Atosuo J T, Lilius E-M
Laboratory of Immunochemistry, Department of Biochemistry and Food Chemistry, University of Turku, Vatselankatu 2, 20014 Turku, Finland.
ScientificWorldJournal. 2011;11:2382-90. doi: 10.1100/2011/376278. Epub 2011 Dec 5.
A recombinant Escherichia coli K-12 strain, transformed with a modified bacterial luciferase gene (luxABCDE) from Photorhabdus luminescens, was constructed in order to monitor the activity of various antimicrobial agents on a real-time basis. This E. coli-lux emitted, without any addition of substrate, constitutive bioluminescence (BL), which correlated to the number of viable bacterial cells. The decrease in BL signal correlated to the number of killed bacterial cells. Antimicrobial activity of hydrogen peroxide (H(2)O(2)) and myeloperoxidase (MPO) was assessed. In high concentrations, H(2)O(2) alone had a bacteriocidic function and MPO enhanced this killing by forming hypochlorous acid (HOCl). Taurine, the known HOCl scavenger, blocked the killing by MPO. When E. coli-lux was incubated with neutrophils, similar killing kinetics was recorded as in H(2)O(2)/MPO experiments. The opsonization of bacteria enhanced the killing, and the maximum rate of the MPO release from lysosomes coincided with the onset of the killing.
构建了一种重组大肠杆菌K-12菌株，其用来自发光杆菌的修饰细菌荧光素酶基因（luxABCDE）进行了转化，以便实时监测各种抗菌剂的活性。这种大肠杆菌-lux在不添加任何底物的情况下发出组成型生物发光（BL），其与活细菌细胞的数量相关。BL信号的降低与被杀死的细菌细胞数量相关。评估了过氧化氢（H₂O₂）和髓过氧化物酶（MPO）的抗菌活性。在高浓度下，单独的H₂O₂具有杀菌功能，MPO通过形成次氯酸（HOCl）增强了这种杀伤作用。已知的HOCl清除剂牛磺酸阻断了MPO的杀伤作用。当大肠杆菌-lux与中性粒细胞一起孵育时，记录到与H₂O₂/MPO实验中相似的杀伤动力学。细菌的调理作用增强了杀伤作用，溶酶体中MPO释放的最大速率与杀伤作用的开始时间一致。
