The Presence of H Antigen in Escherichia Coli K Suspensions

Abstract

Summary Motility in varying degree was observed, after 20 hours' incubation at 37°C, in 74 of 100 Escherichia coli strains grown on nutrient agar slants and in 63 of the same strains grown on glucose agar plates. K suspensions in saline were prepared from cultures of 17 E. coli O 111 B 4 and 26 E. coli O 55 B 5 strains grown on solid media, and H antigen was demonstrated, by means of tube agglutination tests with the appropriate H antisera, in 21 of the 43 suspensions from nutrient agar alant cultures and in 19 of those from glucose agar plate cultures. K antisera prepared with saline suspensions of an E. coli O 55 B 5 strain grown on glucose agar plates contained H 6 agglutinin to titres ranging from 1 in 6,400 to 1 in 51,200. Problems relating to the presence of H antigen in K suspensions prepared from solid medium cultures and of H agglutinin in K antisera are discussed.