【摘要】：查明廣西南寧、貴港和桂平養(yǎng)殖山瑞鱉細菌性敗血癥的病原菌及其6種毒力基因的攜帶情況,為有效防控山瑞鱉細菌性敗血癥提供參考。本研究以常規(guī)方法從患病山瑞鱉的心臟和肝臟取樣、分離細菌,人工感染方法確定分離菌株的致病性,細菌鑒定采用API 20NE生化鑒定和16S rRNA分子鑒定相結(jié)合的方法進行,PCR擴增法對菌株的溶血素基因(hemolysin gene,hly)、氣溶素基因(aerolysin gene,Aer)、細胞興奮性腸毒素基因(cytotonic enterotoxin gene,Alt)、細胞毒性腸毒素基因(cytotoxic enterotoxin gene,Act)、黏附素基因(major adhesin gene,ahal)和絲氨酸蛋白酶基因(serine protease gene,ahp)6種毒力基因進行檢測。結(jié)果顯示,從患病山瑞鱉心臟和肝臟中共分離到4株優(yōu)勢菌SRB125、SRB142、SRB143和SRB345,對健康山瑞鱉的平均致死率為97.50%~100.00%,是引起山瑞鱉細菌性敗血癥的病原菌;生化和分子鑒定結(jié)果顯示,4株分離菌均為嗜水氣單胞菌(Aeromonas hydrophila),與A.hydrophila L3-5(KP716701)菌株的親緣關系最近,同源相似性均達到99.9%;6種毒力基因共包含2種毒力基因型,在4株菌株中的分布為hly~+Aer~+Alt~+Act~+ahal~+ahp~+和hly~+Aer~+Alt~+Act~+ahal~+ahp~ 各2株,來源于南寧的SRB143和桂平的SRB345菌株均缺失ahp基因。
[Abstract]:To find out the pathogen of bacterial septicemia and the carrying of six virulence genes in cultured Trionyx sinensis in Nanning, Guigang and Guiping, Guangxi, so as to provide reference for the effective prevention and control of bacterial septicemia of Trionyx sinensis. In this study, bacteria were isolated from the heart and liver of Trionyx sinensis by routine method, and the pathogenicity of the isolated strains was determined by artificial infection. API 20NE biochemical identification and 16s rRNA molecular identification were used to identify the bacteria. The hemolysin gene (hemolysin gene,hly), aerosol gene (aerolysin gene,Aer), cellular excitatory enterotoxin gene (cytotonic enterotoxin gene,Alt), cytotoxicity enterotoxin gene (cytotoxic enterotoxin gene,Act and adhesin gene (major adhesin gene, were amplified by PCR. Ahal) and serine protease gene (serine protease gene,ahp) were detected by six virulence genes. The results showed that four strains of dominant bacteria SRB125,SRB142,SRB143 and SRB345, were isolated from the heart and liver of the diseased soft-shelled turtle (Trionyx sinensis), and the average fatality rate of the four dominant bacteria to the healthy soft-shelled turtle was 97.50% and 100.00%, which was the pathogen of bacterial septicemia in the soft-shelled turtle (Trionyx sinensis). The results of biochemical and molecular identification showed that the four isolates were (Aeromonas hydrophila), and A.hydrophila L3 鈮，

本文編號：2496899