Characteristics and outcomes of carbapenemase harbouring carbapenem resistant Klebsiella (CRK) blood stream infections: a multicentre prospective cohort study in an OXA-48 endemic setting

A prospective, multicentre observational cohort study was conducted in thirteen tertiary care centres in Turkey from June 2018 to June 2019 (ClinicalTrials.gov identifier NCT03597841). Carbapenemase genes were detected with whole genome sequencing. Sequence types were assigned using MLST profiles from pubMLST on bacterial genomes.A total of 187 patients with CRK bacteraemia were recruited (95% Klebsiella pneumoniae). ST2096 was the predominant clonal type (33%), followed by ST101 (20%) and ST14 (15%). Single OXA-48-like carbapenemases predominated (75%), followed by OXA-48-like/NDM coproducers (16%). OXA-232 constituted 31% of all OXA-48-like carbapenemases and was mainly carried on ST2096. 30-day mortality was 44% overall and 51% for ST2096. In the multivariate cox regression analysis, SOFA score and immunosuppression were significant predictors of 30-day mortality (HR: 1.24, CI 1.15-1.34, P<0.001; HR: 2.14, CI 1.15-4.00, P=0.02), and ST2096 had a non-significant effect (HR: 1.94, CI 0.95-3.96, P=0.07). Colistin resistance rate was 77% overall and 82% for the ST2096 isolates. All non-NDM producers, including all ST2096, remained susceptible to ceftazidime-avibactam in vitro.An emerging OXA-232 carrying ST2096 clone with high mortality and colistin resistance rates predominated among Klebsiella bacteraemia isolates in a previously OXA-48 endemic setting. Ceftazidime-avibactam remained active in vitro against these isolates. High number of OXA-48/NDM coproducers is concerning