Wren Brendan W
Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK.
Nat Rev Microbiol. 2003 Oct;1(1):55-64. doi: 10.1038/nrmicro730.
Yersinia pestis, the causative agent of plague, seems to have evolved from a gastrointestinal pathogen, Yersinia pseudotuberculosis, in just 1,500-20,000 years--an 'eye blink' in evolutionary time. The third pathogenic Yersinia, Yersinia enterocolitica, also causes gastroenteritis but is distantly related to Y. pestis and Y. pseudotuberculosis. Why do the two closely related species cause remarkably different diseases, whereas the distantly related enteropathogens cause similar symptoms? The recent availability of whole-genome sequences and information on the biology of the pathogenic yersiniae have shed light on this paradox, and revealed ways in which new, highly virulent pathogens can evolve.
鼠疫耶尔森菌是鼠疫的病原体，它似乎在短短1500至20000年的时间里从一种胃肠道病原体——假结核耶尔森菌进化而来，这在进化时间上只是“一眨眼的功夫”。第三种致病性耶尔森菌——小肠结肠炎耶尔森菌，也会引发肠胃炎，但与鼠疫耶尔森菌和假结核耶尔森菌的亲缘关系较远。为什么这两种亲缘关系密切的物种会引发截然不同的疾病，而亲缘关系较远的肠道病原体却会引发相似的症状呢？致病性耶尔森菌全基因组序列以及相关生物学信息的最新可得性为这一矛盾现象提供了线索，并揭示了新型高致病性病原体的进化方式。
