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: bla KPC, bla NDM, bla VIM, bla IMP-1, bla OXA-48, bla CTX-M, bla TEM, bla SHV and amp C for β-lactam resistance; qnr A, qnr B, qnrS, aac(6′)-Ib-cr, qep A and mutations of gyr A and par C for fluoroquinolone resistance; and aac A4, aac C2, aad A1, aph A6, arm A and rmt B for aminoglycoside resistance. Enterobacterial repetitive intergenic consensus sequence-based PCR was performed to detect the clonal relatedness. Results. All isolates encoded bla CTX-M, aac C2 and aph A6, together with mutations in gyr A and par C. b la OXA-48, bla NDM-1, aad A1, aac A4, qnr B, aac(6′)-Ib-cr, arm A and/or rmt B 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.