自十七世纪八十年代 Pasteur 创立了细菌致病学说以来,特异性病原体引起机体损害已深为人们接受。所谓特异性就是一种病原体只能特异地引起机体产生一定的疾病,而不是产生其它疾病。如痢疾杆菌只能经消化道进入机体,在乙状结肠部位引起病损,临床上表现为一系列细菌性痢疾的症状和体征。而不能引起结核病,也不能导致伤寒病。这是病原体本质所 Since the discovery of bacterial pathology by Pasteur in the 1780s, it has become widely accepted that specific pathogens cause damage to the body. The so-called specificity is a kind of pathogen can only cause the body to produce certain diseases, but not to produce other diseases. Such as Shigella can only enter the body through the digestive tract, causing lesions in the sigmoid colon, the clinical manifestations of a series of symptoms and signs of bacterial dysentery. And can not cause tuberculosis, nor can it cause typhoid fever. This is the nature of the pathogen