群体感应信号分子存在下磺胺对大肠杆菌生长、突变及R388质粒接合转移的影响

抗生素的滥用使细菌耐药性问题日益突出,给许多疾病的预防与控制增加了难度。基因突变和质粒接合转移是细菌获得抗生素抗性基因的主要方式,许多研究围绕抗性基因来展开,但是关于群体感应对于抗性基因产生和传播的影响鲜有报道。本文以大肠杆菌(Escherichia coli)为模式生物,群体感应信号分子N-(β-酮己酰)-L-高丝氨酸内酯(3-oxo-C6-HSL,C6)和3种磺胺类抗生素(磺胺嘧啶、磺胺甲恶唑、磺胺氯哒嗪)为研究对象,测定了其对大肠杆菌生长效应、突变效应及接合转移效应的影响。结果表明:C6不影响磺胺对大肠杆菌的生长抑制率,但能够削弱磺胺对大肠杆菌突变的促进作用,并且能增强磺胺对大肠杆菌R388质粒接合转移的抑制作用。本文为从群体感应角度研究大肠杆菌耐药性的产生与传播提供新思路。

Effect of Sulfonamides on Growth and Mutation of Escherichia coli and Conjugal Transfer of Plasmid R388 in the Presence of Quorum Sensing Signal Molecules

Due to the indiscriminate use of antibiotics, bacterial resistance has become increasingly severe, which make the prevention and control of diseases more difficult. Mutation and conjugal transfer of plasmid are two main ways of bacteria getting antibiotic resistance genes. Previous studies have focused on the antibiotics resistance genes, which have frequently neglected the influence of quorum sensing on the formation and the spread of resistance genes. In this study, the effects of three kinds of sulfonamides (SAs, i.e., Sulfadiazine, Sulfamethoxazole, Sulfachloropyridazine) on the growth, mutation and conjugal transfer of plasmid of Escherichia coli (E.coli) were investigated in the presence of N-(beta-ketocaproyl)-dl-homoserine lactone (3-oxo-C6-HSL, C6), a type of quorum sensing signal molecules. The results showed that C6 had no influence on the growth effect of SAs on E. coli, but weakened the stimulatory effect of of SAs on mutation and meanwhile enhanced the inhibitory effect of SAs on conjugal transfer of plasmid R388. This work can provide a new reference for the research on the formation and the spread of E.coli resistance from quorum sensing perspective.