Resistance of carbapenemase-producing Klebsiella pneumoniae isolated from patients with orthopedic infection

Abstract

Objective. To evaluate the resistance rate and production of carbapenemases in Klebsiella pneumoniae with phenotypic resistance to carbapenems isolated from patients with orthopedic infection. Materials and Methods. The materials for the study were tissue samples, aspirates and removed orthopedic devices of patients with orthopedic infection at the Vreden Russian Research Institute of Traumatology and Orthopedics, between 2017 and 2019. K. pneumoniae strains were identified in Microlatest by iEMS ReaderMF. These strains were tested for susceptibility to 15 antimicrobial agents by disk diffusion methods, as described by the EUCAST. The carbapenemase genes were investigated by RT-PCR. Results. Of 858 isolated cultures, 6.8% were resistant to carbapenems. Molecular genetic analysis showed that 43.1% of the cultures had blaNDM gene and 24.1% blaOXA-48. All isolates of K. pneumoniae were characterized by resistance to cefotaxime, moxifloxacin and ciprofloxacin. OXA-48-strains were MDR in 50.0% of cases, XDR in 42.9%, PDR in 7.1%. Strains with NDM-carbapenemases were XDR in 68.0% and PDR in 32.0% of cases. The most effective antibiotic was fosfomycin. Thus, 66.7% of NDM-isolates demonstrated sensitivity to fosfomycin. One isolate was PDR with both NDM and OXA-48. Conclusions. Over the period of three years, carbapenemase-producing K. pneumoniae were isolated in the orthopedic hospital. These isolates were not only resistant to carbapenems, but also to a number of other antimicrobial agents. Isolates differed in resistance phenotypes depending on the presence of carbapenemases group, while strains with gene blaNDM were more resistant than those with blaOXA-48.