This research was carried out to investigate the differences in adhesion and growth during biofilm formation of L. monocytogenes from different sources and clonal complexes. Biofilm by L. monocytogenes (isolates CLIST 441 and 7: both lineage I, serotype 1/2b, CC3; isolates 19 and 508: both lineage II, serotype 1/2c, CC9) was grown on stainless steel coupons under different stressing conditions (NaCl, curing salts and quaternary ammonium compounds—QAC), to determine the expression of different genes involved in biofilm formation and stress response. CLIST 441, which carries a premature stop codon (PMSC) in agrC, formed high-density biofilms in the presence of QAC (7.5% w/v) or curing salts (10% w/v). Reverse Transcriptase-qPCR results revealed that L. monocytogenes isolates presented differences in transcriptional profile of genes related to biofilm formation and adaptation to environmental conditions. 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.

本研究旨在研究不同来源和克隆复合体的单核细胞增生李斯特菌在生物膜形成过程中粘附和生长的差异。单核细胞增生李斯特菌的生物膜（CLIST 441 和 7：两种谱​​系 I，血清型 1/2b，CC3；分离株 19 和 508：两种谱系 II，血清型 1/2c，CC9）在不同压力条件下在不锈钢试样上生长（ NaCl、固化盐和季铵化合物——QAC)，以确定参与生物膜形成和应激反应的不同基因的表达。CLIST 441 在agrC 中携带过早终止密码子 (PMSC)，在QAC (7.5% w/v) 或固化盐 (10% w/v) 存在下形成高密度生物膜。逆转录酶-qPCR 结果显示，单核细胞增生李斯特菌分离株在与生物膜形成和环境条件适应相关的基因转录谱方面存在差异。我们的结果证明了单核细胞增生李斯特菌如何在与食品加工环境相关的不利条件下存活、繁殖和形成生物膜。观察到转录表达的差异，突出了调节基因网络在不同应激反应下对特定血清型的作用。