Fieldsteel A H, Becker F A, Stout J G
Infect Immun. 1977 Oct;18(1):173-82. doi: 10.1128/iai.18.1.173-182.1977.
Survival of Treponema pallidum was found to be prolonged in the presence of tissue culture. Of the 12 cultures studied, cottontail rabbit epithelium (Sf1Ep) supported T. pallidum for the longest time. In horizontal Leighton tubes with reduced medium and an atmosphere of 5% CO2 in N2, the 50% survival time (ST50) was 5 to 6 days for treponemes associated with monolayers of Sf1Ep cells. Comparable cell-free tubes had ST50 values of less than 4 days. In vertical Leighton tubes containing 6 ml of prereduced medium incubated aerobically, gradients of O2 tension and redox potential were established. Attachment and survival of T. pallidum were greatest at a depth of about 10 to 20 mm. Motility was between 70 and 95% in this area throughout the first 14 days of incubation. Occasionally, greater than 50% motility was observed for as long as 21 days. The redox potential and O2 tension in the optimal area of gradient cultures were reproduced by adjusting the medium depth in a shell vial culture system containing cells on a horizontal cover slip. Treponemes associated with the cell monolayer in both gradient and shell vial cultures were still virulent after 21 days in vitro. The dilution of testis extract and the concentration of T. pallidum were found to be important factors in survival of T. pallidum.
研究发现，在组织培养环境下梅毒螺旋体的存活时间会延长。在所研究的12种培养物中，棉尾兔上皮细胞（Sf1Ep）对梅毒螺旋体的支持时间最长。在培养基减少且氮气中含有5%二氧化碳的水平莱顿管中，与Sf1Ep细胞单层相关的梅毒螺旋体的50%存活时间（ST50）为5至6天。类似的无细胞管的ST50值小于4天。在含有6毫升预还原培养基并需氧培养的垂直莱顿管中，建立了氧张力和氧化还原电位梯度。梅毒螺旋体在约10至20毫米深度处的附着和存活情况最佳。在培养的前14天里，该区域的运动性在70%至95%之间。偶尔，在长达21天的时间里观察到运动性大于50%。通过调整含有水平盖玻片上细胞的小瓶培养系统中的培养基深度，可重现梯度培养最佳区域的氧化还原电位和氧张力。在梯度培养和小瓶培养中与细胞单层相关的梅毒螺旋体在体外培养21天后仍具毒性。研究发现，睾丸提取物的稀释度和梅毒螺旋体的浓度是影响梅毒螺旋体存活的重要因素。
