Objective: To probe into the drug resistance mechanism and clinical transmission characteristics of carbapenem-resistant Enterobacteriaceae in children with pneumonia

and to analyze the prevention and control measures and experience of nosocomial infection. Methods: Totally 46 strains of non-repetitive carbapenem-resistant Enterobacteriaceae isolated from 216 children with pneumonia admitted into Jiangsu Xuzhou Central Hospital from Aug. 2017 to Oct. 2019 were collected for strain identification

drug sensitivity test

genetic testing

homology

transmission characteristics and analysis of relevant clinical data. Children with Klebsiella pneumoniae carrying blaNDM-1 gene were divided into type A group and non-type A group according to pulsed field gel electrophoresis (PFGE) typing

and the relevant data were statistically analyzed. Results: Carbapenem-resistant Enterobacteriaceae in children with pneumonia mainly included 25 strains (54.35%) of K. pneumoniae

7 strains (15.22%) of Escherichia coli

4 strains (8.70%) of Enterobacter cloacae

4 strains (8.70%) of Klebsiella acidophilus

3 strains (6.52%) of Citrobacter flaudi and 3 strains (6.52%) of Serratia marcescens. The sensitivity rate of carbapenem-resistant Enterobacteriaceae to amikacin was 86.10%

and the sensitivity rates to cefazolin

ceftazidime

ceftriaxone

ertapenem

meropenem

imipenem and sulbactam/cefoperazone were respectively 100.00%

100.00%

100.00%

97.70%

95.30% and 95.30%. The positive rates of modified Hodge test and ethylenediamine tetraacetic acid (EDTA) test were respectively 58.70% and 36.97%. A total of 27 strains carrying blaKPC-2 gene

16 strains carrying blaNDM-1 gene and 1 strain carrying blaIMP-4 gene were detected by polymerase chain reaction (PCR). Thirteen strains of K. pneumoniae carrying carbapenem-resistant blaNDM-1 gene were classified into 7 strains of type A

2 strains of type B

1 strain of type C

D

E and F by PFGE. There were statistically significant differences in hospitalization history in intensive care unit (ICU) and length of stay more than or equal to 30 d between type A group and non-type A group (P<0.05). Conclusion: Carbapenem-resistant Enterobacteriaceae shows multiple drug resistance in children with pneumonia. The resistance mechanism is mainly due to the cloning and transmission of carbapenem gene

which is related to the hospitalization history in ICU and prolonged length of stay of children. Therefore

the prevention and control measures of nosocomial infection should be strengthened to prevent the transmission of resistant bacteria.