| Summary: | 碩士 === 國立中興大學 === 獸醫學系 === 84 === The aims of this investigation were to evalute the
antibacterial efficiencies of five glycans; namely Barely (Bar),
Krestin (Kre), M-glucan(MG), Scleroglucan (SG), and Zymosan
(Zym), in fish by three different administration. By the
phagocytic index assay, lysozyme assay, complement opsonization
assay, and complement activation assay, the mechanisms of the
non-specific immune response of five glycans in fish were
studied in this study. After challenged with Edwardsiella
tarda, the results revealed that the survival rates of fish
treated with glycans were increased. Treated with 10 and20 mg/kg
b.w. of glycans (Bar, Kre, MG, SG, and Zym) by the
intraperitoneal injection, the survival rates of tilapia,
Tilapia mossanbicus, and grass carp,Ctenopharyngodon idellus,
bighead carp, Aristichthys nobilis, did significantlybe
increased (p<0.05) but not 5 mg/kg b.w. The survival rates of
fish given with 30 mg/kg b.w. of five glycans by the oral
administration were significantly raised (p<0.05). However, fish
received orally with 10 or 20mg/kg b.w. of five glycans were not
fish immersed with 300 ppm of glycans weresignificantly
increased but not 100 ppm and 200 ppm. From the lysozyme,
complement opsonization assays, fish treated with glycans were
able to enhance the abilities of lysozyme, and complement
opsonization. The results of the lysozyme assay revealed
that the lysozyme activity indexes of tilapia and eel treated
with Bar, Kre, MG, SG, and Zym were (5.31,7.01), (5.14, 6.44),
(6.44, 5.79), (5.79, 5.29), and (5.79, 6.76), respectively.The
phagocytic indexes (PIs) of nephro phagocytes of tilapia and eel
treated with Bar,Kre, MG, SG, Zym were (58.6, 61.7), (58.4,
59.2), (62.5, 61.2), (60.7,60.4), (61.9, 59.9), respecectively.
In the complement opsonization assay, the results shown that the
PIs of nephro phagocytes of tilapia and eel treated withBar,
Kre, MG, SG,and Zym were (68.7, 69.7), (65.9, 68.4), (69.2,
70.1), (70.0,70.7), (67.9, 69.3), respectively. The results
of the glycan phagocytosis of monocyte test shown that
glycansincreased the monocyte percentages in fish. The
phagocytic one or three glycangranule`s percentages of monocytes
of tilapia treated with Bar, Kre, MG, SG, and Zym were (39.4％,
24.7％), (36.5％, 19.3％), (41.3％, 26.5％), (39.7％, 20.1％),
(33.8％, 18.3％), (64.1％, 59.0％),(55.8％, 55.4％), (67.8％,
67.8％),(59.7％,56.6％), and (52.1％, 50.6％), respectively. The
phagocytic one or three glycan granules percentages of monocytes
of eel treated with Bar, Kre, MG, SG, and Zym were (37.1％,
21.9％), (34.8％, 20.6％), (39.4％, 28.4％), (32.9％, 23.7％),
and (30.3％, 21.3％), respectively. From the classical and
alternative complement activation assay, the results revealed
that the glycans did active both complement passway functions.In
the classical complement activation assay, the CH50 of tilapia
treated withBar, Kre, MG, SG, and Zym in vitro and in vivo were
(241.45, 201.87), (233.77,199.65), (251.16, 211.74), (255.12,
216.12), and (252.34, 204.29), respectively.In the alternative
complement activation assay, the ACH50 of tilapia treated with
Bar, Kre, MG, SG, and Zym in vitro and in vivo were (861.91,
487.12), (712.60, 599.37), (896.84, 631.58), (637.32, 493.49),
(655.44, 529.63), respectively. However, the ACH50 of the
classical complement activation assay of eel treated with
glycans in vitro and in vivo were not ableto be detected because
there were a lot of unknown factors in the eel serum to break
rabbit`s RBCs. From above assays, the results of this study
reveal that fish treated with glycans (Bar, Kre, MG, SG, and
Zym) by any one of three kinds of minimuneffect dosage of
glycans for intraperitoneal, oral, and immersion
administrationare 10 mg/kg b.w., 30 mg/kg b.w., and 300 ppm,
respectively. All of tested glycans are proven to stimulate the
non-specific immune response in fish.
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