Quinolone Resistance Mechanisms in Salmonella enterica Serovars Hadar, Kentucky, Virchow, Schwarzengrund, and 4,5,12:i:-, Isolated from Humans in Switzerland, and Identification of a Novel qnrD Variant, qnrD2, in S. Hadar

Human isolates of Salmonella enterica serovars Hadar, Kentucky, Virchow, Schwarzengrund, and the monophasic variant of S. Typhimurium, Salmonella enterica subsp. enterica serovar 4,5,12:i:-were examined for mutations within the quinolone resistance target genes gyrA, gyrB, parC, and parE and for plasmid-mediated resistance genes. Differences were observed among the serovars. A novel variant of qnrD, qnrD2, was detected in an S. Hadar isolate.