Perry D, Slade H D
J Bacteriol. 1966 Jun;91(6):2216-22. doi: 10.1128/jb.91.6.2216-2222.1966.
Perry, Dennis (Northwestern University Medical School, Chicago, Ill.), and Hutton D. Slade. Effects of filtrates from transformable and nontransformable streptococci on the transformation of streptococci. J. Bacteriol. 91:2216-2222. 1966.-The nature of the transformation competence factor from a group H streptococcus was investigated. The activity of competence factor reached a maximum at the time that optimal competence was attained, the maxima of both occurring in the early log phase of growth. The decrease in competence factor was much more gradual than the decrease in number of competent cells. No inhibitor, however, was detected as being responsible for the decrease in either competent cells or competence factor activity. Efforts to induce transformation in other serological groups of streptococci with the use of group H competence factor were unsuccessful. The development of competence in group H when grown in the presence of nontransformable group A strains resulted in a significant increase in the number of transformants. Culture filtrates from early log phase group A cells also caused an increase in the number of transformants from the group H strain. The addition of 10(-4)m ethylenediaminetetraacetic acid to group A (or group H) culture filtrates caused significant increases in the number of transformants. These results thus indicate that group A streptococci, although nontransformable, produce low levels of "competence factor." Late culture filtrates from the group H streptococcus and several strains of group A streptococci possessed deoxyribonuclease-like activity which inhibited the transformation of the group H strain. This activity in the A filtrates, however, was not prevented by group A anti-deoxyribonuclease sera. Instead, these sera also inhibited transformation. Evidence indicates that the lack of transformation of group A streptococci is due to factors other than the production of deoxyribonuclease.
佩里，丹尼斯（伊利诺伊州芝加哥西北大学医学院）和赫顿·D·斯莱德。可转化和不可转化链球菌滤液对链球菌转化的影响。《细菌学杂志》91:2216 - 2222。1966年。——对来自H组链球菌的转化感受态因子的性质进行了研究。感受态因子的活性在达到最佳感受态时达到最大值，两者的最大值都出现在生长的对数早期阶段。感受态因子的下降比感受态细胞数量的下降要缓慢得多。然而，未检测到任何抑制剂导致感受态细胞或感受态因子活性的下降。使用H组感受态因子诱导其他血清学组链球菌转化的尝试未成功。当在不可转化的A组菌株存在下生长时，H组感受态的发展导致转化体数量显著增加。A组早期对数期细胞的培养滤液也导致H组菌株转化体数量增加。向A组（或H组）培养滤液中添加10(-4)m乙二胺四乙酸导致转化体数量显著增加。因此，这些结果表明A组链球菌虽然不可转化，但会产生低水平的“感受态因子”。H组链球菌和几株A组链球菌的晚期培养滤液具有类似脱氧核糖核酸酶的活性，可抑制H组菌株的转化。然而，A组滤液中的这种活性不受A组抗脱氧核糖核酸酶血清的抑制。相反，这些血清也抑制转化。有证据表明A组链球菌不能转化是由于除产生脱氧核糖核酸酶以外的其他因素。
