First Clinical Case of Acquisition of DHA-1 Plasmid-Mediated AmpC in a Salmonella enterica subsp. Isolate.

A pan-susceptible serovar Worthington isolate was detected in the stool of a man returning from Sri Lanka. Under ceftriaxone treatment, a third-generation cephalosporin (3GC)-resistant Worthington was isolated after 8 days. Molecular analyses indicated that the two isolates were identical. However, the latter strain acquired a -carrying IncFII plasmid probably from a isolate colonizing the gut. This is the first report of acquisition of plasmid-mediated resistance to 3GCs in .