Uticaj -hidroksi--metilbutirata (hmb) dodavanog u hranu na imunitet i otpornost na bakterijske infekcije kod smuđa (sander lucioperca)

U ovoj studiji je ispitivan uticaj metabolita leucina β-hidroksi-β-metilbutirata (HMB) na imunitet i zaštitu od enterične bolesti crvenih usta (ERM) i furunkuloze kod smuđa (Sander lucioperca). Ribe su bile hranjene 18 sati dnevno komercijalnom hranom za pastrmke. Hrana je formulisana tako da obezbedi ili 0 (kontrolna grupa) ili 50 mg HBM/kg telesne težine na dan (grupa hranjena sa HBM) tokom 4 nedelje. Posle hranjenja sa HBM 20 zdravih smuđeva prosečne težine 35 g je anestezirano i uzeta je krv iz kaudalne vene u heparizovane špriceve. Takođe je aseptično izdvojen pronefros svake ribe i dobijena suspenzija pojedinačnih ćelija za izolovanje ćelija koristeći ili Gradisol (Polfa) ili Percoll (Pharmacia) gradijent. Test na izazivanje bolesti upotrebom Yersinia ruckeri ili Aeromonas salmonicida je obavljen 4 nedelje posle hranjenja. Ukratko, svakoj od 20 riba svake grupe data je jedna intraperitonealna injekcija 48 sati kulture Y.ruckeri ili A. salmonicida (0,2 ml). Zabeležen je mortalitet, a prisustvo patogena potvrđeno izolacijom iz bubrega. Rezultati ovog ogleda pokazuju da HBM u dozi od 50 mg/kg telesne težine statistički značajno stimuliše nespecifične ćelijske i humoralne odbrambene mehanizme i zaštitu od Yersinia ruckeri i Aeromonas salmonicida

DL5o da bactéria Aeromonas hydrophila para o matrinxã, Brycon amazonicus

In order to determine the lethal dose (96-h LD50) of the bacteria Aeromonas hydrophila to matrinxã, Brycon amazonicus, to be applied in challenge tests, 90 fish (63.23 ± 6.39 g) were divided into five treatments, with different bacterial solutionsT1 - Control (0.9% NaCl saline solution); T2 (4 x 10(11) cells/ mL); T3 (5 x 10(11) cells/ mL); T4 (1.36 x 10(12) cells/ mL) and T5 (3.06 x 10(12) cells/ mL). Fish were previously anesthetized with benzocaine (60 mg L-1), inoculated in the peritoneal cavity with the bacterial suspensions and then distributed into fifteen 80-L test chambers, where the water variables were monitored and fish mortality was observed. The experiment was randomly designed in three replicates and the 96-h LD50 was estimated according to the trimmed Spearman-Karber method. Water quality variables remained within adequate ranges for fish health and performance. Fish mortality rate increased with the bacterial concentrations of A. hydrophila (T1 = 0%; T2 = 16.66%; T3 = 44.44%; T4 = 72.22% and T5 = 100%), and the first mortalities were observed after 57 h, although the signs of the bacterial infection were already observed 24 h after the inoculation. The results indicate that the 96-h LD50 value of A. hydrophila to matrinxã is 6.66 x 10(11) cells/ mL.Para determinar a dose letal (DL50 96-h) da bactéria Aeromonas hydrophila para o matrinxã, Brycon amazonicus, com aplicabilidade para testes de desafio, foram utilizados 90 peixes (63,23 ± 6,39 g), divididos em cinco tratamentos, com diferentes soluções bacterianas: T1 - Controle (solução salina 0,9% NaCl); T2 (4 x 10(11) células/ mL); T3 (5 x 10(11) células/ mL-1); T4 (1,36 x 10(12) células/mL-1) e T5 (3,06 x 10(12) células/ mL-1). Os peixes foram previamente anestesiados com benzocaína (60 mg L-1), inoculados na cavidade peritoneal com as suspensões bacterianas e distribuídos em 15 aquários de vidro de 80 L de capacidade, com aeração constante. O experimento teve duração de 96 h, no qual foram monitoradas a mortalidade e a qualidade da água. O delineamento experimental foi inteiramente casualisado com três réplicas e a DL50 96-h foi estimada de acordo com o método Spearman-Karber. Durante o experimento os parâmetros físico-químicos da água permaneceram dentro das condições consideradas adequadas para o desenvolvimento e saúde dos organismos aquáticos. A mortalidade dos peixes aumentou nas concentrações crescentes de A. hydrophila (T1 = 0%; T2 = 16,66%; T3 = 44,44%; T4 = 72,22% e T5 = 100%), contudo, as primeiras mortalidades ocorreram em 57 h após a inoculação das concentrações bacterianas, sendo observados os primeiros sinais de infecção em 24 h após a inoculação. Os resultados indicam que o valor da DL50 96-h da bactéria A. hydrophila para o matrinxã foi igual a 6,66 x 10(11) células/mL de solução salina

The in vitro effect of commercially available noble metal nanocolloids on the rainbow trout (Oncorhynchus mykiss) leukocyte and splenocyte activity

The growing popularity of nanotechnology in the past decade has increased nanomaterial concentrations in the environment and the risk of their toxicity for aquatic organisms. Metal nanoparticles, which are easily absorbed and accumulated by fish, are probably able to interact directly with their immunocompetent cells. The objective of this study was to evaluate the in vitro effect of commercially available silver, gold and copper nanocolloids on the rainbow trout leukocyte and splenocyte activity. At high concentrations, all of the nanocolloids studied had adverse effects on the proliferative response of trout lymphocytes, and the most toxic of them, silver, decreased also the respiratory burst activity of splenocytes. Low concentrations of silver nanocolloid, however, had a stimulating effect on the lymhocyte proliferation

Quantification of antibody secreting cells to Yersinia ruckeri by ELISPOT assay after in vivo and in vitro immunization of rainbow trout (Oncorhynchus mykiss)

International audienc

Commercial metal-based nanocolloids - lack of virucidal activity against ECBO virus

Metallic nanoparticles, mainly silver ones, have been widely used as antibacterial agents, and some studies shown they also exert direct antiviral activity against both enveloped and non-enveloped viruses. The objective of this study has been to evaluate the virucidal activity of commercial silver, gold, copper and platinum nanocolloids, recommended by the manufacturer as antimicrobials, against the ECBO virus, according to Polish Standard PN-EN 14675:2006. The highest experimentally observed decrease in the viral load was 0.875 log, which - when contrasted with the reduction in virus titre of at least 4 log expected from disinfectants - indicates that none of the analyzed nanocolloids had a disinfectant power towards the ECBO virus under the conditions defined by the standard

Effects of lindane exposure on rainbow trout (Oncorhynchus mykiss) immunity. II. In vitro restoration of antibody-secreting cells and lymphocyte proliferation activity by nitrogranulogen after in vivo immunosuppression due to lindane

International audienc

Retroviruses of wild and cultured fish

Retroviruses comprise a large group of enveloped RNA viruses which have been found in a wide range of vertebrate species including fish. To date a number of fish retrovirus genomes have been partially or completely sequenced. Phylogenetic analysis and genome organization indicate a high diversity of fish retroviruses as well as some unique structural features that have not been found in any other retroviruses. Piscine retroviruses comprise both exogenous and endogenous viruses; most of them are associated with proliferative diseases. Because several of these proliferative diseases have a seasonal trend, they provide an excellent model for studying tumor development and regression. The aim of this work was to review the best-described fish retroviruses

Effect of levamisole on the lymphocyte and macrophage activity in carp (Cyprinus carpio)

International audienc

Some effects of dichlorvos on carp metabolism

International audienc