IncHI2 Plasmids Are the Key Vectors Responsible for oqxAB Transmission among Salmonella Species

This study reported and analyzed the complete sequences of two oqxAB -bearing IncHI2 plasmids harbored by a clinical Salmonella enterica serovar Typhimurium strain and an S . Indiana strain of animal origin, respectively. In particular, pA3T recovered from S . Indiana comprised the resistance determinants oqxAB , aac(6′)Ib -cr, fosA3 , and bla CTX-M-14 . Further genetic screening of 63 oqxAB -positive Salmonella isolates revealed that the majority carried IncHI2 plasmids, confirming that such plasmids play a pivotal role in dissemination of oqxAB in Salmonella spp.