Diversity of carbapenem-resistant Klebsiella pneumoniae ST14 and emergence of a subgroup with KL64 capsular locus in the Arabian Peninsula.

To understand the reasons of successful spread of carbapenem-resistant Klebsiella pneumoniae ST14 (CRKP-ST14) in countries of the Arabian Peninsula, the resistome, capsular locus, carbapenemase carrying plasmid types, and core genome of isolates from the region were compared to global isolates. Thirty-nine CRKP-ST14 strains isolated from 13 hospitals in the United Arab Emirates, Bahrain, and Saudi Arabia were selected for whole genome sequencing on Illumina MiSeq platform based on the variety of carbapenemase genes carried and plasmids bearing these genes. Their resistome, capsular locus, and core genome MLST were compared to 173 CRKP-ST14 genomes available in public databases. The selected 39 CRKP-ST14 produced either NDM-1, OXA-48, OXA-162, OXA-232, KPC-2, or co-produced NDM-1 and an OXA-48-like carbapenemase. cgMLST revealed three clusters: 16 isolates from five UAE cities (C1), 11 isolates from three UAE cities and Bahrain (C2), and 5 isolates from Saudi Arabia (C3), respectively, and seven singletons. Resistance gene profile, carbapenemase genes, and their plasmid types were variable in both C1 and C2 clusters. The majority of CRKP-ST14 had KL2, but members of the C2 cluster and two further singletons possessed KL64 capsular locus. Based on cgMLST comparison of regional and global isolates, CRKP-ST14 with KL64 from four continents formed a distinct cluster, suggesting a recent emergence and spread of this variant. Our findings confirmed clonal transmission coupled with likely horizontal gene transfer in carbapenem-resistant Klebsiella pneumoniae ST14. Dissemination of this genetically flexible, highly resistant clone warrants further monitoring.