Recommendations from QUAFETY Project to control L. monocytogenes biofilms

After 28 months of the project, the scientists led by Professor Giuseppe Spano at University of Foggia (Italy), partner in European Project Quafety (www.quafety.eu), have concluded the deliverable titled "Recommendations to control Listeria monocytogenes biofilms" within Work Package 4 on ‘Innovative Processes’.

The objective of the work was to identify some critical parameters that may promote biofilm formation in Listeria monocytogenes.

The work was essentially divided in two activities:

a preliminary analysis of biofilm formation by L. monocytogenes strains from vegetables origin previously isolated by partner AUA (Agricultural University of Athens) and serotyped as 4b and by L. monocytogenes CECT 4031 serotype 1/2a was performed;
the best biofilm forming strains were selected and the influence of four different incubation temperature (37°C, 30 °C, 15 °C and 4°C), media (rich and poor) and surfaces (plastic, glass and stainless steel) were evaluated in order to investigate the biofilm formation by Listeria monocytogenes strains.

The conclusions of the works follow:

Listeria monocytogenes from vegetable origins are able to form biofilms;
Biofilm formation was facilitated by hydrophilic supports;
Biofilm formation was mostly influenced by temperature, resulting in decreased biofilm formation with decreasing temperature;
In general, biofilm formation was enhanced in nutrient-poor medium;
Strain-specificity on biofilm formation was observed. An effect of serotype was even observed on biofilm formation. Serotype 1/2a (animal origin) was a weaker biofilm producer compared with serotype 4/b (vegetables origin).

For further information:
Email: giuseppe.spano@unifg.it