Molecular profile of carbapenemase-producing Enterobacterales in burn patients

Carbapenemase-producing Enterobacterales (CPE) present a threat to public health worldwide.

To study their prevalence at the Trauma and Burn Center's Burn Unit and investigate their molecular characteristics and their associated antibiotics resistance patterns.

This is a retrospective study conducted at the Trauma and Burn Center's laboratory between july 2017 and december 2018. It included all patients hospitalized in the Trauma and Burn Center's Burn Unit infected with Enterobacterales resistant to carbapenems. The search of the carbapenemases genes was performed by PCR amplification GeneXpert® IV (Cepheid, Sunnyvale, CA, USA) by Xpert® Carba-R kit.

During the study period, among 574 Enterobacterales, 64 strains (11.1%) were resistant to carbapenems, 58 strains (90.6%) of which were CPE. K. pneumoniae was the most predominant bacteria (n=50) fllowed by E. cloacae (n=7), P. mirabilis (n=3), E. aerogenes (n=2), E. coli (n=1) and P. rettgeri (n=1). The most common carbapenemase gene was blaNDM gene (58.6%) followed by blaOXA48 (24.1%). The co-existence of these two genes was identified in ten strains (17.3%). For the 58 CPE, resistance to ertapenem, imipenem and meropenem was 100%, 18.4% and 36.2%, respectively. The highest resistance rates were found to third-generation-cephalosporins (100%), ciprofloxacin (95%) and gentamicin (89.7%). Fosfomycin and colistin had the best susceptibility in vitro with only 5.2% and 4.8% of resistance, respectively.

The high prevalence of CPE in our center requires continued screening and reinforcement of hygiene measures.