Østergaard Trine G, Hansen Lars H, Binderup Mona-Lise, Norman Anders, Sørensen Søren J
Department of Microbiology, University of Copenhagen, Sølvgade 83H, 1307 Copenhagen K, Denmark.
Mutat Res. 2007 Jul 28;631(2):77-84. doi: 10.1016/j.mrgentox.2007.02.011. Epub 2007 Apr 21.
A new bacterial test system for detection of genotoxic compounds was developed, based on two new Salmonella typhimurium tester strains, TGO1 and TGO2. Both strains contain a gene fusion between a strong SOS-promotor, P(cda), and the gfp gene, which allows detection of genotoxic compounds that induce the SOS response. SOS induction was detected by means of flow cytometry. TGO1 showed an increased sensitivity to N-methyl-N'-nitro-N-nitrosoguanidine compared with a previously developed strain, which had an Escherichia coli strain as host instead of S. typhimurium. S9 mix was introduced into the assay, making the test system suitable for detection of indirect mutagens. Furthermore, the genes for bacterial nitro-reductase (NR) and o-acetyl transferase (o-AT) were inserted into TGO2, making it an NR- and o-AT-over-expressing strain. This resulted in an assay that was able to detect the nitroarene 1-nitropyrene and the aromatic amine 2-aminoanthracene with high sensitivity.
基于两种新型鼠伤寒沙门氏菌测试菌株TGO1和TGO2，开发了一种用于检测遗传毒性化合物的新型细菌测试系统。两种菌株均包含一个强SOS启动子P(cda)与gfp基因之间的基因融合，这使得能够检测诱导SOS反应的遗传毒性化合物。通过流式细胞术检测SOS诱导。与先前开发的以大肠杆菌菌株为宿主而非鼠伤寒沙门氏菌的菌株相比，TGO1对N-甲基-N'-硝基-N-亚硝基胍表现出更高的敏感性。将S9混合物引入该检测方法中，使测试系统适用于间接诱变剂的检测。此外，将细菌硝基还原酶（NR）和邻乙酰转移酶（o-AT）的基因插入TGO2中，使其成为过表达NR和o-AT的菌株。这导致该检测方法能够高灵敏度地检测硝基芳烃1-硝基芘和芳香胺2-氨基蒽。
