β-glucan (Macrogard®) was administrated to enhance the immunity and growth of Cyprinus carpio fry. The whole body homogenate of fish sampled with one week intervals during 2nd - 6th weeks post hatching was assayed for the total protein content, lysozyme activity, α-2-macroglobulin content, classical complement pathway activation, and weight gain. After the 3rd week of experimental feeding, the total protein content and the classical complement activity of fish fed β-glucan supplemented diet were higher than controls. Significantly higher lysozyme activity and α-2-macroglobulin levels were noted in group fed β-glucan at the 2nd and 3rd week of diet application. It was demonstrated that β-glucan enriched feeding increased the immunity of common carp at the earliest stages of their development.
Genes related to iron metabolism play an important role in inflammatory response. The objective of this study was to investigate the role of ferritin, transferrin receptors 1a and 1b, and transferrin genes in the response to blood parasite infection in common carp (Cyprinuscarpio L.).
Material and Methods
Two genetically distinct carp groups were used: R3 carp, which are established as being sensitive to parasitic infection, and SA carp (Cyprinus carpio haematopterus) of wild origin. An established challenge model with Trypanoplasma borreli was applied. Challenged carp were sampled to determine their expression levels of transferrin receptors 1a and 1b, ferritin, and transferrin mRNA. Mortality and serum iron concentration were also measured.
The study revealed contrasting differences in the expression profiles of all key iron regulatory genes except the transferrin gene. In the case of other parameters, significant differences were also observed.
Our results demonstrate that the level of parasitic infection depends on the blood iron status. This parameter was related to the origin of the fish.
Cyprinid herpesvirus 3 (CyHV-3) is a virus infecting carp with disease symptoms of gill necrosis, fish discoloration, sunken eyes, and mortality reaching 90%. Several research groups have examined how to potentially abate the consequences of viral activity. Recently we showed that acyclovir inhibits CyHV-3 replication in vitro and in the present study we examined the anti-CyHV-3 activity of the tricyclic derivative of acyclovir 6-(4-MeOPh)-TACV (T-ACV), a fluorescent molecule known for higher lipophilicity than acyclovir, and therefore potentially better candidate for application in vivo.
Material and Methods
CCB and KF1 cell lines were incubated with T-ACV at concentrations of 0, 66.67, and 133.33 μM for three days and toxicity examined with MTT and CV assays. To investigate the antiviral activity of T-ACV, the lines were infected with CyHV-3 or mock infected and incubated for three days with the drug at concentrations of 0 or 66.67 μM. The activity of T-ACV was evaluated by plaque assay and TaqMan qPCR.
T-ACV at a concentration of 66.67 μM displayed low toxicity and inhibited CyHV-3 activity by 13–29%, varying by cell line and method.
The low anti-CyHV-3 activity of T-ACV indicates that it would be reasonable to screen several tricyclic derivatives of acyclovir for such activity.