The paradox of Hemophilus infuenzae type B bacteremia in the presence of serum bactericidal activity.
The paradox of Hemophilus infuenzae type B bacteremia in the presence of serum bactericidal activity.
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B 型流感嗜血杆菌菌血症与血清杀菌活性的矛盾。
DOI：
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发表时间：
1976
影响因子：
15.9
通讯作者：
David H Smrm
中科院分区：
文献类型：
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作者：
Stephen Shaw;Arnold L Smith;Porter Anderson;David H Smrm
我们研究了血清杀菌活性在脑膜炎婴儿和大鼠模型中乙型流感嗜血杆菌感染中的作用。在受感染的婴儿中，13/22的入院血清对感染菌株有杀菌活性，有杀菌活性的婴儿（54%）与没有杀菌活性的婴儿（56%）发生菌血症的频率相同。在实验感染的断奶大鼠中再现并研究了杀菌活性和菌血症共存的现象。这些大鼠的血清在体外10分钟内可杀死95%的常规肉汤培养细菌，但不能杀死从受感染动物体内获得的生物体。因此，传统上确定的对流感嗜血杆菌b的杀菌活性可能与体内无关，将肉汁培养的细菌在正常大鼠血清中37℃孵育30分钟，产生与体内生物相似的耐药性。这种表型转化取决于分子量小于1000，在100℃下稳定，但被灰化破坏的因素。当静脉注射到无免疫力的动物体内时，肉汤生长的细菌很快被清除，而血清预孵育的细菌则不能。然而，后者在注射到菌血症大鼠（半衰期30分钟）后被清除。尽管有清除能力，但大鼠的菌血症可能会持续存在，因为细菌是从血管外液体进入血液的，而血管外液体含有超过90%的细菌负荷。
We investigated the role of serum bactericidal activity in Hemophiplus influenzae type b infections in infants with meningitis and in a rat model. In infected infants, 13/22 admission sera had bactericidal activity against the infecting strain, and bacteremia was as frequent in those with bactericidal activity (54%) as those without (56%). The coexistence of bactericidal activity and bacteremia was reproduced and studied in experimentally infected weanling rats. Serum from such rats kills in vitro 95% of conventionally broth-grown bacteria within 10 min, but does not kill organisms obtained from the infected animals. Thus bactericidal activity as conventionally determined for H. influenzae b may have no relevance in vivo, Incubation of broth-grown bacteria in normal rat serum for 30 min at 37 degrees C produces a resistance like that of in vivo organisms. This phenotypic conversion depends on factors that are of molecular weight less than 1,000, stable to 100 degrees C, but destroyed by ashing. When injected intravenously into nonimmune animals, broth-grown bacteria are quickly cleared, while serum-preincubated bacteria are not. The latter, however, are cleared when injected into bacteremic rats (half-life 30 min). Bacteremia in the rats may persist despite this capacity for clearance because bacteria are entering the blood from extravascular fluids, which contain greater than 90% of the total bacterial burden.