Enterobacter cloacae

Enterobacter cloacae is a clinically significant Gram-negative, facultatively-anaerobic, rod-shaped bacterium. In microbiology labs, E. cloacae is frequently grown at 30 °C on nutrient agar or broth or at 35 °C in tryptic soy broth. It is a rod-shaped, Gram-negative bacterium, is facultatively anaerobic, and bears peritrichous flagella. It is oxidase-negative and catalase-positive. Enterobacter cloacae has been used in a bioreactor-based method for the biodegradation of explosives and in the biological control of plant diseases. E. cloacae is considered a biosafety level 1 organism in the United States and level 2 in Canada. A draft genome sequence of Enterobacter cloacae subsp. cloacae was announced in 2012. The bacteria used in the study were isolated from giant panda feces. Enterobacter cloacae is a member of the normal gut flora of many humans and is not usually a primary pathogen. Some strains have been associated with urinary tract and respiratory tract infections in immunocompromised individuals. Treatment with cefepime and gentamicin has been reported. A 2012 study in which Enterobacter cloacae transplanted into previously germ-free mice resulted in increased obesity when compared with germ-free mice fed an identical diet, suggesting a link between obesity and the presence of Enterobacter gut flora. E. cloacae was described for the first time in 1890 by Jordan as Bacillus cloacae, and then underwent numerous taxonomical changes, becoming 'Bacterium cloacae' in 1896 (Lehmann and Neumann), Cloaca cloacae in 1919 (Castellani and Chalmers), it was identified as 'Aerobacter cloacae' in 1923 (Bergey et al.), Aerobacter cloacae in 1958 (Hormaeche and Edwards) and E. cloacae in 1960 (Hormaeche and Edwards), by which it is still known today. E. cloacae is ubiquitous in terrestrial and aquatic environments (water, sewage, soil and food). These strains occur as commensal microflora in the intestinal tracts of humans and animals and play an important role as pathogens in plants and insects. This diversity of habitats is mirrored by the genetic variety of the nomenspecies E. cloacae. E. cloacae is also an important nosocomial pathogen responsible for bacteremia and lower respiratory tract, urinary tract and intra-abdominal infections, as well as endocarditis, septic arthritis, osteomyelitis and skin and soft tissue infections. The skin and the GI tract are the most common sites through which E. cloacae can be contracted.