Sizemore D R, Fink P S, Ou J T, Baron L, Kopecko D J, Warren R L
Department of Microbiology and Immunology, Wright State University, Dayton, Ohio 45435.
Microb Pathog. 1991 Jun;10(6):493-9. doi: 10.1016/0882-4010(91)90116-r.
In this study, the 100 kb plasmid of Salmonella typhimurium, which is known to contribute to the pathogenicity of the organism, was tagged with the transposon Tn5 to define regions of the plasmid contributing to overall virulence. Eleven randomly selected vir::Tn5 plasmids carried by the plasmid-free S. typhimurium strain WS1321 were physically mapped and then examined in mice for subcutaneous LD50 value, ability to induce splenomegaly, and ability to grow to high numbers in the spleens of infected mice. Nine strains were found to be virulence-attenuated and showed varied levels of growth in the spleens of subcutaneously infected BALB/c mice. Eight of these nine strains carried Tn5 insertions which lie outside the previously defined virulence region. These studies corroborate the findings of other investigators as well as defining novel regions of the 100 kb virulence plasmid involved in the pathogenicity of this organism.
在本研究中，已知对鼠伤寒沙门氏菌致病性有作用的100 kb质粒，用转座子Tn5进行标记，以确定该质粒中对整体毒力有作用的区域。由无质粒的鼠伤寒沙门氏菌菌株WS1321携带的11个随机选择的vir::Tn5质粒进行了物理图谱绘制，然后在小鼠中检测其皮下半数致死剂量（LD50）值、诱导脾肿大的能力以及在感染小鼠脾脏中大量生长的能力。发现9个菌株的毒力减弱，并且在皮下感染的BALB/c小鼠脾脏中的生长水平各不相同。这9个菌株中有8个携带的Tn5插入位点位于先前定义的毒力区域之外。这些研究证实了其他研究者的发现，同时也确定了该100 kb毒力质粒中与该生物体致病性有关的新区域。
