[Role of enterotoxin and neuraminidase in the biological activity of E1 Tor vibrios].

The biological activity of the toxigenic strains of cholera vibrios in suckling rabbits used as a model is manifested irrespective of the amount of neuraminidase produced by these strains. Neuraminidase is important only in low-cholerogenic strains, which is confirmed by a significantly greater death rate among suckling rabbits infected with cultures producing 40-2560 ng/ml of the exoenzyme in comparison with that among suckling rabbits infected with strains producing less than 10 ng/ml of the exoenzyme, or not producing it at all. The relation between the amounts of enterotoxin and neuraminidase, produced in vitro, and the biological activity of strains in suckling rabbits has been established, which allows one to study the virulence of strains in the passive immune hemolysis and aggregate hemagglutination tests.