Emergence of IMP-4-Producing Enterobacter aerogenes Clinical Isolate.

Background: IMP-4 class B metallo-p-lactamase-producing Enterobacteriaceae are resistant to carbapenems. The aim of this study was to characterize of IMP-4 metallo-beta-lactamase (MBL)-producing Enterobacter aerogenes clinical isolate. Methods: IMP-4 MBL-producing E. aerogenes clinical isolate was collected from a Korean Hospital in 2017. Antimicrobial susceptibility was determined by disk diffusion methods. Further, minimum inhibitory concentrations of beta-lactams were determined by Etest. Detection of bla genes was performed by PCR The genetic organization of class 1 integron carrying the MBL gene cassette was investigated by PCR mapping and sequencing. Results: E. aerogenes strain YN170501 exhibited resistance to penicillins, cephalosporins, and carbapenems and was susceptible to monobactam, aminoglycosides, fluoroquinolone, tigecycline, and trimethoprim-sulfamethoxazole. The bla(IMP-)(4) gene was located in class 1 integron. Conclusions: The bla(IMP-)(4) gene has never been reported in Enterobacter aerogenes clinical isolate from Korea.