The emergence of Klebsiella pneumoniae sequence type 395 non-susceptible to carbapenems and colistin from Turkey.

Purpose: OXA-48 producing Klebsiella pneumoniae is an emerging threat and outbreaks due to specific sequence types have been commonly reported. Here, we report an outbreak due to multidrug-resistant ST395 K. pneumoniae ST395. To the best of our knowledge, this is the first outbreak of K. pneumoniae ST395 harbouring bla genes in our country.

Methods: The strains were characterized by antimicrobial susceptibility, extended-spectrum β-lactamase (ESBL) and carbapenemase production, plasmid-mediated colistin, high-level aminoglycoside, and quinolone resistance. Also multidrug efflux pumps and porin coding genes were investigated. Pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), wzi typing and plasmid analysis were used for the epidemiological relationships.

Results: All strains were positive for bla with at least one of the β-lactamase genes (bla, bla, bla) and harboured IncL plasmids. 16 of 20 (80%) isolates carried qnrA. All isolates were positive for aac(6')-1b, acrAB-tolC, ompK35, and ompK36 genes but none of them harboured 16s rRNA methyltransferase, mcr-1-5, qepA, oqxAB, and mdtK genes. All strains had the same PFGE pattern, that is, wzi type K2 and found to be ST395 with MLST.

Conclusion: The association of ST395 with OXA-48-producers could be an emerging threat for Turkey and continuous monitoring is crucial to prevent the spread of these powerful strains.