InEurope,E.colistrainsisolatedfromanimals in 2007 showed resistance above all to tetracycline, nalidixic acid and ampicillin. Strains isolated from chicken droppings were found to have the greatest resistance of all to both nalidixic acid (17.4%) and ciprofloxacin (37.8%)(3).Resistancetothisdrugclasscanbe both chromosomal and plasmid (4) and is related to mutations of the target enzymes of these compounds, DNA gyrase and topoisomeraseIV. DNA gyrase is a tetrameric enzyme which catalyses negative DNA supercoiling and consists of two subunitsA andtwosubunitsB.TopoisomeraseIVisalsoa tetrameric enzyme, consisting of two subunitsC and two subunitsE, and is involved in the separation of daughter chromosomes during DNA replication (5). Resistance caused by point mutations arises spontaneously and results in the substitution of amino acids within the gyrase and topoisomerase genes (gyrA, gyrB, parC and parE), often in combination with reduced membrane porin expression and over‐ expressionoftheeffluxpumpsystem(5). Studiesofstrainsisolatedfromclinicalsources demonstrate that most mutations that induce quinolone resistance are found in gyrase subunitA(gyrA)(10).Thesearemainlyfound in a region called the quinolone resistance