Innate immunity of the white shrimp Litopenaeus vannamei weakened by the combination of a Vibrio alginolyticus injection and low-salinity stress

White shrimp Litopenaeus vannamei were reared at a salinity of 35‰ without a Vibrio alginolyticus injection (unchallenged group), and other shrimp were reared at 35‰, injected with tryptic-soy broth (TSB)-grown V. alginolyticus at 1.8 × 10⁵ colony-forming units (cfu) shrimp^?1 (challenged group), and then examined for the hyaline cell (HC) count, granular cell (GC, including semi-granular cell) count, total haemocyte count (THC), phenoloxidase (PO) activity, respiratory burst (RB) and superoxide dismutase (SOD) activity after transfer to 35‰ (control), 25‰, 20‰, and 15‰ for 1, 6, 12, 24, 72, and 120 h. Results indicated that the haemocyte count, PO activity, RB, and SOD activity of unchallenged shrimp and challenged shrimp that were transferred to low-salinity levels all began to significantly decrease at 6, 6, 6, and 1 h, respectively, and reached the lowest levels at 12 h. HC, GC, the THC, PO activity, RB, and SOD activity of unchallenged shrimp that were transferred to 15‰ decreased by 53%, 41%, 49%, 68%, 39%, and 62%, whereas those parameters of challenged shrimp that were transferred to 15‰ decreased by 79%, 78%, 79%, 82%, 54%, and 72%, respectively after 12 h compared to control shrimp. These immune parameters began to recover after 24–72 h for both unchallenged shrimp and challenged shrimp. We concluded that the innate immunity was weakened in white shrimp L. vannamei that received combined stresses of a V. alginolyticus injection, and low-salinity transfer. It was also concluded that shrimp with respectively 21%, 18%, 46%, and 28% lower THC, PO activity, RB, and SOD activity of the original values would be killed due to decreases in their immunity, and resistance to V. alginolyticus infection. Shrimp farming should be maintained at a constant high salinity level to prevent exacerbated decreases in innate immune parameters of shrimp when infected by a pathogen coupled with low-salinity stress leading to mortality.     

White shrimp Litopenaeus vannamei that received the hot-water extract of Gracilaria tenuistipitata showed earlier recovery in immunity after a Vibrio alginolyticus injection

White shrimp Litopenaeus vannamei which had been immersed in seawater containing the hot-water extract of Gracilaria tenuistipitata at 0 (control), 200, 400, and 600 mg L^?1 for 3 h, were challenged with Vibrio alginolyticus at 4.6 × 10⁶ colony-forming units (CFU) shrimp^?1 and then placed in normal seawater (34‰). The survival rates of shrimp immersed in 200, 400, and 600 mg L^?1 of the hot-water extract were significantly higher than those of control shrimp over 48–120 h. In another experiment, L. vannamei which had been immersed in the hot-water extract at 0, 200, 400, and 600 mg L^?1 for 3 h, were challenged with V. alginolyticus at 4.0 × 10⁶ CFU shrimp^?1, and the immune parameters examined included the haemocyte count, phenoloxidase (PO) activity, respiratory burst (RB), and superoxide dismutase (SOD) activity at 12–120 h post-challenge after shrimp had been released into normal seawater. Shrimp not exposed to the hot-water extract or V. alginolyticus served as the background control. Results indicated that the haemocyte count, PO activity, RB, and SOD activity of shrimp immersed in 600 mg L^?1 were significantly higher than those of control shrimp at 12–72 h post-challenge. Results also indicated that total haemocyte count (THC), PO activity, RB and SOD activity of shrimp immersed in 400 and 600 mg L^?1 of the hot-water extract returned to the background values at 96, 48, 48, and 72 h, whereas these parameters of control shrimp returned to the original values at >120, >120, 96, and 96 h post-challenge, respectively. It was therefore concluded that L. vannamei that had been immersed in seawater containing the hot-water extract of G. tenuistipitata exhibited protection against V. alginolyticus as evidenced by the earlier recovery of immune parameters.     

Characteristics of NADH-dependent lipid peroxidation in sarcoplasmic reticulum of white shrimp,Litopenaeus vannamei,and freshwater prawn,Macrobrachium rosenbergii

The iron-catalyzed NADH-dependent lipid peroxidation system in sarcoplasmic reticulum (SR) of cultured white shrimp, Litopenaeus vannamei and freshwater prawn, Macrobrachium rosenbergii was characterized. Production of thiobarbituric acid reactive substances was used to measure the activity of lipid peroxidation. In both species, the system preferred NADH to NADPH as the reducing agent. Lipid peroxidation activities of SR from both species increased when reaction temperatures increased from 6 to 26 °C. At 66 °C, the reaction was no longer NADH-dependent. Acidic pH amplified the lipid peroxidation activity. Sarcoplasmic reticular lipid peroxidation activity in white shrimp was always greater than in freshwater prawn. Fatty acid composition of SR lipids could be a major factor for this outcome. The proportion of n–3 highly unsaturated fatty acids, such as C20:5 and C22:6, in sarcoplasmic reticular lipids of white shrimp was twice of that in freshwater prawn. The results of this study provide important tools required for anti-oxidative nutrient study at sub-cellular level.     

Administration of the hot-water extract of Spirulina platensis enhanced the immune response of white shrimp Litopenaeus vannamei and its resistance against Vibrio alginolyticus

White shrimp Litopenaeus vannamei which had been injected with the hot-water extract of Spirulina platensis at 6, 10, and 20 μg g^?1, or immersed in aerated seawater containing extract at 200, 400, and 600 mg L^?1 were challenged with Vibrio alginolyticus at 1.5 × 10⁶ or 1.4 × 10⁶ colony-forming units (cfu) shrimp^?1, and then placed in seawater. Survival rates of shrimp that received the extract of S. platensis at 6–20 μg g^?1, and those of shrimp immersed in seawater containing the extract at 400 and 600 mg L^?1 were significantly higher than those of control shrimp after 24–96 and 48–96 h, respectively. In a separate experiment, the hyaline cell (HC) count, granular cell (GC, including semi-granular cell) count, total haemocyte count (THC), phenoloxidase (PO) activity, respiratory burst (RB), superoxide dismutase (SOD) activity, glutathione peroxidase (GPx) activity, and lysozyme activity were measured when shrimp were injected with the extract at 6, 10, and 20 μg g^?1, and immersed in seawater containing the extract at 200, 400, and 600 mg L^?1. These parameters directly increased with the concentration, and significantly increased when shrimp were immersed in the seawater containing the extract at 0.5–4 h. L. vannamei that received all doses of the extract via injection or via immersion all had increased phagocytic activity and clearance efficiency to V. alginolyticus at 12–72 h and 3–4 h, respectively. It was concluded that L. vannamei that received the hot-water extract of S. platensis had enhanced innate immunity and increased resistance against V. alginolyticus infection.     

The immune response of white shrimp Litopenaeus vannamei and its susceptibility to Vibrio alginolyticus under low and high pH stress

White shrimp Litopenaeus vannamei (also known as Penaeus vannamei) held in 34 per thousand seawater at pH 8.2 were injected with tryptic soy broth (TSB)-grown Vibrio alginolyticus at 8 x 10(5) colony-forming units (cfu) shrimp(-1), and then transferred to tanks at pH 6.5, 8.2 (control) and 10.1, respectively. After 24-168 h, the mortality of V. alginolyticus-injected shrimp that were transferred to pH 6.5 and pH 10.1 tanks was significantly higher than that of V. alginolyticus-injected shrimp held at pH 8.2. In another experiment, L. vannamei held at pH 8.2 following transfer to pH 6.5, 8.2 (control) and 10.1 for 6, 12, 24, 72 and 120 h were examined for immune parameters, phagocytic activity, and the clearance efficiency of shrimp against V. alginolyticus. The results indicated that the shrimp that were transferred to pH 6.5 and 10.1 showed significantly decreased phenoloxidase (PO) activity, respiratory burst, phagocytic activity, and clearance efficiency against V. alginolyticus over 6-72 h; significantly decreased superoxide dismutase (SOD) activity over 6-24h; and decreased total haemocyte count (THC) over 12-72 h. Shrimp transferred to pH 10.1 showed significantly decreased granular cell counts, and THC after 6h, and decreased SOD activity after 72 h. The immune parameters of shrimp transferred to pH 6.5 and 10.1 returned to the original values after 120 h. However, shrimp transferred to pH 6.5 still maintained lower phagocytic activity, and clearance efficiency against V. alginolyticus, and shrimp transferred to pH 10.1 still maintained lower clearance efficiency against V. alginolyticus. It was therefore concluded that low pH and high pH stress decrease the resistance of white shrimp L. vannamei against V. alginolyticus and decrease several parameters of the immune response.     

Effect of saponin immersion on enhancement of the immune response of white shrimp Litopenaeus vannamei and its resistance against Vibrio alginolyticus

The haemocyte count, phenoloxidase (PO) activity, specific alpha(2)-macroglobulin (alpha2-M) activity, respiratory burst, superoxide dismutase (SOD) activity, glutathione peroxidase (GPx) activity, phagocytic activity, and clearance efficiency against Vibrio alginolyticus were examined when the white shrimp Litopenaeus vannamei (10.42+/-2.0g) were immersed in seawater (34 per thousand) containing different concentrations of saponin (0, 0.5, 1 and 2mgL(-1)) for 24, 48 and 72h. Hyaline cells (HC), the total haemocyte count (THC), specific alpha2-M activity, respiratory burst, SOD activity, and GPx activity directly increased with the saponin concentration, whereas PO activity was inversely related to the saponin concentration. White shrimp L. vannamei that were immersed in saponin at 1 and 2mgL(-1) showed increased phagocytic activity and clearance efficiency to V. alginolyticus over 48-72h. In another experiment, shrimp immersed in seawater containing different concentrations of saponin after 72h were challenged with V. alginolyticus at 3.2x10(5) colony-forming units (cfu)shrimp(-1), and then placed in seawater. The survival rate of shrimp immersed in seawater containing saponin at either dose was significantly higher than that of control shrimp after 12h, as well as at the termination of the experiment (5days after the challenge). It was therefore concluded that L. vannamei immersed in water containing saponin at 2mgL(-1) or less exhibited an immunomodulatory effect, as well as protection against V. alginolyticus infection.     

Effects of dietary mannan oligosaccharide on growth performance, gut morphology and stress tolerance of juvenile Pacific white shrimp, Litopenaeus vannamei

An 8-week feeding trial was conducted to investigate the effects of dietary mannan oligosaccharide (MOS) on growth performance, gut morphology, and NH(3) stress tolerance of Pacific white shrimp Litopenaeus vannamei. Juvenile Pacific white shrimp (1080 individuals with initial weight of 2.52?±?0.01?g) were fed either control diet without MOS or one of five dietary MOS (1.0, 2.0, 4.0, 6.0 and 8.0?g?kg(-1)) diets. After the 8-week feeding trial, growth parameters, immune parameters, intestinal microvilli length and resistance against NH(3) stress were assessed. Weight gain (WG) and specific growth rate (SGR) were significantly higher (P??0.05) in all experimental groups. Compared with control group, TEM analysis revealed that 2.0, 4.0, 6.0 and 8.0?g?kg(-1) MOS supplementation could significantly increase (P?相似文献   

The effects of exposure to critical thermal maxima on the physiological,metabolic, and immunological responses in adult white shrimp Litopenaeus vannamei (Boone)

Exposure to thermal stress was shown to have a significant effect on the osmotic pressure of the hemolymph, glucose levels, total count of hemocyte (TCH), and proPO activity in adult white shrimp Litopenaeus vannamei. Exposure of the shrimp to CTMax significantly increased the osmotic pressure of the hemolymph relative to the control group. In organisms reaching CTMax, temperature elicited a secondary stress response that included an increase in hemolymph glucose of 31?mg?mL^?1. Metabolites in hemolymph such as cholesterol, acylglycerides, and total protein were not significantly affected by exposure to CTMax. CTMax exposure affected several immunological parameters causing decreases in TCH and proPO activity. We suggested that biomarkers such as osmolality, glucose levels, TCH, and proPO activity could be used as sensitive predictors of exposure to CTMax in white shrimp.     

The immune response of white shrimp Litopenaeus vannamei and its susceptibility to Vibrio alginolyticus at different salinity levels

White shrimp Litopenaeus vannamei held in 25 per thousand seawater were injected with TSB-grown Vibrio alginolyticus (1 x 10(4) cfu shrimp(-1)), and then transferred to 5, 15, 25 (control) and 35 per thousand. Over 24-96 h, the mortality of V. alginolyticus-injected shrimp held in 5 per thousand and 15 per thousand was significantly higher than that of shrimp held in 25 per thousand and 35 per thousand, and the mortality of V. alginolyticus-injected shrimp held in 5 per thousand was the highest. Shrimp held in 25 per thousand and then transferred to 5, 15, 25 (control) and 35 per thousand were examined for THC (total haemocyte count), phenoloxidase activity, respiratory burst, superoxide dismutase (SOD) activity, phagocytic activity and clearance efficiency to V. alginolyticus after 12-72 h. The THC, phenoloxidase activity, respiratory burst, SOD activity, phagocytic activity and clearance efficiency decreased significantly for the shrimp held in 5 and 15 per thousand after 12 h. It is concluded that the shrimp transferred from 25 per thousand to low salinity levels (5 and 15 per thousand) had reduced immune ability and decreased resistance against V. alginolyticus infection.     

Noradrenaline modulates the immunity of white shrimp Litopenaeus vannamei

The total haemocyte count (THC), phenoloxidase activity, respiratory burst, superoxide dismutase (SOD) activity, phagocytic activity and clearance efficiency in response to pathogen Vibrio alginolyticus were measured when the white shrimp Litopenaeus vannamei (18.4 +/- 1.2 g) were injected individually with noradrenaline at 10(-8), 10(-7) and 10(-6) mol shrimp(-1). For the shrimp that received noradrenaline at 10(-8), 10(-7) and 10(-6) mol shrimp(-1), the THC decreased by 15%, 21% and 32%, phenoloxidase activity decreased by 15%, 31% and 31%, respiratory burst decreased by 13%, 21% and 32%, and SOD activity decreased by 46%, 56% and 55%, respectively, after 2 h. The phagocytic activity and clearance efficiency of shrimp that received noradrenaline at either dose decreased significantly after 2 h. The THC, phenoloxidase activity, respiratory burst, SOD activity, phagocytic activity and clearance efficiency returned to normal values after 4, 4, 8, 24, 16 and 8 h, respectively, in the shrimp that received noradrenaline at either dose. In another experiment, L. vannamei which had received noradrenaline at 10(-8), 10(-7) and 10(-6) mol shrimp(-1) were challenged after 1h by injection with V. alginolyticus at 1.0 x 10(5) colony-forming units (cfu)shrimp(-1) and then placed in seawater of 20 per thousand. The cumulative mortality of shrimp that received noradrenaline at either dose was significantly higher than that of shrimp that received saline after 4 h, and at the termination of the experiment (48 h after the challenge). It is therefore concluded that noradrenaline administration at 10(-6) mol shrimp(-1) or less causes immune modulation of L. vannamei.     

Effects of dopamine on the immunity of white shrimp Litopenaeus vannamei

The total haemocyte count (THC), phenoloxidase activity, respiratory burst, superoxide dismutase (SOD) activity, phagocytic activity and clearance efficiency in response to pathogen Vibrio alginolyticus were measured when the white shrimp Litopenaeus vannamei (20.0+/-1.5 g) were injected individually with dopamine at 10(-8), 10(-7) and 10(-6)mol shrimp(-1), respectively. For the shrimp that received dopamine at 10(-7) and 10(-6)mol shrimp(-1), the THC decreased by 25% and 39%, phenoloxidase activity decreased by 15% and 32%, respiratory burst decreased by 21% and 36%, and SOD activity decreased by 50% and 63%, respectively, after 4 h. The phagocytic activity and clearance efficiency of shrimp that received dopamine at either dose decreased significantly after 2 h. The THC, phenoloxidase activity, respiratory burst, SOD activity, phagocytic activity and clearance efficiency returned to normal values after 16, 8, 8, 24, 16 and 4 h, respectively, for the shrimp that received dopamine at either dose. In another experiment, L. vannamei which had received dopamine at 10(-8), 10(-7) and 10(-6)mol shrimp(-1) were challenged after 1 h by injection with V. alginolyticus at 1.0x10(5) colony-forming units (cfu) shrimp-1 and then placed in seawater of 20 per thousand. The cumulative mortality of shrimp that received dopamine at either dose was significantly higher than that of shrimp that received saline after 8 h, and of shrimp that received saline at the termination of the experiment (48 h after the challenge). It is therefore concluded that dopamine administration at 10(-6)mol shrimp-1 or less causes immune modulation of L. vannamei.     

Effects of phosphatidyl serine on immune response in the shrimp Litopenaeus vannamei

Phosphatidyl serine plays an important role in animal innate immunity. Given its important functions, numerous investigations have been carried out on its immunological function in many animals. However, studies of phosphatidyl serine in the white shrimp Litopenaeus vannamei, an economically important animal, are rare. In this paper, we demonstrated influences of injecting phosphatidyl serine (PS) on immune response including some parameters from pro-phenol oxidase activating system (pro-PO system) and hemocyanin-derived phenol oxidase activity (Hd-PO) along with antibacterial and bacteriolytic activities in the white shrimp Litopenaeus vannamei with different PS concentrations (5, 10 and 20 μg mL^?1). The results showed that PS could affect immune response of L. vannamei significantly (P<0.05), including total hemocyte counts (THC), PO activity from hemocyte, phenol oxidase (PO) activity from plasma, hemocyanin concentration, Hd-PO activity as well as antibacterial and bacteriolytic activities in the plasma. Among the lines, 20 μg mL^?1 PS had the strongest effect on the above parameters, whereas 5 μg mL^?1 had the least effect. The experimental results indicated that PS was able to activate exocytosis of pro-PO and formation of Hd-PO in white shrimp after injection, further regulating the immune process reflected by variation of antibacterial and bacteriolytic activities in a certain way.     

高盐胁迫对凡纳滨对虾消化及免疫相关酶活力的影响

为探讨高盐对凡纳滨对虾(Litopenaeus vannamei)消化及免疫相关酶活力的影响,实验设置了30、40、50、60共4个盐度梯度。对虾体长(7.84±0.68)cm,养殖密度333尾/m~3,每个梯度设3个平行,实验周期30d。取血淋巴、肌肉、肝胰腺等组织,检测其超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、碱性磷酸酶(AKP)和酸性磷酸酶(ACP)及蛋白酶、脂肪酶、淀粉酶活力。结果表明,盐度显著影响凡纳滨对虾肝胰脏中胃蛋白酶、脂肪酶、淀粉酶的活力(P0.05);随着盐度增加,消化相关酶活力均不断下降,处理间差异显著(P0.05);盐度对凡纳滨对虾不同组织的免疫指标产生影响,表现为随着盐度升高,血淋巴中,AKP活力逐渐升高,ACP、CAT和SOD活力均表现为先升高后降低;肌肉中,AKP、ACP和SOD活力呈现先升高后降低的变化趋势;肝胰脏中,AKP活力呈现先降低后升高再降低的变化趋势,ACP活力高盐处理间差异不显著(P0.05),CAT活力先降低后升高,SOD活力盐度40后逐渐降低。实验结果初步说明,高盐显著影响凡纳滨对虾的消化及免疫相关酶活力,且盐度对不同组织中免疫酶活力影响存在一定的组织特异性,50以上的高盐胁迫对对虾消化和免疫相关酶活力的影响尤为显著。     

Modulation of antioxidant and detoxification responses induced by lipoic acid in the Pacific white shrimp Litopenaeus vannamei (Boone, 1931) subjected to hypoxia and re-oxygenation

The effect of lipoic acid supplementation and moderate hypoxia (3?mg/L), followed by re-oxygenation, was analyzed in terms of antioxidant and oxidative damage responses in juvenile shrimp Litopenaeus vannamei. Lipoic acid (LA)-enriched rations (D1: 76.4?±?6.4; D2: 196.4?±?70.2; and D3: 397.2?±?79.97?mg LA/kg) were offered to shrimps. A control group without LA adding was also run. After 45?days, LA-enriched ration increased the activity of the detoxifying enzyme glutathione-S-transferase in gills. Total antioxidant capacity against peroxy radicals was augmented in gills and hepatopancreas at doses D2 and D3. Doses D1 and D2 of LA reduced the levels of oxidative damage (lipid peroxidation) in gills and hepatopancreas. The results showed that certain LA doses (particularly D2) improved not only antioxidant responses but also weight gain. It can be concluded that LA triggered antioxidant and detoxification protection in L. vannamei, allowing the shrimp to cope with environmental stressful factors.     

Immunotoxic effect of Benzo[α]Pyrene and chrysene in juvenile white shrimp Litopenaeus vannamei

The effects of benzo(a)pyrene (Bap) (0.03, 0.3 and 3 μg L^?1) and chrysene (CHR) (0.3, 2.1 and 14.7 μg L^?1) on the function of the immune system of juvenile white shrimp Litopenaeus vannamei were determined under laboratory conditions. This included the total hemocyte count (THC) in the hemolymph, phagocytic activityand pro-phenoloxidase (pro-PO) activity of the hemocyte, phenoloxidase (PO) activity, α₂-macroglobulin (α₂-M) activity, bacteriolytic activity and antibacterial activity in the hemolymph. The results showed that BaP and CHR could inhibit the immune function of L. vannamei significantly under high concentration BaP and CHR exposure. The results of this study indicated that the immunotoxicity of PAHs in a descending order was BaP>CHR. Moreover, the results indicated the THC in hemolymph, pro-PO activity and phagocytic activity of hemocyte, and bacteriolytic activity in hemolymphcould be used as potentially suitable biomarkersfor early warning indication of PAHs toxicity, this could provide useful information for toxic risk assessment of environmental pollutants.     

Effect of hypoxic stress on the immune response and the resistance to vibriosis of the shrimpPenaeus stylirostris

The immune response of shrimp exposed to severe hypoxia, 1 mg O₂ml⁻¹for 24 h, was measured in terms total haemocyte count (THC), differential haemocyte count (DHC), phenoloxidase activity (PO) and respiratory burst by NBT reduction. Results showed that hypoxia induced a significant decrease (P<5%) of the THC due to a significant decrease of semi-granular cells (SGC) (P<5%) and hyaline cells (HC) (P<5%). There was also a decrease in the NBT reduction. On the other hand, PO activity increased significantly (P<1%) and seemed to be related to a lower amount of plasma inhibitors regulating the prophenoloxidase system. Experimental infection with a virulentVibrio alginolyticuswas carried out by intramuscular injection of 2×10⁴colony forming units (cfu) per shrimp. The mortality of stressed shrimp was 48% while the mortality of control shrimp was 32%. This difference was significant (P<1%). The variations of immunological parameters, except for the PO activity, seem to be consistent with thein vivoresponse against the pathogenicVibrio. Coyright 1998 Academic Press     

Ocean cleaning stations under a changing climate: biological responses of tropical and temperate fish‐cleaner shrimp to global warming

Cleaning symbioses play an important role in the health of certain coastal marine communities. These interspecific associations often occur at specific sites (cleaning stations) where a cleaner organism (commonly a fish or shrimp) removes ectoparasites/damaged tissue from a ‘client’ (a larger cooperating fish). At present, the potential impact of climate change on the fitness of cleaner organisms remains unknown. This study investigated the physiological and biochemical responses of tropical (Lysmata amboinensis) and temperate (L. seticaudata) cleaner shrimp to global warming. Specifically, thermal limits (CTMax), metabolic rates, thermal sensitivity, heat shock response (HSR), lipid peroxidation [malondialdehyde (MDA) concentration], lactate levels, antioxidant (GST, SOD and catalase) and digestive enzyme activities (trypsin and alkaline phosphatase) at current and warming (+3 °C) temperature conditions. In contrast to the temperate species, CTMax values decreased significantly from current (24–27 °C) to warming temperature conditions (30 °C) for the tropical shrimp, where metabolic thermal sensitivity was affected and the HSR was significantly reduced. MDA levels in tropical shrimp increased dramatically, indicating extreme cellular lipid peroxidation, which was not observed in the temperate shrimp. Lactate levels, GST and SOD activities were significantly enhanced within the muscle tissue of the tropical species. Digestive enzyme activities in the hepatopancreas of both species were significantly decreased by warmer temperatures. Our data suggest that the tropical cleaner shrimp will be more vulnerable to global warming than the temperate Lysmata seticaudata; the latter evolved in a relatively unstable environment with seasonal thermal variations that may have conferred greater adaptive plasticity. Thus, tropical cleaning symbioses may be challenged at a greater degree by warming‐related anthropogenic forcing, with potential cascading effects on the health and structuring of tropical coastal communities (e.g. coral reefs).