Characterization of a Novel SXT/R391 Integrative and Conjugative Element Carrying cfr, blaCTX-M-65, fosA3, and aac(6′)-Ib-cr in Proteus mirabilis

A novel 139,487-bp SXT/R391 integrative and conjugative element, ICEPmiChnBCP11, was characterized in Proteus mirabilis of swine origin in China. ICEPmiChnBCP11 harbors 20 different antimicrobial resistance genes, including the clinically important rRNA methyltransferase gene cfr, the extended-spectrum beta-lactamase gene bla(CTX-M-65), fosfomycin resistance gene fosA3, and fluoroquinolone resistance gene aac(6')-Ib-cr. An ISPpu12-mediated composite transposon containing various resistance genes and 10 copies of IS26 is inserted in hot spot 4. ICEPmiChnBCP11 was successfully transferred to Escherichia coli.