Diphtheroid Infections of Man

The corynebacteria are a heterogenous group of organisms commonly present on the skin; in the pharynx, urethra, and vagina; and in soil and water as saprophytes. Their active role as pathogens in a variety of animals is well recognized. However, aside from Corynebacterium diphtheriae, they rarely cause disease in man. Nine patients with this type of infection have been studied over a period of 5 years. Four had bacteremia, two had wound infections, and one each had meningitis, osteomyelitis, and hepatitis. In eight instances diphtheroid invasion occurred in the presence of an unrelated disorder that tended to reduce the effectiveness of normal defense mechanisms. Experience suggests that possibility of diphtheroid infection by these species must be considered in any situation when there is evidence of pyogenic infection by pleomorphic gram-positive bacilli in the presence of impaired host defenses. Penicillin, cephalothin, or erythromycin appear to be the agents of choice for the treatment of this kind of disease, although some strains of the organism may be resistant to them. Other antibiotics are also effective and should be used if those mentioned above fail to produce cure. There is no good evidence that the use of combined chemotherapy offers a significant advantage over the administration of an active, single antimicrobial agent in most cases.