Sullivan G W, Mandell G L
Infect Immun. 1980 Oct;30(1):272-80. doi: 10.1128/iai.30.1.272-280.1980.
Most strains of Streptococcus pyogenes contain a toxin which can kill neutrophils. Previous workers failed to show any correlation between leukotoxin content and virulence of animals or humans. We examined the in vitro interactions of a leukotoxic streptococcus and a nonleukotoxic variant with human neutrophils. At ratios of 200 streptococcal colony-forming units per neutrophil, the toxic strain killed 92.8 +/- 2.0% of neutrophils, and the nontoxic strain killed only 9.0 +/- 1.2%. Despite this, ingestion of the two strains was equal. Postphagocytic oxidative metabolism was equivalent with low numbers of either toxic or nontoxic streptococci but depressed with high numbers of leukotoxic streptococci. At 20 min, neutrophils were able to kill leukotoxic (99.6 +/- 0.3% killed) and nonleukotoxic streptococci (99.5 +/- 0.2% killed) equally efficiently (P = 0.42). Thus, leukotoxicity does not interfere with the ability of neutrophils to destroy streptococci. This may explain why leukotoxicity does not appear to be an important factor in streptococcal virulence.
大多数化脓性链球菌菌株都含有一种能杀死中性粒细胞的毒素。之前的研究人员未能发现白细胞毒素含量与动物或人类毒力之间存在任何关联。我们研究了具有白细胞毒性的链球菌和无白细胞毒性变体与人类中性粒细胞的体外相互作用。当中性粒细胞与链球菌的比例为每中性粒细胞200个链球菌集落形成单位时，有毒菌株杀死了92.8±2.0%的中性粒细胞，而无毒菌株仅杀死了9.0±1.2%。尽管如此，两种菌株的摄取量是相等的。吞噬后氧化代谢在低数量的有毒或无毒链球菌时相当，但在高数量的具有白细胞毒性的链球菌时受到抑制。在20分钟时，中性粒细胞能够同样有效地杀死具有白细胞毒性的链球菌（99.6±0.3%被杀死）和无白细胞毒性的链球菌（99.5±0.2%被杀死）（P = 0.42）。因此，白细胞毒性并不干扰中性粒细胞破坏链球菌的能力。这可能解释了为什么白细胞毒性似乎不是链球菌毒力的一个重要因素。
