Basic analysis of pathogenesis of whooping cough

为了了解百日咳、百日咳杆菌感染中观察到的阵发性咳嗽的发生机制，我们建立了一种与百日咳杆菌密切相关的支气管败血杆菌复制阵发性咳嗽的动物模型。该模型动物经500cfu的支气管败血杆菌鼻腔感染后出现咳嗽。在分析支气管败血杆菌感染的过程中，我们成功地分离出了一株在模型动物中不会引起咳嗽的突变株。对突变株和亲本野生型菌株的基因组进行比较，发现一个名为crg1的基因存在单碱基插入。发现一株缺乏crg1的菌株不会引起动物的阵发性咳嗽，这表明crg1可能参与了阵发性咳嗽。进一步的工作正在进行中，以表征crg1基因。

To understand the mechanism of paroxysmal cough observed in whooping cough, Bordetella pertussis infection, we established an animal model that reproduce the paroxysmal cough by using B. bronchiseptica, which is closely related to B. pertussis. This model animal showed coughing after intranasal infection by 500 cfu of B. bronchiseptica. In the course of analyzing the B. bronchiseptica infection, we succeeded in isolating a mutant strain that did not induce coughing in the model animal. A comparison of the genomes of the mutant strain and the parental wild type strain revealed a single-base insertion in a gene designated crg1. A strain deficient in crg1 was found not to cause the paroxysmal cough in the animals, showing that crg1 might be involved in the paroxysmal cough. Further work is in progress to characterize the crg1 gene.