School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, China.
Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, Hangzhou, China.
Front Cell Infect Microbiol. 2018 Mar 20;8:88. doi: 10.3389/fcimb.2018.00088. eCollection 2018.
Quorum sensing (QS) regulates the behavior of bacterial populations and promotes their adaptation and survival under stress. As QS is responsible for the virulence of vast majority of bacteria, quorum quenching (QQ), the interruption of QS, has become an attractive therapeutic strategy. However, the role of QS in stress tolerance and the efficiency of QQ under stress in bacteria are seldom explored. In this study, we demonstrated that QS-regulated catalase (CAT) expression and biofilm formation help PAO1 resist nicotine stress. CAT activity and biofilm formation in wild type (WT) and Δ strains are significantly higher than those in the Δ strain. Supplementation of Δ strain with 3OC12-HSL showed similar CAT activity and biofilm formation as those of the WT strain. LasIR circuit rather than RhlIR circuit is vital to nicotine tolerance. Acylase I significantly decreased the production of virulence factors, namely elastase, pyocyanin, and pyoverdine under nicotine stress compared to the levels observed in the absence of nicotine stress. Thus, QQ is more efficient under stress. To our knowledge, this is the first study to report that QS contributes to nicotine tolerance in . This work facilitates a better application of QQ for the treatment of bacterial infections, especially under stress.
群体感应（QS）调节细菌种群的行为，促进其在应激下的适应和生存。由于 QS 负责绝大多数细菌的毒力，因此，QS 的中断——群体淬灭（QQ）成为一种有吸引力的治疗策略。然而，QS 在细菌应激耐受中的作用以及 QQ 在应激下的效率很少被探索。在本研究中，我们证明了 QS 调节的过氧化氢酶（CAT）表达和生物膜形成有助于 PAO1 抵抗尼古丁应激。野生型（WT）和Δ菌株的 CAT 活性和生物膜形成明显高于Δ菌株。用 3OC12-HSL 补充Δ菌株可使 CAT 活性和生物膜形成与 WT 菌株相似。LasIR 电路而不是 RhlIR 电路对尼古丁耐受至关重要。与没有尼古丁应激时的水平相比，酰化酶 I 在尼古丁应激下显著降低了毒力因子的产生，即弹性蛋白酶、绿脓菌素和吡咯并喹啉醌。因此，QQ 在应激下更有效。据我们所知，这是第一份报告 QS 有助于 尼古丁耐受的研究。这项工作促进了 QQ 在治疗细菌感染方面的更好应用，尤其是在应激下。
