Biofilm Growth By Listeria Monocytogenes On Stainless Steel and Expression of Biofilm-Related Genes Under Stressing Conditions

Abstract

This research was carried out to assess the ability of L. monocytogenes for adhesion and growth in biofilm on stainless steel coupons under different stressing conditions (NaCl, curing salts and quaternary ammonium compounds - QAC), besides determining the expression of different genes involved in biofilm formation and stress response. Results from crystal violet assay revealed that one isolate carrying a premature stop codon (PMSC) in agrC gene formed high-density biofilms in the presence of QAC or cure salts (7.5% and 10%). Reverse Transcriptase-qPCR results revealed that isolates of L. monocytogenes lineages I and II presented differences in transcriptional profile of genes related to biofilm formation and adaptation to environmental conditions. In conclusion, our results demonstrated how L. monocytogenes can survive, multiply and form biofilm under adverse conditions related to food processing environments. Differences in transcriptional expression were observed, highlighting the role of regulatory gene networks for particular serotypes under different stress responses.

Ecology of Listeria monocytogenes and Listeria species in India: the occurrence, resistance to biocides, genomic landscape and biocontrol

“…Listeria monocytogenes is a foodborne pathogen capable of forming persistent biofilms on a variety of natural and artificial surfaces including the food‐processing equipment. It has a rich range of surface structures allowing it to survive, adapt and persist in various environments (Janež et al ., 2021) and evolved wide‐ranging assortment of mechanisms for surviving with stress and adapting to changing environmental conditions such as extra‐cytoplasmic proteins and biofilm formation ensuring its virulence phenotype expression (Gibhardt et al ., 2020; da Silva et al ., 2021).…”