重组猪β-防御素1对大肠杆菌的抑制作用

发布时间：2018-07-28 15:45

【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(P0.01)。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。
[Abstract]:Objective to evaluate the inhibitory activity of recombinant porcine 尾 -defensin 1 (porcine 尾 -defensin 1) against Escherichia coli (E.coli) in vitro and the therapeutic effect of recombinant porcine 尾 -defensin 1 (尾 -defensin 1) on Escherichia coli (E.coli) chickens. The inhibitory effects of recombinant pBD1 on three E.coli strains (O141SJZ1 and SJZ2) were determined by Agar plate perforation diffusion method and microbacteriostasis test, respectively. Then 40 11-day chicks were randomly divided into 5 groups (n = 8): group A (defensin), group B (antibiotics), group C (combination of defensin and antibiotics), group D (infection without treatment) and group E (blank control). Each chicken was inoculated with 1mL E.coli O141 strain (1.25 脳 10 9 cfu mL ~ (-1) E by oral route, and 1mL broth was inoculated with 1mL broth in the same way. When the infected chickens showed clinical symptoms, pBD1 (50 渭 g / kg), ceftriaxone sodium (50mg kg ~ (-1) and ceftriaxone sodium (50 渭 g / kg ~ (-1) and 50mg kg ~ (-1), respectively) and aseptic saline were taken orally in groups C and D, respectively, once a day. Continuous treatment for 7 days. The results showed that the recombinant pBD1 had obvious inhibitory activity on the three E.coli strains in vitro, and the bacteriostatic effect increased with the increase of the concentration. Compared with the non-treatment group, the clinical symptoms and pathological changes of the three treatment groups were obviously alleviated, the morbidity and mortality were decreased. The body weight of the defensin treatment group and the defensin combined with antibiotic treatment group was significantly higher than that of the infection non-treatment group (P0.01). The results showed that recombinant pBD1 had obvious inhibitory effect on E.coli growth and had a good therapeutic effect on Escherichia coli chickens, and the therapeutic effect of recombinant pBD1 was better than that of ceftriaxone sodium, which was helpful to the recovery of sick chickens. When pBD1 is combined with ceftriaxone sodium, the effect is better. The results can provide scientific basis for the effective treatment of Escherichia coli disease and lay an important foundation for the research and development of new antibacterial agent pBD1.
【作者单位】：吉林师范大学生命科学学院;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;保定市动物疫病预防控制中心;
【基金】：-X)" target="_blank">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
【分类号】：S852.612

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