Corynebacterium is a genus of Gram-positive, facultatively anaerobic, non-motile, non-sporulated, rod-shaped actinobacteria. Most do not cause disease, but are part of normal human skin flora.

Some nondiphtheria species of Corynebacterium produce disease in specific animal species, and some of these are also human pathogens. Some species attack healthy hosts, and others attack immunosuppressed hosts. Some of their effects include granulomatous lymphadenitis, pneumonitis, pharyngitis, skin infections, and endocarditis. Endocarditis caused by Corynebacterium spp. is particularly seen in patients with indwelling intravascular devices.

Infection by diphtheroids tend to occur in elderly, neutropenic, or immunocompromised patients, and those who have indwelling prosthetic devices such as heart valves, neurologic shunts, or catheters.

Some species of Corynebacterium have sequenced genomes that range in size from 2.5 - 3 Mbp. They can be found in many environments including soil, trees and skin. The non-diptheiroid Corynebecterium can also be found in human mucous membranes. They grow slowly, even on enriched media, and undergo "Chinese Letter" division. Species of Corynebacterium have been used in the mass production of various amino acids including L-Glutamic Acid, a popular food additive that is made at a rate of 1.5 million tons/ year by Corynebacterium. The metabolic pathways of Corynebacterium have been further manipulated to produce L-Lysine and L-Threonine.

Species

Corynebacterium diphtheriae

• Corynebacterium diphtheriae, the cause of diphtheria in humans.

Nondiphtheriae Corynebacteria (diphtheroids)

• Corynebacterium amycolatum
• Corynebacterium aquaticum
• Corynebacterium bovis
• Corynebacterium equi
• Corynebacterium flavescens
• Corynebacterium glutamicum
• Corynebacterium haemolyticum
• Corynebacterium jeikeiun (corynebacteria of group JK)
• Corynebacterium parvum (also called Propionibacterium acnes)
• Corynebacterium pseudodiptheriticum (also called Corynebacterium hofmannii)
• Corynebacterium pseudotuberculosis (also called Corynebacterium ovis)
• Corynebacterium pyogenes
• Corynebacterium urealyticum (corynebacteria of group D2)
• Corynebacterium renale
• Corynebacterium striatum, (Axillary odor [1])
• Corynebacterium tenuis (Trichomycosis palmellina, Trichomycosis axillaris) [2]
• Corynebacterium ulcerans
• Corynebacterium xerosis

References

• Ryan KJ; Ray CG (editors) (2004). Sherris Medical Microbiology, 4th ed., McGraw Hill. ISBN 0-8385-8529-9. 
• Database of Corynebacterial Transcription Factors and Regulatory Networks
• Rollins, David M. University of Maryland: Pathogentic Microbiology: Corynebacterium [3]