Enterobacter
Enterobacter is a genus of common Gram-negative, facultatively-anaerobic, rod-shaped bacteria of the family Enterobacteriaceae. Several strains of the these bacteria are pathogenic and cause opportunistic infections in immunocompromised (usually hospitalized) hosts. The urinary and respiratory tract are the most common sites of infection. Enterobacter can be distinguished from other GNR by virtue of being a ‘fast fermenter’ of lactose (as are Escherichia coli and Klebsiella). Two clinically-important species from this genus are E. aerogenes and E. cloacae.