Core genome based phylogenetic analysis of Tunisian B. pertussis isolates

An increase in pertussis cases in some countries has been linked to genetic changes in circulating Bordetella pertussis isolates and pathogen adaptation to pertussis vaccines, amongst others. We have conducted genomic analyses of strains isolated during the 2014 epidemic in Tunisia and compared them to vaccine strains of Serum Institute of India (manufacturer of whole cell pertussis vaccine used in Tunisia) and isolates circulating in countries using the acellular vaccine, including France, UK and USA. Comparative genomic analysis was based on a core genome multi locus sequence typing scheme comprising 2038 loci. We show that Tunisian isolates are closely related to each other and to those circulating worldwide despite the use of different pertussis vaccines.

部分国家百日咳病例数出现回升，该现象与流行的百日咳博德特氏菌（Bordetella pertussis）分离株的遗传变异、病原体对百日咳疫苗的适应性等多种因素相关。本研究对2014年突尼斯百日咳流行期间分离得到的菌株开展了基因组分析，并将其与印度血清研究所（Serum Institute of India）制备的疫苗株（突尼斯所用全细胞百日咳疫苗的对应疫苗株），以及法国、英国、美国等使用无细胞百日咳疫苗的国家的流行分离株进行了比对。本次比较基因组分析基于一套包含2038个基因座的核心基因组多位点序列分型（core genome multi locus sequence typing）方案。研究结果表明，尽管各国所使用的百日咳疫苗类型存在差异，但突尼斯分离株彼此间以及与全球范围内的流行分离株均具有较高的同源性。