Microbiology, Molecular Biology and Biotechnology Research Group, School of Life and Medical Sciences, University of Hertfordshire, Hatfield AL10 9AB, Hertfordshire, UK.
Microbiology, Molecular Biology and Biotechnology Research Group, School of Life and Medical Sciences, University of Hertfordshire, Hatfield AL10 9AB, Hertfordshire, UK.
Biosens Bioelectron. 2017 Nov 15;97:8-15. doi: 10.1016/j.bios.2017.04.029. Epub 2017 Apr 23.
Whole cell biosensors have been seldom used in the pharmaceutical and cosmetics industries for preservative efficacy testing (PET). According to several pharmacopoeias, preservatives should be tested for microbial activity using traditional viable count techniques; the use of whole cell microbial biosensors potentially provides an alternative, fast, and efficient method. The aim of the study was to assess the applicability of Pseudomonas aeruginosa ATCC9027 and its validated bioluminescent strains for preservative efficacy tests using benzalkonium chloride (BKC). Applicability of five constitutively-expressed bioluminescent strains was evaluated for preservative efficacy tests (PET) using bacterial replication, bioluminescence and fluorescence in a three-way study. PET using BKC showed no significant difference between bioluminescence and enumeration. Good correlations between bioluminescence, colony-forming units (CFU) count and fluorescence were obtained for BKC concentrations (R>0.9) between 0.0003-0.0025% against strains containing the constructs lys-pMElux, lpp-pMElux and tat-pMElux. Furthermore, two-way ANOVA analysis showed that the bioluminescent method and traditional plate counting method were equivalent for concentrations of BKC (0.0003-0.01%) during preservative efficacy tests. PET testing with BKC showed that tat-pMElux (R>0.9) had consistently high correlation coefficients between CFU and relative bioluminescence; P. aeruginosa ATCC9027 tatH5-pMElux is the best construct for testing various antimicrobial agents.
整体细胞生物传感器在制药和化妆品行业中很少用于防腐剂效力测试（PET）。根据几部药典，防腐剂的微生物活性应使用传统的活菌计数技术进行测试；整体细胞微生物生物传感器的使用提供了一种替代的、快速和有效的方法。本研究的目的是评估铜绿假单胞菌 ATCC9027 及其经过验证的生物发光菌株在使用苯扎氯铵（BKC）进行防腐剂效力测试中的适用性。在一项三向研究中，使用细菌复制、生物发光和荧光评估了五个组成型表达生物发光菌株在防腐剂效力测试（PET）中的适用性。PET 用 BKC 进行测试，生物发光和计数之间没有显著差异。对于包含构建体 lys-pMElux、lpp-pMElux 和 tat-pMElux 的菌株，BKC 浓度（R>0.9）在 0.0003-0.0025%之间，生物发光、集落形成单位（CFU）计数和荧光之间获得了良好的相关性。此外，双向方差分析表明，在防腐剂效力测试中，生物发光法和传统平板计数法对于 BKC（0.0003-0.01%）浓度等效。用 BKC 进行 PET 测试表明，tat-pMElux（R>0.9）在 CFU 和相对生物发光之间具有一致的高相关系数；铜绿假单胞菌 ATCC9027 tatH5-pMElux 是测试各种抗菌剂的最佳构建体。
