CDC group IIc: phenotypic characteristics, fatty acid composition, and isoprenoid quinone content.

Twenty strains of glucose-utilizing, small gram-negative slightly pleomorphic rods that grew well aerobically and that were isolated from clinical specimens formed a phenotypically similar group that was designated CDC group IIc. The phenotypic characteristics of CDC group IIc were most similar to those of CDC groups IIe and IIh, the major differences being that CDC group IIc produced acid from sucrose, hydrolyzed esculin, and usually reduced nitrate. The CDC group IIc strains were analyzed by gas-liquid chromatography for their cellular fatty acid compositions, and all contained relatively large amounts of isobranched hydroxy and nonhydroxy acids. High-performance liquid chromatography and mass spectrometry analysis of the quinone extract showed menaquinone-6 as the major component. Both the cellular fatty acid and isoprenoid quinone compositions were consistent with the profiles of CDC groups IIe and IIh. Thirty percent of the isolates were from human blood.