997 resultados para Fish farm sludge


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Human nares are the main niche of Staphylococcus aureus, but farm animals can be also infected (cows) or colonized (pigs) constituting significant reservoir of this pathogen. Previous studies indicated that human and animal strains are quite distinct but the extent of cross-species specialization and transmission remains largely unknown. However, recent reports from several European countries as well as USA and Canada have indicated that employment in farming is an emerging risk factor for MRSA carriage. Pigs were found to be frequently colonized with MRSA, usually with a strain belonging to CC398. It is not known whether animal-human transmission was specific to this particular MRSA strain. S. aureus isolates from cow mastitis and pig colonization isolates were collected in parallel to nasal swab isolates from the animals' caretakers. The isolates were genotyped by AFLP, spatyping, and when appropriate by MLST. The isolates from cow mastitis were genetically uniform in comparison with human isolates. They were quite distinct from farmers\' carriage isolates, indicating pronounced hostspecialization. However, several cases where an infected cow and a colonized farmer had the same strain were detected, including one farm where two farmers were colonized and two cows were infected with MRSA belonging to CC398. Pig isolates were genetically more diverse than cow isolates. They were different from both human and cow isolates with one notable exception. Large fraction of pigs (20%) and pig caretakers (50%) were colonized with isolates belonging to CC398, majority of which were MSSA (2 cases of MRSA). These results indicate that host specialization in S. aureus is quite pronounced. Transmission between humans and farm animals was consequently quite rare. Both MSSA and MRSA strains belonging to otherwise pig-specific CC398 had increased capacity to colonize humans. Study of the genetic factors responsible for host specialization is underway.

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The objective of this work was to evaluate fish oil replacement by soybean oil in diets, as for the effects on the performance and body composition of juveniles of fat snook (Centropomus parallelus). The experiment was carried out in a randomized block design, with three treatments (lipid sources) and six replicates, in a 60-day period. Fat snook juveniles (24.17±0.28g) were distributed in 18 experimental tanks of 200 L each, equipped with aeration and heating systems, under continuous water renovation (800% per day). Three isoproteic (44% CP) and isoenergetic (4,635 kcal CE kg-1) diets were formulated to comprise three replacement rates (0, 50, and 100%) of fish oil by soybean oil. Biometric analyses were done to evaluate fish performance, and two entire specimens from each replicate were used for body composition analyses. The zootechnical indices of weight gain (38.68±5.41 g), feed conversion (1.38±0.10), and specific growth at 1.70±0.18% weight gain per day were considered satisfactory. Lipid source substitution does not affect the performance and body composition of fat snook juveniles, which suggests that soybean oil can replace fish oil in diet formulation.

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Selostus: Kauran kuorinnan aiheuttama jyvien rikkoutuminen ei heikennä säilyvyyttä

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Selostus: Kotoisen kauran ravitsemuksellista arvoa ja energiapitoisuutta voidaan parantaa kuorinnalla

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OBJECTIVES: Immunohistochemistry (IHC) has become a promising method for pre-screening ALK-rearrangements in non-small cell lung carcinomas (NSCLC). Various ALK antibodies, detection systems and automated immunostainers are available. We therefore aimed to compare the performance of the monoclonal 5A4 (Novocastra, Leica) and D5F3 (Cell Signaling, Ventana) antibodies using two different immunostainers. Additionally we analyzed the accuracy of prospective ALK IHC-testing in routine diagnostics. MATERIALS AND METHODS: Seventy-two NSCLC with available ALK FISH results and enriched for FISH-positive carcinomas were retrospectively analyzed. IHC was performed on BenchMarkXT (Ventana) using 5A4 and D5F3, respectively, and additionally with 5A4 on Bond-MAX (Leica). Data from our routine diagnostics on prospective ALK-testing with parallel IHC, using 5A4, and FISH were available from 303 NSCLC. RESULTS: All three IHC protocols showed congruent results. Only 1/25 FISH-positive NSCLC (4%) was false negative by IHC. For all three IHC protocols the sensitivity, specificity, positive (PPV) and negative predictive values (NPV) compared to FISH were 96%, 100%, 100% and 97.8%, respectively. In the prospective cohort 3/32 FISH-positive (9.4%) and 2/271 FISH-negative (0.7%) NSCLC were false negative and false positive by IHC, respectively. In routine diagnostics the sensitivity, specificity, PPV and NPV of IHC compared to FISH were 90.6%, 99.3%, 93.5% and 98.9%, respectively. CONCLUSIONS: 5A4 and D5F3 are equally well suited for detecting ALK-rearranged NSCLC. BenchMark and BOND-MAX immunostainers can be used for IHC with 5A4. True discrepancies between IHC and FISH results do exist and need to be addressed when implementing IHC in an ALK-testing algorithm.

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AMPK, a master metabolic switch, mediates the observed increase of glucose uptake in locomotory muscle of mammals during exercise. AMPK is activated by changes in the intracellular AMP:ATP ratio when ATP consumption is stimulated by contractile activity but also by AICAR and metformin, compounds that increase glucose transport in mammalian muscle cells. However, the possible role of AMPK in the regulation of glucose metabolism in skeletal muscle has not been investigated in other vertebrates, including fish. In this study, we investigated the effects of AMPK activators on glucose uptake, AMPK activity, cell surface levels of trout GLUT4 and expression of GLUT1 and GLUT4 as well as the expression of enzymes regulating glucose disposal and PGC1α in trout myotubes derived from a primary muscle cell culture. We show that AICAR and metformin significantly stimulated glucose uptake (1.6 and 1.3 fold, respectively) and that Compound C completely abrogated the stimulatory effects of the AMPK activators on glucose uptake. The combination of insulin and AMPK activators did not result in additive nor synergistic effects on glucose uptake. Moreover, exposure of trout myotubes to AICAR and metformin resulted in an increase in AMPK activity (3.8 and 3 fold, respectively). We also provide evidence suggesting that stimulation of glucose uptake by AMPK activators in trout myotubes may take place, at least in part, by increasing the cell surface and mRNA levels of trout GLUT4. Finally, AICAR increased the mRNA levels of genes involved in glucose disposal (hexokinase, 6-phosphofructokinase, pyruvate kinase and citrate synthase) and mitochondrial biogenesis (PGC-1α) and did not affect glycogen content or glycogen synthase mRNA levels in trout myotubes. Therefore, we provide evidence, for the first time in non-mammalian vertebrates, suggesting a potentially important role of AMPK in stimulating glucose uptake and utilization in the skeletal muscle of fish.

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Postprint (published version)

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Postprint (published version)

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Epitheliocystis is an infectious disease affecting gills and skin of various freshwater and marine fishes, associated with high mortality and reduced growth of survivors. Candidatus Piscichlamydia salmonis and Clavochlamydia salmonicola have recently been identified as aetiological agents of epitheliocystis in Atlantic Salmon. In addition, several other members of the Chlamydiales order have been identified in other fish species. To clarify the pathogenicity of Chlamydia-like organisms towards fishes, we investigated the permissivity of two fish cell lines, EPC-175 (Fathead Minnow) and RTG-2 (rainbow trout) to three Chlamydia-related bacteria: Waddlia chondrophila, Parachlamydia acanthamoebae and Estrella lausannensis. Quantitative PCR and immunofluorescence demonstrated that W. chondrophila and, to a lesser extent, E. lausannensis were able to replicate in the two cell lines tested. Waddlia chondrophila multiplied rapidly in its host cell and a strong cytopathic effect was observed. During E. lausannensis infection, we observed a limited replication of the bacteria not followed by host cell lysis. Very limited replication of P. acanthamoebae was observed in both cell lines tested. Given its high infectivity and cytopathic effect towards fish cell lines, W. chondrophila represents the most interesting Chlamydia-related bacteria to be used to develop an in vivo model of epitheliocystis disease in fishes.

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The problem concerning livestock waste handling in the Leningrad region has been subjected to a number of research works. However, the requirements for use of manure and sewage sludge as well as for treatment processes are not certain. So, this problem remains relevant and, therefore, further investigation ought to be made. Currently a large amount of sewage sludge and manure is generated in the Leningrad region. These livestock wastes have to be obligatory treated. The most common methods for treatment in the region, such as anaerobic digestion, composting and aging as well as the most potential methods are described in the thesis. The most potential methods for the Leningrad region are anaerobic digestion, composting and combustion. Each method has strengths and weaknesses, which are also considered in the paper. Aging was not considered as potential treatment method because it does not meet the sanitary and epidemiological requirements. Furthermore, the work gives an overview and comparison of Finnish and Russian legislative and normative acts concerning livestock wastes handling. On the whole the requirements of the Russian Federation concerning sewage sludge and manure are not much different from the Finnish ones.

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Artificial reefs have barely been used in Neotropical reservoirs (about five studies in three reservoirs), despite their potential as a fishery management tool to create new habitats and also to understand fish ecology. We experimentally assessed how reef material (ceramic, concrete, and PVC) and time modulated fish colonization of artificial reefs deployed in Itaipu Reservoir, a large reservoir of the mainstem Parana´ River, Brazil. Fish richness, abundance, and biomass were significantly greater in the reef treatments than at control sites. Among the experimental reefs, ceramic followed by the concrete treatments were the materials most effectively colonized, harboring the majority of the 13 fish species recorded. Although dependent on material type, many of the regularities of ecological successions were also observed in the artificial reefs, including decelerating increases in species richness, abundance, mean individual size, and species loss rates with time and decelerating decreases of species gain and turnover rates. Species composition also varied with material type and time, together with suites of life history traits: more equilibrium species (i.e., fishes of intermediate size that often exhibit parental care and produce fewer but larger offspring) of the Winemiller-Rose model of fish life histories prevailed in later successional stages. Overall, our study suggests that experimental reefs are a promising tool to understand ecological succession of fish assemblages, particularly in tropical ecosystems given their high species richness and low seasonality

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Mediterranean endemic freshwater fish are among the most threatened biota in the world. Distinguishing the role of different extinction drivers and their potential interactions is crucial for achieving conservation goals. While some authors argue that invasive species are a main driver of native species declines, others see their proliferation as a co-occurring process to biodiversity loss driven by habitat degradation. It is difficult to discern between the two potential causes given that few invaded ecosystems are free from habitat degradation, and that both factors may interact in different ways. Here we analyze the relative importance of habitat degradation and invasive species in the decline of native fish assemblages in the Guadiana River basin (southwestern Iberian Peninsula) using an information theoretic approach to evaluate interaction pathways between invasive species and habitat degradation (structural equation modeling, SEM). We also tested the possible changes in the functional relationships between invasive and native species, measured as the per capita effect of invasive species, using ANCOVA. We found that the abundance of invasive species was the best single predictor of natives’ decline and had the highest Akaike weight among the set of predictor variables examined. Habitat degradation neither played an active role nor influenced the per capita effect of invasive species on natives. Our analyses indicated that downstream reaches and areas close to reservoirs had the most invaded fish assemblages, independently of their habitat degradation status. The proliferation of invasive species poses a strong threat to the persistence of native assemblages in highly fluctuating environments. Therefore, conservation efforts to reduce native freshwater fish diversity loss in Mediterranean rivers should focus on mitigating the effect of invasive species and preventing future invasions

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Nonnative invasive species are one of the main global threats to biodiversity. The understanding of the traits characterizing successful invaders and invasion-prone ecosystems is increasing, but our predictive ability is still limited. Quantitative information on biotic homogenization and particularly its temporal dynamics is even scarcer. We used freshwater fish distribution data in the Iberian Peninsula in four periods (before human intervention, 1991, 1995, and 2001) to assess the temporal dynamics of biotic homogenization among river basins. The percentage of introduced species among fish faunas has increased in recent times (from 41.8% in 1991 to 52.5% in 2001), leading to a clear increase in the similarity of community composition among basins. The mean Jaccard's index increase (a measure of biotic homogenization) from the pristine situation to the present (17.1%) was similar to that for Californian fish but higher than for other studies. However, biotic homogenization was found to be a temporally dynamic process, with finer temporal grain analyses detecting transient stages of biotic differentiation. Introduced species assemblages were spatially structured along a latitudinal gradient in the Iberian Peninsula, with species related to sport fishing being characteristic of northern basins. Although the comparison of fish distributions in the Iberian Peninsula and France showed significant and generalized biotic homogenization, nonnative assemblages of northeastern Iberian basins were more similar to those of France than to those of the rest of the Iberian Peninsula, indicating a main introduction route. Species introduced to the Iberian Peninsula tended to be mainly piscivores or widely introduced species that previously had been introduced to France. Our results indicate that the simultaneous analysis of the spatial distribution of introduced assemblages (excluding native species that reflect other biogeographical patterns) and their specific traits can be an effective tool to detect introduction and invasion routes and to predict future invaders from donor regions