Laboratory of Microbiology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 3-1, 7-Chome, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Microb Pathog. 2010 Jul-Aug;49(1-2):1-7. doi: 10.1016/j.micpath.2010.03.010. Epub 2010 Mar 27.
The cvfC operon of Staphylococcus aureus comprises four genes, cvfC1, cvfC2, cvfC3, and cvfC4. The cvfC3-disrupted mutant, M1262, produces less hemolysin and has attenuated virulence in silkworms and mice. Although introduction of the cvfC3 gene restores the decreased hemolysin production of M1262, the cvfC operon is more effective for the complementation, suggesting that cvfC operon function is impaired in M1262. In this study, we performed a microarray analysis and identified 21 genes with altered expression in M1262. The expression of virulence genes and metabolic genes, including thyA, was changed in M1262. The decreased expression of thyA in M1262 was restored by introducing a plasmid containing the cvfC operon. Introduction of a thyA gene-containing plasmid in M1262 restored hemolysin production and virulence against silkworms. Both M1262 and a thyA-deletion mutant exhibited slow growth in the presence of the detergent Triton-X 100. The growth defect of M1262 in the presence of Triton-X 100 was restored by the introduction of thyA. These results suggest that the cvfC operon contributes to hemolysin production, detergent resistance, and virulence of S. aureus in host animals via thyA expression.
金黄色葡萄球菌的 cvfC 操纵子包含四个基因，cvfC1、cvfC2、cvfC3 和 cvfC4。cvfC3 缺失突变体 M1262 产生的溶血素较少，对家蚕和小鼠的毒力减弱。尽管引入 cvfC3 基因恢复了 M1262 减少的溶血素产生，但 cvfC 操纵子对于互补更为有效，表明 M1262 中的 cvfC 操纵子功能受损。在这项研究中，我们进行了微阵列分析，鉴定出 M1262 中表达改变的 21 个基因。M1262 中毒力基因和代谢基因（包括 thyA）的表达发生了变化。在 M1262 中引入含有 cvfC 操纵子的质粒可恢复 thyA 的表达。在 M1262 中引入含有 thyA 基因的质粒可恢复溶血素的产生和对家蚕的毒力。M1262 和 thyA 缺失突变体在去污剂 Triton-X 100 存在下的生长均受到抑制。在 Triton-X 100 存在下，M1262 的生长缺陷可通过引入 thyA 得到恢复。这些结果表明，cvfC 操纵子通过 thyA 表达促进金黄色葡萄球菌溶血素产生、去污剂抗性和宿主动物中的毒力。
