摘要: |
用平板划线分离方法,从呈群体死亡的日本对虾溞状幼体中分离到同种细菌,经对从分离做纯培养的6株菌(HL010406-1至HL010406-6)进行形态特征、理化特性、代表菌株(HL010406-1)的16S rRNA基因序列测定及系统发育学等方面的鉴定,初步表明其为微杆菌属(Microbacterium Orla-Jensen 1919)细菌的一个新种;选择代表菌株(HL010406-1)送中国典型培养物保藏中心(CCTCC)进行了复核鉴定,将其暂定名为杀虾微杆菌(Microbacterium shrimpcida sp.nov.)。根据用HL010406-1为代表菌株对健康虾及牙鲆做感染试验,初步认为该菌可能是造成所检虾苗死亡的病原菌。经用37种抗菌类药物对3株菌所做的药敏试验,结果发现对供试的青霉素G等30种药物呈敏感或高度敏感、对诺氟沙星低度敏感、对苯唑青霉素等6种具有耐药性。 |
关键词: 日本对虾 虾苗 杀虾微杆菌 检验 |
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基金项目:河北省科学技术研究与发展计划资助项目,04220401D号 |
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ISOLATION AND IDENTIFICATION OF MICROBACT ERIUM SHRIMPCIDA SP. NOV. |
FANG Hai, CHEN Cui-Zhen, ZHANG Xiao-Jun, HE Zhen-Ping, GE Mu-Xiang
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Department of Animal Science,Hebei Normal University of Science and Technology,Qinhuangdao,066004
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Abstract: |
Acute high-level mortalities of zoea of Penaeus japonicus occurred in one aquaculture hatchery of Hebei of China in April 2001. The suffered shrimp showed loss of feeding, listless behaviour, impaired swimming, floating up to the water surface, with sudden death boost.
For understanding the death-causative disease, bacteria were isolated and characterized from dead larvae. Representative strains (HL01 0406-1 to HL01 0406-6) were selected for molecular identification by partial 16S rRNA gene sequencing and a molecular phylogenetic tree was constructed.
Six strains (HL01 0406-1 to HL01 0406-6) were identified in morphology, physiology and biochemistry. The strains were examined and found quite similar in morphology, being Gram-positive (some strains were between Gram-positive and Gram-negative), rod-shaped (some were short rod-shaped or spherical), single or paired with round ends, no endospores, and (0.2 - 0.4) μm × (0.3 - 1.4) μm in size. Some flagella were revealed on electronic micrographs for negatively stained strains. The mol% G+C of the DNA was 64.5. The sequenced 16S rRNA gene of strain HL0l0406-l (GenBank accession No. DQ377339) is 1381 bp in length. They shared high similarity at 95%*98% to that of Microbacterium. The results showed that the isolates is a new species of Microbacterium; the selected representative strain (HL010406-1) has been re-checked by China Center for Type Culture Collection (CCTCC), and designated it as Microbacterium shrimpcida sp. nov. The isolates were probably the pathogenic bacteria of acute larvae death shown in pathogenicity of representative strain (HL01 0406-1) by artificial infection experiment to healthy shrimp and flounder. |
Key words: Penaeus japonicus, Shrimp larvae, Microbacterium shrimpcida sp. nov., Examination |