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The Israeli Journal of Aquaculture - Bamidgeh 62(3), 2010, 181-188
The IJA appears now exclusively as a peerreviewed on-line Open Access journal at
http://www.siamb.org.il
Characterization and Phylogenetic Analysis of the
Bitrichous Pathogenic Aeromonas hydrophila Isolated
from Diseased Siberian sturgeon (Acipenser baerii)
Haipeng Cao1, Shan He1, Liqun Lu1*, Lundeng Hou2*
Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources,
Aquatic Pathogen Collection Center of Ministry of Agriculture, Shanghai Ocean
University, Shanghai 201306, P.R. China
1
2
Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, P.R.
China
(Received 3.11.09, Accepted 11.12.09)
Key words: Acipenser baerii, septicemia, Aeromonas hydrophila, bitrichous
Abstract
Diseases have been the bottle-neck to sustainable development of
sturgeon cultivation. Bacterial septicemia that caused mass
mortalities of sturgeons is still prevalent in Shanxi and Yunnan
provinces in China. The epidemiology and pathogenicity of the
disease were investigated. Four predominant isolates of bacteria
were isolated from Siberian sturgeons (Acipenser baerii) suffering
from bacterial septicemia in outdoor culture ponds. Induced
infection experiments with these isolates of bacteria showed that
only one isolate was pathogenic and showed the same signs as in
naturally infected sturgeon. Re-isolates from diseased sturgeon
had the same morphological characteristics. Physiological and
biochemical tests and sequence similarity analysis of the 16S rDNA
genes of this isolate indentify it as Aeromonas hydrophila. An
antibiotic sensitivity test showed that the isolate was sensitive to
netilmicin, cefur oxime, cephradine, gentamicin, neomycin,
* Corresponding authors. Tel: +86-216-1900453, +86-591-83715175, fax: +86-2161900452, email: [email protected], [email protected]
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Cao et al.
streptomycin, and cefobid, and moderately sensitive to nalidixic
acid, kanamycin, cephalothin V.