The Mutation of Corynebacterium pyogenes to Corynebacterium haemolyticum

Abstract

Strains of C. pyogenes, when subcultured repeatedly on blood agar, occasionally give rise to a large colony variant which shows all the properties of C. haemolyticum. C. pyogenes ferments lactose and xylose, produces a soluble hemolysin, and/or proteinase, and contains glucose in its cell-wall. Mutant C. haemolyticum ferments lactose but not xylose, does not produce a soluble hemolysin, and glucose is not detectable in its cell-wall hydrolysates. It is suggested that a single mutation involving cell-wall structure could account for the apparent change from Xyl+H+ to XYl-H-It is probable that neither C. pyogenes nor C. haemolyticum is a Corynebacterium, and that taxonomically both organisms belong to the genus Streptococcus.