Comparison between the Aged and Children of the Normal Distribution of Pharyngeal and Intestinal Hemolytic Streptococci

Abstract

A marked difference between the aged and children has been observed in the group distribution of hemolytic streptococci isolated from various clinical specimens. Group B strains from the urine and sputum, and group G from the sputum, pus and exudate have been predominant in the aged, whereas group A strains from the throat swab have dominated in children.
The present study was undertaken to clarify the background for such a marked difference by investigating the normal state of pharyngeal and intestinal carriage of hemolytic streptococci both in the aged and children.
1. As to the pharyngeal carriage, quite a contrast was observed between the aged and children. In the former, the rate of carriers was low and the predominant groups among the streptococcus isolates were B (Streptococcus aglactiae) and G (identified as Streptococcus equisimilis), while in the latter, the rate was high and group A (Streptococcus pyogenes) strains comprised approximately 75% of the isolates, most of them being from the throat swab.
2. Both the aged and children showed a similar state of streptococcus carriage in the intestine. The rate of carriers was low and the predominant group among the isolates was B in both populations. Although group G strains were occasionally isolated, group A strains were isolated neither in the aged nor in children.
These results explain well the difference between the aged and children in the group distribution of the clinical isolates of hemolytic streptococci.