OXA-48-Like-Producing Klebsiella pneumoniae in Southern Spain in 2014-2015

The aim of this study was to characterize the population structure of 56 OXA-48-like-producing isolates, as well as extended-spectrum β-lactamase (ESBL) and carbapenemase genes, recovered in 2014 and 2015 from 16 hospitals in southern Spain. XbaI pulsed-field gel electrophoresis and multilocus sequence typing were performed to assess clonal relatedness. Representative isolates belonging to OXA-48-like-producing and CTX-M-15-coproducing pulsotypes were selected for characterization of - and -carrying plasmids by PCR-based replicon typing, IncF subtyping, whole-genome sequencing analysis, and typing of Tn structures. Forty-three OXA-48-producing isolates (77%) were recovered from clinical samples and 13 from rectal swabs. All isolates showed ertapenem MIC values of ≥1 mg/liter, although 70% remained susceptible to imipenem and meropenem. Forty-nine isolates (88%) produced OXA-48, 5 produced OXA-245, and 2 produced OXA-181. Twenty-eight different pulsotypes (5 detected in more than 1 hospital) and 16 sequence types (STs) were found. The most prevalent clones were ST15 (29 isolates [52%]) and ST11 (7 isolates [13%]). Forty-five (80%) isolates were also carriers. The gene was mostly (82%) located on IncR plasmids, although ST15 and ST11 isolates also carried this gene on IncF plasmids. The composite transposon variant Tn -like was the most frequent. Among ST15 and ST11 isolates, different transposon variants were observed. The gene was mainly located on IncL plasmids, although IncM plasmids were also observed. The spread of OXA-48-like-producing in southern Spain is mainly due to ST15 and ST11 clones. Variation within clonal lineages could indicate different acquisition events for both ESBL and carbapenemase traits.