Jones R H, Finn M A, Thomas J J, Folger C
Br J Vener Dis. 1976 Feb;52(1):18-23. doi: 10.1136/sti.52.1.18.
The growth and nine subcultivations of the experimental Nichols strain of pathogenic Treponema pallidum were successfully accomplished in cultured baby hamster kidney tissue cells (BHK-21) using serum-free media. The number (motile and non-motile cells occurring extracellulary) of cell generations generally increased with each subcultivation, the largest increases (greater than 3-0) occurring in subcultures 4, 5, 7, 8, and 9. Also, the number of motile cells decreased with each subcultivation. Virulent organisms were demonstrated in subcultures 1, 4, 5, 7, and 8, and their numbers estimated with the use of standards established by the animal inoculation titration of counted numbers of organisms freshly harvested from experimental infections; the estimated number of virulent organisms was higher than or equal to the counted cultivated treponemes injected, which may be attributable to uncounted virulent spirochaetes occurring intracellularly.
利用无血清培养基，致病性梅毒螺旋体实验Nichols菌株在培养的幼仓鼠肾组织细胞（BHK - 21）中成功实现生长及九次传代培养。细胞代的数量（细胞外出现的活动和不活动细胞）通常随每次传代而增加，最大增幅（大于3 - 0）出现在第4、5、7、8和9代培养物中。此外，活动细胞的数量随每次传代而减少。在第1、4、5、7和8代培养物中证实存在有毒力的生物体，并根据从实验感染中新鲜收获的生物体计数通过动物接种滴定法建立的标准对其数量进行估计；估计的有毒力生物体数量高于或等于注射的计数培养梅毒螺旋体数量，这可能归因于细胞内存在未计数的有毒力螺旋体。
