[The hemagglutinating activity of bacteria in the genus Klebsiella and the morphofunctional characteristics of their fimbriae].

The hemagglutinating activity of 77 Klebsiella strains from the international collection, grown in a culture medium prepared on the basis of soy-bean flour enzymatic hydrolysate, was studied. These strains could be divided into four groups according to their capacity for synthesizing different types of hemagglutinins on their surface: 2 strains carried mannose-sensitive hemagglutinins, 18 strains had mannose-resistant K-type hemagglutinins, 48 strains exhibited the signs indicating the presence of both mannose-sensitive and mannose-resistant hemagglutinins, and 9 strains showed no hemagglutinating activity. The hemagglutinating activity of strains K-74, K-79, K-80, K-81 and K-82 was characterized. Of the reference strains under study, 22 strains were found to have mannose-resistant hemagglutinating activity with respect to fresh chick red blood cells. The occurrence of hemagglutinins in Klebsiella was shown to depend on the temperature of cultivation and the consistency of the culture medium. The formation of large-sized capsules in Klebsiella grown in the Werfel-Fergusson medium with a considerable content of saccharose was shown to cause the absorption of their fimbrial structures by the capsular substance and, as a consequence, the suppression of their hemagglutinating activity.