Effect of salinity on the immune response of tiger shrimp Penaeus monodon and its susceptibility to Photobacterium damselae subsp. damselae.
Addition of NaCl at 2.5% to tryptic soy broth (TSB) significantly increased the growth of Photobacterium damselae subsp. damselae. Tiger shrimp Penaeus monodon held in 25 per thousand seawater were injected with P. damsela subsp. damselae grown in TSB containing NaCl at 0.5%, 1.5%, 2.5% and 3.5% at a dose of 8.48 x 10(4)colony-forming units (cfu)shrimp(-1). Over 24-96 h, the cumulative mortality was significantly higher for the shrimp challenged with P. damselae subsp. damselae grown in 2.5% NaCl than those grown in 0.5%, 1.5% and 3.5% NaCl. In another experiment, P. monodon held in 25 per thousand were injected with TSB-grown P. damselae subsp. damselae (8.48 x 10(4)cfushrimp(-1)), and then transferred to 5 per thousand, 15 per thousand, 25 per thousand (control) and 35 per thousand. After 96 h, the mortality was highest for the P. damselae subsp. damselae-injected shrimp held in 5 per thousand, and the lowest for the P. damselae subsp. damselae-injected shrimp held in 25 per thousand. In a separate experiment, P. monodon held in 25 per thousand and then transferred to 5 per thousand, 15 per thousand, 25 per thousand (control) and 35 per thousand were examined for immune parameters, and phagocytic activity and clearance efficiency of P. damselae subsp. damselae after 12-96 h. The THC, hyaline cell, phenoloxidase activity, respiratory burst, superoxide dismutase (SOD) activity, phagocytic activity and clearance efficiency decreased significantly for the shrimp held in 5 per thousand, 15 per thousand and 35 per thousand after 12h. It is concluded that tiger shrimp P. monodon transferred from 25 per thousand to low salinity levels (5 per thousand and 15 per thousand) and high salinity (35 per thousand) had reduced immune ability and decreased resistance against P. damselae subsp. damselae infection.
Wang
Feng-I
FI
Department of Aquaculture, College of Life Sciences, National Taiwan Ocean University, Keelung, Taiwan 202, ROC.
Chen
Jiann-Chu
JC
D000818:Animals; D017756:Aquaculture; D004198:Disease Susceptibility; D006434:Hemocytes / Q000187:drug effects / Q000276:immunology; D007113:Immunity, Innate / Q000187:drug effects*; D014442:Monophenol Monooxygenase / Q000032:analysis; D033561:Penaeidae / Q000187:drug effects / Q000201:enzymology / Q000276:immunology* / Q000382:microbiology*; D010587:Phagocytosis / Q000187:drug effects / Q000276:immunology; D010776:Photobacterium / Q000187:drug effects / Q000254:growth & development / Q000302:isolation & purification / Q000472:pathogenicity*; D016897:Respiratory Burst / Q000276:immunology; D012965:Sodium Chloride / Q000494:pharmacology; D013482:Superoxide Dismutase / Q000032:analysis; D013997:Time Factors; D014774:Virulence
D012965:Sodium Chloride; D014442:Monophenol Monooxygenase; D013482:Superoxide Dismutase