Abstract:
OBJECTIVE To investigate the epidemiological characteristics of bloodstream infections caused by Escherichia coli ST692 co-producing NDM-5 and OXA-181 carbapenemases, and to provide a reference for the rational use of antimicrobial agents in clinical practice.
METHODS From Mar. to Jun. 2022, carbapenem-resistant Escherichia coli (CRECO) strains isolated from infected neonatal bloodstream in a tertiary hospital were collected. The minimum inhibitory concentrations (MIC) of antimicrobial agents were determined by the microbroth dilution method. Carbapenemases were tested by the modified Hodge test, modified carbapenem inactivation method(mCIM) and ethylenediaminetetraacetic acid-carbapenem inactivation method(eCIM). Carbapenemase genes (blaKPC, blaNDM, blaVIM, blaIMP, blaOXA-48) were detected by polymerase chain reaction(PCR), and homogeneity was assessed by multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE).
RESULTS Of 17 CRECO strains isolated from Mar. to Jun. 2022, four were identified in bloodstream from the neonatal intensive care unit. Three of them were ST692 coharboring blaNDM-5 and blaOXA-181, which were 100.00% resistant to cephalosporins, quinolones, sulfonamides and carbapenems, but sensitive to tetracyclines, polypeptides and aminoglycosides. Homogeneity analysis showed that the three strains were highly homologous.
CONCLUSION The three strains of CRECO were all ST692 co-harboring blaNDM-5 and blaOXA-181 and exhibited high resistance to multiple antimicrobial agents. There is a need to strengthen the targeted detection of such type of strains and control its prevalence in healthcare institutions.
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