The impact of frost-damage on the quality and quantity of the secreted antigen-specific IgG repertoire

Freezing of alum-based vaccines drastically alters their colloidal composition and leads to irreversible cluster formation. The loss of stability is well described, but the impact of frost damage on the functionality of the induced and secreted antibody repertoire has not been studied in detail. We therefore applied our single-cell measurement platform to extract the frequencies of Immunoglobulin G-secreting cells in combination with individual secretion rates and affinities. We showed that, frost-damaged or not, the tested vaccine was able to generate similar frequencies of total and antigen-affine IgG-secreting cells. Additionally, the frost-damaged vaccine stimulated a similar T-cell cytokine secretion pattern when compared to the regularly stored vaccine. However, frost-damaged vaccines induced no efficient affinity maturation and a complete collapse of the affinity distribution was observed. This study unveiled the impact of frost-damage to alum-based vaccines on the induced secreted antibody repertoire, and illustrated the power of functional single-antibody analysis.     

Evaluation of human antibody responses to diphtheria toxin subunits A and B in various age groups

This study aimed to evaluate human antibody responses to diphtheria toxin subunits in various age groups. Antibodies against the intact diphtheria toxin and the diphtheria toxin subunits A and B were evaluated in 1319 individuals using a double-antigen ELISA. Although high levels of protection (83.6%, 95% CI 79.2-87.4) were found in children and adolescents, the middle-aged adult population was less protected (28.8%, 95% CI 24.3-33.6). An increase in age was associated with a decrease in the frequency of protected individuals in the 0-39-year age group (p <0.001). Anti-subunit B levels correlated well (p <0.01) with levels of antibodies against the intact toxin. In children aged < or =16 years, the intervals at which the peaks in geometric mean titres of anti-subunit B antibodies were observed were found to correlate with the ages at which booster doses are administered. Overall, males appeared to be more protected than females (OR 1.67, 95% CI 1.34-2.08, p <0.001). A small group of individuals had antibody levels of > or =0.1 IU/mL against the intact toxin, but did not have protective antibody against subunit B. Determination of anti-subunit B antibody levels should help in evaluating the effectiveness of diphtheria boosters and other aspects of diphtheria immunity.     

Characterization of bacteriophages fromtox-containing, non-toxigenic isolates ofCorynebacterium diphtheriae

Non-toxigenic strains ofCorynebacterium diphtheriaecontinue to cause disease within immunized populations. A subset of these corynebacteria carry the diphtheria toxin gene but in a cryptic form. To determine whether such strains might contribute to the re-emergence of functional toxin genes, the phages andtoxmutations within three clone types were examined.tox-containing, β-related phages were isolated from two of the strain types. The third isolate appeared to harbour a defective prophage. One of thetox⁻phages encoded truncated, yet enzymatically-active, forms of diphtheria toxin, suggesting that it had sustained a point mutation within the latter half of its toxin gene. In contrast, the other mutant phage did not elicit the production of either a cross-reacting material or an ADP-ribosylating activity. Complementation tests employing a series of double lysogens confirmed that the mutations responsible for the non-toxigenic phenotype of all of the phages werecisdominant. Given these findings, it is reasonable to hypothesize thattox⁺genes can arise within human populations by either homologous recombination between two distincttox⁻phages or spontaneous reversion within a single mutant allele.     

A fatal case of necrotizing sinusitis due to toxigenic Corynebacterium ulcerans

A 77-year-old farmer developed cough with sputum production, fever, bloody nasal discharge and a mass in his right maxillary sinus leading to necrotic ulceration of the sinus. Corynebacterium ulcerans, carrying the beta-phage for the diphtheria toxin and secreting the toxin, was detected microscopically and by culture from the sinusoidal and ulcer discharge. Despite immediate antimicrobial chemotherapy the patient died of pulmonary failure associated with the production of large amounts of very viscous sputum. Identification of the causative agent, pathophysiological aspects and risk factors of this unusal infection are discussed.     

两种百白破联合疫苗基础免疫后百日咳凝集抗体和白喉抗体监测分析

为了解无细胞百白破联合疫苗(DTaP)和全细胞百白破联合疫苗(DTwP)接种后的血清学免疫效果,在东莞市随机选取3月龄健康婴儿107名,分两组分别用DTaP和DTwP做基础免疫,在免疫前和免疫后1个月分别采血,用微量凝集试验检测百日咳凝集抗体,采用间接血球凝集试验检测白喉抗体.结果表明:经DTaP基础免疫后,百日咳凝集抗体保护率为95.83%,≥4倍增长率为100.00%,几何平均滴度(GMT)为1:783.43;白喉抗体的保护率为100.00%,≥4倍增长率为100.00%,平均白喉抗毒素含量(DAT)为0.68IU/ml.经DTwP基础免疫后百日咳凝集抗体保护率为98.04%,≥4倍增长率为100.00%,GMT为1:1 634.93;白喉抗体保护率为100.00%,≥4倍增长率为100.00%,DAT为1.28IU/ml.DTaP和DTwP两组免疫前各项指标差异均无显著的统计学意义,但免疫后两组的百日咳凝集抗体GMT的差异有非常显著的统计学意义(t=4.68,P＜0.01).采用DTaP和DTwP作基础免疫均可获得良好的百日咳和白喉的血清学免疫效果.     

Zoonotic Transmission of Diphtheria from Domestic Animal Reservoir,Spain

Toxigenic Corynebacterium ulcerans is as an emerging zoonotic agent of diphtheria. We describe the zoonotic transmission of diphtheria caused by toxigenic C. ulcerans from domestic animals in Spain, confirmed by core-genome multilocus sequence typing. Alongside an increasing number of recent publications, our findings highlight the public health threat posed by diphtheria reemergence.     

23F型肺炎球菌多糖与CRM197蛋白结合物制备及特性研究

目的采用改良胺化还原法,白喉无毒突变体CRM197蛋白作为载体,制备23F型肺炎球菌多糖蛋白结合物。方法在还原胺法的基础上,以1,6-己二酰肼（ADH）为分子臂,在碳二亚胺（EDAC）作用下衍化CRM197蛋白,衍化后蛋白再与多糖上的醛基反应,形成共轭结合;采用高效液相色谱技术（HPLC）、免疫扩散等方法分析结合物,并将获得的结合物免疫NIH小鼠,用ELISA方法检测多糖IgG水平。结果HPLC图谱和免疫扩散检测结果证明了结合物的获得;动物免疫产生了较多糖高的抗23F肺炎多糖抗体,并有免疫记忆发生。结论采用改良还原氨化法可以制备出动物免疫原性良好的23F型多糖蛋白结合物。     

新型纳米金修饰铂金电极固载白喉抗原免疫传感器的研究

目的报道制作新型电流型免疫传感器的方法。方法用金纳米颗粒吸附白喉抗原,采用聚乙烯醇缩丁醛（PVB）为辅助固定抗原膜基质将其固定在铂金电极的表面,制成白喉抗原免疫传感器。根据抗原抗体特异性结合形成的免疫复合物使电极敏感膜有效扩散面积减小,电流减少的特性,实现对白喉抗体的定量检测。结果该传感器对白喉抗体检测的线性范围是24～600 ng/mL,线性相关系数r为0.9979,检出下限为5.2 ng/mL（S/N=3）。结论我们成功的构建了白喉抗原免疫传感器,并将其用于生物制品中白喉类毒素的检测,其结果较满意。     

一起溶血隐秘杆菌引起的疑似白喉病例的调查处理

目的评价一起疑似白喉疫情的调查处理过程。方法采用现场流行病学方法 ,通过现场调查、标本采集、实验室检测和查阅文献,综合判定结果。结果病例排除白喉诊断,认定为溶血隐秘杆菌感染造成的化脓性中毒性扁桃体炎。结论本次疫情调查处理较规范,值得以后借鉴。     

Prevention of pertussis across the age spectrum through the use of the combination vaccines PENTACEL™ and ADACEL™

Acellular pertussis-containing combination vaccines are widely used in the developed world for the control of pertussis and have been successful in controlling disease in preschool-aged children. Combination vaccines formulated for use in adolescents and adults have been developed more recently and are increasingly being implemented for the control of pertussis in these age groups. One such family of products is PENTACEL? (Haemophilus influenzae type b conjugate vaccine reconstituted with component pertussis vaccine and diphtheria and tetanus toxoids adsorbed combined with inactivated poliomyelitis vaccine, DTaP-IPV-Hib), for use in young children, and ADACEL? (tetanus and diphtheria toxoids adsorbed combined with component pertussis vaccine, dTap) for use in adolescents and adults. These products have been demonstrated to be safe, immunogenic and effective for the control of pertussis and the other included diseases.