**2. Bacteriological characteristics of** *Corynebacterium* **species**

**Morphology**: The size of *Corynebacterium* species varies from 0.3–0.8 × 1–8 μm. They exsist in a variety of shapes, even in pure cultures. In the clinical samples, they mostly appear as rod-shaped bacteria in palisade-, ring-, or 'I, N, T, V, W, or Y' letter-shaped arrangments.

© 2013 Eguchi; licensee InTech. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2013 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

**Lipophilicity**: Few *Corynebacterium* species generally have high lipophilicity. In vitro, they can be easily become unculturable if the final concentration of Tween 80 (polysorbate 80) in the medium is slightly different from the optimal concentration. Presumably, this is the rea‐ son why particular *Corynebacterium* species prefer the ocular surfaces as these are area where fatty acids are always present because they are secreted from the meibomian gland. This re‐ quirement may also explain why *Corynebacterium*-induced endophthalmitis is very rare.
