重组猪β-防御素1对大肠杆菌的抑制作用  

Inhibitory Effects of Recombinant Porcine Beta-defensin 1 on Escherichia coli

作　　者：郭海勇[1] 袁洪兴[2] 王云霄 徐瑞涛[2] 宋勤叶[2] 

机构地区：[1]吉林师范大学生命科学学院,四平136000 [2]河北农业大学动物医学院河北省兽医生物技术工程技术研究中心,保定071000 [3]保定市动物疫病预防控制中心,保定071001

出　　处：《畜牧兽医学报》2017年第7期1342-1348,共7页ACTA VETERINARIA ET ZOOTECHNICA SINICA

基　　金：河北省科技计划项目(13226603D-1<2013>-X);河北省生猪产业技术体系疫病控制专项资金

摘　　要：旨在评价重组猪β-防御素1(porcineβ-defensin 1,pBD1)对大肠杆菌(E.coli)的体外抑制活性及其对大肠杆菌病鸡的治疗效果。应用琼脂板打孔扩散法和微量抑菌试验,分别测定重组pBD1对3株E.coli(O141、SJZ1和SJZ2株)的体外抑制效果,继而将40只11d的雏鸡随机分为5组(n=8),即A(防御素)组、B(抗生素)组、C(防御素与抗生素联合治疗)组、D(感染非治疗)组和E(空白对照)组。A、B、C和D组:同时经颈部皮下和口服途径分别给每只鸡接种1mL E.coli O141株(1.25×109 cfu·mL^(-1));E组:以同样途径分别给每只鸡接种1mL肉汤。当感染鸡表现临床症状时,A、B、C和D组分别口服pBD1[50μg·(只·次)^(-1)]、头孢曲松钠(50mg·kg^(-1),按体重给药,下同)、pBD1和头孢曲松钠[分别为50μg·(只·次)-1和50mg·kg^(-1)]及等体积的无菌生理盐水,每天1次,连续治疗7d。结果表明,重组pBD1在体外对3株E.coli均具有明显的抑制活性,抑菌效果随浓度增加而增强。与非治疗组相比,三个治疗组的临床症状和病理变化明显减轻,发病率、死亡率降低,感染后期防御素治疗组、防御素与抗生素联合治疗组的体重极显著高于感染非治疗组(P<0.01)。以上结果显示,重组pBD1对E.coli生长具有明显抑制作用,对大肠杆菌病鸡具有良好的治疗效果;重组pBD1的治疗效果优于头孢曲松钠,有助于病鸡恢复;当pBD1与头孢曲松钠联合使用时,疗效更佳。该研究结果可以为大肠杆菌病的有效治疗提供科学依据,为新型抗菌制剂pBD1的研究与开发奠定重要基础。The present study aimed to evaluate the antibacterial activity and treatment effect of porcine beta-defensin 1（pBD1）against E.coli in vitro and in sick chicken infected with E.coli.The inhibitory effects of pBD1 on three E.coli strains（O141,SJZ1 and SJZ2）were detected through agar-gel diffusion method and micro-antibacterial assay in vitro,respectively.Then forty11-day-old chickens were divided into 5groups（n=8）randomly,including the defensin group（A）,antibiotic group（B）,defensin and antibiotic group（C）,non-treatment group after infection（D）and negative control group（E）.Group A,B,C and D were challenged with 1 mL E.coliO141（1.25×109 cfu·mL-1）via the neck subcutaneous injection and oral administration respectively,and Group E was inoculated 1 mL nutrient broth with the same administration routes.While the E.coli-infected chicken showing the clinical symptoms,the group A,B,C and D were given orally pBD1（50μg per chicken each time）,ceftriaxone sodium（50 mg per kg of body weight）,pBD1（50μg per chicken each time）and ceftriaxone sodium（50 mg per kg of body weight）,and the same volume of sterilized saline water once a day,respectively,and the chickens in each group were continuously treated for seven days.The results showed that the recombinant pBD1 displayed clearly antibacterial activity against E.coli in vitro and this antibacterial effect increased as the concentration of pBD1 rose within certain ranges.Compared with the non-treatment group,the reduction were exhibited in clinical symptoms,pathological changes,morbidity and mortality of the three treated group（A,B and C）.The body weights of the group A treated with pBD1 and the group C with defensin and antibiotic were significantly higher（P0.01）than that of the non-treated group（D）in the later period of infection.These results showed that the recombinant pBD1 has obviously inhibitory effect on E.coli,and has effective therapeutic effects on the sick chicken suffering the colibacillosis.The treatmen

关 键 词：重组猪β-防御素1 大肠杆菌 雏鸡 抑制作用 治疗 

分 类 号：S859.797[农业科学—临床兽医学]