全雄黄颡鱼红头病病原菌的分离鉴定

Isolation and Identification of Pathogenic Bacteria of Red Head Disease in All-male Yellow Catfish

以患红头病的全雄黄颡鱼为研究对象,从其病灶处分离纯化得到病原菌,通过形态和生理生化特征、16S rRNA基因序列及特异性PCR扩增检测等鉴定,以及药敏性斑马鱼人工感染试验,分析其药敏性和致病性。结果显示,从患病全雄黄颡鱼病灶处分离获得的优势菌株为鮰爱德华菌;该菌株具有较强的致病性,LD_(50)为2.3×10^(5)CFU,感染该菌株的斑马鱼发病症状与自然发病症状相似。药敏试验结果显示,该菌株对青霉素、氯霉素、四环素等28种抗菌药物高度敏感,对红霉素中度敏感,对苯唑西啉、克拉霉素、万古霉素等6种药物耐药。

Using all-male yellow catfish with red head disease as the research object,the pathogen was isolated and purified from the lesion site,and identified by morphology,physiological and biochemical characteristics,16S rRNA gene sequence and specific PCR amplification detection.The drug sensitivity characteristics and pathogenicity of it were analyzed by drug sensitivity assay and zebrafish artificial infection test respectively.The results showed that the dominant strain isolated from the lesions o£the diseased all-male yellow catfish was Edwardsiella ictaluri,which was highly pathogenic with an LDso of 2.3×10^(5)CFU.The symptoms of zebrafish infected with this strain were similar to those of natural disease.The drug sensitivity assay results showed that the strain was highly sensitive to 28 antibiotics such as penicillin,chloramphenicol,and tetracycline,moderately sensitive to erythromycin,and resistant to 6 drags such as benzimidazole,cloramphenicol,and vancomycin.