Rapid Identification of Pathogenic Fich Bacteria

采用API - ZYM体系对鱼类病原菌进行鉴定。革兰氏染色检测细胞色素氧化酶和过氧化氢酶活性。原料药ZYM及附加试验结果均进行编码，便于鉴别。对细菌性肾病（BKD）病原菌沙门氏菌的几种诊断方法进行了比较。酶免疫分析法灵敏度最高，每克肾组织可检出10^2个细菌细胞。间接荧光抗体试验（IFAT）和凝血试验显示阳性的最低细菌浓度分别为10^3和10^4个细胞/g肾。革兰氏染色法、免疫扩散法和乳胶凝集试验的敏感性较低，这些方法仅适用于有明显BKD症状的鱼。采用直接点印迹法（DDBA）和间接点印迹法（IDBA）及免疫印迹法（IFAT）对656条银鲑进行了沙门氏菌抗原检测。DDBA的阳性反应率为11.8%，IDBA的阳性反应率为28.2%，IFAT的阳性反应率为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.