Cox D L, Riley B, Chang P, Sayahtaheri S, Tassell S, Hevelone J
Division of Sexually Transmitted Diseases Laboratory Research, Centers for Disease Control, Atlanta, Georgia 30333.
Appl Environ Microbiol. 1990 Oct;56(10):3063-72. doi: 10.1128/aem.56.10.3063-3072.1990.
The effects of various concentrations of dithiothreitol, molecular oxygen, and several antioxidants upon the in vitro replication of Treponema pallidum were studied. The optimal dithiothreitol concentration was between 0.65 and 1.62 mM, and the optimum oxygen concentration was 3.0% +/- 0.5% in both the presence and absence of additional antioxidants. It was discovered that the reduced sulfhydryl concentration and the oxidation-reduction potential of the medium were stabilized after 5 days. The water-soluble antioxidants cobalt chloride, cocarboxylase, mannitol, and histidine were individually tested for their ability to increase treponemal growth in vitro. The optimum concentrations for these antioxidants were 21 nM, 4.3 nM, 0.55 mM, and 0.23 mM, respectively. When combined at these concentrations, the mixture of antioxidants stimulated the in vitro replication of T. pallidum. The number of treponemes in cultures with the antioxidants averaged a 59-fold increase, compared with a 43-fold increase in cultures lacking the antioxidants. It was further demonstrated that histidine and mannitol were the most critical components of this mixture. Catalase and superoxide dismutase were investigated for their ability to promote the growth and maintain viability of T. pallidum in tissue culture. The optimum concentrations for these enzymes were 10,000 U/liter and 25,000 U/liter, respectively. When these enzymes and the above antioxidants were combined and added to a chemically reduced modified Eagle medium, the treponemes increased an average of 70-fold, compared with an average of 35-fold in cultures lacking them. Furthermore, this medium, T. pallidum culture medium, supported the replication of T. pallidum at oxygen concentrations from 5 to 7% with little loss in yield or viability. The lipid-soluble antioxidants vitamin A and vitamin E acetate were also shown to enhance the in vitro growth of T. pallidum in this medium.
研究了不同浓度的二硫苏糖醇、分子氧和几种抗氧化剂对梅毒螺旋体体外复制的影响。最佳二硫苏糖醇浓度在0.65至1.62 mM之间，在有无额外抗氧化剂的情况下，最佳氧浓度均为3.0%±0.5%。研究发现，5天后培养基中还原巯基浓度和氧化还原电位趋于稳定。分别测试了水溶性抗氧化剂氯化钴、硫胺素焦磷酸、甘露醇和组氨酸在体外促进梅毒螺旋体生长的能力。这些抗氧化剂的最佳浓度分别为21 nM、4.3 nM、0.55 mM和0.23 mM。当以这些浓度组合时，抗氧化剂混合物刺激了梅毒螺旋体的体外复制。含有抗氧化剂的培养物中梅毒螺旋体数量平均增加了59倍，而不含抗氧化剂的培养物中增加了43倍。进一步证明，组氨酸和甘露醇是该混合物中最关键的成分。研究了过氧化氢酶和超氧化物歧化酶在组织培养中促进梅毒螺旋体生长和维持其活力的能力。这些酶的最佳浓度分别为10,000 U/升和25,000 U/升。当将这些酶与上述抗氧化剂组合并添加到化学还原的改良伊格尔培养基中时，梅毒螺旋体数量平均增加了70倍，而不含它们的培养物中平均增加了35倍。此外，这种梅毒螺旋体培养基在氧浓度为5%至7%时支持梅毒螺旋体的复制，产量或活力几乎没有损失。脂溶性抗氧化剂维生素A和维生素E醋酸酯也被证明可增强梅毒螺旋体在该培养基中的体外生长。
