Tinge S A, Curtiss R
Department of Biology, Washington University, St. Louis, Missouri 63130.
Infect Immun. 1990 Sep;58(9):3084-92. doi: 10.1128/iai.58.9.3084-3092.1990.
The association of large plasmids with virulence in invasive Salmonella serovars has led to a number of studies designed to uncover the role of these plasmids in virulence. This study addresses two aspects of virulence-associated plasmids. The first is the distribution of the replication and maintenance regions among the plasmids of different Salmonella serovars, and the second is the use of the conserved virulence plasmid par region to provide a rapid method for eliminating the virulence plasmids specifically. Colony blots revealed that the par and repB regions of the S. typhimurium virulence plasmid hybridized with 80% of the isolates of S. choleraesuis, S. dublin, S. enteritidis, S. gallinarum, S. pullorum, and S. typhimurium, while the repC region was not detected in any of the isolates of S. dublin, S. gallinarum, or S. pullorum. None of these maintenance regions was found in any of the 30 additional serovars tested. The large plasmids of those serovars that hybridized with par were labeled with a Kmr insert within parA via P22HTint or P1L4 transduction, which destabilized the plasmids and allowed the rapid isolation of plasmid-free derivatives for all of the serovars, except for S. dublin, which exhibited weak homology with par.
侵袭性沙门氏菌血清型中大型质粒与毒力的关联引发了一系列旨在揭示这些质粒在毒力中作用的研究。本研究探讨了与毒力相关质粒的两个方面。第一个方面是不同沙门氏菌血清型质粒中复制和维持区域的分布，第二个方面是利用保守的毒力质粒par区域提供一种快速方法来特异性消除毒力质粒。菌落杂交结果显示，鼠伤寒沙门氏菌毒力质粒的par和repB区域与80%的猪霍乱沙门氏菌、都柏林沙门氏菌、肠炎沙门氏菌、鸡沙门氏菌、鸡白痢沙门氏菌和鼠伤寒沙门氏菌分离株杂交，而在都柏林沙门氏菌、鸡沙门氏菌或鸡白痢沙门氏菌的任何分离株中均未检测到repC区域。在另外测试的30种血清型中均未发现这些维持区域。通过P22HTint或P1L4转导，用parA内的Kmr插入片段标记与par杂交的那些血清型的大型质粒，这使质粒不稳定，并允许快速分离除都柏林沙门氏菌外所有血清型的无质粒衍生物，都柏林沙门氏菌与par表现出较弱的同源性。
