The first report of Enterobacter gergoviae carrying bla(NDM-1) in Iran

OBJECTIVE(S): Prompt detection of extended-spectrum β-lactamases (ESBL) and carbapenemase-producing enterobacteriaceae is crucial for infection prevention and control strategies. The present study aimed to characterize the ESBL and carbapenemase genes among Enterobacter isolates from an Iranian inpatient population. MATERIALS AND METHODS: A total of 96 Enterobacter isolates obtained from inpatients between June 2016 and March 2017, were identified by the conventional microbiological methods and diagnostic kits. Antimicrobial susceptibility pattern was performed using the disk diffusion method. The ESBL and carbapenemase genes were screened using polymerase chain reaction (PCR). RESULTS: All clinical isolates of Enterobacter were classified as E. gergoviae (52, 54.2%), E. aerogenes (34, 35.4%), E. cloacae (7, 7.3%), Cronobacter (E). sakazakii (3, 3.1%). The highest and lowest antimicrobial resistance rates were observed against ampicillin (93.8%) and imipenem (21.9%). High prevalence of multi-drug resistance (MDR=96.9%) was substantial. Of the 96 Enterobacter isolates, 35 (36.5%) and 28 (29.2%) were phenotypically ESBL-positive and non-susceptible carbapenem, respectively. Overall, the frequency of evaluated genes was as follows: bla(CTX-M) =25 (26%), bla(TEM) =30 (31.3%), bla(SHV) =12 (12.5%), bla(IMP) =3 (3.1%), bla(VIM) =0 (0%), bla(NDM) =8 (8.3%), and bla(KPC) =0 (0%). CONCLUSION: In this study, we report for the first time the presence of E. gergoviae harboring bla(NDM) from an Iranian population. Regarding the increase of MDR Enterobacter spp. in our region, strict hygiene rules will be needed to control the quick spread of ESBL and carbapenemase-producing Enterobacter isolates in healthcare facilities of developing countries.