Benton K A, Paton J C, Briles D E
Department of Microbiology, The University of Alabama at Birmingham, USA.
Infect Immun. 1997 Apr;65(4):1237-44. doi: 10.1128/iai.65.4.1237-1244.1997.
We observed that differences in the in vivo growth kinetics of pneumococcal strains of capsular types 3, 4, 5, and 6 were reminiscent of differences that we had previously reported for type 2 strain D39 and its pneumolysin-deficient mutant, PLN. Capsular type 2 Streptococcus pneumoniae D39 exhibits exponential growth in the blood of XID mice until the death of the mice at 24 to 36 h. In contrast, PLN reaches a plateau in growth that is maintained for several days. Capsular type 3 and 5 strains exhibited exponential growth and caused rapid death of XID mice following intravenous challenge, similar to the observation with D39. Strains of capsular types 4 and 6 exhibited growth kinetics reminiscent of PLN. Since the observed differences in the pathogenesis of types 3 and 5 compared to 4 and 6 were reminiscent of the effects of pneumolysin deficiency in type 2, we examined the levels of in vitro pneumolysin production for the entire panel of strains. The onset of pneumolysin production in most strains was rapid and occurred near the end of log-phase growth. Differences in in vivo growth patterns of capsular type 2, 3, 4, 5, and 6 strains were not found to be associated with differences in the levels of pneumolysin.
我们观察到，3、4、5和6型肺炎球菌菌株在体内的生长动力学差异，让人联想到我们之前报道的2型菌株D39及其肺炎溶血素缺陷突变体PLN的差异。2型肺炎链球菌D39在XID小鼠血液中呈指数生长，直至小鼠在24至36小时死亡。相比之下，PLN的生长达到一个平台期，并维持数天。3型和5型菌株在静脉注射攻击后呈指数生长，并导致XID小鼠迅速死亡，这与D39的观察结果相似。4型和6型菌株的生长动力学让人联想到PLN。由于观察到3型和5型与4型和6型在发病机制上的差异，让人联想到2型中肺炎溶血素缺陷的影响，我们检测了所有菌株的体外肺炎溶血素产生水平。大多数菌株肺炎溶血素的产生开始迅速，且发生在对数生长期末期附近。未发现2、3、4、5和6型菌株在体内生长模式上的差异与肺炎溶血素水平的差异有关。
