The aim of this study was to characterize the population structure of 56 OXA-48-like-producing K. pneumoniae isolates, as well as ESBLs and carbapenemases genes, recovered in 2014 and 2015 from 16 hospitals in southern Spain. XbaI PFGE and MLST were performed to assess clonal relatedness. Representative isolates belonging to OXA-48-like-producing and CTX-M-15-co-producing pulsotypes were selected for characterization of blaOXA-48-like- and blaCTX-M-15-carrying plasmids by PCR-based replicon typing, IncF subtyping, WGS analysis and typing of Tn1999 structures. Forty-three (77%) OXA-48-producing isolates were recovered from clinical samples and 13 from rectal swabs. All isolates showed ertapenem MIC values ≥ 1 mg/L, 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 one hospital) and 16 sequencetypes were found. The most prevalent clones were ST15 (29 isolates, 52%) and ST11 (7 isolates, 13%). Forty-five (80%) isolates were also blaCTX-M-15 carriers. The blaCTX-M-15 gene was mostly (82%) located on IncR plasmids, although ST15 and ST11 isolates also carried this gene on IncF plasmids. The composite transposon variant Tn1999.2-like was the most frequent. Among ST15 and ST11 isolates, different transposon variants were observed. The blaOXA-48 gene was mainly located on IncL plasmids, although IncM plasmids were also observed. The spread of OXA-48-like-producing K. pneumoniae 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.
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