In an attempt to study the role of neuraminidase in cholera vibrio pathogenesis, the dermatonecrotic effect of a purified neuraminidase preparation was studied in rabbits. The experiments demonstrated that dermatonecrotic lesions resulted from intracutaneous injection of a purified neuraminidase preparation (0.5 specific human dose or 1 NU) as well as significant doses of cholera toxoid containing the enzyme (4,12,18 specific human doses).