Prevalence of Gemella haemolysans on the pharyngeal mucosa of man.

By culturing pharyngeal swabs from 199 students a carrier rate for Gemella haemolysans of 29.7% was detected. Demonstration of hemolysis depended on blood species and on agar base. Optimum growth was obtained under aerobic conditions in a 10% CO2-enriched atmosphere. The cells divided in two planes which were not regularly at right angles to each other. They appeared to be surrounded by a small capsule. Contrary to earlier descriptions, acid was produced from galactose, acetoin was produced by practically all strains and nitrite was reduced by all strains. Acid production from trehalose and N-acetyl-glucosamine, alkaline and acid phosphatase, C4 and C8 esterase, pyrrolidone arylamidase and phosphoamidase activities were detected. In tube precipitation, antigenic relations between type strain and the new isolates were demonstrated.