Ceftazidime/avibactam and eravacycline susceptibility of carbapenem-resistant Klebsiella pneumoniae in two Greek tertiary teaching hospitals

The present study evaluated the carbapenem resistance mechanisms of Klebsiella pneumoniae strains isolated in two Greek tertiary teaching hospitals and their susceptibility to currently used and novel antimicrobial agents. Forty-seven carbapenem resistant K. pneumoniae strains were collected in G. Papanikolaou and Ippokrateio hospital of Thessaloniki between 2016 and 2018. Strain identification and antimicrobial susceptibility was conducted by Vitek 2 system (Biomerieux France). Susceptibility against new anti-microbial agents was examined by disk diffusion method. Polymerase chain reaction (PCR) was used to detect bla(KPC), bla(VIM), bla(NDM) and bla(OXA-48) genes. The meropenem-EDTA and meropenem-boronic acid synergy test performed on the 24 K. pneumoniae strains demonstrated that 8 (33.3%) yielded positive for metallo-beta-lactamases (MBL) and 16 (66.6%) for K. pneumonia carbapenemases (KPC) production. Colistin demonstrated the highest in vitro activity (87.7%) among the 47 K. pneumoniae strains followed by gentamicin (76.5%) and tigecycline (51%). Among new antibiotics ceftazidime/avibactam showed the highest sensitivity (76.6%) in all strains followed by eravacycline (66.6%). The bla(KPC) gene was present in 30 strains (63.8%), the bla(NDM) in 11 (23.4%) and the bla(VIM) in 6 (12.8%). The bla(OXA-48) gene was not detected. Well established antimicrobial agents such as colistin, gentamicin and tigecycline and novel antibiotics like ceftazidime/avibactam and eravacycline can be reliable options for the treatment of invasive infections caused by carbapenem-resistant K. pneumoniae