磺胺类抗生素对不同革兰氏阴性菌的毒物兴奋效应研究

摘要

抗生素滥用所导致的环境问题日益受到人们的关注,抗生素在环境中常以低剂量的形式暴露,生物体在低浓度的抗生素作用下通常会表现出毒物兴奋效应(hormesis).因此,研究抗生素的hormesis,对抗生素的生态风险评价极其重要.为了研究抗生素的hormesis,本文选取4种磺胺类抗生素为研究对象,观测了不同浓度培养基下磺胺对大肠杆菌能否产生hormesis.结果表明,磺胺对大肠杆菌在原倍和0.8倍浓度的培养基下不产生hormesis,在0.6和0.4倍浓度的培养基下产生hormesis;并且,结合我们之前对另一种革兰氏阴性菌——费氏弧菌hormesis的研究可知,对于具有不同群体感应系统的2种革兰氏阴性菌,都存在hormesis,磺胺可以通过作用群体感应系统使革兰氏阴性菌产生hormesis,只是hormesis的大小不同.上述研究结果为抗生素的生态风险评价提供了依据,为hormesis的相关研究提供了参考.%The environmental problems caused by the overuse of antibiotics have attracted increasing concern. An-tibiotics in the environment are commonly at low concentrations, which is likely to induce hormetic effects on the organisms. Therefore, the study on the hormesis of antibiotics is significantly important to the ecological risk as-sessment. In this research, four sulfonamides were investigated for their hormetic effects on Escherichia coli under different concentrations of culture medium. The results showed that the sulfonmides induced no hormesis on Escherichia coli in undiluted and 0.8-fold dilution of MH media, whilst obvious hormetic effects in 0.6 and 0.4-fold dilu-tions of MH media. Moreover, in combination with our previous study on hormesis with another Gram-negative bacterium, Aliivibrio fischeri, it can be inferred that hormesis could occur for both species irrespective of the types of quorum sensing systems. This study provides evidence for the ecological risk assessment of antibiotics, and it provides reference for the related research of hormesis.