Shewen P E, Wilkie B N
Am J Vet Res. 1985 May;46(5):1212-4.
The release of soluble cytotoxin from Pasteurella haemolytica type 1 cultured at 37 C in RPMI 1640 medium containing 7% bovine fetal serum was evaluated, using bovine alveolar macrophages in a microplate 51Cr-release assay. Heat-labile leukotoxic activity was detected in culture supernatant during the lag and logarithmic-growth phases, but not in stationary-phase culture; toxic activity could not be demonstrated in sonicates of logarithmic (1 hour) or stationary (18 hour) phase organisms. This pattern of toxin release, typical of a bacterial exotoxin or metabolic enzyme, is unique among bacterial leukotoxins, which are typically cell-associated and released after autolysis or sonication from outgrown cultures.
采用微孔板51Cr释放试验，以牛肺泡巨噬细胞为材料，评估了在含7%胎牛血清的RPMI 1640培养基中于37℃培养的1型溶血巴斯德菌可溶性细胞毒素的释放情况。在延迟期和对数生长期的培养上清液中检测到热不稳定白细胞毒性活性，但在稳定期培养物中未检测到；对数期（1小时）或稳定期（18小时）菌体的超声裂解物中未显示出毒性活性。这种毒素释放模式是典型的细菌外毒素或代谢酶的模式，在细菌白细胞毒素中是独特的，细菌白细胞毒素通常与细胞相关，在自溶或超声处理后从生长的培养物中释放。
