The protective effect of chitin and chitosan against Vibrio alginolyticus in white shrimp Litopenaeus vannamei.
White shrimp, Litopenaeus vannamei, which had been injected with chitin at 4, 6 and 8 microg g(-1) or chitosan at 2, 4 and 6 microg g(-1), were challenged with pathogen Vibrio alginolyticus at 2 x 10(6) colony-forming units (cfu) shrimp(-1) and then placed in seawater of 34 per thousand. The survival of shrimp that received chitin or chitosan at either dose was significantly higher than that of control shrimp after 1 day, and at the termination of the experiment (6 days after the challenge). In another experiment, the total haemocyte count (THC), phenoloxidase activity, respiratory burst, superoxide dismutase (SOD) activity, and phagocytic activity to V. alginolyticus were measured when L. vannamei (10.4 +/- 0.7 g) were injected individually with chitin at 4 and 6 microg g(-1) or chitosan at 2 and 4 microg g(-1). L. vannamei received chitin at 6 microg g(-1) or chitosan at 2 and 4 microg g(-1) increased significantly its THC and respiratory burst after 2 days. L. vannamei received chitin at 6 microg g(-1) or chitosan at 2 and 4 microg g(-1) still maintained significantly higher phenoloxidase activity after 6 days. L. vannamei received chitin at 4 and 6 microg g(-1) or chitosan at 2 and 4 microg g(-1) increased its phagocytic activity against V. alginolyticus after 1 day, respectively. It is therefore concluded that L. vannamei that received chitin at 6 microg g(-1) or chitosan at 4 microg g(-1) or less increased its immune ability and resistance to V. alginolyticus infection.
Wang
Shi-Hong
SH
Department of Aquaculture, College of Life and Resource Sciences, National Taiwan Ocean University, ROC.
Chen
Jiann-Chu
JC
D000818:Animals; D001772:Blood Cell Count; D002686:Chitin / Q000276:immunology / Q000494:pharmacology*; D048271:Chitosan / Q000276:immunology / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D007113:Immunity, Innate / Q000187:drug effects*; D014442:Monophenol Monooxygenase / Q000378:metabolism; D033561:Penaeidae / Q000276:immunology* / Q000382:microbiology*; D010587:Phagocytosis / Q000187:drug effects / Q000276:immunology; D016897:Respiratory Burst / Q000187:drug effects / Q000276:immunology; D012623:Seawater; D013482:Superoxide Dismutase / Q000276:immunology; D016019:Survival Analysis; D044149:Vibrio alginolyticus
D002686:Chitin; D048271:Chitosan; D014442:Monophenol Monooxygenase; D013482:Superoxide Dismutase