Kalopanax pictus as feed additive controls bacterial and parasitic infections in kelp grouper, Epinephelus bruneus

Feeding kelp grouper, Epinephelus bruneus (26.1 ± 1.4), with 0%, 0.1%, 1.0%, and 2.0% Kalopanax pictus extract-supplementation diets, for 30 days reduced mortality on being challenged intraperitoneally 100 μl with bacterium Vibrio alginolyticus (2.1 × 10(7) cfu ml(-1)) and ciliate parasite Philasterides dicentrarchi (2.3 × 10(7) ciliates ml(-1)). The red blood cells (RBC), white blood cells (WBC), haemoglobin, haematocrit, lymphocytes, and monocytes levels significantly increased in kelp grouper fed with all doses of K. pictus-supplementation diets and challenged with bacterium and parasite when compared to control. However, the levels of mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), neutrophils, and thrombocytes did not significantly. The phagocytic activity, complement activity, and antiprotease activity did not significantly change in kelp grouper fed with 0.1% K. pictus-supplementation diets and challenged with bacterium and parasite. The respiratory activity, lysozyme activity, bactericidal activity, total protein level, and myeloperoxidase levels significantly increased in kelp grouper fed with all the doses of K. pictus-supplementation diet and challenged with bacterium and parasite. However, α2-macroglobulin level significantly increased with 1.0% diet, but not with 0.1% and 2.0% diets. Therefore this study suggests that 1.0% and 2.0% K. pictus-supplementation diets positively protected and enhanced the immune system in kelp grouper E. bruneus against V. alginolyticus and P. dicentrarchi infection.     

Influence of diet enriched with green tea on innate humoral and cellular immune response of kelp grouper (Epinephelus bruneus) to Vibrio carchariae infection

Effect of diet enriched with green tea at 0, 0.01, 0.1 or 1.0% levels on immune responses such as non-specific humoral (lysozyme, antiprotease and complement) and cellular (myeloperoxidase content, production of reactive oxygen, and nitrogen species) and disease resistance on week 1, 2 or 4 in kelp grouper Epinephelus bruneus challenged with Vibrio carchariae (2.47 × 10(8) CFU ml(-1)) was quantified. At all doses green tea supplementation significantly enhanced the serum lysozyme activity from weeks 1 to 4. On the other hand, after week 2 the serum hemolytic complement activity, leucocyte myeloperoxidase content and reactive nitrogen species protection significantly increased in groups fed with 0.01 and 0.1% green tea supplementation diets. The serum antiprotease activity significantly increased in group fed with at 1.0% green tea from week 1 to 4. However, all diets except at 0.01% level resulted in a significant decrease in reactive oxygen species protection during the experimental period. Challenged groups fed with green tea enriched diet at 0.01 and 0.1% level had a higher relative percent survival than with 1.0% diet on week 1, 2 or 4. The results suggest that dietary administration of green tea supplementation at a concentration of 0.01 and 0.1% level positively enhances the non-specific humoral and cellular immune responses and disease resistance of kelp grouper E. bruneus to V. carchariae.     

Non-specific immune response and disease resistance induced by Siegesbeckia glabrescens against Vibrio parahaemolyticus in Epinephelus bruneus

The immunomodulatory effect of Siegesbeckia glabrescens extract-supplementation diets on innate immune response and disease resistance of kelp grouper, Epinephelus bruneus against Vibrio parahaemolyticus at weeks 1, 2, and 4 is reported. The serum lysozyme activity was significantly enhanced with any enriched diet from weeks 1-4 when compared to control diet (0%). The alternative complement haemolytic activities significantly were enhanced with all enriched diets on weeks 2 and 4 whereas the cellular reactive oxygen species (ROS) was significantly enhanced only with 1.0% and 2.0% diets. The reactive nitrogen intermediate (RNI) value was significantly enhanced with any enriched diet on weeks 2 and 4, but on first week it did not differ from control. The myeloperoxidase (MPO) production significantly increased with 1.0% and 2.0% diets from second week onwards; with other enriched diets the increase manifested on fourth week; but during first week it did not vary from that of the control with any enriched diet. The protection in terms of cumulative mortality was the least being 25% and 20% when fed with 1.0% and 2.0% diets. The present results indicate that feeding kelp grouper with S. glabrescens extract enriched diet at 1.0% and 2.0% levels significantly enhance the immunological parameters, increase the disease resistance and minimize the cumulative mortality in E. bruneus against V. parahaemolyticus.     

Enhancement of Eriobotrya japonica extracts on non-specific immune response and disease resistance in kelp grouper Epinephelus bruneus against Vibrio carchariae

The present study investigated the effect of Eriobotrya japonica extracts at 0%, 0.1%, 1.0%, and 2.0% doses supplementation with feed on non-specific immune response, hematological and biochemical profile, and disease resistance against Vibrio carchariae in kelp grouper Epinephelus bruneus at weeks 1, 2, and 4. The white blood cell (WBC) significantly increased in fish fed with 0.1%, 1.0%, and 2.0% diets on weeks 1 and 2 when compared to the control. However, the glucose always decreased from the control except on week 2 against pathogen. The serum total protein, albumin, and globulin significantly increased at week 2 but they did not changed significantly at weeks 1 and 4. The superoxide anion, lymphokines production index, and phogocytosis did not significantly increased in any diet on the first week whereas it was significantly enhanced in 1.0% and 2.0% supplementation diets on weeks 2 and 4 against V. carchariae when compared to control. All diets significantly enhanced the serum lysozyme activity, bactericidal activity, and haemolytic complement activity from weeks 1-4 as compared to control. The serum agglutinating antibody titre did not significantly enhance on the first week whereas it was significantly enhanced on weeks 2 and 4. Fish fed with 1.0% and 2.0% doses diets was found lower mortality than 0.1% diet. Thus, this study suggested that 1.0% and 2.0% doses supplementation diets could be advocated to enhance the immune response and production disease from V. carchariae in E. bruneus.     

Styrax japonica supplementation diet enhances the innate immune response in Epinephelus bruneus against bacterial and protozoan infections

Kelp grouper, Epinephelus bruneus, fed for 30 days with 0% (control), 0.1%, 1.0%, and 2.0% of Styrax japonica supplementation diets, led to reductions in mortality after being challenged with a bacterium (Vibrio harveyi) and a ciliate protozoan (Uronema marinum). The enriched diets significantly increased the survival rate as compared to the controls. The phagocytic and respiratory activities were significantly increased in kelp groupers given 1.0% and 2.0% enriched diets. The complement activity, lysozyme activity, serum bactericidal activity, and total protein level significantly increased with any enriched diet against the pathogens; however antiprotease activity and myeloperoxidase levels significantly increased only with 1.0% and 2.0% enriched diets while the α2-macroglobulin level was significantly enhanced with 1.0% enriched diet. The study suggests that incorporation of S. japonica at 1.0% and 2.0% level in the diet significantly enhances the immune responses in the kelp grouper E. bruneus against V. harveyi and U. marinum.     

Effect of dietary supplementation with Suaeda maritima on blood physiology, innate immune response, and disease resistance in olive flounder against Miamiensis avidus

The effect of Suaeda maritima enriched diet on blood physiology, innate immune response, and disease resistance in olive flounder Paralichythys olivaceus against Miamiensis avidus on weeks 1, 2, and 4 was investigated. Feeding with any enriched diet and then challenging with M. avidus significantly increased white blood cells (WBC) on weeks 2 and 4; the red blood cells (RBC) significantly increased with 0.1% and 1.0% enriched diets on week 4. The hemoglobin (Hb) and hematocrit (Ht) levels significantly increased when fed with 0.1% and 1.0% supplementation diets on weeks 2 and 4. The mean corpuscular volume (MCV) did not significantly vary with any diet and time; however the mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC) significantly increased with 0.1% and 1.0% supplementation diets on weeks 2 and 4. The leukocytes such as lymphocytes (Lym), monocytes (Mon), neutrophils (Neu) and biochemical parameters such as total protein (TP), glucose (GLU), and calcium (CAL) levels significantly increased in 0.1% and 1.0% supplementation diet fed groups on weeks 2 and 4. The serum lysozyme activity was significantly enhanced in 0.1% and 1.0% supplementation diet fed groups from weeks 1 to 4 when compared to the control (0% herbal extract enriched diet). The scuticocidal activity and respiratory burst activity were significantly enhanced when fish were fed with 0.1% and 1.0% supplementation diets from weeks 2 and 4. The protective effect in terms of cumulative mortality (50% and 40%) was low in groups on being fed with 0.1% and 1.0% supplemented diet. Therefore the present study suggested that 0.1% and 1.0% S. maritime-supplemented diets protect the hematological and biochemical parameters, improving the innate immunity, affording protection disease from M. avidus infection in olive flounder.     

Effect of Coriolus versicolor supplemented diet on innate immune response and disease resistance in kelp grouper Epinephelus bruneus against Listonella anguillarum

The effect of Coriolus versicolor extract supplemented diets on innate immune response and disease resistance in kelp grouper, Epinephelus bruneus against Listonella anguillarum, is reported. Kelp grouper were divided into four groups of 25 each and fed with C. versicolor enriched diets at 0% (control), 0.01%, 0.1%, and 1.0% level. After 30 days of feeding, all fish were injected interaperitoneally (i.p.) with 50 μl of L. anguillarum (4.7 × 10⁷ CFU) to investigate the immune parameters at weeks 1, 2, and 4. The reactive oxygen species and reactive nitrogen species production were significantly enhanced in fish fed with 0.1% and 1.0% supplementation diets from weeks 1-4 when compared to the non enriched diet fed and infected control. The phagocytic activity significantly increased with 0.1% and 1.0% diets on weeks 2 and 4. The leucocyte myeloperoxidase content, lysozyme activity, and total protein level significantly increased when fed with 0.1% and 1.0% supplementation diets from weeks 1-4. The cumulative mortality was 35% and 45% in 1.0% and 0.1% enriched diet fed groups whereas it was 55% and 80% in 0.01% and 0% groups respectively. The present results suggest that diets enriched with C. versicolor at 0.1% or 1.0% level positively enhance the innate immune system and affords protection from L. anguillarum.     

Diet enriched with mushroom Phellinus linteus extract enhances the growth, innate immune response, and disease resistance of kelp grouper, Epinephelus bruneus against vibriosis

The effect of diet supplemented with Phellinus linteus fed for 30 days was investigated in grouper Epinephelus bruneus challenged with Vibrio anguillarum, Vibrio harveyi, Vibrio alginolyticus, and Vibrio carchariae; infected and treated fish had a significantly higher percent weight gain and feed efficiency. In groups fed with enriched diet and challenged with V. anguillarum and V. harveyi the mortality rate declined with a consequent rise in survival rate than with other pathogens. On the other hand, in groups fed with P. linteus enriched diet and challenged with V. anguillarum, V. harveyi, and V. alginolyticus the cellular and humoral immune responses, such as the alternative complement activity (ACH(50)), serum lysozyme activity, phagocytic activity (PA), phagocytic index (PI) significantly higher than in the control group. The respiratory bursts (RB), superoxide dismutase (SOD), and glutathione peroxidase (GPx) activities were found significantly enhanced when the groups fed with enriched diet against V. anguillarum and V. harveyi. The results reveal that kelp grouper fed for 30 days with P. linteus enriched diet had higher cellular and humoral immune response and disease protection from vibriosis than the group fed on basal diet with the protection linked to stimulation of immune system.     

Immunomodulatory effect of sodium alginate enriched diet in kelp grouper Epinephelus brneus against Streptococcus iniae

The effect of diets containing sodium alginate at 0, 0.5, 1.0, and 2.0 g kg^?1 following challenge with Streptococcus iniae in kelp grouper Epinephelus bruneus were assessed with reference to survival rate and innate immune parameters such as alternative complement, lysozyme, natural haemagglutination, respiratory burst, superoxide dismutase, and phagocytic activities on week 1, 2, and 4. Fish fed with sodium alginate containing diet at 1.0 and 2.0 g kg^?1 after being challenged with S. iniae had higher survival rates of 75% and 60%, respectively than those fed with control diet (0 g kg^?1). With any enriched diet the percentage of macrophages significantly decreased from week 1–4, while the percentage of neutrophils and lymphocytes significantly increased. The alternate complement activity, natural haemagglutination, and phagocytic activities of infected fish fed with sodium alginate containing diet at 1.0 g kg^?1 on week 2 and 1.0 and 2.0 g kg^?1 diets on week 4 were significantly higher when compared to the control. The lysozyme, respiratory bursts, and superoxide dismutase activities of fish fed with enriched diets at 1.0 and 2.0 g kg^?1 were significantly increased on week 2 and 4. We therefore recommend that at 1.0 or 2.0 g kg^?1 dietary administration of sodium alginate can enhance innate immunity and disease resistance in kelp grouper against S. iniae.     

Dietary sodium alginate administration affects fingerling growth and resistance to Streptococcus sp. and iridovirus, and juvenile non-specific immune responses of the orange-spotted grouper, Epinephelus coioides

The percent weight gain (PWG) and feeding efficiency (FE) of fingerling orange-spotted grouper, Epinephelus coioides, fed diets containing sodium alginate at 1.0 and 2.0 g kg(-1) were calculated on the 2nd, 4th, 6th, and 8th weeks after feeding. Survival rates of the fingerling grouper against Streptococcus sp. and an iridovirus, and non-specific immune parameters such as alternative complement activity (ACH50), lysozyme activity, natural haemagglutination activity, respiratory bursts, superoxide dismutase (SOD) activity, and phagocytic activity of juvenile grouper were also determined when the fish were fed diets containing sodium alginate at 0.5, 1.0, or 2.0 g kg(-1). The PWG and FE of fish were better when the fish were fed diets containing sodium alginate at 1.0, and 1.0 and 2.0 g kg(-1), respectively. The PWG and FE of fish fed the 0, 1.0 and 2.0 g kg(-1) sodium alginate-containing diets after 8 weeks were 271.0%, 454.4% and 327.8%, and 0.61, 0.72 and 0.68, respectively. Fish fed a diet containing sodium alginate at the level of 2.0 g kg(-1) had a significantly higher survival rate than those fed the control diet after challenge with Streptococcus sp. and an iridovirus causing an increase of survival rate by 25.0% and 16.7%, respectively, compared to the control group. The ACH(50) level of fish fed the sodium alginate-containing diets at 2.0 g kg(-1) was significantly higher than those fed the 1.0 g kg(-1) sodium alginate diet and control diet after 12 days, and had increased to 1.9-fold, compared to those fed the control diet. The lysozyme activity, phagocytic activity, respiratory bursts, and SOD level of fish fed the sodium alginate-containing diets at 1.0 and 2.0 g kg(-1) were significantly higher than those fed the control diet after 12 days, and had increased to 1.97- and 1.68-fold, 1.35- and 1.50-fold, 1.63- and 1.81-fold, and 1.23- and 1.31-fold, respectively, compared to those fed the control diet. We therefore recommend dietary sodium alginate administration at 1.0 and 2.0 g kg(-1), respectively, to promote growth and enhance immunity and resistance against Streptococcus sp. and an iridovirus.     

Inonotus obliquus containing diet enhances the innate immune mechanism and disease resistance in olive flounder Paralichythys olivaceus against Uronema marinum

The present study describes the effect of diet supplementation with Chaga mushroom, Inonotus obliquus extract at 0%, 0.01%, 0.1%, and 1.0% levels on the innate humoral (lysozyme, antiprotease, and complement), cellular responses (production of reactive oxygen and nitrogen species and myeloperoxidase), and disease resistance in olive flounder, Paralichythys olivaceus against Uronema marinum. The lysozyme activity and complement activity significantly increased in each diet on weeks 2 and 4 against pathogen. The serum antiprotease activity and reactive nitrogen intermediates production significantly increased in fish fed with 0.1% and 1.0% diets from weeks 1-4. However, reactive oxygen species production and myeloperoxidase activity significantly increased in 1.0% and 2.0% diets on weeks 2 and 4. In fish fed with 0.1% and 1.0% diets and challenged with U. marinum the cumulative mortality was 50% and 40% while in 0% and 0.01% diets the mortality was 85% and 55%. The results clearly indicate that supplementation diet with I. obliquus at 0.1% and 1.0% level positively enhance the immune system and confer disease resistance which may be potentially used as an immunoprophylactic in finfish culture.     

Stimulatory effects of chitinase on growth and immune defense of orange-spotted grouper (Epinephelus coioides)

Chitinase, belonging to either family 18 or family 19 of the glycosylhydrolases, hydrolyze chitin into oligosaccharides. In the present study, the cDNA fragment encoding orange-spotted grouper (Epinephelus coioides) chitinase1 was subcloned into pPIC3.5K vector and expressed in Pichia pastoris GS115. The results showed that a band with the size of about 53 kDa could be detected by SDS-PAGE and Western blot. The recombinant protein of grouper chitinase1 (rgChi1) was added into the fish diet containing shrimp shell chitin for feeding experiment lasting 8 weeks. The weight of orange-spotted grouper, fed with diets containing rgChi1 at 0, 5, 10 and 20 μg/g was calculated on the 2nd, 4th, 6th and 8th weeks, and difference in growth rates was first observed in the 6th week of the feeding period and it kept until the end of the feeding experiment. At the end of 8 weeks feeding trial, the percent weight gain (PWG), growth rate (GR) and specific growth rate (SGR) of fish fed with 10 and 20 μg rgChi1/g feed were significantly higher compared to the control group. The neuropeptide Y (NPY), growth-hormone-releasing hormone (GHRH), growth-hormone (GH), interleukin-1beta (IL-1β), cyclooxygenase-2 (COX-2), superoxide dismutase (SOD) (Cu/Zn) and SOD (Mn) mRNA expression of fish fed with diet containing 10 μg/g or/and 20 μg/g rgChi1 were obviously higher than the control group. The lysozyme (LZM) and total SOD activity of fish fed with diet containing rgChi1 at 10 and 20 μg/g were significantly higher than that of the control. The aspartate aminotransferase (AST)/glutamic oxalacetic transaminases (GOT) activity in 20 μg/g group decreased compared to the control group. These results indicated that the grouper chitinase1 was successfully produced using the P. pastoris expression system and the recombinant protein had obvious effects on growth and immune defense. The mRNA expression and protein secretion of grouper chitinase1 and chitinase2 were significantly stimulated in spleen in response to bacterial lipopolysaccharide (LPS) challenge, strongly suggesting the existence of an innate pathway for local defense against chitin-containing organisms. Moreover, the pathogen such as Escherichia coli and Staphylococcus aureus could be inhibited by the recombinant protein of grouper chitinase1 to a certain extent.     

Effects of dietary chitosan and Bacillus subtilis on the growth performance, non-specific immunity and disease resistance of cobia, Rachycentron canadum

The present study was performed to investigate the effects of various levels of dietary Bacillus subtilis and chitosan on the growth performance, non-specific immunity and protection against Vibrio harveyi infection in cobia, Rachycentron canadum. Fish were fed with the control diet and six different experimental diets containing three graded levels of B. subtilis at 2 × 10(10) CFU g(-1) (0.0, 1.0, 2.0 g kg(-1) diet) for each of two levels of chitosan (3.0 and 6.0 g kg(-1) diet). The results of 8 weeks feeding trial showed that the survival rate ranged from 81.3% to 84.0% with no significant difference (P > 0.05). The SGR (%) in the fish fed with dietary treatments was significantly higher than that of the control fish except diet 6 group with 2.0 g kg(-1)B. subtilis and 3.0 g kg(-1) chitosan. The serum lysozyme activities were significantly higher in 6.0 g kg(-1) chitosan groups and no significant differences were observed among B. subtilis levels. The serum ACP activities were significantly higher in 3.0 g kg(-1) chitosan groups at 0.0 and 1.0 g kg(-1)B. subtilis levels; at low chitosan level, the cobia fed diets with 1.0 g kg(-1)B. subtilis had significantly higher serum ACP activity, but at high chitosan level, the cobia fed diets with 2.0 g kg(-1)B. subtilis had significantly higher serum ACP activity. The phagocytosis and respiratory burst activity in the fish fed with dietary treatments was significantly higher than that of the control fish except diet 3 group with 6.0 g kg(-1) chitosan. Moreover, fish fed the diet containing 2.0 g kg(-1)B. subtilis and 6.0 g kg(-1) chitosan had significantly higher post-challenge survival on the 7th day following V. harveyi infection and post-challenge survival showed clearly the synergistic effect of chitosan and B. subtilis. Based on these results, the combination of 1.0 g kg(-1)B. subtilis and 6.0 g kg(-1) chitosan is optimal for the growth, innate immunity and disease resistance of cobia with an 8-week oral administration.     

Haemato-immunological and growth response of mirror carp (Cyprinus carpio) fed a tropical earthworm meal in experimental diets

An investigation was conducted to evaluate the effect of feeding a tropical earthworm meal (Perionyx escavatus) on the haemato-immunological response and growth performance of mirror carp (Cyprinus carpio). Fish were fed diets for a total of 88 days, fishmeal served as the main protein source in the control diet. Two remaining diets consisted of fishmeal fixed at 33.65% provision of protein and the remaining 66.35% protein was provided by soybean meal (SBM diet) or P. excavatus meal (EW diet). Compared to control and SBM fed fish (7.69 ± 0.28 and 5.92 ± 0.31 g/dl, respectively), a significant increase in haemoglobin was measured in EW fed fish (9.57 ± 0.24 g/dl). Consequently significant elevations were also observed in mean corpuscular haemoglobin (MCH; 79.13 ± 4.59 pg) and mean corpuscular haemoglobin concentration (MCHC; 22.69 ± 0.54 pg) in EW fed fish. On the contrary, compared to control and SBM fed carp total leukocyte levels (2.72 ± 0.17 and 3.10 ± 0.17 × 10(4)/mm(3), respectively) were significantly decreased in the EW group (2.15 ± 0.14 × 10(4)/mm(3)). Moreover at day 14 and 21 post immunisation with bacterin isolated from Aeromonas hydrophila fish fed the EW diet displayed a significant reduction in respiratory burst activity (RBA) compared to control and SBM fed fish. After 60 days of feeding, fish fed EW diet showed a significant elevation in final body weight compared to fish fed a fishmeal based diet (control treatment) and fish fed a soybean meal based diet. Similar improvements were observed in feed utilisation efficiency. The present study shows that feeding P. excavatus meal to mirror carp decreases some aspects of the innate immune response, but at the same time gives rise to significant enhancement of growth and feed utilisation efficiency.     

Immunomodulatory effect of Withania somnifera supplementation diet in the giant freshwater prawn Macrobrachium rosenbergii (de Man) against Aeromonas hydrophila

The effect of Withania somnifera extract supplementation diets on innate immune response in giant freshwater prawn Macrobrachium rosenbergii (de Man) against Aeromonas hydrophila was investigated. The bacterial clearance efficiency significantly increased in prawn fed with 0.1% and 1.0% doses of W. somnifera supplementation diet against pathogen from weeks 1-4 as compared to the control. The innate immune parameters such as, phenoloxidase activity, superoxide anion level, superoxide dismutase activity, nitrate, and nitrite concentrations were significantly enhanced in prawn fed with 0.1% and 1.0% doses of W. somnifera supplementation diet from weeks 1-4 against pathogen. The total hemocyte counts (THC) significantly increased in prawn fed with 0.1% and 1.0% doses diet from weeks 1-4 against pathogen as compared to the control. These results strongly suggested that administration of W. somnifera through supplementation diet positively enhances the innate immune system and enhanced survival rate in M. rosenbergii against A. hydrophila infection.     

Effects of dietary beta-1, 3 glucan on innate immune response of large yellow croaker, Pseudosciaena crocea

The present study was conducted to investigate the effects of dietary beta-1, 3 glucan on the innate immune response and protection against Vibrio harveyi infection in large yellow croaker, Pseudosciaena crocea. A basal diet was supplemented with 0% (control), 0.09% (low) and 0.18% (high) beta-1, 3 glucan to formulate three experimental diets. Each diet was randomly allocated to triplicate groups of fish in floating sea cages (1.5 x 1.5 x 2.0m), and each cage was stocked with 100 fish (initial average weight 9.75+/-0.35 g). Fish were fed twice daily (05:00 and 17:00) to apparent satiation for 8 weeks. The results of 8 weeks feeding trial showed that low glucan supplementation (0.09%) significantly enhanced fish growth, whereas high supplementation (0.18%) did not. The serum lysozyme activity was significantly increased with the increase of dietary glucan (P < 0.05), and fish fed the diet with high glucan had significantly higher lysozyme activity compared with low glucan. There were no significant differences in alternative complement pathway (ACP) activity between fish fed diets with and without supplementation of glucan. The phagocytosis percentage (PP) and respiratory burst activity in fish fed the diet with 0.09% glucan were significantly higher than those in fish fed with the control diet (P < 0.05), but both immunological parameters significantly decreased in fish fed the diet with high supplementation compared with low supplementation and no significant difference was observed between the control and high supplementation groups. The challenge experiment showed that fish fed the diet with low glucan had significantly lower cumulative mortality compared with the control and high glucan groups (P < 0.05), but no significant difference was observed between the control and high supplementation groups. These results suggested that low glucan could enhance growth and innate immunity of large yellow croaker with an 8-week oral administration, but higher supplementation did not influence growth, or further improve immunity of large yellow croaker.     

Poly D,L-lactide-co-glycolic acid (PLGA)-encapsulated vaccine on immune system in Epinephelus bruneus against Uronema marinum

We investigate the efficacy of poly D,L-lactide-co-glycolic acid (PLGA)-encapsulated vaccine on innate and adaptive immune response in kelp grouper (Epinephelus bruneus) against Uronema marinum at weeks 1, 2, and 4. The respiratory burst (RB) activity, complement activity, and α2-macroglobulin were significantly enhanced in fish immunization with vaccine on week 4 whereas vaccine and PLGA-encapsulated vaccine from weeks 1 to 4. The serum lysozyme activity, antiprotease activity, and antibody level were significantly enhanced in fish immunized with vaccine and PLGA-encapsulated vaccine on weeks 2 and 4. The cumulative mortality was low in PLGA-encapsulated vaccine with 20% whereas high in PLGA and vaccine with 40% and 30%. The results from the present study suggest that PLGA-encapsulated vaccine is useful for further design of immunoprophylatic nano formulation against scuticociliatosis.     

Herbal supplementation diets on hematology and innate immunity in goldfish against Aeromonas hydrophila

Goldfish, Carassius auratus (47 ± 3 g, n = 300) were inoculated intramuscularly (50 μl) with Aeromonas hydrophila (1.8 × 10⁶ cells ml^?1). On the 6th day of post-infection the fishes were divided into i) control, without infection fed with normal diet (C), ii) infected fish, fed with normal diet (IU), and infected fishes treated with different doses of iii) 100 mg kg^?1, iv) 200 mg kg^?1, iv) 400 mg kg^?1 and vi) 800 mg kg^?1 mixed herbal extracts supplementation diets. Hematological and immunological parameters were determined on week 1, 2 and 4. In infected goldfish were fed diets containing 100 and 200 mg kg^?1 of mixed herbal extracts supplementation feeds, the white blood cell (WBC) levels significantly increased (P < 0.05) throughout the experimental trial compared to the control. During the experimental period, the red blood cell (RBC) and haemoglobin (Hb) level in goldfish significantly decreased (P < 0.05) when fish fed with 100 and 200 mg kg^?1 of mixed herbal extracts supplementation feeds while it was restored near control when infected fish fed with 400 or 800 mg kg^?1 of herbal extracts supplementation feeds. On the other hand, the haematocrit (Ht) values decline significantly (P < 0.05) in 100, 200 and 400 mg kg^?1 of mixed herbal supplementation feeding groups on weeks 2 and 4 when compared to control group. The mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC) values almost significantly differ from the control values. The infected goldfish and treated with 100 or 200 mg kg^?1 of herbal supplementation feeds exhibited significantly decline (P < 0.05) in total protein (TP), glucose (GLU) and cholesterol (CHO) levels on week 1–4 whereas it was restored when infected fish fed with 400 or 800 mg kg^?1 of herbal supplementation feeds on week 4. In comparison to untreated control goldfish, the respiratory burst activity and phagocytic activity of blood cells was significantly enhanced in infected fish feeding with 200, 400 and 800 mg kg^?1 of herbal supplementation feeds compared to the control. On the other hand, infected fish fed with all the doses of mixed herbal supplementation feeds, the lysozyme activity was significantly enhanced throughout the experimental period. This study shows that the infected goldfish treated with 400 and 800 mg kg^?1 of herbal supplementation feeds preceding the challenge with live A. hydrophila had 30% and 25% mortality. However, 100 and 200 mg kg^?1 of herbal supplementation feeds treated groups were found the percentage mortality 50% and 45%, respectively. Our results indicate that 400 or 800 mg kg^?1 of mixed herbal supplementation feeds were restored the altered hematological parameters and triggering the innate immune system of goldfish against A. hydrophila.     

Effects of dietary katuk (Sauropus androgynus L. Merr.) on growth,non-specific immune and diseases resistance against Vibrio alginolyticus infection in grouper Epinephelus coioides

This study was conducted to investigate the effect of katuk (Sauropus androgynus L. Merr) on growth, non-specific immune and diseases resistance against Vibrio alginolyticus in grouper (Epinephelus coioides). Grouper juveniles (mean weight 10.97 ± 1.99 g, and length 9.67 ± 0.33 cm) were separated into four groups and cultivated in 100-L tank. Each group was fed with diets containing 0, 1.0, 2.5 and 5.0 g/kg herbs diet twice daily. Fish were sampled for non-specific immune parameters at 0, 1, 2, 4, 7, 14 and 30 days. Results showed that fish received S. androgynus at 1.0 and 2.5 g/kg diets affected the growth and non-specific immune responses. Weight gain, specific growth rate, respiratory burst activity, phagocytosis and reactive oxygen species significantly increased in fish administered with 1.0 and 2.5 g/kg S. androgynus diets. The mortality rate after V. alginolyticus challenge decreased in fish fed with 1.0 g/kg S. androgynus extract. Thus, this study indicated that administration of grouper with S. androgynus supplemented diets can affect the growth performances, diseases resistance and enhances non-specific immune responses.     

Effect of dietary ascorbic acid on growth and non-specific immune responses of tiger puffer, Takifugu rubripes

We report nutritional physiology and non-specific immune responses of ascorbic acid (AA) in puffer fish for the first time. This study aimed to examine the essentiality and requirements of AA in diets for the tiger puffer, Takifugu rubripes based on growth performance, liver AA and bone collagen concentration, and non-specific immune responses. Five casein-gelatin based semi-purified diets were formulated to contain five graded levels of l-ascorbyl-2-monophosphate at 0, 40, 80, 160 and 700mg/kg (designated as AMP0, AMP40, AMP80, AMP160 and AMP700, respectively) and fed to triplicate groups of fish. After 10weeks of feeding trial, growth performances of fish (initial body weight, 35g) fed the AMP0 were significantly lower compared to that of fish fed diets supplemented with AMP. The fish fed the AMP0 diet also exhibited significantly lower hematocrit, condition factor and hepatosomatic index compared to the fish fed diets supplemented with AMP. Phagocytic activity (NBT assay) was significantly lower in fish fed the AMP0 diet than in fish fed the AMP containing diets. Plasma lysozyme activity of fish fed the AMP80 and AMP160 was significantly higher than that of fish fed the AMP0. Dietary supplementation of AMP significantly increased the liver superoxide dismutase in the fish. Myeloperoxidase activity of fish fed the AMP0 was significantly lower compared to that of fish fed the AMP containing diets. Bone collagen level tended to increase numerically and total AA concentration in liver of fish was significantly increased in a dose dependent manner by the supplementation of AMP. Therefore, tiger puffer requires exogenous ascorbic acid and the optimum dietary level could be 29mg AA/kg diet for normal growth and physiology. Dietary AA concentration over 82mg/kg could be required to enhance non-specific immune responses of the fish. However, it does not seem that the fish needs an overdose of dietary AA (>160mg/kg) for better non-specific immune responses.