Yuk M H, Cotter P A, Miller J F
Department of Microbiology and Immunology, School of Medicine, University of California, Los Angeles, USA.
Am J Respir Crit Care Med. 1996 Oct;154(4 Pt 2):S150-4. doi: 10.1164/ajrccm/154.4_Pt_2.S150.
Bordetella species are respiratory pathogens that infect humans and other animals. A majority of the virulence factors expressed by these bacteria are regulated by a master control locus, BvgAS, a member of the two-component family of signal transduction systems. BvgAS senses environmental signals and mediates signal transduction by a phosphorylation cascade that leads to a biphasic transition between the Bvg+ and Bvg- phases. From natural host studies using Bordetella bronchiseptica, we have found that expression of Bvg+ phase factors, which include adhesins and toxins, is required for successful colonization of the mammalian respiratory tract. Suppression of the Bvg- phase motility phenotype is necessary for a successful interaction with the host. Although the Bvg- phase does not appear to be required in vivo, it does confer the ability to survive under conditions of severe nutrient deprivation. We hypothesize that the Bvg+ phase is necessary and sufficient for respiratory tract colonization and the Bvg- phase is adapted for survival in environments encountered during transmission between hosts.
博德特氏菌属是感染人类和其他动物的呼吸道病原体。这些细菌表达的大多数毒力因子受主调控位点BvgAS调控，BvgAS是双组分信号转导系统家族的成员。BvgAS感知环境信号，并通过磷酸化级联介导信号转导，导致Bvg +和Bvg -阶段之间的双相转变。通过使用支气管败血博德特氏菌的天然宿主研究，我们发现表达包括粘附素和毒素在内的Bvg +阶段因子是成功定殖于哺乳动物呼吸道所必需的。抑制Bvg -阶段的运动表型是与宿主成功相互作用所必需的。虽然Bvg -阶段在体内似乎不是必需的，但它确实赋予了在严重营养剥夺条件下生存的能力。我们假设Bvg +阶段对于呼吸道定殖是必要且充分的，而Bvg -阶段则适合在宿主间传播过程中遇到的环境中生存。
