从病(死)罗氏沼虾(Macrobrachium rosenbergii)仔虾的匀浆液中分离到了一株大量生长的优势菌,感染试验表明分离菌对罗氏沼虾仔虾有较强的致病作用.对分离菌进行了形态、培养、生化和理化等表现生物学特性检验,同时对该菌进行了分子生物学鉴定,扩增了该菌的gyrB基因和16S rRNA基因并进行测序和序列同源性分析.综合分离菌的表型特征、理化特性及分子生物学鉴定结果,判定病原菌为气单胞菌属(Aeromonas)的嗜水气单胞菌(Aeromonas hydrophila).采用纸片扩散法(K-B法)测试了分离株对44种抗菌类药物的敏感性,结果表明,供试菌均对所测定的44种抗菌类药物中的氨曲南等24种药物敏感.对青霉素G等8种药物耐药.%The dominant bacteria were obtained from diseased juvenile Macrobrachium rosenbergii and strong pathogenicity to M. rosenbergii were determined by immersion. The phenotypie characteristics of the isolate strain were examined, including morphological characteristics, and physical and chemical characteristics; the 16S rRNA and gyrB genes were amplified by PCR and compared with sequences deposited in database. The isolates were identified as Aeromonas hydrophila based on comprehensive analysis of their phenotepie and molecular characteristics. Antibiotic susceptibility tests showed that the isolates exhibited susceptible to 24 kinds of agents (eg. astreonam), resistant to 8 agents (eg. penicillin G) by disc diffusion method (K-B).
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