Serratia rubidaea isolated from a silastic foam dressing.

A pigment-producing strain of Serratia rubidaea was isolated from two consecutive cultures from a sponge of silastic foam used as a dressing for chronic crural ulcers. The bacterium caused a red discolouration of the sponge and the surrounding part of the leg. The silastic sponge creates a new type of environment for microorganisms. The growth of previously rare bacteria such as S. rubidaea may be favoured by conditions within the sponge.