Idigbe E O
Microbios. 1987;49(199):79-89.
The pattern of loss of histamine-sensitizing factor (HSF) during antigenic modulation of Bordetella pertussis in Hornibrook medium was examined. The aim was to determine the possible underlying mechanism involved in modulation. Normal (X-mode) B. pertussis cells were grown in Hornibrook medium in which 0.5% (w/v) NaCl had been replaced with 0.5% (w/v) MgSO4. 7H2O (C-medium). At various time intervals during growth, the viable cell numbers and optical densities of both cultures in the X- and C-media were estimated. Whole cells were harvested from the cultures at the same time intervals and aliquots from the cultures were assayed for the levels of their histamine-sensitizing properties. Correlation of the increase in viable cell numbers with rate of loss of histamine-sensitizing activity in both the cells and whole cultures indicated that components responsible for the histamine-sensitizing activity were not synthesized during modulation. Moreover, the loss of HSF from B. pertussis cells was faster than can be explained by dilution of the original factor in the inoculum among progeny cells. Modulation may involve cessation of synthesis and selective degradation or denaturation of some envelope polypeptides immediately upon inoculation of normal X-mode B. pertussis cells into C-medium.
研究了百日咳博德特氏菌在霍尼布鲁克培养基中进行抗原调制时组胺致敏因子（HSF）的丧失模式。目的是确定调制过程中可能涉及的潜在机制。将正常（X模式）百日咳博德特氏菌细胞接种于霍尼布鲁克培养基中，其中0.5%（w/v）氯化钠已被0.5%（w/v）七水硫酸镁（C培养基）取代。在生长过程中的不同时间间隔，估算X培养基和C培养基中两种培养物的活菌数和光密度。在相同时间间隔从培养物中收获全细胞，并对培养物的等分试样进行组胺致敏特性水平的测定。活菌数的增加与细胞和全培养物中组胺致敏活性丧失速率之间的相关性表明，在调制过程中不合成负责组胺致敏活性的成分。此外，百日咳博德特氏菌细胞中HSF的丧失速度比通过接种物中原始因子在子代细胞中的稀释所能解释的速度要快。调制可能涉及在将正常X模式百日咳博德特氏菌细胞接种到C培养基后立即停止某些包膜多肽的合成以及选择性降解或变性。
