The emerging development of antibiotic resistant bacteria calls for novel types of antibacterial agents. In this work we examined the putative antibacterial effect of purine analogs in Listeria monocytogenes. We show that, among several tested purine analogs, only 6-N-hydroxylaminopurine (6-N-HAP) reduces the viability of the Gram-positive pathogen Listeria monocytogenes. As in Bacillus subtilis, 6-N-HAP terminates expression at guanine riboswitches in L. monocytogenes hence preventing expression of their downstream genes. However, we show that the bacteriocidal effect of the compound was unlinked to the terminated expression at the guanine riboswitches. When further examining the antimicrobial effect, we observed that 6-N-HAP acts as a potent mutagen in L. monocytogenes, by increasing the mutation rate and inducing the SOS-response. Also, addition of 6-N-HAP decreased virulence gene expression by reducing both the levels and activity of the virulence regulator PrfA.

中文翻译：

---

6- N-羟基氨基嘌呤对单核细胞增生性李斯特菌的抗菌和抗毒作用

抗生素抗性细菌的新兴发展要求新型抗菌剂。在这项工作中，我们研究了嘌呤类似物在单核细胞增生性李斯特菌中的假定抗菌效果。我们表明，在几个测试的嘌呤类似物中，只有6- N-羟基氨基嘌呤（6- N- HAP）降低了革兰氏阳性病原体李斯特菌的生存能力。如枯草芽孢杆菌中一样，6- N -HAP终止单核细胞增生李斯特氏菌中鸟嘌呤核糖开关的表达。因此阻止了其下游基因的表达。但是，我们表明该化合物的杀菌作用与鸟嘌呤核糖开关处的终止表达无关。当进一步检查抗微生物作用时，我们观察到6- N -HAP通过增加突变率和诱导SOS反应，在单核细胞增生李斯特菌中起有效的诱变作用。另外，添加6- N -HAP通过降低毒力调节剂PrfA的水平和活性降低毒力基因表达。