Three strains ST1642 Escherichia coli producing NDM-5 carbapenemase from neonatal department / 临床检验杂志

ABSTRACT

Objective@#To analyze the molecular epidemiological characteristics of Escherichia coli producing NDM-5 carbapenemase in the neonatal department of our hospital. @*Methods@#Three carbapenem-resistant Escherichia coli strains（E1, E2 and E3） isolated from neonatal ward of our hospital from August to September of 2017 were collected. Vitek 2 Compact system combined with K-B disk method was used for drug sensitivity test. The resistance genes were detected by PCR amplification. Plasmid replicon typing was detected by PCR. Plasmid conjugation tests were performed to explore the conjugating transfer of plasmids in the three strains. The homology of the three strains was analyzed by multiple locus sequence typing (MLST) and pulse field gel electrophoresis (PFGE). @*Results@#Drug susceptibility test showed that the three bacteria were resistant to most β-lactam antibiotics except Aztreonam, and resistant to quinolones and SMZ-TMP, but sensitive to aminoglycosides drugs. PCR and sequencing results indicated that the three strains carried bla SHV gene and extended-spectrum beta-lactamase gene (bla SHV , bla TEM and bla CTX-M ). The plasmid replicon type was IncX3. Transfer test of E1 strain was successful. MLST results indicated that all the three strains were ST1642 type. MLST and PFGE results indicated that the bands of the three bacteria were identical. @*Conclusion@#Both NDM-5 carbapenemase and extended-spectrum beta-lactamase were detectable in the three strains of carbapenem-resistant bacteria from neonatal department. MLST and PFGE results suggested that the three strains were from the same clonal source.