Comparison of carbapenemase producing Klebsiella pneumoniae ST14 isolated in the Arabian Peninsula. Carbapenemase producing Klebsiella pneumoniae ST14 of the Arabian Peninsula

AIMSWe studied the core genome and the variety of plasmids carrying carbapenemase genes in carbapenem-resistant Klebsiella pneumoniae ST14 (CRKP-ST14), i.e. a sequence type increasingly encountered in countries of the Arabian Peninsula.METHODSAs a preliminary screening, 760 independent CRKP isolated between June 2011-June 2016 in Bahrain (n=20), Kuwait (n=66), Saudi Arabia (n=151), Oman (n=41) and the United Arab Emirates (UAE) (n=482) exhibiting PFGE profiles with ≥80% similarity to known CRKP-ST14 were identified. KPC-, NDM-, OXA-48-like, VIM-, IMP-carbapenemase alleles were identified by PCR and sequencing. Carbapenemase genes were localised by hybridizing the plasmid gels with the respective probes. Whole genome sequencing (WGS) of selected isolates was performed for cgMLST by Ridom SeqSphere+. Sequences of carbapenemase-coding plasmids of representative isolates were established from single plasmid-containing transformants/transconjugants.RESULTSOne hundred and seventy three (22.8%) isolates exhibiting PFGE patterns similar to known ST14 strains were identified. Of these, based on the allele and localisation of carbapenemase genes, as well as on the geographical origin, 39 isolates were subjected to WGS, which confirmed they were ST14. cgMLST revealed three clusters that differed by up to 14 out of 2365 alleles. Representatives of the two major clusters were geographically dispersed and the different carbapenemase plasmids were not associated with any cgMLST clusters.CONCLUSIONSThe emergence of CRKP-ST14 in the Arabian Peninsula is a complex phenomenon exhibiting wide geographical spread of different sub-clones combined with a variety of carbapenemase carrying plasmids, not restricted to any specific cgMLST clusters.