Biofilm Formation and Resistance to Benzalkonium Chloride in Listeria monocytogenes Isolated from a Fish Processing Plant
Biofilm Formation and Resistance to Benzalkonium Chloride in Listeria monocytogenes Isolated from a Fish Processing Plant
复制标题
DOI：
10.4315/0362-028x.jfp-12-225
复制
发表时间：
2013-07-01
影响因子：
2
通讯作者：
Nishikawa, Yoshikazu
中科院分区：
文献类型：
--
作者：
Nakamura, Hiromi;Takakura, Koh-Ichi;Nishikawa, Yoshikazu
单核细胞增多性李斯特菌是一种食源性病原体，可导致潜在威胁生命的李斯特菌病。此前，在冷熏鱼加工厂中持续存在的几个单核细胞增多性李斯特菌克隆不断地从工厂的产品中分离出来。为了评价生物膜在该植物特有的单核细胞增多性李斯特菌菌株持续存在中的作用，比较了在该植物中发现的单核细胞增多性李斯特氏菌的持久性菌株(PS)和暂时性菌株(TS)形成生物膜的能力以及对苯扎氯铵(BC)消毒效果的抗性。PS在48h内比TS产生更多的生物膜，PS的半最大有效浓度(EC50)，也就是每株细菌的ATP生物发光相对于其最大活性降低50%的BC浓度，在PS中比TS中高约150fdd。相比之下，当在浮游状态下的生物体中测量这些值时，PS的EC50仅比TS高2.2倍。从生物膜中提取胞外聚合物(EPS)，并用苯酚-硫酸法测定这些生物膜的葡萄糖含量以估算EPS的量。PS生物膜中EPS总量高于TS生物膜。这些发现表明，PS比TS产生更多的生物被膜和EPS，从而导致PS对消毒剂更大的抵抗力。该菌株在水产品加工厂中的持续存在可能归因于这些特性。
Listeria monocytogenes is a foodborne pathogen that causes the potentially life-threatening illness listeriosis. Previously, a few clones of L. monocytogenes persisting in a cold-smoked fish processing plant were isolated from the plant's products continuously. To evaluate the role of biofilms in the persistence of L. monocytogenes strains specific to this plant, the abilities of the persistent strain (PS) and transient strain (TS) of L. monocytogenes found in this plant to form biofilms were compared, as was resistance to the sanitizing effects of benzalkonium chloride (BC). The PS produced more biofilm than the TS in 48 h. The half-maximal effective concentration (EC50), the BC concentration at which the ATP bioluminescence of each bacterial strain decreased by 50% relative to its maximum activity, was about 150-fdld higher in the PS than in the TS. In contrast, when these values were measured in organisms in a planktonic state, the EC50 of the PS was only 2.2-fold higher than that of the TS. Extracellular polymeric substances (EPS) were extracted from biofilms, and the glucose content of these biofilms was determined with the phenol sulfuric acid method to estimate the quantity of EPS. The total amount of EPS in the PS biofilm was higher than that in the TS biofilm. These findings suggest that the PS produces greater amounts of biofilm and EPS than the TS, which results in greater resistance of the PS to disinfectants. The persistence of the strain in the fish processing plant might he attributable to these properties.