Anacker R L, Philip R N, Williams J C, List R H, Mann R E
Infect Immun. 1984 Jun;44(3):559-64. doi: 10.1128/iai.44.3.559-564.1984.
Six strains of Rickettsia rickettsii from Montana and North Carolina were examined in an effort to identify rickettsial constituents associated with virulence. Fever responses, scrotal reactions, and mortalities of male guinea pigs inoculated intraperitoneally with 1,000 PFU of rickettsial strains revealed that the two Montana patient strains ( Sheila Smith and Norgaard ) and one Montana strain ( Sawtooth female 2) from the wood tick, Dermacentor andersoni, could be placed in the group of highest virulence, the two North Carolina strains (Morgan and Simpson) in the group of lesser virulence, and the Montana strain (HLP) from the rabbit tick, Haemaphysalis leporispalustris , in the group of lowest virulence. The HLP strain was differentiated from the other strains by sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by staining with Coomassie brilliant blue or with silver. The patient strains could not be differentiated from each other by these procedures. All of the strains apparently had three heat-modifiable proteins. Analysis of proteinase K-digested rickettsial lysates by sodium dodecyl sulfate-polyacrylamide gel electrophoresis suggested that the strains had a complex mixture of polysaccharides. These putative polysaccharides probably were not related to the differences in virulence of the strains, since the patterns for all of the strains were identical. At least five antigens (molecular weights of 128,000, 105,000, 84,000, 30,500, and 20,500) were demonstrated by radioimmune precipitation tests employing extracts from radioiodine-labeled rickettsiae and antibodies from infected guinea pigs. With these same sera a minimum of 14 antigens was detected in these strains by an immunoblotting procedure. The apparent molecular weights of several of the HLP antigens differed from those of the presumed corresponding antigens of the other strains. The electrophoretic techniques utilized in this study were not sufficiently sensitive to demonstrate compositional differences in the patient strains which differed in their virulence for guinea pigs.
对来自蒙大拿州和北卡罗来纳州的6株立氏立克次体菌株进行了检测，以鉴定与毒力相关的立克次体成分。给雄性豚鼠腹腔注射1000个噬斑形成单位（PFU）的立克次体菌株后，观察其发热反应、阴囊反应和死亡率，结果显示，来自蒙大拿州的2株患者菌株（希拉·史密斯和诺尔加德）以及来自安德森革蜱的1株蒙大拿州菌株（锯齿雌性2）可归为毒力最强的一组，2株北卡罗来纳州菌株（摩根和辛普森）归为毒力较弱的一组，而来自兔蜱的蒙大拿州菌株（HLP）归为毒力最弱的一组。通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳，然后用考马斯亮蓝或银染色，将HLP菌株与其他菌株区分开来。通过这些方法无法区分患者菌株。所有菌株显然都有三种热可变蛋白。用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳分析蛋白酶K消化的立克次体裂解物表明，这些菌株含有复杂的多糖混合物。这些假定的多糖可能与菌株毒力差异无关，因为所有菌株的模式都是相同的。通过使用放射性碘标记的立克次体提取物和感染豚鼠的抗体进行放射免疫沉淀试验，证明至少有5种抗原（分子量分别为128,000、105,000、84,000、30,500和20,500）。用这些相同的血清通过免疫印迹法在这些菌株中检测到至少14种抗原。HLP菌株的几种抗原的表观分子量与其他菌株假定的相应抗原不同。本研究中使用的电泳技术不够灵敏，无法证明对豚鼠毒力不同的患者菌株在成分上的差异。
