First description of methyltransferases in extensively drug-resistant Klebsiella pneumoniae isolates from Saudi Arabia.

PURPOSE: The resistance determinants for carbapenems, fluoroquinolones and aminoglycosides were characterized in 16 extensively drug-resistant Klebsiella pneumoniae (XDRKPN) strains collected from Saudi hospitals during 2014.

METHODOLOGY: PCR and sequencing were used to detect: blaKPC, blaNDM, blaVIM, blaIMP-1,blaOXA-48, blaCTX-M, blaTEM, blaSHV and ampC for β-lactam resistance; qnrA, qnrB, qnrS, aac(6')-Ib-cr, qepA and mutations of gyrA and parC for fluoroquinolone resistance; and aacA4, aacC2, aadA1, aphA6, armA and rmtB for aminoglycoside resistance. Enterobacterial repetitive intergenic consensus sequence-based PCR was performed to detect the clonal relatedness.

RESULTS: All isolates encoded blaCTX-M, aacC2 and aphA6, together with mutations in gyrA and parC. blaOXA-48, blaNDM-1, aadA1, aacA4, qnrB, aac(6')-Ib-cr, armA and/or rmtB were detected in different strains. At least 93.2 % clonal relatedness was detected among these strains.

CONCLUSIONS: To our knowledge, this is the first report describing XDRKPN encoding at least seven resistance determinants and harbouring methyltransferases in Saudi Arabia.