultrastructural investigations indicated severe disturbance of hepatic cell metabolism in field fish from the more contaminated sites Rottenacker and Ehingen, compared to both control fish and field fish from the less contaminated site Riedlingen. The ultrastructural analysis provided information about reactions of e.g. the rough endoplasmic reticulum, peroxisomes, andmitochondria, indicating an impaired health status of barbel at the sampling sites Rottenacker and Ehingen. Even though a straightforward cause-effect relationship between sediment contamination and ultrastructural alterations could not be established, based on a meta-analysis and toxicity assays it may be suggested that sediment-bound xenobiotics at least partly account for the hepatocellular changes. A relationship between impaired fish health status and the decline of fish catches along the Upper Danube River cannot be excluded.
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| 9. |
- Hallett, S. L., et al.
(författare)
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Dissemination of triactinomyxons (Myxozoa) via oligochaetes used as live food for aquarium fishes
- 2005
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Ingår i: Diseases of Aquatic Organisms. - 0177-5103. ; 65:2, s. 137-152
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Tidskriftsartikel (refereegranskat)abstract
- Freshwater 'tubifex' oligochaetes sold as live food for aquarium fishes were purchased from several pet shops in Munich, Germany, over a 1 yr period (March 2001 to February 2002). These samples were screened for parasitic infections of actinosporean myxozoans to gauge the possibility of parasite dispersal via this route. Of 7 samples, 6 contained infected oligochaetes; waterborne spores were present in 5 samples at the time of purchase. In the laboratory, 12 different types of actinosporeans were released by the oligochaetes. These could be assigned to 4 collective groups: triactinomyxon, aurantiactinomyxon, raabeia and hexactinomyxon; 4 novel triactinomyxons are described herein, a fifth triactinomyxon has been described earlier. Phenotypic descriptions of the spores are accompanied by molecular sequence data (18S rDNA). Descriptions of the other actinosporean types appear elsewhere. The worms sold as 'tubifex' originated from eastern European countries and were identified as a mix of Tubifex tubifex, Limnodrilus hoffmeisteri and L. udekemianus. Sale of live worms (and their accompanying parasite load) has clearly the potential to facilitate introduction both of parasites and suitable hosts to new areas.
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| 10. |
- Hallett, S. L., et al.
(författare)
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Myxozoan parasites disseminated via oligochaete worms as live food for aquarium fishes: descriptions of aurantiactinomyxon and raabeia actinospore types
- 2006
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Ingår i: Diseases of Aquatic Organisms. - 0177-5103. ; 69:2-3, s. 213-225
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Tidskriftsartikel (refereegranskat)abstract
- A total of 7 samples of live freshwater oligochaetes (mixed species), sold as 'tubifex' worms as food for aquarium fishes, were purchased over a 1 yr period from several pet shops in Munich, Germany, and screened for parasitic infections of myxozoans. The water associated with 5 samples contained actinospores at the time of purchase; 6 samples subsequently released spores in the laboratory. In all, 12 types of actinospores (Myxozoa: Myxosporea) from 4 collective groups were released by the oligochaetes. In the current study we provide descriptions of 2 aurantiactinomyxons (Myxobolus intimus Zaika, 1965 and type 1 nov.) and 3 raabeias (type 1 and 2 nov., Raabeia type 1 of Oumouna et al., 2003); descriptions of the 5 triactinomyxon and 2 hexactinomyxon types have been published previously. We include both raabeia and echinactinomyxon types in differential diagnoses of our raabeia forms because a clear distinction between these groups no longer exists in the literature. Comparison of 18S rDNA sequence data revealed that 1 of the novel aurantiactinomyxons was Myxobolus intimus. The sale of worms hundreds of km away from their point of origin is a means of dissemination of myxozoan parasites.
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| 11. |
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| 12. |
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| 13. |
- Kallert, D. M., et al.
(författare)
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Life cycle studies of Myxobolus parviformis sp n. (Myxozoa : Myxobolidae) from bream
- 2005
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Ingår i: Diseases of Aquatic Organisms. - 0177-5103. ; 66:3, s. 233-243
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Tidskriftsartikel (refereegranskat)abstract
- We experimentally followed the life cycle of Myxobolus parviformis sp. n., a myxozoan parasite from the gills of common bream Abramis brama L. Establishing the development of both stages (myxospore and actinospore) in 2 consecutive, full transmission trials, we were able to separate plasmodia of a common genotype from sympatric Myxobolus spp. occurring in naturally infected gill lamellae. Therefore, isolated gill plasmodia representing individual myxosporean 'clones' were used for subsequent infection of oligochaetes after molecular and morphological identification. The plasmodia of this species are located in median to distal regions of the primary gill filaments, forming small spherical pseudocysts. The comparatively small myxospores share some uniform characteristics: they taper posteriorly, have 2 inward inclining polar capsules that occupy half of the spores' interior space, and usually show 4 posterior sutural edge markings. The corresponding actinosporean has already been described morphologically and molecularly. The 18S rDNA sequence of the actinosporean stage was identical in all our samples, including myxospores. The triactinomyxon had a stout style, 32 sporozoites and short tapering caudal processes, and was shed by the tubificid oligochaete Limnodrilus hoffmeisteri. The ellipsoid sporoplasm was covered by a soft sheath which was emitted after valve shell opening upon stimulation by agitation or fish mucus. The molecular data (unique restriction fragment length polymorphism pattern and a 1586 bp 18S rDNA sequence) clearly differ from those for similar species and, together with the morphological data, justify the description of this parasite as a new species.
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| 14. |
- Kärvemo, Simon, 1979-, et al.
(författare)
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Urban environment and reservoir host species are associated with Batrachochytrium dendrobatidis infection prevalence in the common toad
- 2019
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Ingår i: Diseases of Aquatic Organisms. - : INTER-RESEARCH. - 0177-5103 .- 1616-1580. ; 134:1, s. 33-42
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Tidskriftsartikel (refereegranskat)abstract
- Human-induced changes of the environment, including landscape alteration and habitat loss, may affect wildlife disease dynamics and have important ramifications for wildlife conservation. Amphibians are among the vertebrate taxa most threatened by anthropogenic habitat change. The emerging fungal pathogen Batrachochytrium dendrobatidis (Bd) has caused extinctions and population declines in hundreds of anuran species globally. We studied how the urban landscape is associated with the prevalence of Bd infections by sampling 655 anurans of 3 species (mainly the common toad Bufo bufo) in 42 ponds surrounded by different amounts of urban habitat (defined as towns, cities or villages). We also examined the association between Bd infections and a potential reservoir host species (the moor frog Rana arvalis). We found that 38% of the sites were positive for Bd with an infection prevalence of 4.4%. The extent of urban landscape was negatively correlated with Bd infection prevalence. However, the positive association of Bd with the presence of the possible reservoir species was substantially stronger than the urban effects. The body condition index of B. bufo was negatively associated with Bd infection. This Bd effect was stronger than the negative effect of urban landscape on body condition. Our results suggest that urban environments in Sweden have a negative impact on Bd infections, while the presence of the reservoir species has a positive impact on Bd prevalence. Our study also highlights the potential importance of Bd infection on host fitness, especially in rural landscapes.
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| 15. |
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| 16. |
- Lund, Vonne, et al.
(författare)
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Expanding the moral circle: farmed fish as objects of moral concern
- 2007
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Ingår i: Diseases of Aquatic Organisms. - 0177-5103. ; 75:2, s. 109-118
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Tidskriftsartikel (refereegranskat)abstract
- Until recently fish welfare attracted little attention, but international and national legislation and standards of fish welfare are now emerging and an overview of these developments is presented in this study. Whereas animal welfare legislation is based on public morality, animal ethics does not automatically accept public morality as normative and elaborates arguments regarding the way humans should treat animals (referred to as moral standards). In this study we present the most common animal ethics theories. For most of these, sentience is considered a demarcation line for moral concern: if an animal is sentient, then it should be included in the moral circle, i.e. receive moral consideration in its own right and some basic welfare should be ensured. As for fish, research has revealed that the sensory system of teleosts can detect noxious stimuli, and that some kind of phenomenal consciousness, allowing the fish to feel pain, seems to be present. This raises the ethical question as to how much evidence we need in order to act on such indications of fish sentience. A simple risk analysis shows that the probability that fishes can feel pain is not negligible and that if they do indeed experience pain the consequences in terms of the number of suffering individuals are great. We conclude that farmed fish should be given the benefit of the doubt and we should make efforts that their welfare needs are met as well as possible. Finally, the way forward is briefly discussed: efforts must be made to understand what fish welfare means in practical fish farming. This will involve the development of research and education, greater accountability and transparency, compliance with and control of policies, and quality assurance schemes.
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| 17. |
- Meurling, Sara, et al.
(författare)
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Occurrence of Batrachochytrium dendrobatidis in Sweden : higher infection prevalence in southern species
- 2020
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Ingår i: Diseases of Aquatic Organisms. - : Inter-Research Science Center. - 0177-5103 .- 1616-1580. ; 140, s. 209-218
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Tidskriftsartikel (refereegranskat)abstract
- The chytrid fungus Batrachochytrium dendrobatidis (Bd) has caused worldwide declines in amphibian populations. While Bd is widespread in southern and central Europe, its occurrence and distribution in northernmost Europe is mostly unknown. We surveyed for Bd in breeding anurans in Sweden by sampling 1917 amphibians from 101 localities and 3 regions in Sweden (southern, northern and central). We found that Bd was widespread in southern and central Sweden, occurring in all 9 investigated species and in 45.5% of the 101 localities with an overall prevalence of 13.8%. No infected individuals were found in the 4 northern sites sampled. The records from central Sweden represent the northernmost records of Bd in Europe. While the proportion of sites positive for Bd was similar between the southern and central regions, prevalence was much higher in the southern region. This was because southern species with a distribution mainly restricted to southernmost Sweden had a higher prevalence than widespread generalist species. The nationally red-listed green toad Bufotes variabilis and the fire-bellied toad Bombina bombina had the highest prevalence (61.4 and 48.9%, respectively). Across species, Bd prevalence was strongly positively, correlated with water temperature at the start of egg laying. However, no individuals showing visual signs of chytridiomycosis were found in the field. These results indicate that Bd is widespread and common in southern and central Sweden with southern species, breeding in higher temperatures and with longer breeding periods, having higher prevalence. However, the impact of Bd on amphibian populations in northernmost Europe remains unknown.
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| 18. |
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| 19. |
- Ozerov, Mikhail, et al.
(författare)
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Distribution and prevalence of the myxozoan parasite Tetracapsuloides bryosalmonae in northernmost Europe: analysis of three salmonid species
- 2022
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Ingår i: Diseases of Aquatic Organisms. - : Inter-Research Science Center. - 0177-5103 .- 1616-1580. ; 151, s. 37-49
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Tidskriftsartikel (refereegranskat)abstract
- Global climate change is altering the abundance and spread of many aquatic parasites and pathogens. Proliferative kidney disease (PKD) of salmonids caused by the myxozoan Tetracapsuloides bryosalmonae is one such emerging disorder, and its impact is expected to increase with rising water temperature. Yet, the distribution and prevalence of T. bryosalmonae in Northern Europe remain poorly characterized. Here, we studied 43 locations in 27 rivers in northernmost Norway and Finland to describe T. bryosalmonae infection frequency and patterns in 1389 juvenile salmonids. T. bryosalmonae was discovered in 12 out of 27 rivers (44%) and prevalence ranged from 4.2 to 55.5% in Atlantic salmon and from 5.8 to 75% in brown trout among infected rivers. In sympatric populations, brown trout was more frequently infected with T. bryosalmonae than was salmon. Age-specific parasite prevalence patterns revealed that in contrast to lower latitudes, the infection of juvenile fish predominantly occurs during the second summer or later. Temperature monitoring over 2 yr indicated that the mean water temperature in June was 2.1 to 3.2 degrees C higher in rivers containing T. bryosalmonae compared to parasite-free rivers, confirming the important role of temperature in parasite occurrence. Temporal comparison in T. bryosalmonae prevalence over a 10 yr period in 11 rivers did not reveal any signs of contemporary parasite spread to previously uninfected rivers. However, the wide distribution of T. bryosalmonae in rivers flowing to the Barents Sea indicates that climate change and heat waves may cause new disease outbreaks in northern regions.
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| 20. |
- S, Mortensen, et al.
(författare)
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Summer mortalities and detection of ostreid herpesvirus microvariant in Pacific oysterCrassostrea gigasin Sweden and Norway
- 2016
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Ingår i: Diseases of Aquatic Organisms. - : Inter-Research Science Center. - 0177-5103 .- 1616-1580. ; 117:3, s. 171-176
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Tidskriftsartikel (refereegranskat)abstract
- The Pacific oyster Crassostrea gigas has recently expanded its range in Scandinavia. The expansion is presumably a result of northwards larval drift. Massive settlements were recorded in many areas along the Swedish west coast and southern Norway in 2013 and 2014. After the spawning season in 2014, the temperature of the surface water peaked at 24−26°C. After this period, high and sudden mortalities occurred in a Swedish hatchery and in wild populations along the Swedish west coast and south coast of Norway. Surveys and collected data showed that mortalities mainly occurred during 3 wk in September. All size classes were affected, and affected populations displayed a patchy distribution with heavily affected and unaffected populations in close proximity. Flat oysters Ostrea edulis and blue mussels Mytilus edulis were unaffected. Ostreid herpesvirus (OsHV) was detected in moribund Pacific oyster spat as well as in surviving adults. The virus was identified as OsHV-1 μvar. This is the first detection of this variant in Scandinavia, showing that OsHV-1 μvar is present in areas with recent establishments of Pacific oysters, and where there is no aquaculture of this species.
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| 21. |
- Small, H J, et al.
(författare)
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Laser-assisted microdissection: a new tool for aquatic molecular parasitology.
- 2008
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Ingår i: Diseases of aquatic organisms. - 0177-5103. ; 82:2, s. 151-6
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Tidskriftsartikel (refereegranskat)abstract
- Laser-assisted microdissection (LMD) has been developed to isolate distinct cell populations from heterogeneous tissue sections, cytological preparations, or live cell samples. Downstream applications typically include gene expression studies using real-time PCR and array platforms, diagnostic PCR, and protein expression studies. LMD techniques are now commonplace in mainstream biological research and clearly have suitable applications in the field of aquatic pathology and parasitology. The present study used LMD to isolate 2 dinoflagellate parasites (Hematodinium spp.) from formalin-fixed paraffin-embedded tissue sections from 2 crustacean hosts, Cancer pagurus and Portunus trituberculatus. DNA was isolated from LMD parasite preparations, and partial regions (up to 300 bp) of the small subunit and the first internal transcribed spacer region of the rRNA gene complex from the Hematodinium spp. were PCR amplified using diagnostic primers. The amplification products were sequenced to confirm the identity of the targeted regions. The techniques, applications, and limitations of LMD to address questions in aquatic molecular pathology and parasitology are discussed.
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| 22. |
- Smolarz, Katarzyna, et al.
(författare)
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Argyrophilic nucleolar organizer regions (AgNORs) in interphases and metaphases of normal and neoplastic gill cells of Macoma balthica (Bivalvia: Tellinidae) from the Gulf of Gdansk, Baltic Sea
- 2003
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Ingår i: Diseases of Aquatic Organisms. - 0177-5103 .- 1616-1580. ; 56, s. 269-274
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Tidskriftsartikel (refereegranskat)abstract
- Chromosome analysis of gill cells of different populations of Macoma balthica (L.) from the Bay of Gdansk (Baltic Sea) revealed 2 clam categories, 1 with neoplastic features and 1 without. Silver-staining was performed on interphase and metaphase cells of both categories. The mean argyrophilic nucleolar organizer region (AgNOR) count per abnormal interphase cell was significantly higher than in normal interphase cells. Normal silver-stained metaphases had 3 nucleolar organizer region (NOR) chromosome phenotypes. The location of the NORs in the most frequent phenotype (55.6% in 54 metaphases scored) was interstitial on the largest metacentric chromosome pair, Pair No. 1. Abnormal silver-stained metaphases had a higher number of active NOR sites. Different phenotypes were observed (frequency greater than 10% for 67 metaphases scored); 2 were similar to those in normal metaphases and 5 were ectopic. The higher activity of AgNORs observed in abnormal cells confirmed the diagnosis of malignant neoplasia
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| 23. |
- Smolarz, Kasia, et al.
(författare)
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Neoplasia detection in Macoma balthica (Bivalvia) from the Gulf of Gdansk (Baltic Sea, Poland) : comparison of flow cytometry, histology and chromosome analysis
- 2005
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Ingår i: Diseases of Aquatic Organisms. - 0177-5103 .- 1616-1580. ; 65:3, s. 187-195
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Tidskriftsartikel (refereegranskat)abstract
- A flow cytometry protocol was applied for the detection of neoplasia in Macoma balthica L. from the Gulf of Gdansk (Baltic Sea, Poland). A simple method, based on an osmotic shock, was used to permeabilise gill cells. The cytometric pattern of normal clams consisted of 2 peaks, a major peak B and a smaller peak C. The cytometric pattern of affected clams consisted of 2 peaks named B' and C'. Two parameters were used to define the stages of abnormalities in M. balthica clams based on the percentage of cells in peaks B, C, B' and C' and on the ratio between the fluorescence value of peaks B, C, B' and C' in all individuals. Three stages of neoplasia were clearly distinguished by flow cytometry considering peak C'. Stage 1 was characterised by a major population of cells in peak B' and more than 10 % of cells in the C' peak. Stage 2 consisted of a lower percentage of cells in peak B' and more than 25 % of cells in peak C'. Stage 3 of the neoplasia was characterised by a further reduction in peak B' and more than 40 % of cells in peak C'. Flow cytometry allowed for objective detection of neoplasia and provided a rapid method for measuring the DNA content of thousands of cells per individual. The accuracy of flow cytometry was assessed by comparing with standard histological techniques, used here as a reference technique for the detection of neoplasia, and with chromosome analysis. All individuals were analysed in parallel using the 3 techniques. The proportion of normal and affected individuals diagnosed using flow cytometry was comparable to the proportion determined by histology and chromosome analysis
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| 24. |
- Smolarz, Kasia, et al.
(författare)
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Survey for neoplasia in Macoma balthica from the Gulf of Gdansk by flow cytometry
- 2005
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Ingår i: Diseases of Aquatic Organisms. - : Inter-Research Science Center. - 0177-5103 .- 1616-1580. ; 66:1, s. 41-46
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Tidskriftsartikel (refereegranskat)abstract
- Using flow cytometry, 234 Macoma balthica were examined during a survey to determine frequency of neoplasia in the Gulf of Gdansk (Poland). Clams were collected in 4 locations and DNA content in gill tissue cells was determined by flow cytometry using propidium iodide staining. Cell permeabilization was induced by osmotic shock. Prevalence of neoplasia ranged from 9.6 to 26.7 % depending on location. DNA content in aneuploid cells was higher than in normal dividing cells. The fluorescence value for aneuploid cells corresponded to tetraploid/pentaploid cells. Three stages of neoplasia were defined, based on the percentage of aneuploid cells determined by flow cytometry. Histopathological and cytogenetic analyses were also carried out on the same clams for comparative study. Proportions of normal and affected clams detected using flow cytometry were similar to those identified using both methods. In the present study, no clear relationship was demonstrated between prevalence of neoplasia and pollutant detection in the different sampling sites.
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| 25. |
- Stokholm, Iben, et al.
(författare)
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Phylogenomic insights to the origin and spread of phocine distemper virus in European harbour seals in 1988 and 2002
- 2019
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Ingår i: Diseases of Aquatic Organisms. - : Inter-Research Science Center. - 0177-5103 .- 1616-1580. ; 133, s. 47-56
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Tidskriftsartikel (refereegranskat)abstract
- © Inter-Research 2019 · www.int-res.com The 1988 and 2002 phocine distemper virus (PDV) outbreaks in European harbour seals Phoca vitulina are among the largest mass mortality events recorded in marine mammals. Despite its large impact on harbour seal population numbers, and 3 decades of studies, many questions regarding the spread and temporal origin of PDV remain unanswered. Here, we sequenced and analysed 7123 bp of the PDV genome, including the coding and non-coding regions of the entire P, M, F and H genes in tissues from 44 harbour seals to shed new light on the origin and spread of PDV in 1988 and 2002. The phylogenetic analyses trace the origin of the PDV strain causing the 1988 outbreak to between June 1987 and April 1988, while the origin of the strain causing the 2002 outbreak can be traced back to between July 2001 and April 2002. The analyses further point to several independent introductions of PDV in 1988, possibly linked to a southward mass immigration of harp seals in the winter and spring of 1987−1988. The vector for the 2002 outbreak is unknown, but the epidemiological analyses suggest the subsequent spread of PDV from the epicentre in the Kattegat, Denmark, to haul-out sites in the North Sea through several independent introductions.
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