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.