Bacterial species characterized by being fermentative, Gram-positive, slightly curved rod-shape, typically lacking end swellings, and occurring as a commensal in human skin and conjunctival sac either singly or in pairs in the shapes of V or Y
C. xerosis is a type of bacteria that is generally innocuous. However, it can grow prolifically in a compromised host and cause secondary infections, e.g. bacteremia, endocarditis, skin infections, pneumonia, and other illnesses. While C. xerosis rarely causes infections other Corynebacterium species are important agents of disease. One in particular is the more aggressive C. diphtheriae causing diphtheria.
C. xerosis is referred to as diphtheroid to tell it apart from C. diphtheriae. Diphtheroids do not usually form end swellings commonly observed in C. diphtheriae. In laboratory identification methods, C. xerosis is hemolysis(-), and metabolizes both glucose and sucrose. C. diphtheriae, in comparison, is hemolysis(+), and metabolizes glucose only, not sucrose.