Recent horizontal transmission of plasmids between natural populations of Escherichia coli and Salmonella enterica
Recent horizontal transmission of plasmids between natural populations of Escherichia coli and Salmonella enterica
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DOI：
10.1128/jb.179.5.1622-1627.1997
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发表时间：
1997-03-01
影响因子：
3.2
通讯作者：
Hartl, DL
中科院分区：
文献类型：
--
作者：
Boyd, EF;Hartl, DL
对从沙门氏菌参考标本中获得的71株天然分离物进行了检测，以确定是否存在与大肠杆菌F质粒密切相关的质粒。该集合由鼠伤寒沙门氏菌复合体I亚种的几个血清型组成，99%的致病沙门氏菌属于该亚种。应用DNA杂交的分子遗传学技术，结合聚合酶链式反应和DNA测序技术，对沙门氏菌F-类质粒的出现、分布和遗传多样性进行了研究。所检测的F-质粒基因分别为Fino、Trad、Tray和repa，它们定位在大肠杆菌F-质粒上的分散位置。对沙门氏菌质粒中4个基因的序列比较分析表明，它们与大肠杆菌自然分离株的F质粒中的基因具有同源性(在某些情况下，几乎完全相同)。此外，沙门氏菌菌株中F-样质粒的频率与大肠杆菌参考文献中观察到的频率大致相同。然而，在沙门氏菌中，分布主要限于鼠伤寒沙门氏菌和慕尼黑血清型。肠杆菌和大肠杆菌共有的F-样质粒池的意外发现证明了接合在这些重要细菌物种的历史中的重要作用。
Seventy-one natural isolates obtained from a Salmonella reference collection were examined for the presence of plasmids closely related to the Escherichia coli F plasmid. The collection consists of several serovars of the S. enterica Typhimurium complex, subspecies I, to which 99% of pathogenic salmonellae belong. Molecular genetic techniques of DNA hybridization, along with PCR and DNA sequencing, were used to examine the occurrence, distribution, and genetic diversity of F-like plasmids among Salmonella strains, The F plasmid genes examined were finO, traD, traY, and repA, which map at dispersed positions on the F plasmid of E. coli. Comparative sequence analysis of each of thf four genes in Salmonella plasmids showed them to be homologous (in some cases, virtually identical) to those found in F plasmids of E. coli natural isolates. Furthermore, the frequency of F-like plasmids in Salmonella strains was approximately the same as that observed in the E. coli Reference Collection. However, in Salmonella, the distribution was confined predominately to the serovars Typhimurium and Muenchen. The unexpected finding of a shared pool of F-like plasmids between S. enterica and E. coli demonstrates the significant role of conjugation in the histories of these important bacterial species.