Karaolis D K, Somara S, Maneval D R, Johnson J A, Kaper J B
Center for Vaccine Development, Division of Hospital Epidemiology, University of Maryland School of Medicine, Baltimore 21201, USA.
Nature. 1999 May 27;399(6734):375-9. doi: 10.1038/20715.
The virulence properties of many pathogenic bacteria are due to proteins encoded by large gene clusters called pathogenicity islands, which are found in a variety of human pathogens including Escherichia coli, Salmonella, Shigella, Yersinia, Helicobacter pylori, Vibrio cholerae, and animal and plant pathogens such as Dichelobacter nodosus and Pseudomonas syringae. Although the presence of pathogenicity islands is a prerequisite for many bacterial diseases, little is known about their origins or mechanism of transfer into the bacterium. The bacterial agent of epidemic cholera, Vibrio cholerae, contains a bacteriophage known as cholera-toxin phage (CTXphi), which encodes the cholera toxin, and a large pathogenicity island called the VPI (for V. cholerae pathogenicity island) which itself encodes a toxin-coregulated pilus that functions as a colonization factor and as a CTXphi receptor. We have now identified the VPI pathogenicity island as the genome of another filamentous bacteriophage, VPIphi. We show that VPIphi is transferred between V. cholerae strains and provide evidence that the TcpA subunit of the toxin-coregulated type IV pilus is in fact a coat protein of VPIphi. Our results are the first description of a phage that encodes a receptor for another phage and of a virus-virus interaction that is necessary for bacterial pathogenicity.
许多致病细菌的毒力特性归因于由称为致病岛的大基因簇编码的蛋白质，这些致病岛存在于多种人类病原体中，包括大肠杆菌、沙门氏菌、志贺氏菌、耶尔森氏菌、幽门螺杆菌、霍乱弧菌，以及动植物病原体，如结节拟杆菌和丁香假单胞菌。尽管致病岛的存在是许多细菌性疾病的先决条件，但对于它们的起源或转移到细菌中的机制知之甚少。霍乱的病原体霍乱弧菌含有一种称为霍乱毒素噬菌体（CTXphi）的噬菌体，它编码霍乱毒素，以及一个称为VPI（霍乱弧菌致病岛）的大型致病岛，其本身编码一种毒素调节菌毛，其功能是作为定植因子和CTXphi受体。我们现在已将VPI致病岛鉴定为另一种丝状噬菌体VPIphi的基因组。我们表明VPIphi在霍乱弧菌菌株之间转移，并提供证据表明毒素调节IV型菌毛的TcpA亚基实际上是VPIphi的一种外壳蛋白。我们的结果首次描述了一种编码另一种噬菌体受体的噬菌体以及一种对细菌致病性必不可少的病毒-病毒相互作用。
