First Clinical Case of In VivoAcquisition of DHA-1 Plasmid-Mediated AmpC in a Salmonella entericasubsp. entericaIsolate

A pan-susceptible Salmonella entericaserovar Worthington isolate was detected in the stool of a man returning from Sri Lanka. Under ceftriaxone treatment, a third-generation cephalosporin (3GC)-resistant SalmonellaWorthington was isolated after 8 days. Molecular analyses indicated that the two isolates were identical. However, the latter strain acquired a blaDHA-1-carrying IncFII plasmid probably from a Citrobacter amalonaticusisolate colonizing the gut.