INTRODUCTION: Honey bee viruses have been shown to negatively affect the vigour and longevity of European honey bees (Apis mellifera L). In the present work, beehive materials were tested for their potential to serve as non-invasive samples for honey bee virus detection. MATERIAL AND METHODS: Honey, pollen, hive debris, hive grid smears and forager honey bees were collected from 24 hives at four locations in the Czech Republic. Deformed wing virus (DWV), acute bee paralysis virus (ABPV), sacbrood virus (SBV) and black queen cell virus (BQCV) were detected using a reverse transcription PCR (RT-PCR) and real-time quantitative RT-PCR and the results for bees and alternative materials compared. RESULTS: All forager bee samples contained DWV, BQCV and SBV and 54.2% had ABPV. When comparing beehive materials to bees, the most promising results were obtained from honey and pollen samples, with BQCV and SBV detected in all honey samples and ABPV in 12.5%. Detection of SBV was achieved in 91.6% of pollen samples, detection of BQCV in 87.5% and detection of DWW in 75%. The results for debris and smears were less consistent with the viral profile of the forager samples. CONCLUSION: The best candidate materials for honey bee virus detection in a non-invasive technique are honey and pollen.
- Klíčová slova
- acute bee paralysis virus, black queen cell virus, deformed wing virus, honey bee viruses, sacbrood virus,
- Publikační typ
- časopisecké články MeSH
- Klíčová slova
- Ligula intestinalis, Cyprinidae, atypical location, plerocercoids,
- MeSH
- Cestoda * MeSH
- cestodózy * veterinární MeSH
- Cyprinidae * MeSH
- máloostní * MeSH
- nemoci ryb * MeSH
- sladká voda MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
In the present study, we describe a natural outbreak of carp edema virus disease (CEVD) in koi carp, concentrating on clinical manifestation, gross and microscopic pathology, immunological parameters, viral diagnostics, and phylogenetic analysis. Examination of white blood cell parameters showed increased monocyte and decreased lymphocyte counts in CEV-affected fish compared to healthy control fish. Regarding immune system functioning, the present work shows, for the first time, enhanced phagocytic activity in CEV-affected fish. Respiratory burst of phagocytes was strongly increased in diseased fish, the increase being attributed to an increased phagocyte count rather than enhancement of their metabolic activity. The present work also newly shows histopathological changes in the pancreatic tissue of diseased koi.
- Klíčová slova
- histology, immunology, koi sleepy disease, respiratory burst,
- MeSH
- edém MeSH
- fylogeneze MeSH
- infekce vyvolané poxviry * MeSH
- kapři * MeSH
- nemoci ryb * MeSH
- Poxviridae * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- kazuistiky MeSH
- práce podpořená grantem MeSH
Disease conditions that involve multiple predisposing or contributing factors, or manifest as low performance and/or low-level mortality, can pose a diagnostic challenge that requires an interdisciplinary approach. Reaching a diagnosis may also be limited by a lack of available clinical profile parameter reference ranges to discriminate healthy fish from those affected by specific disease conditions. Here, we describe our experience investigating poorly performing rainbow trout (Oncorhynchus mykiss) in an intensive recirculation aquaculture, where reaching a final diagnosis of nephrocalcinosis was not as straightforward as one would wish. To list the issues making the diagnosis difficult, it was necessary to consider the creeping onset of the problem. Further diagnostic steps needed to ensure success included obtaining comparative data for fish blood profiles and water quality from both test and control aquacultural systems, excluding infections with salmonid pathogenic agents and evaluating necropsy findings. Major events in the pathophysiology of nephrocalcinosis could be reconstructed as follows: aquatic environment hyperoxia and hypercapnia → blood hypercapnia → blood acid-base perturbation (respiratory acidosis) → metabolic compensation (blood bicarbonate elevation and kidney phosphate excretion) → a rise in blood pH → calcium phosphate precipitation and deposition in tissues. This case highlights the need to consider the interplay between water quality and fish health when diagnosing fish diseases and reaching causal diagnoses.
- Klíčová slova
- acid-base, aquaculture, blood acid-base balance, carbon dioxide, fish health, rainbow trout, water quality,
- Publikační typ
- časopisecké články MeSH
Understanding disease aetiology and pathologic mechanisms is essential for fish health evaluation. Carp edema virus (CEV) is the causative agent of a disease (CEVD) responsible for high mortality rates in both wild and cultured common carp Cyprinus carpio. Inspection of two carp specimens from a pond with high fish mortality revealed CEV infection in both the host and its ectoparasite (Argulus foliaceus). In addition to flavobacteria, well known to be associated with gill lesions, we found that free-living eukaryotes (amoebae and ciliates) and a temporary parasite (Ichthyobodo spp.) colonizing the gills may also contribute to alterations in gill structure and/or function, either directly, through firm (Ichthyobodo) or weak (amoebae) attachment of trophozoites to the gill epithelium, or indirectly, through carriage of pathogenic bacteria. Bacterial assemblages rich in families and genera, with predominance of Cetobacterium spp. in low-intensity alteration of the gill tissue and of Flavobacterium spp. in gills with extensive necrotic lesions, were detected in gills and within the cytoplasm of associated amoebae using high-throughput sequencing. Quantitative PCR indicated F. swingsii as the prevailing flavobacterial species within amoebae from less affected gills and F. psychrophilum within amoebae from extensively affected gills. This case study suggests that eukaryotic organisms as part of the gill pathobiome may also contribute to irreversible gill lesions seen in CEVD. Emphasizing the complexity of mutual relationships between bacterial assemblages and eukaryotic co-pathogens, further studies regarding factors that trigger pathology and influence severity in the CEV-positive carp are needed.
- Klíčová slova
- Cyprinus carpio, CEV, fish, pathogenic assemblage, virus diseases,
- MeSH
- edém MeSH
- Flavobacterium MeSH
- infekce vyvolané poxviry * veterinární MeSH
- kapři * MeSH
- nemoci ryb * mikrobiologie MeSH
- Poxviridae * MeSH
- žábry patologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- kazuistiky MeSH
While the potential effects of pathogens spread from farmed fish to wild populations have frequently been studied, evidence for the transmission of parasites from wild to farmed fish is scarce. In the present study, we evaluated natural bacterial and parasitic infections in brown trout (Salmo trutta m. fario) collected from the Černá Opava river (Czech Republic) as a potential source of infections for rainbow trout (Oncorhynchus mykiss) reared in a flow-through farm system fed by the same river. The prevalence of bacterial and protozoan infections in farmed fish was comparable, or higher, than for riverine fish. Despite this, none of the infected farmed fish showed any signs of severe diseases. Substantial differences in metazoan parasite infections were observed between wild and farmed fish regarding monogeneans, adult trematodes, nematodes, the myxozoan Tetracapsuloides bryosalmonae found in riverine fish only, and larval eye-fluke trematodes sporadically found in farmed fish. The different distribution of metazoan parasites between brown and rainbow trout most probably reflects the availability of infected intermediate hosts in the two habitats. Despite the river being the main water source for the farm, there was no significant threat of parasite infection to the farmed fish from naturally infected riverine fish.
- Klíčová slova
- bacteria, brown trout, freshwater fish farm, parasites, rainbow trout,
- Publikační typ
- časopisecké články MeSH
Fish are exposed to numerous stressors in the environment including pollution, bacterial and viral agents, and toxic substances. Our study with common carps leveraged an integrated approach (i.e., histology, biochemical and hematological measurements, and analytical chemistry) to understand how cyanobacteria interfere with the impact of a model viral agent, Carp sprivivirus (SVCV), on fish. In addition to the specific effects of a single stressor (SVCV or cyanobacteria), the combination of both stressors worsens markers related to the immune system and liver health. Solely combined exposure resulted in the rise in the production of immunoglobulins, changes in glucose and cholesterol levels, and an elevated marker of impaired liver, alanine aminotransferase (ALT). Analytical determination of the cyanobacterial toxin microcystin-LR (MC-LR) and its structurally similar congener MC-RR and their conjugates showed that SVCV affects neither the levels of MC in the liver nor the detoxification capacity of the liver. MC-LR and MC-RR were depurated from liver mostly in the form of cysteine conjugates (MC-LR-Cys, MC-RR-Cys) in comparison to glutathione conjugates (LR-GSH, RR-GSH). Our study brought new evidence that cyanobacteria worsen the effect of viral agents. Such inclusion of multiple stressor concept helps us to understand how and to what extent the relevant environmental stressors co-influence the health of the fish population.
- Klíčová slova
- conjugates, cyanobacteria, immune system, microcystins, spring viraemia of carp,
- MeSH
- chemické látky znečišťující vodu toxicita MeSH
- kapři mikrobiologie MeSH
- Microcystis chemie MeSH
- mikrocystiny toxicita MeSH
- nemoci ryb chemicky indukované patofyziologie MeSH
- roční období MeSH
- stupeň závažnosti nemoci * MeSH
- testy toxicity MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- chemické látky znečišťující vodu MeSH
- mikrocystiny MeSH
Diagnostic accuracy of pathogen detection depends upon the selection of suitable tests. Problems can arise when the selected diagnostic test gives false-positive or false-negative results, which can affect control measures, with consequences for the population health. The aim of this study was to compare sensitivity of different diagnostic methods IHC, PCR and qPCR detecting Tetracapsuloides bryosalmonae, the causative agent of proliferative kidney disease in salmonid fish and as a consequence differences in disease prevalence. We analysed tissue from 388 salmonid specimens sampled from a recirculating system and rivers in the Czech Republic. Overall prevalence of T. bryosalmonae was extremely high at 92.0%, based on positive results of at least one of the above-mentioned screening methods. IHC resulted in a much lower detection rate (30.2%) than both PCR methods (qPCR32: 65.4%, PCR: 81.9%). While qPCR32 produced a good match with IHC (60.8%), all other methods differed significantly (p < .001) in the proportion of samples determined positive. Both PCR methods showed similar sensitivity, though specificity (i.e., the proportion of non-diseased fish classified correctly) differed significantly (p < .05). Sample preservation method significantly (p < .05) influenced the results of PCR, with a much lower DNA yield extracted from paraffin-embedded samples. Use of different methods that differ in diagnostic sensitivity and specificity resulted in random and systematic diagnosis errors, illustrating the importance of interpreting the results of each method carefully.
- Klíčová slova
- diagnostic sensitivity, diagnostic specificity, immunohistochemistry, polymerase chain reaction, prevalence, proliferative kidney disease,
- MeSH
- diagnostické testy rutinní metody veterinární MeSH
- Myxozoa izolace a purifikace MeSH
- nemoci ryb diagnóza epidemiologie parazitologie MeSH
- Oncorhynchus mykiss * MeSH
- parazitární nemoci u zvířat diagnóza epidemiologie parazitologie MeSH
- parazitologie metody MeSH
- prevalence MeSH
- pstruh * MeSH
- řeky MeSH
- vodní hospodářství MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- srovnávací studie MeSH
- Geografické názvy
- Česká republika epidemiologie MeSH
Significant mortalities associated with emerging viral diseases are challenging the economy of common carp aquaculture. As such, there is an increased need to disentangle how infected fish cope with progressive disease pathology and lose the ability for homeostatic maintenance of key physiological parameters. A natural carp edema virus (CEV) infection outbreak at a carp fish farm provided an opportunity to examine diseased and healthy carp in the same storage pond, thereby contributing to our better understanding of CEV disease pathophysiology. The disease status of fish was determined using PCR-based virus identification combined with analysis of gill pathology. Compared with healthy control carp, the blood chemistry profile of CEV-infected fish revealed major disruptions in electrolyte and acid-base balance (i.e., hyponatraemia, hypochloraemia, hyperphosphatemia, elevated pH, base excess, and anion gap and decreased partial dissolved carbon dioxide). In addition, we recorded hyperproteinaemia, hyperalbuminaemia, hypotonic dehydration, endogenous hyperammonaemia, and decreased lactate along with increased creatinine, alkaline phosphatase, alanine aminotransferase, and aspartate aminotransferase. Red blood cell associated hematology variables were also elevated. The multivariate pattern of responses for blood chemistry variables (driven by sodium, pH, partial dissolved carbon dioxide, ammonia, and albumin in the principal component analysis) clearly discriminated between CEV-infected and control carp. To conclude, we show that CEV infection in carp exerts complex adverse effects and results in severe metabolic disturbance due to the impaired gill respiratory and excretory functioning.
- Klíčová slova
- electrolyte and acid-base imbalance, emerging viral diseases, endogenous hyperammonaemia, fish, hypotonic dehydration, pathophysiology,
- Publikační typ
- časopisecké články MeSH
Tetracapsuloides bryosalmonae (Myxozoa: Malacosporea) is the causative agent of proliferative kidney disease (PKD), which affects both wild and farmed salmonid fish. The objective of this study was to outline differences in susceptibility to PKD in different salmonid species, hybrids and breeding lineages. Susceptibility to T. bryosalmonae infection was established based on cumulative mortality, pathological findings and detection of T. bryosalmonae in the kidney using immunohistochemistry and molecular methods. Determination of pure and hybrid individuals of different species in the genus Salvelinus, and dissimilarity of rainbow trout lineages, was performed using traditional polymerase chain reaction (PCR) and microsatellite analyses. Rainbow trout displayed higher disease severity compared with brook trout and Alsatian charr. Moreover, the results indicated differences in infection susceptibility, not only among different salmonid species but also among different lineages of charr and rainbow trout. Our study indicated that some salmonid species and even different lineages of the same species are more suitable for farming under PKD pressure.
- Klíčová slova
- Tetracapsuloides bryosalmonae, Alsatian charr, brook trout, genetic lineage, rainbow trout,
- MeSH
- imunohistochemie veterinární MeSH
- mikrosatelitní repetice MeSH
- Myxozoa genetika patogenita MeSH
- nemoci ledvin patologie MeSH
- nemoci ryb patologie MeSH
- Oncorhynchus mykiss parazitologie MeSH
- parazitární nemoci u zvířat patologie MeSH
- polymerázová řetězová reakce veterinární MeSH
- pstruh parazitologie MeSH
- vodní hospodářství MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH
