Effects of hirami lemon, Citrus depressa Hayata, leaf meal in diets on the immune response and disease resistance of juvenile barramundi, Lates calcarifer (bloch), against Aeromonas hydrophila.

The present study was conducted to evaluate the dietary supplementation of leaf meal from Citrus depressa Hayata on the growth, innate immune response, and disease resistance of juvenile barramundi, Lates calcarifer. Four diets were formulated to contain 0% (control), 1% (C1), 3% (C3), and 5% (C5) leaf meal, respectively. During a 56 d feeding trial, fish survival, growth performance, and feed efficiency were not significantly different among all groups. For immune response, respiratory burst, superoxide dismutase and lysozyme activities were not significantly different among all groups. However, fish fed the C5 diet for 56 d had significantly higher phagocytic activity. Also, fish fed C3 and C5 diets had significantly higher Mx gene expressions in spleens and head kidneys with nerve necrosis virus injections after 24 h. Disease resistance against Aeromonas hydrophila was increased by the C5 diet. In this study, barramundi fed on a diet containing 5% C. depressa Hayata leaf meal had significantly better innate immune response and disease resistance against A. hydrophila.

A smaller particle size improved the oral bioavailability of monkey head mushroom, Hericium erinaceum, powder resulting in enhancement of the immune response and disease resistance of white shrimp, Litopenaeus vannamei.

The effects of different particle sizes (100-150, 74-100, and <74 µm) of powder of the dried and ground stipe from the monkey head mushroom, Hericium erinaceum, on the immune response and disease resistance of white shrimp, Litopenaeus vannamei, against the pathogen, Vibrio alginolyticus, were examined. Mushroom powder with a particle size of <74 µm had a significantly higher effect on the disease resistance of shrimp compared to particle sizes of >74 µm. Mortality of shrimp after being injected with V. alginolyticus was particle size-dependent, increasing from 66.7% ± 3.3%-93.3% ± 3.3% with diets containing stipe particle sizes of <74 and 100-150 µm, respectively. The mortality of shrimp fed the diet containing <74-µm stipe powder for 28 days was significant lower than that of shrimp fed with the control diet and the diet containing 74-100-µm stipe powder after being challenged by V. alginolyticus. The optimal concentration of the <74-µm mushroom powder for enhancing the immune response and disease resistance of shrimp was 0.2 µg (g shrimp)(-1) day(-1). No significant change in the total hemocyte count, differential hemocyte count, glutathione reductase, or phagocytic activity was found in shrimp fed the control diet and mushroom powder-containing diet at a level of up to 0.2 µg (g shrimp)(-1) day(-1). Shrimp fed 0.2 µg (g shrimp)(-1) day(-1) of a mushroom-containing diet had a significantly higher disease resistance to V. alginolyticus via an increase in phenoloxidase activity, respiratory bursts, superoxide dismutase activity, and glutathione peroxidase activity. Therefore, a diet containing the stipe powder of monkey head mushroom with a particle size <74 µm at a level of 0.2 µg (g shrimp)(-1) day(-1) was found to enhance the immunity and disease resistance of shrimp.

The increase of immunity and disease resistance of the giant freshwater prawn, Macrobrachium rosenbergii by feeding with selenium enriched-diet.

The effects of inorganic selenium (Se) (sodium selenate, SSe) and organic selenium (seleno-l-methionine, MSe) supplementation on the immune response, antioxidant status, and disease resistance of the giant freshwater prawn, Macrobrachium rosenbergii, were studied. Five experimental diets, including a control diet (without Se enrichment), 0.5 mg (kg diet)(-1) of MSe, 1 mg (kg diet)(-1) of MSe, 0.5 mg (kg diet)(-1) of SSe, and 1 mg (kg diet)(-1) of SSe, were used. After 75 days of culture, prawn fed the Se-enriched diets had lower mortality compared to that of prawn fed the control diet after being challenged by the pathogen, Debaryomyces hansenii. No significant differences in the total hemocyte count, superoxide dismutase activity, or clearance efficiency of prawn were recorded among the control and treated groups. Significantly increased phenoloxidase and phagocytic activities in prawn fed the Se-enriched diets were found compared to the controls. Respiratory bursts of prawn fed both forms of 1 mg Se (kg diet)(-1) significantly increased compared to control prawns. For the antioxidant status analysis, glutathione peroxidase, glutathione reductase, and glutathione s-transferase of prawn fed the SSe-enriched diet at 1 mg (kg diet)(-1) were significantly increased. The results indicated that the cheaper selenium, SSe is recommended to be added in prawn feed at the concentration of 0.5 mg resulting in 1.5 mg SSe (kg diet)(-1) increased prawn immunity and disease resistance against the pathogen, D. hansenii.

Identification and cloning of a selenium dependent glutathione peroxidase from giant freshwater prawn, Macrobrachium rosenbergii.

A selenium dependent glutathione peroxidase (Se-GPx) cDNA was cloned from haemocyte by a reverse-transcription polymerase chain reaction (RT-PCR) and rapid amplification of cDNA (RACE). The 913 bp cDNA contained an open reading frame (ORF) of 558 bp encoded a deduced amino acid sequence of 186 amino acids. The prawn Se-GPx sequence contains a selenocysteine (Sec) residue which is encoded by the unusual stop codon, (115)TGA(117). According to the molecular modeling analysis, the active site Sec residue, located in the loop between beta3 and alpha2 in a pocket on the protein surface, and hydrogen bonded to Gln(73) and Trp(141). A GPx signature motif 2, (63)LAFPCNQF(70) and active site motif, (151)WNFEKF(156), two arginine (R) residues, R(89) and R(167) contribute to the electrostatic architecture that directs the glutathione donor substrate, and two putative N-glycosylation site, (75)NNT(77) and (107)NGS(109) were observed in the prawn Se-GPx sequence. In addition, the eukaryotic selenocysteine insertion sequence element is conserved in the 3'-UTR. Comparison of amino acid sequences showed that prawn Se-GPx is more closely related to vertebrate GPx 1. The prawn Se-GPx was synthesized in haemocyte, hepatopancreas, muscle, stomach, gill, intestine, eyestalk, heart, epidermis, lymph organ, ventral nerve cord, testis and ovary. The increase of respiratory burst in haemocyte was observed in pathogen, Debaryomyces hansenii-injected prawn in order to kill the pathogen, and the up-regulation in SOD and GPx acitivity, and prawn Se-GPx mRNA transcription were involved with the protection against damage from oxidation.

Immune response of white shrimp, Litopenaeus vannamei, after a concurrent infection with white spot syndrome virus and infectious hypodermal and hematopoietic necrosis virus.

In the present study, we investigated immunological changes in viral-infected white shrimp, Litopenaeus vannamei. White shrimp were infected with white spot syndrome virus (WSSV) or co-infected with WSSV and infectious hypodermal and hematopoietic necrosis virus (IHHNV) as detected by polymerase chain reaction (PCR). The complete (100%) mortality rate of shrimp was caused by viral infection due to immune parameters being suppressed including decreases in phenoloxidase activity, total hemocyte counts, differential hemocyte counts, and the gene expressions of prophenoloxidase and peroxinectin. In addition, increases in lipopolysaccharide and beta-1,3-glucan-binding protein of hemocytes and the hepatopancreas, and respiratory bursts per cell, and a decrease in superoxide dismutase were found in viral-infected shrimp, which may have been related to the defense against viral infection.

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.

Peroxinectin gene transcription of the giant freshwater prawn Macrobrachium rosenbergii under intrinsic, immunostimulant, and chemotherapeutant influences.

Peroxinectin (PE) gene expressions were determined using real-time PCR in the giant freshwater prawn Macrobrachium rosenbergii based on moulting; prawns were fed diets containing different concentrations of sodium alginate, and were exposed to different concentrations of copper sulphate, benzalkonium chloride (BKC), and trichlorfon. Results showed that PE mRNA expression of prawns was the highest in stage A, significantly decreased in stage B, and reached the lowest level in stages D0/D1. The PE transcript was significantly higher in prawns fed the 1.0 gkg(-1) sodium alginate-containing diet than those fed the 2.0 gkg(-1) sodium alginate-containing diet and those fed the control diet. PE transcripts significantly decreased in prawns exposed to 0.1-0.4 mgL(-1) copper sulphate after 96 h, 0.3-1.0 mgL(-1) BKC after 96 h, and 0.2-0.4 mgL(-1) trichlorfon after 48 h. It was concluded that the status of PE gene expression was seriously affected by the moult cycle, immunostimulant, and chemotherapeutants.

The effect of sodium alginate on the immune response of tiger shrimp via dietary administration: activity and gene transcription.

The total haemocyte count (THC), phenoloxidase (PO) activity, respiratory bursts (release of superoxide anions), and superoxide dismutase (SOD) activity, as well as expressions of beta-1,3-glucan-binding protein (betaGBP), prophenoloxidase (proPO), peroxinectin (PE), cytosolic SOD (cyt-SOD), penaeidin-5 (PA-5), and a single whey acidic protein (WAP) domain protein (SWDP) gene were determined in the tiger shrimp Penaeus monodon (15.6-19.5g) which had individually been fed diets containing sodium alginate at 0, 1.0, or 2.0gkg(-1) for 5months. Results showed that shrimp fed a diet containing 1.0 and 2.0gkg(-1) sodium alginate had significantly increased SOD activity but decreased respiratory bursts. The expressions of betaGBP, PE, cyt-SOD, PA-5, and SWDP were significantly elevated in shrimp fed the