Molecular typing and epidemiology of Bordetella pertussis in Australia

百日咳，俗称百日咳，是由百日咳杆菌引起的一种急性呼吸道疾病。尽管接种了半个多世纪的疫苗，百日咳在澳大利亚仍然是地方病，每3到4年就会爆发一次疫情。事实上，近年来百日咳的发病率一直在上升，2005年报告的病例超过11,000例。百日咳是澳大利亚标准疫苗接种时间表所针对的所有疫苗可预防的疾病中最常见的。为了控制百日咳，必须实施适当的流行病学监测，以监测流行的百日咳杆菌菌株和任何新菌株的出现，特别是那些逃脱疫苗保护的菌株。该项目将使用一种新的基因组比较方法来发现基因组周围存在的称为单核苷酸多态(SNP)的变异。我们将使用这些SNP来分析澳大利亚和世界各地的大量分离株，以确定最适合分型的SNPs，并确定区分所需的SNPs的最佳数量。建立规范、一致、可靠的菌株鉴定分型方法。我们将进一步开发一种综合方法来检测编码五种无细胞疫苗抗原的基因的已知变异。然后，将开发一种用于菌株鉴定和检测抗原变异的组合方法，用于独立于培养的分型，从而能够从临床样本中直接识别感染个人的菌株，而不需要培养。这项研究将建立澳大利亚百日咳监测的分子方法，这对进一步改进无细胞百日咳疫苗和公共卫生控制措施至关重要。

Pertussis, commonly known as whooping cough, is an acute respiratory disease caused by Bordetella pertussis. Despite more than half a century of vaccination, pertussis has remained endemic in Australia, causing epidemic outbreaks every 3 to 4 years. Indeed the incidence has been increasing in recent years with over 11,000 cases notified in 2005.Pertussis is the commonest of all vaccine preventable diseases targeted by the Australian standard vaccination schedule. To control pertussis, appropriate epidemiological surveillance must be implemented to monitor the circulating B. pertussis strains and emergence of any new strains, in particular those that escape the protection by vaccines. This project will use a novel genomic comparison approach to find variation known as single nucleotide polymorphisms (SNP) present around the genome. We will use these SNPs to analyse a large collection of Australian and worldwide isolates to identify those SNPs most suitable for typing and determine the optimal number of SNPs needed for discrimination. A standardized, consistent and reliable typing method for strain identification will be established. We will further develop an integrated method for detecting known variation in the genes encoding the five acellular vaccine antigens. A combined method for strain identification and detection of antigenic variation will then be developed for culture-independent typing, enabling identification of the strain infecting an individual directly from a clinical sample without the need for culture. This study will establish molecular methods for surveillance of pertussis in Australia, essential for further improvement of acellular pertussis vaccines and public health control measures.