Variable assortment of prophages provides a transferable repertoire of pathogenic determinants in Salmonella
Variable assortment of prophages provides a transferable repertoire of pathogenic determinants in Salmonella
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DOI：
10.1046/j.1365-2958.2001.02234.x
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发表时间：
2001-01-01
影响因子：
3.6
通讯作者：
Bossi, L
中科院分区：
文献类型：
--
作者：
Figueroa-Bossi, N;Uzzau, S;Bossi, L
细菌病原体的不同谱系之间的基因转移可以促进重组分歧和新的致病性变体的出现。温和的噬菌体，凭借其携带外源DNA的能力，是这一过程中潜在的关键参与者。我们以前的工作表明，鼠伤寒沙门氏菌的代表菌株（LT 2，ATCC 14028和SL 1344）是两个温和的噬菌体：Gifsy-1和Gifsy-2溶原性。一些证据表明，这两种元素都携带有助于沙门氏菌毒力的基因。一个这样的基因，在Gifsy-2原噬菌体上，编码[Cu，Zn]超氧化物歧化酶SodCI。最近发现了其他假定的致病性决定因素。这些包括已知或推定的III型易位蛋白的基因和在两种原噬菌体上重复的基因座，显示出与沙门氏菌肠道致病基因（pipA）的序列相似性。除了Gifsy-1和Gifsy-2外，发现上述菌株中的每一种都含有一组特定的前噬菌体，这些前噬菌体也携带推定的致病性决定簇。从菌株LT 2释放的噬菌体Fels-1携带nanH基因和一个新的sodC基因，命名为sodC III。菌株ATCC 14028释放出一种名为Giffsy-3的类噬菌体，它含有phoP/phoQ激活的pagJ基因和分泌的富含亮氨酸的重复蛋白SspH 1的基因。最后，从菌株SL 1344特异性释放的噬菌体被鉴定为SopE Phi。大多数噬菌体相关位点在相同或不同血清型的沙门氏菌菌株之间有效转移。总的来说，这些结果表明溶原性转化是驱动沙门氏菌进化的主要机制。
Gene transfer between separate lineages of a bacterial pathogen can promote recombinational divergence and the emergence of new pathogenic variants. Temperate bacteriophages, by virtue of their ability to carry foreign DNA, are potential key players in this process. Our previous work has shown that representative strains of Salmonella typhimurium (LT2, ATCC14028 and SL1344) are lysogenic for two temperate bacteriophages: Gifsy-1 and Gifsy-2. Several lines of evidence suggested that both elements carry genes that contribute to Salmonella virulence. One such gene, on the Gifsy-2 prophage, codes for the [Cu, Zn] superoxide dismutase SodCI. Other putative pathogenicity determinants were uncovered more recently. These include genes for known or presumptive type III-translocated proteins and a locus, duplicated on both prophages, showing sequence similarity to a gene involved in Salmonella enteropathogenesis (pipA). In addition to Gifsy-1 and Gifsy-2, each of the above strains was found to harbour a specific set of prophages also carrying putative pathogenicity determinants. A phage released from strain LT2 and identified as phage Fels-1 carries the nanH gene and a novel sodC gene, which was named sodCIII. Strain ATCC14028 releases a lambdoid phage, named Gifsy-3, which contains the phoP/phoQ-activated pagJ gene and the gene for the secreted leucine-rich repeat protein SspH1. Finally, a phage specifically released from strain SL1344 was identified as SopE Phi. Most phage-associated loci transferred efficiently between Salmonella strains of the same or different serovars. Overall, these results suggest that lysogenic conversion is a major mechanism driving the evolution of Salmonella bacteria.