AUTHOR=Manageiro Vera , Félix David , Jones-Dias Daniela , Sampaio Daniel A. , Vieira Luís , Sancho Luísa , Ferreira Eugénia , Caniça Manuela 

TITLE=Genetic Background and Expression of the New qepA4 Gene Variant Recovered in Clinical TEM-1- and CMY-2-Producing Escherichia coli

JOURNAL=Frontiers in Microbiology

VOLUME=8

YEAR=2017

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2017.01899

DOI=10.3389/fmicb.2017.01899

ISSN=1664-302X

ABSTRACT=<p>A new QepA4 variant was detected in an O86:H28 ST156-<italic>fimH38 Escherichia coli</italic>, showing a multidrug-resistance phenotype. PAβN inhibition of <italic>qepA4-</italic>harboring transconjugant resulted in increase of nalidixic acid accumulation. The <italic>qepA4</italic> and <italic>catA1</italic> genes were clustered in a 26.0-kp contig matching an IncF-type plasmid, and containing a Tn21-type transposon with multiple mobile genetic elements. This QepA variant is worrisome because these determinants might facilitate the selection of higher-level resistance mutants, playing a role in the development of resistance, and/or confer higher-level resistance to fluoroquinolones in association with chromosomal mutations.</p>