Enterobacter cloacae

Enterobacter cloacae is a clinically significant Gram-negative, facultatively-anaerobic, rod-shaped bacterium.

Microbiology
In microbiology laboratories, E. cloacae is frequently grown at 30 °C on nutrient agar 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.

Industrial use
Enterobacter cloacae has been used in a bioreactor-based method for the biodegradation of explosives and in the biological control of plant diseases. Enterobacter cloacae strain MBB8 isolated from the Gulf of Mannar, India was reported to degrade poly vinyl alcohol (PVA). This was the first report of a PVA degrader from the Enterobacter genus. E. cloacae was also reported to produce exopolysaccharide (EPS) as high as 18.3g/L. GC-MS analysis of E. cloacae EPS showed the presence of glucose and mannose in the molar ratio of 1: 1.5e−2.

Enterobacter cloacae subsp. cloacae strain PR-4 was isolated and identified by 16S rDNA gene sequence with phylogenetic tree view from explosive-laden soil by P. Ravikumar (GenBank accession number KP261383).

E. cloacae SG208 identified as a predominant microorganism in mixed culture isolated from petrochemical sludge (IOCL, Guwahati) responsible for degradation of benzene was reported by Padhi and Gokhale (2016).

Safety
Enterobacter cloacae is considered a biosafety level 1 organism in the United States and level 2 in Canada.

Genomics
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.

Clinical significance
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. It is a high risk AmpC producer and treatment with cefepime is recommended by the IDSA if causing disease rather than simply colonising. Treatment using cefepime and gentamicin has been reported.

A 2012 study in which Enterobacter cloacae was 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.