TEM-24 Produced by Four Different Species of Enterobacteriaceae, Including Providencia rettgeri, in a Single Patient

Four species of members of the family Enterobacteriaceae harboring extended-spectrum β-lactamase (ESBL) were recovered in a single patient hospitalized in an intensive care unit. Among these isolates, we describe for the first time an ESBL-producing Providencia rettgeri strain. Bacteria from the same species were shown to be genetically related by pulsed-field gel electrophoresis analysis. These strains produced the same TEM derivative ESBL, characterized as TEM-24. This enzyme had the peculiarity of being encoded by a large conjugative plasmid of 180 kb, never previously described for such an ESBL.