Rapid Identification of Pathogenic Fich Bacteria

采用API ZYM系统对鱼类病原菌进行鉴定。作为附加试验，还检测了革兰氏染色、细胞色素氧化酶和过氧化氢酶的活性。对API ZYM和其他试验的结果进行了编码，并对细菌性肾脏病（BKD）病原体鲑肾杆菌（Renibacterium salmoninarum）的各种诊断方法进行了比较。最敏感的方法是酶免疫测定法，每克肾组织可以检测到10^2个细菌细胞。对间接荧光抗体试验（IFAT）和凝血试验显示阳性反应的最低细菌浓度分别为10^3和10^4个细胞/g肾脏。革兰氏染色法、免疫扩散法和乳胶凝集法的敏感性较低，仅适用于有明显BKD症状的鱼。用直接斑点杂交法（DDBA）、间接斑点杂交法（IDBA）和间接荧光抗体试验（IFAT）检测了656尾银鲑鲑鳟抗原，DDBA阳性率为11.8%，IDBA阳性率为28.2%，IFAT阳性率为12.9%。

The API ZYM system was used to identify the bacterial fish pathogens. As additional test, Gram stain and the activities of cytochrome oxidase and catalase were examined. The results of API ZYM and the additional tests were coded for easy identification.Various diagnostic methods used to detect Renibacterium salmoninarum, the causative agent of bacterial kidney disease (BKD) , were compared. The most sensitive method was the enzyme immunoassay, which could detect 10^2 bacterial cells per gram of kidney tissue. The minimum bacteria concentrations showing posotive reactions to the indirect fluorescent antibody test (IFAT) and the coagglutination test were 10^3 and 10^4 cells/g kidney, respectively. The sensitivities of the Gram stain, immunodiffusion procedure, and latex agglutination test were low, and these methods could only be applied to fish with overt BKD symptoms. Altogether, 656 coho salmon Oncorhynchus kisutch were examined for R.salmoninarum antigen with the direct and indirect dot blot assays (DDBA and IDBA) and the IFAT.Among the fish sampled, positive reactions were obtained in 11.8% by the DDBA, 28.2% by the IDBA, and 12.9% by the IFAT.