去甲肾上腺素对大肠杆菌耐药质粒接合转移的影响

发布时间：2018-05-16 20:32

本文选题：去甲肾上腺素 + 大肠杆菌　；参考：《南京农业大学学报》2017年05期

【摘要】：[目的]本研究旨在探讨生产中普遍存在的急性应激因素对细菌耐药基因水平转移的可能影响。[方法]选取分离自断奶香猪粪便的2株喹诺酮类敏感型大肠杆菌作为试验菌株,通过测定D600值比较菌株在添加不同浓度去甲肾上腺素培养液中的生长曲线,确定去甲肾上腺素对于大肠杆菌的最佳促生长浓度;分离自断奶香猪粪便的7株携带质粒喹诺酮类耐药基因(aac(6')-lb-cr、oqx AB、qnr S)的大肠杆菌,采用滤膜接合法,计算去甲肾上腺素诱导和未诱导的大肠杆菌分离株(供体菌)与大肠杆菌J53(受体菌)的接合转移率;PCR检测接合子及供、受体菌质粒介导抗性基因的携带情况;采用K-B纸片扩散法和琼脂稀释法测定接合子及供、受体菌的多种抗生素最小抑菌浓度(MIC)。[结果]去甲肾上腺素对于大肠杆菌的促生长效果具有浓度依赖性,最佳促生长浓度为100μmol·L-1。7株携带质粒介导的喹诺酮类耐药基因的大肠杆菌中有4株(A、B、C、D)成功获得接合子,经去甲肾上腺素(100μmol·L-1)诱导后与受体菌的接合转移率与去甲肾上腺素未诱导组相比均升高,其中A、B、C 3株供体菌极显著升高(P0.01)。所有接合子均扩增到恩诺沙星3种耐药基因:aac(6')-lb-cr、oqx AB、qnr S。接合子菌株对6种抗菌药物的MIC值与大部分供体菌株相同。[结论]去甲肾上腺素对于大肠杆菌的促生长效果具有浓度依赖性,且提高了大肠杆菌分离株耐药质粒体外接合转移率。提示:动物养殖生产中应加强应激管理,以减少细菌耐药基因水平传播的发生。
[Abstract]:[objective] to investigate the possible effects of acute stress factors in production on the horizontal transfer of bacterial drug resistance genes. [methods] two strains of Quinolone-sensitive Escherichia coli isolated from weaning pig feces were selected as experimental strains. The growth curves of the strains were compared by measuring the D600 values in the medium supplemented with different concentrations of norepinephrine. To determine the optimal concentration of norepinephrine for the growth of Escherichia coli, and to isolate 7 strains of E. The conjugation transfer rates of norepinephrine induced and uninduced Escherichia coli isolates (donors) and Escherichia coli J53 (receptor bacteria) were calculated. The conjugates and donors were detected by PCR. K-B disk diffusion method and Agar dilution method were used to determine the minimal inhibitory concentration (MIC) of conjugate and donor antibiotics. [results] the effect of norepinephrine on the growth of Escherichia coli was concentration-dependent. The best concentration was 100 渭 mol L-1.7 strain of Escherichia coli carrying plasmid mediated quinolone resistance gene. After induction with norepinephrine (100 渭 mol L ~ (-1), the rate of conjugated transfer with the receptor bacteria was significantly higher than that of the non-norepinephrine induced group, among which the Agnerinic C _ (3) donor strain was significantly higher than that of the norepinephrine group (P _ (0.01). All the conjugates amplified Enrofloxacin 3 kinds of resistance gene: aacanine 6Con -lb-croqx ABN Qnr S. The MIC values of conjugate strains to 6 antimicrobial agents were the same as those of most donor strains. [conclusion] norepinephrine has a concentration-dependent effect on the growth of Escherichia coli, and increases the in vitro conjugation transfer rate of Escherichia coli resistant plasmids. It is suggested that stress management should be strengthened in animal breeding in order to reduce the horizontal transmission of bacterial drug resistance genes.
【作者单位】：南京农业大学动物科技学院;
【基金】：国家重点研发计划项目(2016YFD0500500) 国家自然科学基金项目(31372321)
【分类号】：S852.612

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