Microbes and human Normal flora =Normal microbiota(beneficial or ignored) GI track, skin, upper respiratory track Opportunistic bacteria(when host with underline problem) Pseudomonas aeruginosa: cystic fibrosis/burn Kaposis sarcoma(herpesvirus): AIDS E coll, Staphylococcus Virulent bacteria (actively cause disease) Mobile genetic elements pathogenic islandsMicrobes and Human Normal flora =Normal microbiota (beneficial or ignored):  GI track, skin, upper respiratory track… Opportunistic bacteria (when host with underline problem):  Pseudomonas aeruginosa: cystic fibrosis/ burn  Kaposi’s sarcoma (herpesvirus): AIDS  E.coli，Staphylococcus Virulent bacteria (actively cause disease): Mobile genetic elements pathogenic islands