Abstract

Bacterial adhesion and biofilm formation of Listeria monocytogenes on food-contact surfaces result in serious safety concerns. This study aimed to explore the antibiofilm efficacy of pyrrole-2-carboxylic acid (PCA) against L. monocytogenes. Crystal violet staining assay demonstrated that PCA reduced the biofilm biomass of L. monocytogenes. The 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide reduction and flow cytometric assays indicated that PCA attenuated the metabolic activity of L. monocytogenes biofilm together with a decrease in viability. Morphologic observations revealed that PCA exposure collapsed the biofilm architecture. PCA administration of 0.75 mg ml⁻¹ decreased the excretion of extracellular DNA, protein and polysaccharide by 48.58%, 61.60% and 75.63%, respectively. PCA failed to disperse the mature biofilm, even at 1.5 mg ml⁻¹. However, PCA suppressed L. monocytogenes adhesion on common food-contact surfaces. Additionally, PCA exposure suppressed the hemolytic activity of L. monocytogenes. These findings suggested that PCA might serve as an alternative antibiofilm agent to control L. monocytogenes contamination.

摘要

单核细胞增生李斯特氏菌在食品接触表面上的细菌粘附和生物膜形成导致严重的安全问题。本研究旨在探讨吡咯-2-羧酸（PCA）对单核细胞增生李斯特菌的抗生物膜功效。结晶紫染色分析表明PCA降低了单核细胞增生李斯特菌的生物膜生物量。2,3-双-(2-甲氧基-4-硝基-5-磺基苯基)-2H-四唑鎓-5-甲酰苯胺还原和流式细胞术测定表明，PCA 减弱了单增李斯特菌生物膜的代谢活性，同时降低了可行性。形态学观察表明，PCA 暴露破坏了生物膜结构。0.75 mg ml ^-1的PCA给药使细胞外DNA、蛋白质和多糖的排泄分别减少48.58%、61.60%和75.63%。PCA 未能分散成熟的生物膜，即使浓度为 1.5 mg ml ^-1。然而，PCA 抑制了单核细胞增生李斯特菌在常见食品接触表面上的粘附。此外，PCA 暴露抑制了单核细胞增生利斯特氏菌的溶血活性。这些发现表明 PCA 可能作为控制单核细胞增生李斯特菌污染的替代抗生物膜剂。