抗生素对溶藻弧菌SXT/R391元件转移频率的影响

Effects of antibiotics on the transfer frequency of SXT/R391 element of Vibrio alginolyticus

摘要:

[目的] 研究萘啶酸、诺氟沙星、卡那霉素3种抗生素对溶藻弧菌(Vibrio alginolyticus) SXT/R391元件ICEValA056-1转移频率的影响。[方法] 利用PCR检测溶藻弧菌A056中ICEValA056-1的自我剪切、转移潜力。通过溶藻弧菌A056与大肠杆菌菌株VB111的接合实验,研究溶藻弧菌分别在含不同浓度萘啶酸、诺氟沙星、卡那霉素的LB培养基中培养15 min或30 min后,ICEValA056-1转移频率的变化规律。[结果] 溶藻弧菌A056细胞中有环状形式的 ICEValA056-1分子存在,具有水平转移潜力;溶藻弧菌A056在含40 μg/mL萘啶酸的LB中培养30 min后,ICEValA056-1转移频率是对照组的19.59倍;在含50 μg/mL诺氟沙星的LB中培养15 min后,ICEValA056-1转移频率是对照组的31.25倍;在含不同浓度卡那霉素的LB中培养30 min后,ICEValA056-1转移频率与对照组没有显著差别。[结论] 部分抗生素的使用可以明显促进溶藻弧菌ICEValA056-1向大肠杆菌的转移,因此海洋环境中抗生素的滥用及随意排放很可能加剧ICEs (integrating conjugative elements)从溶藻弧菌到其他细菌的传播。

关键词:溶藻弧菌;SXT/R391元件;转移频率;抗生素

Abstract:

[Objective] We studied the effects of nalidixic acid, norfloxacin and kanamycin on the transfer frequency of SXT/R391 element ICEValA056-1 in Vibrio alginolyticus. [Methods] The circular ICEValA056-1 in V. alginolyticus A056 was detected by PCR. Conjugation experiments were conducted between V. alginolyticus A056 and Escherichia coli VB111 to explore the frequency variation of the integrating conjugative elements transfer after donor strain A056 was cultured in Luria Broth containing nalidixic acid or norfloxacin or kanamycin in different concentrations for 15 min or 30 min. [Results] Circular ICEValA056-1 was detected in V. alginolyticus A056, indicating that ICEValA056-1 had the potential to transfer. Treatment with 40 μg/mL nalidixic acid for 30 min increased the transfer frequency of ICEValA056-1 to19.59 folds. Treatment with 50 μg/mL norfloxacin for 15 min increased the transfer frequency of ICEValA056-1 to 31.25 folds. The transfer frequency of ICEValA056-1 had no significant changes under treatment with different concentrations of kanamycin for 30 min. [Conclusion] This study indicates that some antibiotics can obviously increase the transfer frequency of ICEValA056-1, and that antibiotics abuse and arbitrarily discharge might intensify dissemination of integrating conjugative elements from V. alginolyticus to other bacteria.

Key words:Vibrio alginolyticus;SXT/R391 element;transfer frequency;antibiotics