Antibiotic succeptability and some virulence factors of Klebsiella spp. strains isolated from trophic ulcers


  • G.G. Balan Nicolae Testemitanu State University of Medicine and Pharmacy of the Republic of Moldova,



trophic ulcers, Klebsiella spp., antibiotic susceptibility and virulence factors


Background. Recently, a particular attention has been drawn to the study of the microbial virulence factors and their correlation with the rate of elimination from the source of infection, as well as the prognosis of the disease progression. The purpose of this study was to assess the factors affecting antibiotic susceptibility and virulence factors of Klebsiella spp. strains isolated from trophic ulcers. Materials and methods. The study was conducted on 76 strains of Klebsiella spp. isolated from trophic ulcers. The isolated strains were identified and tested according to the current guidelines. Antibiotic susceptibility testing and interpretation of the results were performed in accordance with EUCAST.  Lecithinase activity was assayed on the egg yolk salt agar, hemolytic activity – on blood agar, and antilysozyme and anti-complementary activity was determined according to O. Bukharin et al. method. The microtiter method was applied for quantitative biofilm formation assays. Results. Klebsiella spp. strains, isolated from trophic ulcers, showed both high resistance to antimicrobial drugs and presence of many pathogenicity factors. Hemolytic activity was found in 53.9%, antilysozyme activity– in 90.8%, lecithinase activity– in 56.6%, anticomplementary activity – in 97.4% and 86.8% of strains produced a detectable biofilm. The strains isolated from mixed infection showed a greater antibiotic susceptibility and a higher virulence factor expression compared to those isolated within monoinfections. Conclusions. Klebsiella spp. strains isolated from infected trophic ulcers exhibit a range of pathogenicity factors and a greater resistance to antimicrobial drugs. The biofilm-producing strains showed a high and multiple antibacterial susceptibility. Regular monitoring of the virulence factors and their antibiotic resistance profile can increase efficacy in the treatment of trophic ulcers.


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