Abstract：
This study investigated the synergistic effects of ε-poly- L -lysine (ε-PL) and lysozyme against P. aeruginosa and L. monocytogenes biofilms. Single-culture biofilms of two bacteria were formed on silicone rubber (SR), stainless steel (SS), and beef surfaces and then treated with lysozyme (0.05-5 mg/mL) and ε-PL at minimum inhibitory concentrations (MICs) of 1 to 4 separately or in combination. On the SR surface, P. aeruginosa biofilm was reduced by 1.4 and 1.9 log CFU/cm2 within 2 h when treated with lysozyme (5 mg/mL) and ε-PL (4 MIC), respectively, but this reduction increased significantly to 4.1 log CFU/cm2 (P < 0.05) with the combined treatment. On beef surface, P. aeruginosa and L. monocytogenes biofilm was reduced by 4.2-5.0, and 3.3-4.2 log CFU/g when lysozyme was combined with 1, 2, and 4 MIC of ε-PL at 25 °C, respectively. Compared to 5 mg/mL lysozyme alone, the combined treatment with 1, 2, and 4 MIC of ε-PL on beef surface achieved additional reduction against P. aeruginosa biofilm of 0.5, 0.8, and 0.7 log CFU/g, respectively, at 25 °C. In addition, 0.25 mg/mL lysozyme and 0.5 MIC of ε-PL significantly (P < 0.05) suppressed the quorum-sensing (agrA) and virulence-associated (hlyA and prfA) genes of L. monocytogenes.
摘要：
这项研究调查了ε-聚-L-赖氨酸（ε-PL）和溶菌酶对铜绿假单胞菌和单核细胞增生李斯特菌生物膜的协同作用。在硅橡胶（SR）上形成两种细菌的单一培养生物膜，不锈钢(SS),和牛肉表面，然后用溶菌酶（0.05-5mg/mL）和ε-PL分别或组合以1至4的最低抑制浓度（MIC）进行处理。在SR表面,当用溶菌酶（5mg/mL）和ε-PL（4MIC）处理时，铜绿假单胞菌生物膜在2小时内减少了1.4和1.9logCFU/cm2，分别,但在联合治疗下，这种降低显着增加到4.1logCFU/cm2（P<0.05）。在牛肉表面，当溶菌酶与ε-PL的1、2和4MIC在25°C时，铜绿假单胞菌和单核细胞增生性乳杆菌生物膜减少了4.2-5.0和3.3-4.2logCFU/g，分别。与单独使用5mg/mL溶菌酶相比，用1、2和4MIC的ε-PL在牛肉表面的联合处理实现了对0.5、0.8和0.7logCFU/g的铜绿假单胞菌生物膜的额外减少，分别,25°C此外,0.25mg/mL溶菌酶和ε-PL的0.5MIC显着（P<0.05）抑制了单核细胞增生李斯特菌的群体感应（agrA）和毒力相关（hlyA和prfA）基因。
