The paper presents the microecological characteristics of regional populations of Klebsiella spp. in the intestinal microbiota of children and adults. The sensitivity of autostrains to a number of antibiotic drugs (of groups: β-lactams, aminoglycosides and quinolones) and their phage sensitivity (to purified Klebsiella pneumoniae phage and purified Klebsiella polyvalent phage). The sample of isolates (n = 60) was characterized by a high proportion of antibiotic susceptible Klebsiella. A high proportion of strains resistant to studied bacteriophages may be the cause of the low efficiency of phage therapy in children. Gene bfp is present in 18,3 % of Klebsiella strains, which indicates the adhesive potential of Klebsiella spp. by the pili formation.