Laboratory of Food Microbiology, P.O. Box 8129, 6700 EV Wageningen, Netherlands.
Appl Environ Microbiol. 2010 Dec;76(23):7854-60. doi: 10.1128/AEM.01519-10. Epub 2010 Oct 1.
Listeria monocytogenes is a food-borne pathogen that is able to form biofilms in food processing facilities. Biofilms are generally more resistant to antimicrobial agents, making it difficult to eradicate them during cleanup procedures. So far, little is known about the function of stress resistance mechanisms in biofilm formation and their resistance to disinfectants. In this study, we investigated the role of sigB, which encodes a major transcriptional regulator of stress response genes, in L. monocytogenes static and continuous-flow biofilm formation and its function in the resistance of biofilm cells to the disinfectants benzalkonium chloride and peracetic acid. Quantitative real-time PCR and promoter reporter studies showed that sigB is activated in static and continuous-flow biofilms. Biofilm formation studies using an in-frame sigB deletion mutant and complementation mutant showed that the presence of SigB is required to obtain wild-type levels of both static and continuous-flow biofilms. Finally, disinfection treatments of planktonically grown cells and cells dispersed from static and continuous-flow biofilms showed that SigB is involved in the resistance of both planktonic cells and biofilms to the disinfectants benzalkonium chloride and peracetic acid.
李斯特菌是一种食源性病原体，能够在食品加工设施中形成生物膜。生物膜通常对抗菌剂具有更强的抵抗力，因此在清洁过程中很难将其根除。迄今为止，人们对生物膜形成过程中应激抵抗机制的功能及其对消毒剂的抗性知之甚少。在这项研究中，我们研究了编码应激反应基因主要转录调节剂的 sigB 在李斯特菌静态和连续流动生物膜形成中的作用，以及其在生物膜细胞对消毒剂苯扎氯铵和过氧乙酸的抗性中的功能。定量实时 PCR 和启动子报告研究表明，sigB 在静态和连续流动生物膜中被激活。使用无义 sigB 缺失突变体和互补突变体进行的生物膜形成研究表明，SigB 的存在对于获得野生型水平的静态和连续流动生物膜都是必需的。最后，对浮游细胞和从静态和连续流动生物膜中分散的细胞进行消毒处理表明，SigB 参与了浮游细胞和生物膜对消毒剂苯扎氯铵和过氧乙酸的抗性。
