碩士 / 國立海洋大學 / 水產養殖學系 / 84 / This study attempts to investigate the characteristics and
pathogenicity of Vibrio strain EmI82KL isolated from swollen
intestinal fluids of diseased grouper, Epinephelus coicoides.
The EmI82KL strain is a Gram-negative, straight rod, motile by
polar and /or lateral flagella, oxidase- and catalase-positive.
The bacteria may produce H2S, and reveals yellow colonies on
thio sulfate-citrate-bile-salt-sucrose (TCBS) agar and
transparent colonies on MacConkey agar. In addition, ths strain
failed to produce acetoin, but it was Methyl red- andgelatinase-
positive and sensitive to the vibriostatic compound O/129.
Furthermore, it utilized glucose, starch, urea and chitin. It
grew on TSA with up to 7 % NaCl and at temperature between 10 to
40℃. The optimal growth rate of the strain on TSA was at 30℃,
pH 8.0, supplemented with 1.5 % NaCl. The strain survived in
filtered-autoclaved water up to 2 months. This strain was
identified to be Vibrio carchariae and was susceptible to
chloramphenicol, doxycycline-HCl, nalidixic acid, oxolinic acid,
oxytetracycline and sulphonamide while resistant to ampicillin
and penicillin G. The extracellular products (ECP) exhibited
hemolytic, protease, phospholipase and cholinesterase
activities. But, neuraminidase and cholera toxin-like toxin in
the ECP were undetectable. Hydroxamate siderophore was produced
under iron restricted condition. The strain was weakly
hydrophobic, and was neither hemoagglutinating nor
autoagglutinating. The attachment of the bacteria to grouper
intestine was not observed. Groupers were killed after
intraperitoneal (i.p.) injection of the bacteria with a dose of
10^8 CFU/g fish and observed for two weeks, however, the fishes
were not killed after i.p. injection of the ECP produced in
vitro. Some of the unknown serum components in the moribund
grouper injected with the bacteria were affect either fast
migrated or appearance changed as visualized in crossed
immunoelectrophoresis gels. Grouper were passively protected
by pre-injection of rabbit antisera to the formalinized-bacteria
or -ECP against a lethal dose challenge of the bacteria.
However, in active immunization trial, the fishes vaccinated
with formalinized-bacteria by immersion or i.p. injection
resting for eight weeks failed to survive during two weeks
observation period post-bacterial challenge. It seems that
formalinized-bacteria was less or not immunogenic in the grouper
since the fish was passively protected by rabbit antiserum to
the same bacterin. A detailed study concerning the immunogencity
of the bacteria in the grouper is needed.
| Identifer | oai:union.ndltd.org:TW/084NTOU0086002 |
| Date | January 1996 |
| Creators | YII, KAH CHING, 余家振 |
| Contributors | LEE KUO-KAU, 李國誥 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 124 |
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