Clinical and molecular epidemiology of carbapenem-resistant Enterobacteriaceae in pediatric inpatients in South China.

Carbapenem-resistant Enterobacteriaceae (CRE) are a substantial health burden. Existing management guidelines are primarily based on clonal evidence. Therefore, epidemiological data are required. We evaluated the risk factors for CRE colonization and described the molecular and clinical characteristics of CRE colonization in pediatric inpatients in Guangzhou, China. Pediatric inpatients from three hospitals in Guangzhou, China, between July 2019 and January 2021 were included. Fecal samples were collected and screened for CRE. Microbiological cultures were grown on MacConkey agar plates, and bacteria were identified with a mass spectrometry microbial identification system. Antimicrobial susceptibility was tested with a VITEK2 system, and carbapenemase genes were amplified. A case-control study was conducted to evaluate the risk factors for fecal CRE colonization in pediatric inpatients. Of 4,033 patients screened, 158 (3.92%) were positive for CRE, including Escherichia coli (51.27%), Klebsiella pneumoniae (37.97%), and Enterobacter cloacae (6.96%). The most common carbapenemase genes were blaNDM-5 (51.89%), blaNDM-1 (15.19%), and blaIMP-4 (7.60%) and blaKPC-2 (3.80%). Hematological malignancies, respiratory diseases, otolaryngological diseases, nervous system diseases, oral administration of third-generation cephalosporins, and the combined use of two or more antibiotics were independently associated with CRE colonization. The most prevalent carbapenem-resistant K. pneumoniae sequence types (STs) were ST11 (8.06%), ST37 (8.06%), and ST76 (8.06%), and the most prevalent carbapenem-resistant E. coli STs were ST10 (9.88%), ST48 (13.58%), and ST58 (8.64%). Pediatric inpatients were colonized by a diversity of CRE strains. Infection control and prevention measures should be implemented to reduce CRE colonization. IMPORTANCE This study assessed the clinical and molecular epidemiology of carbapenem-resistant Enterobacteriaceae in pediatric inpatients at three hospitals in South China by means of screening stool samples for carbapenem-resistant genes and a nested case-control study to determine risk factors for carriage of carbapenem-resistant Enterobacteriaceae. Of 4,033 fecal samples screened, 158 (3.92%) were positive for CRE, including Escherichia coli (51.27 %), Klebsiella pneumoniae (37.97%), and Enterobacter cloacae (6.96%). The most common carbapenemase genes harbored by gastrointestinal CRE strains were blaNDM-5, blaNDM-1, and blaIMP-4. Hematological malignancies, respiratory diseases, otolaryngological diseases, nervous system diseases, oral administration of third-generation cephalosporins, and the combined use of two or more antibiotics were independently associated with CRE colonization.