Carriage of group D streptococci in the human bowel

Sixty faecal samples, 39 from adults and 21 from neonates, were investigated by means of a simple scheme to isolate and identify any group D streptococci present. A number of differences were found between the two groups. Group D streptococci were absent from 43% of the neonates compared with only 13% of the adults; Streptococcus bovis was commoner in the neonates (23.8%) than in the adults (5%), and Streptococcus faecium was not isolated from any of the infant samples although it was common in the adult samples (25%). The viable counts of Strep. faecium were found to be, on average, 100-fold lower than those of Streptococcus faecalis. The methods and results are discussed with reference to the clinical significance of group D streptococci, especially in bacterial endocarditis and carcinoma of the colon.