Isler, BurcuFalconer, CaitlinVatansever, CanselOzer, BernaCinar, GuleAslan, Abdullah TarikPaterson, David L.2024-07-052024-07-05202210022-26151473-564410.1099/jmm.0.0016292-s2.0-85147460921https://doi.org/10.1099/jmm.0.001629https://hdl.handle.net/20.500.14411/1645Tukenmez Tigen, Elif/0000-0003-2027-4116; DOGAN, OZLEM/0000-0002-6505-4582; Azap, Alpay/0000-0001-5035-055X; Keske, Şiran/0000-0003-3823-4454; Vatansever, Cansel/0000-0003-3703-1882; Kapmaz, Mahir/0000-0002-4115-3914; Harris, Patrick/0000-0002-2895-0345; Isler, Burcu/0000-0003-1362-2434; Ergonul, Onder/0000-0003-1935-9235Introduction. Aminoglycosides are used for the treatment of carbapenemase-producing Klebsiella pneumoniae (CPK) infections. 16S rRNA methyltransferases (RMTs) confer resistance to all aminoglycosides and are often cocarried with NDM. Hypothesis/Gap Statement. There is a dart of studies looking at the aminoglycoside resistance mechanisms for invasive CPK isolates, particularly in OXA-48 endemic settings. Aim. We aimed to determine the prevalence of RMTs and their association with beta lactamases and MLSTs amongst aminoglycoside-resistant CPK bloodstream isolates in an OXA-48 endemic setting. Methodology. CPK isolates (n=181), collected as part of a multicentre cohort study, were tested for amikacin, gentamicin and tobramycin susceptibility using custom-made sensititre plates (GN2XF, Thermo Fisher Scientific). All isolates were previously subjected to whole-genome sequencing. Carbapenemases, RMTs, MLSTs and plasmid incompatibility groups were detected on the assembled genomes. Results. Of the 181 isolates, 109(60 %) were resistant to all three aminoglycosides, and 96 of 109(88 %) aminoglycoside-resistant isolates carried an RMT (85 ArmA, 10 RmtC, 4 RmtF1; three isolates cocarried ArmA and RmtC). Main clonal types associated with ArmA were ST2096 (49/85, 58%) and ST14 (24/85, 28 %), harbouring mainly OXA-232 and OXA-48 +NDM, respectively. RmtC was cocarried with NDM (5/10) on ST395, and NDM +OXA-48 or NDM +KPC (4/10) on ST14, ST15 and ST16. All RMT producers also carried CTX-M- 15, and the majority cocarried SHV-106, TEM-150 and multiple other antibiotic resistance genes. The majority of the isolates harboured a combination of IncFIB, IncH and IncL/M type plasmids. Non-NDM producing isolates remained susceptible to ceftazidime-avibactam. Conclusion. Aminoglycoside resistance amongst CPK bloodstream isolates is extremely common and mainly driven by clonal spread of ArmA carried on ST2096 and ST14, associated with OXA-232 and OXA48 +NDM carriage, respectively.eninfo:eu-repo/semantics/closedAccess16S rRNA methyltransferaseArmAaminoglycoside resistancebloodstreamcarbapenem-resistantKlebsiella pneumoniaeNDMOXA-48OXA-232ArticleQ37112WOS:00112957990001236748503