Facultatively Aerobic Gram-Negative Rods Enteric bacteria Gamma Purple bacteria Gram-negative straight rods Facultative aerobes Nonsporulating Motile by peritrichous flagella or nonmotile Large number of strains have been isolated Identification is now based on computer analysis of a large number of diagnostic tests carried out using miniaturized rapid diagnostic media kits and immunological and nucleic acid probesFacultatively Aerobic Gram-Negative Rods Enteric Bacteria Gamma Purple bacteria Gram-negative straight rods Facultative aerobes Nonsporulating Motile by peritrichous flagella or nonmotile Large number of strains have been isolated Identification is now based on computer analysis of a large number of diagnostic tests carried out using miniaturized rapid diagnostic media kits and immunological and nucleic acid probes