Reversal of Carbapenemase-producing Klebsiella Pneumoniae Epidemiology from BlaKPC- to BlaVIM-harbouring Isolates in a Greek ICU After Introduction of Ceftazidime/avibactam

Objectives: Our aim was to determine the epidemiology of bloodstream infections (BSIs) by carbapenemase-producing Klebsiella pneumoniae (CP-Kp) after the introduction of ceftazidime/avibactam in January 2018 among ICU patients.

Patients And Methods: All patients hospitalized at the ICU of the University General Hospital of Patras, Greece with CP-Kp BSI during 2015-18 were included. MICs of meropenem, fosfomycin, tigecycline and ceftazidime/avibactam (only for isolates from 2018) were determined by Etest, whereas for colistin, the broth microdilution method was applied. All isolates were tested by PCR for the presence of blaKPC, blaVIM, blaNDM and blaOXA-48 genes.

Results: Among 170 BSIs due to CP-Kp (2015-18), 132 (78%) were caused by isolates carrying blaKPC (4 ceftazidime/avibactam-resistant), 17 blaVIM (10%), 16 blaNDM (9%) and 5 carrying both blaKPC and blaVIM (3%). From 2015 to 2017 (125 BSIs), KPC-producing strains (110; 88%) predominated, followed by NDM-producing strains (15; 12%), whereas no VIM-producing strain was isolated. Among the 45 BSIs in 2018, 22 (49%) were due to isolates carrying blaKPC (4 ceftazidime/avibactam resistant), followed by 17 (38%) carrying blaVIM, 5 (11%) carrying both blaKPC and blaVIM, and 1 isolate carrying blaNDM (2%). MBLs were more frequent in 2018 compared with 2015-17 (51% versus 12%; P < 0.001). Multivariate analysis found that prior administration of ceftazidime/avibactam (P = 0.014; OR 16.7, 95% CI 1.8-158.6) was independently associated with the development of BSI due to ceftazidime/avibactam-resistant isolates.

Conclusions: Widespread ceftazidime/avibactam use may lead to a change in the palette of carbapenemases by replacing KPC with MBL-producing isolates.