Attached and Planktonic Listeria monocytogenes Global Proteomic Responses and Associated Influence of Strain Genetics and Temperature

Contamination
of industrial and domestic food usage environments
by the attachement of bacterial food-borne pathogen Listeria monocytogenes has public health and economic
implications. Comprehensive proteomics experiments using label-free
liquid chromatography/tandem mass spectrometry were used to compare
the proteomes of two different L. monocytogenes strains (Siliken_1/2c and F2365_4b), which show very different capacities
to attach to surfaces. Growth temperature and strain type were highly
influential on the proteomes in both attached and planktonic cells.
On the basis of the proteomic data, it is highly unlikely that specific
surface proteins play a direct role in adherence to inanimate surfaces.
Instead, strain-dependent responses related to cell envelope polymer
biosynthesis and stress response regulation likely contribute to a
different ability to attach and also to survive external stressors.
Collectively, the divergent proteome-level responses observed define
strain- and growth-temperature-dependent differences relevant to attachment
efficacy, highlight relevant proteins involved in stress protection
in attached cells, and suggest that strain differences and growth
conditions are important in relation to environmental persistence.

工业及家用食品使用环境受到食源性致病菌单核细胞增生李斯特氏菌（Listeria monocytogenes）的附着污染，会对公共卫生与经济产生影响。本研究采用无标记液相色谱-串联质谱（label-free liquid chromatography/tandem mass spectrometry）技术开展全蛋白质组学实验，对比两株附着表面能力差异显著的单核细胞增生李斯特氏菌菌株（Siliken_1/2c与F2365_4b）的蛋白质组表达谱。生长温度与菌株类型对附着态与浮游态细胞的蛋白质组表达均具有显著影响。基于蛋白质组学数据，特定表面蛋白直接介导非生物表面黏附的可能性极低。与之相反，与细胞壁包膜聚合物生物合成及应激反应调控相关的菌株特异性应答，可能是导致不同菌株附着能力与外界胁迫耐受能力存在差异的关键因素。综上，本研究观测到的蛋白质组层面差异化应答，明确了与附着效能相关的菌株及生长温度依赖性差异，揭示了附着细胞中参与应激保护的相关蛋白，并表明菌株差异与生长条件对于环境持久性具有重要影响。