The estimation of the bactericidal power of the blood
The estimation of the bactericidal power of the blood
复制标题
DOI：
10.1017/s002217240001158x
复制
发表时间：
1938-11-01
影响因子：
--
通讯作者：
Irwin, JO
中科院分区：
文献类型：
--
作者：
Miles, AA;Misra, SS;Irwin, JO
测定的葡萄球菌接种物的存活率p。金黄色葡萄球菌在标准体积的脱盐水血液中的浓度是血液杀菌能力的可靠定量测量。接种物和血-细菌混合物中活微生物的数量可通过测定落到固体培养基表面的液体体积中形成的菌落计数来估计，并具有必要的准确度。菲尔德斯琼脂是最适合这种表面活菌计数的培养基，并根据四个标准进行选择;在测试的培养基中，它产生了最高的计数，计数最接近泊松级数;在它上面，平均菌落大小最大，菌落大小的变异系数最小。在这种培养基上，单独的计数值与泊松级数的密切一致性使得存活率的标准误差能够从比率的标准误差的一般表达式的简化中确定。从血液-细菌混合物样品生长的菌落数可能减少，不是通过杀死单个球菌，而是由于它们通过血液中的凝集素聚集，或在吞噬但不杀菌的白细胞的细胞质中。看来，这些机制是不太可能在血液细菌混合物中含有相对较少的生物体，在这样的混合物中的生存率是一个反射的杀伤力ONLY.的免疫学意义的p还没有调查，但健康的成年人的值的范围显着不同的慢性葡萄球菌感染的患者。此外，通过所采用的技术，可以检测到p的个体值之间的差异，这些差异不能合理地归因于技术或抽样误差。
The survival rate, p, of a measured inoculum of Staph. aureus in a standard volume of denbrinated blood, is a reliable quantitative measure of the bactericidal power of blood. The number of viable organisms in the inoculum and in the blood-bacterium mixture may be estimated with the necessary accuracy by counts of colonies developing from measured volumes of the fluids let fall on to the surface of solid media. Fildes' agar was the most suitable medium for this surface-viable count, and was selected on the basis of four criteria; of the media tested it yielded the highest counts, and the counts conformed most closely to a Poisson series; and on it the mean colony size was maximum, and the coefficient of variation of colony size was minimum. On this medium, the close conformity of the separate count values to a Poisson series enabled the standard error of the survival rate to be determined from a simplification of the general expression for the standard error of a ratio.The number of colonies growing from a sample of a blood-bacterium mixture may be reduced, not by killing of the individual cocci, but as a result of their aggregation either by agglutinins in the blood, or in the cytoplasm of leucocytes that are phagocytic but not bactericidal. It appears that these mechanisms are unlikely to operate in blood-bacterium mixture containing relatively few organisms; in such mixtures the survival rate is a reflexion of the killing power only.The immunological significance of p has not been investigated, but the range of values for healthy human adults differs significantly from that for sufferers from chronic staphylococcal infection. Moreover, by the technique employed differences may be detected between individual values of p that cannot reasonably be attributed to technical or sampling errors.