title: Dietary administration of a Gracilaria tenuistipitata extract enhances the immune response and resistance against Vibrio alginolyticus and white spot syndrome virus in the white shrimp Litopenaeus vannamei.
abstract: The haemogram, phenoloxidase (PO) activity, respiratory bursts (RBs), superoxide dismutase (SOD) activity, glutathione peroxidase (GPx) activity, lysozyme activity, and the mitotic index of haematopoietic tissue (HPT) were examined after the white shrimp Litopenaeus vannamei had been fed diets containing the hot-water extract of Gracilaria tenuistipitata at 0 (control), 0.5, 1.0, and 2.0 g kg(-1) for 7-35 days. Results indicated that these parameters directly increased with the amount of extract and time, but slightly decreased after 35 days. RBs, SOD activity, and GPx activity reached the highest levels after 14 days, whereas PO and lysozyme activities reached the highest levels after 28 days. In a separate experiment, white shrimp L. vannamei, which had been fed diets containing the extract for 14 days, were challenged with Vibrio alginolyticus at 2 × 10(6) cfu shrimp(-1) and white spot syndrome virus (WSSV) at 1 × 10(3) copies shrimp(-1), and then placed in seawater. The survival rate of shrimp fed the extract-containing diets was significantly higher than that of shrimp fed the control diet at 72-144 h post-challenge. We concluded that dietary administration of the G. tenuistipitata extract at ≤1.0 g kg(-1) could enhance the innate immunity within 14 days as evidenced by the increases in immune parameters and mitotic index of HPT in shrimp and their enhanced resistance against V. alginolyticus and WSSV infections. Shrimp fed the extract-containing diets showed a higher and continuous increase in the humoral response indicating its persistent role in innate immunity.
authors.affiliation: Department of Aquaculture, College of Life Sciences, National Taiwan Ocean University, Keelung 202, Taiwan, ROC.
authors.forename: Nuttarin
authors.initials: N
authors.lastname: Sirirustananun
authors.forename: Jiann-Chu
authors.initials: JC
authors.lastname: Chen
authors.forename: Yong-Chin
authors.initials: YC
authors.lastname: Lin
authors.forename: Su-Tuen
authors.initials: ST
authors.lastname: Yeh
authors.forename: Chyng-Hwa
authors.initials: CH
authors.lastname: Liou
authors.forename: Li-Li
authors.initials: LL
authors.lastname: Chen
authors.forename: Su Sing
authors.initials: SS
authors.lastname: Sim
authors.forename: Siau Li
authors.initials: SL
authors.lastname: Chiew
mesh_terms: D000818:Animals; D060467:Disease Resistance / Q000187:drug effects / Q000276:immunology*; D004305:Dose-Response Relationship, Drug; D005979:Glutathione Peroxidase / Q000378:metabolism; D044724:Gracilaria / Q000737:chemistry*; D007113:Immunity, Innate / Q000187:drug effects / Q000276:immunology*; D008940:Mitotic Index / Q000662:veterinary; D014442:Monophenol Monooxygenase / Q000378:metabolism; D009113:Muramidase / Q000378:metabolism; D033561:Penaeidae / Q000276:immunology* / Q000382:microbiology / Q000821:virology; D010936:Plant Extracts / Q000494:pharmacology*; D016897:Respiratory Burst / Q000187:drug effects; D013482:Superoxide Dismutase / Q000378:metabolism; D016019:Survival Analysis; D013997:Time Factors; D044149:Vibrio alginolyticus / Q000276:immunology*; D046848:White spot syndrome virus 1 / Q000276:immunology*
chemical_list: D010936:Plant Extracts; D005979:Glutathione Peroxidase; D014442:Monophenol Monooxygenase; D013482:Superoxide Dismutase; D009113:Muramidase