摘要
从患病地图鱼Astronotus ocellatus肝脏组织中分离到菌株AO1,经人工感染试验证实其为致病菌。通过ATB Expression半自动细菌鉴定仪和常规生理生化特性的分析,初步鉴定该菌株为迟钝爱德华氏菌Ed-wardsiella tarda。测定菌株AO1的16S rRNA基因序列并进行分析,结果显示,该菌株与迟钝爱德华氏菌的同源性最高,达99.9%。因此,可鉴定该菌株为迟钝爱德华氏菌。根据迟钝爱德华氏菌的毒力基因菌毛亚基(fimA)基因序列设计引物,进行PCR扩增,得到383 bp序列,该序列与迟钝爱德华氏菌的fimA基因序列相似性达99.0%,进一步说明菌株AO1具有fimA基因,有一定的致病力。药物敏感试验结果表明,菌株AO1对阿米卡星、氧氟沙星、庆大霉素、新生霉素、氨苄西林、氨曲南、卡那霉素、头孢咪啉、诺氟沙星、环丙沙星、呋喃妥因、妥布霉素、氨苄青霉素13种抗生素较为敏感。
Bacterial strain AO1 isolated from liver of the diseased oscar Astronotus ocellatus was proved to be a pathogen by an artificial infection experiment. The strain AO1 was preliminarily identified as Edwardsiella tarda by TAB Expression systematic identification, and traditional physiological and biochemical characteristics. The 16S rRNA gene sequence analysis revealed that the strain AO1 exhibited the highest level of similarity （99.9% identity） with Edwardsiella tarda compared with GenBank database. Thus, the strain AO1 was identified as Edwardsiella tarda. Fimbrial subunit gene （fimA） is one of the primary virulence genes of Edwardsiella tarda. A 383 bp fragment of the strain was amplified by PCR amplification using the specific primers designed according to the fimA gene sequences of Edwardsiella tarda. It was found that the sequences similarity of the fragment and fimA gene of Edwardsiella tarda was 99.0%, indicating that the strain AO1 as a virulent strain possessed fimA gene. The strain AO1 was shown sensitive to some antibiotics, such as Amikacin, Ofloxacin, Gentamycin, Novobiocin and Amplocilin.
出处
《大连水产学院学报》
CSCD
北大核心
2007年第6期403-408,共6页
Journal of Dalian Fisheries University
基金
广东省重大科技兴海(兴渔)项目(070103)
