Lund M E, Matsen J M, Blazevic D J
Appl Microbiol. 1974 Jul;28(1):22-5. doi: 10.1128/am.28.1.22-25.1974.
Ninety-four strains of H(2)S-negative Citrobacter were biochemically characterized and their antibiograms were determined. The antibiograms demonstrated not only a difference from Enterobacter cloacae but also a difference within the Citrobacter group between the indole-negative and indole-positive strains. These differences were statistically significant and emphasize the importance of the indole reaction as an aid to speciation of the H(2)S-negative Citrobacter.