Numerical spatio-temporal characterization of Listeria monocytogenes biofilms

Abstract

As the structure of biofilms plays a key role in their resistance and persistence, this work presents for the first time the numerical characterization of the temporal evolution of biofilm structures formed by three Listeria monocytogenes strains on two types of stainless-steel supports, AISI 304 SS No. 2B and AISI 316 SS No. 2R. Counting methods, motility tests, fluorescence microscopy and image analysis were combined to study the dynamic evolution of biofilm formation and structure. Image analysis was performed with several well-known parameters as well as a newly defined parameter to quantify spatio-temporal distribution. The results confirm the interstrain variability of L. monocytogenes species regarding biofilm structure and structure evolution. Two types of biofilm were observed: homogeneous or flat and heterogeneous or clustered. Differences in clusters and in attachment and detachment processes were due mainly to the topography and composition of the two surfaces although an effect due to motility was also found.

Listeria monocytogenes-carrying consortia in food industry. Composition, subtyping and numerical characterisation of mono-species biofilm dynamics on stainless steel

“…In contrast with results showed by A1, evolution dynamics in this particular case was characterised by several episodes of attachment-detachment. Similar results, two patterns characterised by two different dynamic profiles and parameter values, were reported previously after studying three different L. monocytogenes strains under same conditions (Mosquera-Fernández et al, 2014).…”

Efficacy of Synthetic Furanones on Listeria monocytogenes Biofilm Formation

“…Among strains tested, and regardless of the subtype, there were no differences among the levels of AVC on SS ( Figure 2) in concordance with previously published data showing no differences among different L. monocytogenes strains [28] but in contrast to previous studies demonstrating that biofilm formation is strain-specific [36][37][38]. Such controversy can be attributed to the experimental design based on plate count that does not permit the identification of dynamic differences as other methods, such as microscopy plus image analysis, do [39,40].…”

Architecture and Viability of the Biofilms Formed by Nine Listeria Strains on Various Hydrophobic and Hydrophilic Materials

“…An intra-specific variability in biofilm architecture has also been reported by other authors. Among the different structures seen are one-cell-thick layers, flat layers of cells consisting of several layers without a given structure, honeycomb structures, and networks of interwoven clumps [35][36][37][38][39][40][41][42]. The great variability observed in the structure of the biofilms formed by Listeria spp.…”