Early events and pattern formation in Listeria monocytogenes biofilms

Abstract

Biofilm initiation and development is a complex process that includes several major stages. This study examined the process of Listeria monocytogenes biofilm initiation and consequent spatial and physiological patterns formed in the biofilm as the result of bacterial response to a changing environment. This is a first attempt at establishing a link between the spatial organization of biofilm-associated bacteria and major stress factors such as surface bioavailability and nutrient content. Developed linear models allow evaluation of some important parameters of the surface population, such as the critical colony size and the intercolony distance in the case of diffusion-limited nutrient access. Variations in bacterial physiological patterns during biofilm initiation as a function of bacterial population density during surface colonization are reported.

Molecular Ecology of Listeria monocytogenes : Evidence for a Reservoir in Milking Equipment on a Dairy Farm

“…Our data suggest that the presence of L. monocytogenes in the milk system was initially caused by fecal or environmental contamination and that specific strains could have subsequently established themselves in the milking system as a biofilm. Listeria monocytogenes has the ability to form biofilms (16,31) on stainless steel surfaces and other materials (1) that can be present in dairy operations. Bacterial cells can detach from biofilms (15), and this could explain the presence of the same L. monocytogenes PFGE types in bulk tank milk and filters for prolonged periods of time.…”

PFGE characterisation and adhesion ability of Listeria monocytogenes isolates obtained from bovine carcasses and beef processing facilities

“…Culture concentration Culture media a Supplements pH Incubation 2006; Takhistov & George, 2004). Fragments of mature biofilms can detach, releasing micro-colonies that are capable of adhering to new surfaces and begin the process again, causing new contamination spots (Møretrø & Langsrud, 2004;Takhistov & George, 2004).…”

“…Fragments of mature biofilms can detach, releasing micro-colonies that are capable of adhering to new surfaces and begin the process again, causing new contamination spots (Møretrø & Langsrud, 2004;Takhistov & George, 2004). Therefore, the biofilm cycle may support the persistence of specific strains in a specific environment (McLandsborough et al, 2006;Moltz & Martin, 2005;Takhistov & George, 2004).…”

“…Fragments of mature biofilms can detach, releasing micro-colonies that are capable of adhering to new surfaces and begin the process again, causing new contamination spots (Møretrø & Langsrud, 2004;Takhistov & George, 2004). Therefore, the biofilm cycle may support the persistence of specific strains in a specific environment (McLandsborough et al, 2006;Moltz & Martin, 2005;Takhistov & George, 2004). This persistence can be detected using molecular tools, in order to identify strains with identical genetic profiles on different equipment and utensils (Graves & Swaminathan, 2001;Møretrø & Langsrud, 2004;Senczek, Stephan, & Untermann, 2000;Slade, 1992).…”

Growth responses of Escherichia coli and Myxococcus xanthus on agar gel substrates with different levels of stiffness

“…Bacteria in the colony detect environmental signals and respond to the physicochemical properties of substrates with change in their physiology and morphology, which can affect their motility and growth (Harshey, 2003;Park et al, 2003;Hochbaum and Aizenberg, 2010). Bacteria colonize surfaces and proliferate themselves in various growth patterns according to the substrate bioavailability and nutrient level (Takhistov and George, 2004;Steager et al, 2008).…”