BIOTYPES OF ARCANOBACTERIUM-HAEMOLYTICUM

Colony morphology, beta hemolysis on horse blood agar, beta-glucuronid ase activity, and ability to ferment sucrose and/or trehalose defined two biotypes of Arcanobacterium haemolyticum. One, the smooth type, gr ew as smooth, beta-hemolytic colonies and was beta-glucuronidase negat ive but often fermented sucrose and/or trehalose, while the other, the rough type, grew as rough colonies and was nonhemolytic, P-glucuronid ase positive, and negative for sucrose and trehalose fermentation. Abo ut 75% of the A. haemolyticum strains studied (n = 138) were of the sm ooth type. The smooth type predominated in wound infections, while the rough type was isolated almost exclusively from respiratory tract spe cimens; thus, 84% of the smooth type strains were derived from wounds and 91% of the rough-type strains were isolated from respiratory tract s.