Aeromonas hydrophila as the etiologic agent in severe gastroenteritis: report of a case.

Aeromonas hydrophila was isolated from stool of an 82-year-old female with severe gastroenteritis. The stool was foamy and varied in color from green to yellow. The isolated organism was susceptible to most aminoglycosides. The tetracycline therapy cleared the organism from the stool and the patient's condition improved. The biochemical characteristics of the organism were similar to coliform bacilli: the oxidase test was necessary to differentiate Aeromonas sp. from coliforms. The patient did not have any major underlying disease. This case report documented the need to test all isolates resembling coliform bacilli by the oxidase test.