[The adhesive activity of Klebsiella pneumoniae controlled by plasmid 55 MD].

In K. pneumoniae clinical strains a nonconjugative plasmid, denoted as pAdh-55 and responsible for their adhesive activity with respect to HEp-2 cells, was detected. The comparison of genetically related pairs of K. pneumoniae strains differing in the presence of pAdh-55 revealed that the loss of this plasmid by bacteria was accompanied by a decrease, and its acquisition by a considerable increase, in the number of Klebsiella-affected cells in the monolayer. The correlation between the presence of pAdh-55 in K. pneumoniae strains and their adhesive activity was established both in experiments aimed at the morphological study of preparations stained with azure eosin and in experiments with isotope-labeled bacteria.