Multiplication in human blood and deoxyribonuclease production by group G streptococci isolated from animals and humans

An M protein or an M protein-like substance was found to be present in a large proportion of group G streptococci isolated from animals and humans. Forty-seven percent of the isolates from cat throats and 38% of the isolates from the vagina of cats were able to multiply in human blood. Only 14% of the human isolates of group G isolated from various anatomical sites and sources were able to multiply in fresh human blood. Deoxyribonuclease was produced by 81% of cat vagina isolates, by 80% of cat throat isolates and by only 27% of the group G isolates from humans. Thirty-five percent of the cat isolates but only 5% of the human isolates were able to both grow in blood and produce DNase.