Biochemical and clinical characteristics and antibiotic susceptibility of atypical Enterobacter cloacae

The characteristics of an atypical group of the family Enterobacteriaceae resembling Enterobacter cloacae were studied. The urinary tract was the most common source of these organisms, and most strains represented infections of secondary clinical significance. In contrast to typical Enterobacter strains, the atypical strains were highly susceptible to the cephalosporins; otherwise, there was a high degree of susceptibility to five other antibiotics and resistance to ampicillin except in very high concentration.