Stress resistance, motility and biofilm formation mediated by a 25kb plasmid pLMSZ08 in Listeria monocytogenes

• Published in: Food control Vol. 94; pp. 345 - 352
• Main Authors: Zhang, Hui, Hu, Yunhe, Zhou, Chenglu, Yang, Zhenquan, Wu, Litin, Zhu, Mengya, Bao, Hongduo, Zhou, Yan, Pang, Maoda, Wang, Ran, Zhou, Xiaohui
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.12.2018
• Subjects: Biofilm; Listeria monocytogenes; Motility; Plasmid; Plasmid; Listeria monocytogenes; Biofilm; Motility
• ISSN: 0956-7135; 1873-7129
• DOI: 10.1016/j.foodcont.2018.07.002

Listeria monocytogenes is a foodborne pathogen that can form biofilm and tolerate severe environment condition and thus persist in food product for a prolonged period, which poses a significant risk to food safety. While some chromosomal genetic determinants associated with stress resistance and biofilm formation have been characterized, plasmid-mediated stress resistance in particular L. monocytogenes strains are less known. In this study, we showed a L. monocytogenes strain SZ08 (serovar 1/2b) isolated from a raw meat processing environment harbored a 25kb plasmid, designated as pLMSZ08. After incubation under the selective condition containing novobiocin, pLMSZ08 was successfully cured from SZ08. Compared to its parental strain SZ08, the cured strain SZ08* was not able to grow well under the high concentration of sodium chloride (5.5%). SZ08* displayed higher efficiency of plaque formation compared with its parental strain SZ08. There were no significant growth difference under different temperature and pH conditions between SZ08 and SZ08*. Biofilm formation of SZ08* reduced significantly compared with SZ08 after 48hr incubation. Furthermore, the relative expression levels of flagella-associated genes in SZ08* were up-regulated comparing to those in SZ08. We have sequenced the pLMSZ08 and the sequencing results showed that pLMSZ08 harbors genes associated with transcriptional regulation, metal/drug transport, histidine kinase and ATPase. These results suggested that these genes encoded by pLMSZ08 are associated with tolerance, motility and biofilm formation in L. monocytogenes SZ08. •L. monocytogenes pLMSZ08 plasmid mediates biofilm formation and motility.•pLMSZ08 harbors genes associated with multiple functions.•pLMSZ08 affects the transcription of genes encoding flagella.•Plasmid-mediated biofilm formation in SZ08 is independent of attachment.