title: Fluoroquinolone-resistance mechanisms and phylogenetic background of clinical Escherichia coli strains isolated in south-east Poland.
abstract: Fluorochinolones are a class of broad-spectrum antimicrobials in the treatment of several infections, including those caused by Escherichia coli. Due to the increasing resistance of bacteria to antimicrobials, an understanding of fluoroquinolone resistance is important for infection control. The aim of this study was to determine susceptibility of clinical E. coli strains to fluoroquinolones and characterize their mechanisms of quinolone resistance. Totally, 79 non-duplicate clinical E. coli isolates included in this study were mainly from skin lesion -36 (45.6%) isolates; 54 (68.4%) isolates were assigned to phylogenetic B2 group. Resistance to ciprofloxacin was found in 20 isolates. In the quinolone resistance-determining region (QRDR) region of gyrA and parC, 4 types of point mutations were detected. Mutations in parC gene were found in all strains with gyrA mutations. Predominance of double mutation in codon 83 and 87 of gyrA (90%) and in codon 80 of parC (90%) was found. Moreover, plasmid-mediated quinolone resistance (PMRQ) determinants (qnrA or qnrB and/or aac(6')-Ib-cr) were present in 5 (25%) out of 20 fluoroquinolone-resistant isolates. Resistance to fluoroquinolones in all of the tested clinical E. coli isolates correlated with point mutations in both gyrA and parC. The majority of fluoroquinolone-resistant strains belonged to D and B2 phylogenetic groups.
authors.affiliation: Department of Pharmaceutical Microbiology with Laboratory for Microbiological Diagnostics, Medical University of Lublin, Poland.
authors.forename: Izabela
authors.initials: I
authors.lastname: Korona-Glowniak
authors.affiliation: Department of Pharmaceutical Microbiology with Laboratory for Microbiological Diagnostics, Medical University of Lublin, Poland.
authors.forename: Kinga
authors.initials: K
authors.lastname: Skrzypek
authors.affiliation: Department of Pharmaceutical Microbiology with Laboratory for Microbiological Diagnostics, Medical University of Lublin, Poland.
authors.forename: Radosław
authors.initials: R
authors.lastname: Siwiec
authors.affiliation: History of Medical Sciences Department, Medical University of Lublin, Poland.
authors.forename: Andrzej
authors.initials: A
authors.lastname: Wrobel
authors.affiliation: Department of Pharmaceutical Microbiology with Laboratory for Microbiological Diagnostics, Medical University of Lublin, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Malm
mesh_terms: D000900:Anti-Bacterial Agents / Q000145:classification / Q000494:pharmacology*; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics; D004927:Escherichia coli Infections / Q000453:epidemiology* / Q000382:microbiology*; D024841:Fluoroquinolones / Q000494:pharmacology*; D006801:Humans; D010802:Phylogeny; D011044:Poland / Q000453:epidemiology
chemical_list: D000900:Anti-Bacterial Agents; D024841:Fluoroquinolones
keywords: Escherichia coli; Fluorochinolone resistance; PMQR determinants; Phylogenetic groups; QRDR mutations