Group B streptococci: extracellular neuraminidase production and virulence in mouse.

Neuraminidase production by reference strains of various group B streptococci serotypes was investigated before and after serial passages in mouse. The enzyme production was tested in culture filtrates using bovine submaxillary mucin as substrate. Although passages in mouse markedly increased the virulence of all the strains it was not possible to demonstrate a relationship between the increased virulence and the enzyme production.