Observation of corynebacterium species using Scanning Electron Microscopy

Abstract

Bacteria of the genus Corynebacterium are considered part of the bacterial flora of skin and mucosa. Even C. diphtheriae, a long recognized pathogen, may be isolated from the throat of healthy individuals. Recent evidence indicates that other Corynebacteria are associated with opportunistic conjunctival infections in aging laboratory mice.Our goal of using scanning electron microscopy was to expand previous studies and to observe the association of the bacteria with the conjunctival surface of aged mice. To accomplish this, we needed a point of reference for identification of the corynebacteria which were frequently present in the company of other bacteria. We studied cultures of known corynebacteria of ocular origin during the exponential growth phase. These cultures contained pleomorphic cells that were round, ovoid and rod shaped, clustered together and surrounded by a biofilm. Several of the cylindrical rods appeared as V-shaped pairs, classic features of the genus Corynebacterium. The V-shape arrangement is accomplished by a snapping postfission movement.