Within-lineage variability of ST131 Escherichia coli isolates from humans and companion animals in the south of Europe.

Supplementary data at JAC Online). An additional promoter was predicted by Softberry BPROM promoter prediction and consisted of the 235 box of IS18 and a 210 box separated by 13 bp (Figure S1, available as Supplementary data at JAC Online). 10 Interestingly , the TTCAAT 235 box identical to that from Baz (bla OXA-228) was adjacent to the left inverted repeat. OXA-228-like expression in isolate KH243 was compared with that in carbapenem-susceptible A. bereziniae isolate G3-59 by semi-quantitative RT–PCR (qRT– PCR) using rpoB as the reference gene. The primers used for qRT –PCR are shown in Table 1. Three independent experiments were performed using freshly prepared RNA and cDNA and revealed a 56-fold (+3.84) overexpression of bla OXA-228-like in isolate KH243 compared with that in G3-59. To investigate the potential to mediate carbapenem resistance, IS18::bla OXA-257 was cloned into the shuttle vector pWH1266, but we were unable to transfer this into A. bereziniae G3-59. However, the construct was successfully transferred into A. baumannii ATCC 17978 byelectroporation, as previously described for Pseudomonas aeruginosa. 11 Expression of bla OXA-257 in A. baumannii ATCC 17978 raised both imipenem and meropenem MICs from 0.25 to .32 mg/L, demonstrating that IS18::bla OXA-257 is able to confer carbapenem resistance. In conclusion, this study has detected an IS upstream of the intrinsic bla OXA in A. bereziniae, a phenomenon that has not been described in this species so far. IS18 conferred overexpression of OXA-257, which mediated carbapenem resistance in A. bereziniae and A. baumannii. Moreover, because IS18 has previously been described adjacent to acquired bla OXA in A. baumannii, 8 these data suggest a potential for dissemination of OXA-257 in the genus Acinetobacter. 4 Gundi VA, Dijkshoorn L, Burignat S et al. Validation of partial rpoB gene sequence analysis for the identification of clinically important and emerging Acinetobacter species. the Acinetobacter-derived cephalosporinase, carbapenem-hydrolysing oxacillinase and metallo-b-lactamase genes, and of common insertion sequences, in epidemic clones of Acinetobacter baumannii from Spain. Identification of a novel insertion sequence element associated with carbapenem resistance and the development of fluoroquinolone resistance in Acinetobacter radio-resistens. A 10 min method for preparation of highly electrocompetent Pseudomonas aeruginosa cells: application for DNA fragment transfer between chromosomes and plasmid transformation. Research letters 271 JAC Sir, A multiresistant CTX-M-15-producing clonal group of Escherichia coli isolates belonging to phylogroup B2, namely O25b:H4/ ST131, has recently emerged and spread across three continents ; it predominantly causes community-onset infections …