| 摘要: |
| 采用病原分离与鉴定、人工感染试验等方法,在对养殖牙鲆病例进行发病情况、病理变化特征检验的基础上,进行病原学检验。结果表明,此病例属于由弧菌属(Vibrio Pacini 1854)细菌引起的败血感染症。经对12株纯培养菌(HQ010712-1—HQ010712-12)进行形态特征、理化特性等表观分类学指征的检验,选择代表菌株(HQ010712-1株)进行16S rRNA基因的测定与系统发育学分析等,判定为弧菌属的一个新种。将HQ010712-1株送中国典型培养物保藏中心(CCTCC)进行了复核鉴定与分类定名,依据分离地定名为秦皇岛弧菌(Vibrio qinhuangdaora sp.nov.);参考菌株为HQ010712-1。 |
| 关键词: 牙鲆, 细菌性败血症, 病原细菌, 系统发育学分析, 16S rRNA |
| DOI： |
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| 基金项目:河北省科技厅科技攻关项目, 02220502D号; 河北省自然科学基金项目, C2005000498号 |
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| INFECTION AND CHARACTERIZATION OF VIBRIO QINHUANGDAORA SP. NOV ISOLATED FROM FLOUNDER PARALICHTHYS OLIVACEUS L. |
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CHEN Cui-Zhen, ZHANG Xiao-Jun, FANG Hai, JIN Xiao-Min, WANG Xiu-Yun
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Department of Animal Science, Hebei Normal University of Science and Technology, Qinhuangdao
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| Abstract: |
| Continuous high-level mortalities occurred in cultured flounder o f a farm in Qinhuangdao, Hebei Province. Examination of naturally diseased fish had indicated a range of symptoms including poor or no appetite, slowly swimming, and often floating onto the water surface. Pathological examinations of 17 moribund and dead fish displayed haemorrhages on the opercula, mouth and fins; rot of muscles from head to dorsal fin, and anus extrusion. Internally, there were swelling of the liver, gallbladder, kidney and spleen, haemorrhaging in the liver, kidney and intestinal walls, ascitic fluid in the peritoneum. The main objective of this study was to examine infection, isolate and identify the pathogenic bacteria, and clarify the pathogenicity, so as to provide further in formation for examination and control infectious diseases of flounder.
Preliminary identification based on morphological, physiological and biochemical characteristics, and the mol% G+C ratio of the DNA for representative strains, showed that the isolates belonged to species of Vibrio. In addition, molecular identification of analysis of the nucleotide sequence of the 16S rRNA gene was conducted, molecular phylogenetic trees were constructed. The morphological characteristics of 12 strains (numbered as HQ010712-1 to HQ010712-12) were consistent: Gram-negative, rod shaped with rounded ends to coccoid, slightly curved, (0.5–1.2) μm × (0.5–2.2) μm in size, occur singly, in pairs or irregularly short chains, no-endospores; electron micrographs revealed a single polar flagellum. The 16S rRNA of representative strain (HQ010712-1) were sequenced, the length o f the 16S rRNA gene sequence is 1431bp, accession numbers in NCB I is AY863432. Infection trials o f healthy flounder using selected representative strains, revealed that all infected groups experienced morbidities and mortalities regardless of the site of injection, and infected flounder manifested a septicaemia and clinical disease as in the naturally infected fish. In addition, the representative strain (HQ010712-1) was confirmed by China Center for Type Culture Collection (CCTCC), which the results consistent with ours, and were regarded as new species of Vibrio, which were designated as Vibrio qinhuangdaora sp. nov based on its biological properties following "Rules o f International Code of Nomenclature of Bacteria". |
| Key words: Flounder, Paralichthys olivaceus L., Bacterial septicaemia, Pathogenic bacteria, Phylogenetic analysis, 16S rRNA |
