易位是微生物群离开原生存环境转移到另一生存环境或栖息地的一种生态现象,也受宿主(如免疫功能低下或长期使用激素、同位素、免疫抑制剂、放疗化疗以及其解剖结构功能变化等)和微生物(致病性、产毒、耐药、遗传性改变等)两方面因素影响。易位特征为定植性、繁殖性、拮抗性和顺序性(又称多相性)。细菌易位与宿主防御、细菌穿越黏膜的能力、在不利环境下存活能 Metabolism is an ecological phenomenon in which micro-organisms migrate from their original habitat to another habitat or habitat and are also affected by host (such as immunocompromised or long-term use of hormones, isotopes, immunosuppressants, radiotherapy and chemotherapy, and their anatomical features Change, etc.) and microorganisms (pathogenic, toxigenic, resistant, genetic changes, etc.) two factors. Translocation characteristics of colonization, reproductive, antagonistic and order (also known as heterogeneity). Bacterial translocation and host defense, the ability of bacteria to cross the mucosa, survive under adverse conditions