Samoilova S V, Samoilova L V, Yezhov I N, Drozdov I G, Anisimov A P
Laboratory of Applied Genetics, Russian Research Anti-Plague Institute Microbe, Saratov, Russia.
J Med Microbiol. 1996 Dec;45(6):440-4. doi: 10.1099/00222615-45-6-440.
Guinea-pigs were infected subcutaneously or by respiratory challenge with plasmid-containing (pPst+pCad+pFra+) Yersinia pestis strain 358 and its pPst-pCad+pFra+, pPst+pCad+pFra- and pPst-pCad+pFra- derivatives, grown in vitro at 28 degrees C or at 37 degrees C. Lack of plasmid pPst did not lead to an increase in LD50 with either route of challenge. When the virulence of the four Y. pestis strains grown at the two temperatures was compared, the LD50 values of those grown at 37 degrees C were lower. Respiratory challenge with cultures grown at 37 degrees C mimics the man-to-man pneumonic plague cycle. The average LD50 values decreased c. two-fold and 10-fold for pPst+ and pPst- Y. pestis variants, respectively. The data suggest that historical epidemic outbreaks of pneumonic plague in the human population residing in the Caucasus region where there are natural plague foci in common voles may have been caused by pPst- Y. pestis strains.
用含质粒（pPst + pCad + pFra +）的鼠疫耶尔森氏菌358菌株及其pPst - pCad + pFra +、pPst + pCad + pFra - 和pPst - pCad + pFra - 衍生物，在28℃或37℃体外培养后，对豚鼠进行皮下感染或呼吸道攻击。缺乏质粒pPst并不会导致任何一种攻击途径的半数致死剂量（LD50）增加。当比较在两种温度下培养的四种鼠疫耶尔森氏菌菌株的毒力时，在37℃培养的菌株的LD50值较低。用在37℃培养的培养物进行呼吸道攻击模拟了人与人之间的肺鼠疫传播循环。pPst + 和pPst - 鼠疫耶尔森氏菌变体的平均LD50值分别降低了约两倍和十倍。数据表明，在有普通田鼠自然疫源地的高加索地区居住的人群中，历史上肺鼠疫的流行爆发可能是由pPst - 鼠疫耶尔森氏菌菌株引起的。
