Tn <i>6450</i> , a Novel Multidrug Resistance Transposon Characterized in a Proteus mirabilis Isolate from Chicken in China

Abstract

A novel 65.8-kb multidrug resistance transposon, designated Tn<i>6450</i>, was characterized in a <i>Proteus mirabilis</i> isolate from chicken in China. Tn<i>6450</i> contains 18 different antimicrobial resistance genes, including cephalosporinase gene <i>bla</i>_DHA-1 and fluoroquinolone resistance genes <i>qnrA1</i> and <i>aac(6</i>'<i>)-Ib-cr</i> It carries a class 1/2 hybrid integron composed of <i>intI2</i> and a 3' conserved segment of the class 1 integron. Tn<i>6450</i> is derived from Tn<i>7</i> via acquisition of new mobile elements and resistance genes.