Antibiotic susceptibility and molecular analyses of clinical Enterobacter cloacae isolates in Eastern Heilongjiang Province, China.

BACKGROUND

Enterobacter cloacae is an emerging opportunistic pathogen. We retrospectively conducted a study to assess antimicrobial susceptibility and investigated the Molecular characteristics of carbapenem-resistant Enterobacter cloacae (CREL) isolates.

METHODS

Three hundred forty-two isolates of Enterobacter cloacae were collected from January 2014 to December 2018. Ten strains of CREL were collected for further research. The species identifications and minimum inhibitory concentrations (MICs) of all antibiotics tested were analyzed using the Vitek 2 Compact system (BioMerieux, France) and supplemented by the disk diffusion method. Polymerase chain reaction (PCR) was performed to detect extended-spectrum β-lactamase (ESBL) and carbapenemase resistance genes.

RESULTS

The results showed that most of the isolates remained susceptible to tested antibiotics; however, the resistance rate of Cefepime has been increasing in recent years. One strain co-producing New Delhi Metallo-β-lactamase NDM-1 and Imipenem hydrolase IMP-4. NDM-1 and IMP-4-producing isolates highlight that active surveillance is necessary to prevent the further spread of the bacteria. Multilocus sequence typing (MLST) showed that two KPC-producing isolates assigned to ST93, two isolates carrying NDM-1 assigned to ST1120. Moreover, the MEGA analysis showed that ST93, ST256, and ST1120 have homology, showing that CREL in our area has a potential spread risk.

CONCLUSIONS

These findings indicating that CREL clonal dissemination may occurred in this region and should be taken seriously concern. Our study highlights an urgent need to monitor these isolates to prevent their further spread.