Characterization of the Plasmid-Borne Quinolone Resistance Gene qnrB19 in Salmonella enterica Serovar Typhimurium

A qnrB19 gene variant, carried by an IncL/M-like plasmid, was detected in a multidrug Salmonella enterica serovar Typhimurium human strain with reduced susceptibility to ciprofloxacin. The genetic environment around the gene was fully sequenced (20 kb). A large gene cluster, containing the aph, qnrB19, and bla(SHV-12)-like resistance genes, is inserted inside a Tn3 transposon.