Emergence of carbapenemase-producing and colistin resistant Klebsiella pneumoniae ST101 high-risk clone in Turkey.

Carbapenemase-producing and colistin resistant Klebsiella pneumoniae has become a worldwide healthcare problem. This study describes molecular characterization of carbapenemase-producing and colistin resistant clinical K. pneumoniae isolates.A total of 93 non-replicate carbapenem and colistin resistant K. pneumoniae were recovered from clinical specimens in a university hospital during 2017-2019. Detection of blaOXA-48, blaKPC, blaNDM-1, blaIMP, blaVIM-1 and mcr-1, -2, -3, -4, -5, -6, -7, and -8 genes was performed by PCR. The bacterial isolates were assigned to clonal lineages by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST).All isolates harbored blaOXA-48 and only two isolates harbored blaOXA-48, and blaNDM-1 genes together. In colistin resistant K. pneumoniae, mcr-1 was detected in two (2.1%) isolates. Ninety three isolates of K. pneumoniae were categorized into three clusters and five pulsotypes. MLST revealed two different sequence types, ST101 (89/93) and ST147 (4/93).In our study ST101 was found to be a significantly dominant clone carrying blaOXA-48 and among our strains a low frequency of mcr-1 gene was determined. The emergence of colistin resistance was observed in K. pneumoniae ST101 isolates. ST101 may become a global threat in the dissemination of carbapenem and colistin resistance.