Alcaligenes faecalis, naturally found in soil and water is also found to be present as a member of normal human microbiota. Some of the strains are found to cause diseases of human, both adult and new-born, some of which are life threatening. A faecalis strains are also found to cause diseases in birds like poultry birds and turkeys; some vertebrates and nematodes. The most dangerous fact is that most of these strains are resistant to almost all existing antibiotics and this resistance is conferred by antibiotic resistant genes (ARG), constituting the resistomes. Being a free-living organism, under the stress of environment and antimicrobials present therein, A faecalis finds shelter in living body.  In course of time, it turns to opportunistic pathogen in the immune compromised hosts and as result of rampant use of antibiotics for both empiric and definitive therapy of the diseases, few strains become multi drug resistant. The biofilm mediated infections conferred by these antibiotic resistant strains give rise to various chronic and nosocomial diseases in human.