引用

吸入炭疽芽孢杆菌孢子可导致迅速进展的致命感染。炭疽杆菌分泌三种蛋白质毒素:致死因子(LF)、水肿因子(EF)和保护抗原(PA)。EF和LF可以作为自由或pa结合形式循环。游离EF (EF)和pa结合EF (ETx)均具有腺苷酸环化酶活性，可将ATP转化为cAMP。我们开发了一种基于腺苷酸环化酶活性的检测和定量血浆中总EF (EF+ETx)的方法。三步法包括单克隆抗体磁免疫捕获、与ATP反应生成cAMP、同位素稀释HPLC-MS/MS定量cAMP。总EF由cAMP vs ETx浓度的5PL回归量化。检出限为20 fg/mL (89 kDa蛋白为225 zeeptomoles /mL)。0.3、6.0和90 pg/mL对照的相对标准偏差为11.7-16.6%，准确度为91.2-99.5%。该方法在未接触过炭疽菌的健康个体的238份人血清/血浆样本中具有100%的特异性，在3例吸入性炭疽菌的人和5例吸入性炭疽菌的恒河猴样本中具有100%的敏感性。 Analysis of EF in the rhesus macaques showed that it was detected earlier post-exposure than B. anthracis by culture and PCR. Similar to LF, the kinetics of EF over the course of infection were triphasic, with an initial rise (phase-1), decline (phase-2), and final rapid rise (phase-3). EF levels were ~2-4 orders of magnitude lower than LF during phase-1 and phase-2 and only ~6-fold lower at death/euthanasia. Analysis of EF improves early diagnosis and adds to our understanding of anthrax toxemia throughout infection. The LF/EF ratio may also indicate the stage of infection and need for advanced treatments.