3-磷酸甘油醛脱氢酶在鸭疫里默氏杆菌感染过程中的致病作用  

Evidence indicating that RaGAPDH is apathogenic factor of Riemerella anatiestifer

作　　者：高继业 李金蓉 黄伟[1] 李继祥[1] 李德龙 陈思怀 GAO Jiye;LI Jinrong;HUANG Wei;LI Jixiang;LI Delong;CHEN Sihuai(College of Veterinary Medicine,Southwest University,Chongqing 402460,China)

机构地区：[1]西南大学动物医学学院,重庆402460

出　　处：《中国兽医学报》2023年第3期488-496,共9页Chinese Journal of Veterinary Science

基　　金：重庆科技局基础与前沿研究基金资助项目(cstc2016jcyjA0240)。

摘　　要：为深入探讨3-磷酸甘油醛脱氢酶(RaGAPDH)在鸭疫里默氏菌(Riemerella anatipestifer,R.anatipestifer)致病过程中的作用,研究采用等位基因交换技术将RaGAPDH的编码基因gap从血清Ⅰ型R.anatipestifer菌株CZ2中敲除,产生gap基因缺失突株CZ2△gap,比较研究该突变菌株与野生型菌株生物学特征的异同及抗RaGAPDH多克隆抗体对雏鸭的被动免疫保护效率。结果显示,突变菌株CZ2△gap在生长曲线、生化特性、细菌菌落形态等方面与野生菌株非常相似,但是对14日龄樱桃谷鸭的LD50由野生株的4.2×10^(7)CFU下降到109CFU,突变株对鸭胚成纤维细胞的黏附、入侵能力明显下降(P<0.01)。此外,动物试验研究表明,抗RaGAPDH多克隆抗体可保护14日龄樱桃谷鸭抗R.anatipestifer感染,0.5,1.0,1.5 mL剂量组的保护率分别为19.5%,50.0%,52.8%,其中1.0,1.5 mL剂量组的差异不显著(P<0.01)。结果表明,RaGAPDH是R.anatipestifer的一个致病因子,并可能作为黏附素发挥作用。Riemerella anatipestifer(R.anatipestifer)is one of the major causative agents in economic losses for the duck-rearing industry worldwide.However,little is known about its pathogenesis and virulence factors.We previously demonstrated the binding ability of RaGAPDH purified from R.anatipestifer to duck plasminogen and histidine-rich glycoprotein(HRG),indicating that it may plays a potential role in virulence.However,the role in R.anatipestifer remains unclear.In the present study,the gap gene encoding RaGAPDH was deleted from the R.anatipestifer serotype 1 strain CZ2 to generate the mutant CZ2Δgap.Data showed that there were similarities in the growth curve,biological characteristics,bacterial and colony morphology between the mutant and the wild strain.However,the LD50of 14-day-old Cherry Valley duckling was attenuated from 4.2×10^(7)colony forming units(CFUs)(wild strain)to>109CFUs(mutant).The data also showed that the ability of adhesion and invasion of the mutant to duck embryo fibroblasts was significantly reduced.In addition,the challenge experiments demonstrated that anti-RaGAPDH polyclonal antibody of 0.5,1.0,1.5 mL increased passive immune protection to about 19.5%,50.0%,52.8%respectively for 14-day-old Cherry Valley ducklings infected with R.anatipestifer,and there was no significant difference between the dose groups of 1.0 mL and 1.5mL(P<0.01).These findings further indicate that RaGAPDH is a pathogenic factor and possible adhesin in R.anatipestifer.

关 键 词：3-磷酸甘油醛脱氢酶 鸭疫里默氏杆菌 毒力因子 黏附素 细胞外蛋白质 

分 类 号：S852.61[农业科学—基础兽医学]