“条件致病菌”感染的的概念人体在正常生理情况下,体表的天然防御机制(皮肤、器官表面及它们的产物)和组织中体液和细胞因素的作用,机体可以抑制各种外源或寄生微生物的过度繁殖而中止感染。但在异常情况下,由于生体抵抗力降低,微生物将冲破天然屏障(如上皮细胞),破坏宿主防御功能平衡,从而大量繁殖而导致感染。流感并发肺炎就是其例,在上呼吸道寄生着各 The concept of “opportunistic pathogen” infection The human body under normal physiological conditions, the body’s natural defense mechanisms (skin, organ surfaces and their products) and the role of body fluids and cytokines, the body can inhibit a variety of exogenous Or parasitic micro-organisms and over-breeding stop the infection. However, under abnormal conditions, microorganisms will break through the natural barrier (such as epithelial cells) and destroy the balance of host defense functions due to the reduction of biological resistance, resulting in multiplication and infection. Influenza complicated pneumonia is an example of parasitism in the upper respiratory tract