Edwardsiella, and Acinetobacter are components of the normal animal and human colonic flora and/or of the flora of a variety of environmental habitats, including long-term-care facilities (LTCFs) and hospitals. As a result, except for certain pathotypes of intestinal pathogenic E. coli, these genera are global pathogens. In healthy humans, E. coli is the predominant species of gram-negative bacilli (GNB) in the colonic flora. GNB (primarily E. coli, Klebsiella, and Proteus) only transiently colonize the oropharynx and skin of healthy individuals. In contrast, in LTCF and hospital settings, a variety of GNB emerge as the dominant flora of both mucosal.
