Innate immune response of Indian major carp, Labeo rohita infected with oomycete pathogen Aphanomyces invadans.

The fish pathogenic oomycete Aphanomyces invadans is the causative agent of epizootic ulcerative syndrome (EUS), a fish disease of international significance and reportable to the World Organisation for Animal Health. In spite of the current and potential impact of A. invadans infection on fisheries and aquaculture sectors of the world, very little is known about the host-A. invadans interactions. In the present study, following experimental infection with A. invadans in one of the Indian major carps, Labeo rohita, sequential changes in various innate immune parameters were monitored. The results indicated that at early stages of infection, no significant changes in any of the studied innate immune parameters were observed. However, at the advanced stages of infection from 6 to 12 days post infection (dpi), the respiratory burst and alternate complement activity were significantly higher whereas lysozyme, antiproteases and α-2 macroglobulin values were significantly lower than the control group and also from the infected group at earlier stages of infection. Since, the possibility of vaccination of fish against A. invadans appears remote due to difficulties in eliciting a specific antibody response, the information generated in the present study could be useful for developing strategies for improving resistance to A. invadans infection by stimulating the innate immunity through immunomodulation.

Alteration in cerebral blood flow, kynurenines with respect to mood profile in freshly recruited armed forces personnel.

The present study is conducted to understand the association of mood profile with the kynurenine pathway (KP) metabolites, and cerebral hemodynamics in freshly recruited central armed forces personnel. Profile of Mood States questionnaire was utilized to assess mood profile, and Total Mood Disturbance (TMD) score was calculated. Transcranial Doppler was used to record blood flow velocity bilaterally of the middle cerebral artery. Chromatographic profile of the kynurenine metabolites was obtained in serum. Further, personnel were stratified according to sociodemographic variables (gender, age and diet) to observe the changes in their KP metabolic status. An activation of the kynurenic acid branch of the KP and the reduction in the mean blood flow velocity, and an increase in Gosling pulsatility index (PI) were observed in females having high TMD score. On gender comparative analysis, kynurenine metabolites of quinolinic acid branch and serotonin were significantly high in males. In males, with increase in age, a significant increase in the quinolinic acid branch of the KP was observed. Furthermore, a significant difference in level metabolites of the KP among the vegetarian and non-vegetarian groups was also observed. In conclusion we observed that increased TMD score was associated with cerebral hypoperfusion and higher vascular resistance along with activation of the KP. Our findings highlighted the importance of multi-facet brain function to showcase the close interaction of various dimensionalities and true picture of the assessee.

Effect of beta-glucan on immunity and survival of early stage of Anabas testudineus (Bloch).

The present experiment was carried out to study the effect of different dosages of beta-glucan suspension derived from barley on the innate immune response and disease resistance of Anabas testudineus spawns against infection caused by Aeromonas hydrophila. Four different dosages of beta-glucan suspension in phosphate buffered saline at the rate of 0, 5, 10, 15 mg l(-1) were taken and 8 days old spawn were exposed for 2 h and 3 h. The cell suspension of spawn was assayed for total protein, acid phosphatase activity, lysozyme activity, bactericidal and NBT. Further, the spawns were challenged with 3 x 10(5) cells ml(-1) of A. hydrophila and survivability percentage and immunological parameters were assayed upto day 7. On day 7, most of the immunological parameters such as lysozyme activity, bactericidal activity and NBT activity were significantly enhanced after exposing the fish to all the concentrations of beta-glucan. Challenge study indicated least mortality in the group of spawns immersed in 15 mg l(-1) beta-glucan suspension for 3 h. Thus, 3 h exposure to beta-glucan suspension could reduce the mortality and increase the immunity of A. testudineus spawns.

Effect of feeding Lipopolysaccharide as an immunostimulant on immune response and immune gene expression of Labeo bata.

This study investigates the effects of dietary lipopolysaccharide (LPS) as an immunostimulant on hematology, innate immunity, immune gene expression and protection against Edwardsiella tarda on Labeo bata. A basal diet supplemented with 0, 50, 100 and 150mg LPS kg-1diet was fed to the four different groups for 30days. The haematological (total erythrocyte count, total leukocyte count, total serum protein, albumin and globulin), innate immune parameters (respiratory burst, serum lysozyme, myeloperoxidase and serum bactericidal activity), immune gene expression (C3, ß-2 microglobulin, lysozyme g, transferrin, IFN-1, IFN-γ) were monitored at 7th, 15th, 30th day and one day post challenge (DPC) with E. tarda. All the studied haematological, innate immune parameters and expression of immune gene increased significantly (p≤0.05) in LPS fed group in comparison with control. However the group fed 100mgkg-1 LPS in feed showed highest activity on 7th day and 1DPC. The group fed 100mgkg-1 LPS also recorded highest relative percent survivability after challenge with E. tarda. Therefore this study suggests that LPS at 100mgkg-1 could be used as an immunostimulant in feed to enhance the protection of bata during periods of increased disease risk.

Effect of ß-glucan on the immune response of early stage of Anabas testudineus (Bloch) challenged with fungus Saprolegnia parasitica.

The present study was carried out to study the effect of different dosages of ß-glucan suspension on immune response and disease resistance in Anabas testudineus spawns against a fungal pathogen Saprolegnia parasitica. Eight day old spawns were exposed for 3 h in four different dosages of ß-glucan suspension in phosphate buffered saline at the rate of 0, 5, 10, 15 mg l(-1). The cell suspension of spawn was assayed for total protein, acid phosphate, lysozyme, bactericidal and NBT activity. The spawns were then challenged with 3x10(5) CFU ml(-1) of S. parasitica. The survivability percentage and immunological parameters were assayed upto day 7. Exposure of fish for 3h to all the concentrations of ß-glucan recorded a significant enhancement in the immunological parameters such as lysozyme activity, bactericidal activity and NBT activity by the end of day 7. The challenge study indicated least mortality in the groups exposed to 10 mgl(-1) and 15 mgl(-1) but 15 mgl(-1) gives little higher survivability. Thus 3 h exposure of ß-glucan suspension could reduce the mortality and increase the immunity of A. testudineus spawns against S. parasitica.