Biological Properties and Mouse Virulence of Streptococcus agalactiae and Lancefield's Group "B" Streptococci from Human Sources.

Summary and ConclusionsThe biological properties and mouse virulence of 70 Lance-field's group B cultures (50 bovine and 20 human) have been studied and compared. The fermentation reactions show that, aside from the inability to ferment lactose by 8 of the human strains and some difference in the fermentation of glycerol, dextrin and salicin, the reactions are very similar for both groups. In some instances the biological properties studied were identical for strains of bovine and human origin. It has been observed with the majority of strains that the differences between single bovine and human cultures were not greater than those between individual strains from the same source.There is an indication that human strains are more likely to reduce methylene blue.It is known that the mouse virulence of group B streptococci is low. Inoculation of the 70 cultures studied into mice gave results which indicated that the strains from human sources possessed a higher mouse virulence than the bovine strains.In spit...