Hübner Anette, Revel Andrew T, Nolen Dena M, Hagman Kayla E, Norgard Michael V
Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA.
Infect Immun. 2003 May;71(5):2892-6. doi: 10.1128/IAI.71.5.2892-2896.2003.
The luxS gene product is an integral component of LuxS/autoinducer-2 (AI-2) quorum-sensing systems in bacteria. A putative luxS gene was expressed at comparable levels by Borrelia burgdorferi strain 297 cultivated either in vitro or in dialysis membrane chambers implanted in rat peritoneal cavities. Although the borrelial luxS gene functionally complemented a LuxS deficiency in Escherichia coli DH5 alpha, AI-2-like activity could not be detected within B. burgdorferi culture supernatants or concentrated cell lysates. Finally, a luxS-deficient mutant of B. burgdorferi was infectious at wild-type levels when it was intradermally needle inoculated into mice, indicating that expression of luxS probably is not required for infectivity but, at the very least, is not essential for mammalian host adaptation. Our findings also challenge the notion that a LuxS/AI-2 quorum-sensing system is operative in B. burgdorferi.
luxS基因产物是细菌中LuxS/自诱导物-2（AI-2）群体感应系统的一个组成部分。在体外培养或植入大鼠腹腔的透析膜小室中培养的伯氏疏螺旋体菌株297，其假定的luxS基因以相当的水平表达。尽管伯氏疏螺旋体的luxS基因在功能上补充了大肠杆菌DH5α中的LuxS缺陷，但在伯氏疏螺旋体培养上清液或浓缩细胞裂解物中未检测到AI-2样活性。最后，当将伯氏疏螺旋体的luxS缺陷突变体皮内针刺接种到小鼠体内时，它具有野生型水平的感染性，这表明luxS的表达可能不是感染性所必需的，但至少对于适应哺乳动物宿主不是必不可少的。我们的研究结果也对LuxS/AI-2群体感应系统在伯氏疏螺旋体中起作用这一观点提出了质疑。
