A bacteriological study of non-chromogenic variants of Serratia marcescens from human sources

The culture and biochemical features of 10 non-chromogenic variants of S. marcescens isolated from clinical sources are reported. Autoagglutination titres were significantly high in sera from those patients in whom Serratia bacilli appeared to contribute to the illness. Since the taxonomic stature of the Serratia bacilli is not clear it might be better to limit the identification of this group to Serratia species.