No abstract

An 85-year-old woman with the diagnosis of diabetic ketoacidosis developed septicemia during hospitalization. Cultures of the patient's blood revealed the presence of Gram-variable coccobacilli, later identified as Corynebacterium aquaticum. The microorganisms grew aerobically on blood agar plates after incubation overnight. The colonies were convex, non-hemolytic and slightly yellow-pigmented. No growth was observed on MacConkey and endo agar plates. The organisms were catalase-positive, oxidase-negative, motile, and oxidized glucose and mannitol. The morphologic and biochemical properties of Corynebacterium aquaticum should be considered for separation from related organisms such as Listeria monocytogenes, Corynebacterium species and oxidative Gram-negative rods that do not grow on MacConkey medium (Flavobacterium spp.).

A case of subacute bacterial endocarditis in which Cardiobacterium hominis was isolated from the blood of a 55-year old woman who had rheumatic heart disease is reported. A survey of the literature revealed very few reports in which this organism has been implicated in human lesions. The colonies grew after 48 hours of incubation in a candle jar. They were small, convex, nonhemolytic, and oxidase-positive. The indole reaction was positive, the catalase and nitrate reactions were negative, and acid reaction was obtained from the following carbohydrates: glucose, maltose, mannitol, sucrose, and sorbitol. The morphologic and biochemical properties served to distinguish these organisms from similar bacteria implicated in human disease, such as Haemophilus aphrophilus, Actinobacillus actinomycetemcomitans, Streptobacillus moniliformis, and HB-1.