First clinical case of in vivo acquisition of DHA-1 plasmid-mediated AmpC in a salmonella enterica subsp. enterica isolate

Abstract

A pan-susceptible <jats:named-content content-type="genus-species">Salmonella enterica</jats:named-content> serovar Worthington isolate was detected in the stool of a man returning from Sri Lanka. Under ceftriaxone treatment, a third-generation cephalosporin (3GC)-resistant <jats:italic>Salmonella</jats:italic> Worthington was isolated after 8 days. Molecular analyses indicated that the two isolates were identical. However, the latter strain acquired a <jats:italic>bla</jats:italic><jats:sub>DHA-1</jats:sub>-carrying IncFII plasmid probably from a <jats:named-content content-type="genus-species">Citrobacter amalonaticus</jats:named-content> isolate colonizing the gut. This is the first report of <jats:italic>in vivo</jats:italic> acquisition of plasmid-mediated resistance to 3GCs in <jats:named-content content-type="genus-species">S. enterica</jats:named-content>.