Abstract:

Shewanella aquimarina is one of the pathogenic bacteria of sea urchin Strongylocentrotus intermedius. To establish PCR detection process of S. aquimarina, 3 pairs of primer were designed according to the specified region of gyrB genes of S. aquimarina, and the specificity and sensitivity were analyzed. The results showed that the amplified fragments of PCR applied with primer SA-9 was agreed with the expected sizes. SA-9 could detect the minimum bacteria concentration of 4.6×103 cfu/mL, and the minimum detectable concentration of bacteria DNA was 0.315 pg/μL. These experiments showed that primer SA-9 had high specificity and sensitivity to S. aquimarina. S. aquimarina in coelomic fluid of sea urchins and the environmental samples were detected by the method. The results of healthy sea urchins, breeding seawater and feeding kelp were negative, while the sample of seawater from natural sea area had a certain amount of S. aquimarina.

Key words: Shewanell aquimarina, gyrB gene, PCR, specification, sensitivity

摘要：

海水希瓦氏菌（Shewanella aquimarina）是虾夷马粪海胆的一种致病菌。为建立海水希瓦氏菌PCR快速检测方法，根据海水希瓦氏菌gyrB基因的高变区序列设计3对引物，随后进行了其特异性和灵敏度分析。结果显示引物SA-9可扩增出片段大小为815 bp的海水希瓦氏菌特异片段。引物可检测的最低细菌量为4.6×103 cfu/mL,最低DNA含量为3.15×10-4 ng/μL。表明以SA-9为引物的PCR检测方法特异性强，灵敏度高。 另外以该方法对海胆及其生境样品进行初步检测，发现健康海胆、养殖海水及投喂海带为阴性，而自然海域的海水具有一定量的海水希瓦氏菌。

关键词: 海水希瓦氏菌;gyrB基因;PCR;特异性；灵敏度