MICROBIOLOGICAL EFFICIENCY OF ANTIBIOTIC COMBINATIONS AGAINST INVASIVE KLEBSIELLA PNEUMONIAE STRAINS

Background. Combined antibiotic therapy is the main treatment for infections caused by antibiotic-resistant bacteria. The aim of this research was to identify the synergistic activity of antibiotic combinations against invasive extensively drug-resistant K. pneumoniae strains producing carbapenemases. Material and methods. For 12 invasive KPC-, OXA-48- and NDM-producing K. pneumoniae strains, the minimum inhibiting concentrations of antibiotics were determined. The susceptibility to antibiotic combinations was determined using the modified disk diffusion method. Results. The effect of potentiating the activity of colistin with aztreonam (58.3% of strains), azithromycin (33.3%), clarithromycin (41.7%), rifampicin (33.3%) as well as doxycycline (50%) was noted. High microbiological efficiency of ceftazidime/avibactam against all producers of KPC and OXA-48-carbapenemases was demonstrated. For MBLNDM-producing strains, a synergistic effect of the combination of ceftazidime/avibactam and aztreonam with restoration of susceptibility was revealed. Conclusion. The obtained findings open up perspectives for combination therapy of bloodstream infections caused by XDR-strains of K. pneumoniae.