ObjectiveTo study the antibacterial activity of ceftazidime/avibactam against carbapenem-resistant Klebaiella pneumoniae (CRKP) in vitro and detect the resistance genes of CRKP, so as to provide reference for the treatment of patients with CRKP infection.MethodsA total of 120 CRKP strains isolated from clinical specimens from May 2014 to November 2017 were collected. The activitis of 11 antimicrobial agents against those CRKP strains were detected by broth microdilution method, and the genes related to resistance to ceftazidime/avibactam were detected by polymerase chain reaction in the 120 CRKP isolates.ResultsThe resistance rate of the 120 CRKP isolates against ceftazidime/avibactam was 16.67% (20/120), which was significantly lower than that against cefotaxime (100.00%), aztreonam (98.33%), ceftazidime (95.83%), cefoperazone/sulbactam (95.83%), meropenem (95.83%), imipenem (95.00%), levofloxacin(92.50%), amikacin (54.17%), minocycline (39.17%), and tegacycline (23.33%). Among the 20 CRKP strains resistant to ceftazidime/avibactam, there were 12 Klebsiella pneumoniae carbapenemase (KPC)-2-producing strains, 3 KPC-3-producing strains, 1 New Delhi metallo-β-lactamase-1 (NDM-1)-producing strain, and 1 oxacillin β-lactamase-48-producing strain; none of the 20 strains had KPC mutation.ConclusionsCeftazidime/avibactam is an effective agent agianst CRKP, and its resistance rate is significantly lower than that of other commonly used antimicrobial agents, especially other β-lactam antibiotics. In terms of resistance genes, except for one isolate producing NDM-1, no other known gene resistant to ceftazidime/avibactam has been found.
