Detection Of Carbapenemase Gene And Homology Analysis Of Carbapenem-resistant Escherichia Coli From Neonatology

Objectives: To investigate the carbapenemase gene and homology of carbapenem-resistant Escherichia coli isolated from Neonatology in our hospital.Methods: A total of eighteen strains of Escherichia coli suspected to be resistant to carbapenems were collected from stool specimens in Neonatology of our hospital from October 2016 to March 2017.The eighteen strains were detected and their drug sensitivity were tested by VITEK 2 Compact automatic bacterial sensitivity instrument.The phenotype of carbapenemase was identified by modified carbapenem inactivation method(mCIM)and EDTA-carbapenem inactivation method(eCIM).Carbapenemase genes of the strains were determined by PCR.The PCR products of two random strains were purified and the genotype were confirmed by DNA sequencing and BLAST database.Matrix-assisted laser desorption/ionization time-flight mass spectrometry,MALDI-TOF MS,was used to identify the homology of the eighteen strains.Result: The eighteen strains of carbapenem-resistant Escherichia coli were resistant to nearly all of the antimicrobial agents tested,except amikacin and colistin.All the strains were to be positive phenotype and carried NDM gene.The two random strains were confirmed to carry NDM-5 carbapenemase gene.The results of homology analysis showed that eighteen strains of carbapenem-resistant Escherichia coli were the same type.Conclusion: The eighteen carbapenem-resistant strains are homologous and carry NDM-5 carbapenemase gene.To provide a basis for the prevention and treatment of infection,the multi-drug resistant bacteria colonized in the intestinal tract of neonates should be screened.