Fecal Carriage and Molecular Epidemiology of Carbapenem-Resistant Enterobacteriaceae from Inpatient Children in a Pediatric Hospital of Shanghai

Qi Xu, Fen Pan, Yan Sun, Chun Wang, Yingying Shi, Tiandong Zhang, Fangyuan Yu, Hong Zhang Department of Clinical Laboratory, Shanghai Children’s Hospital, Shanghai Jiaotong University, Shanghai, People’s Republic of ChinaCorrespondence: Hong Zhang Department of Clinical LaboratoryShanghai Children’s Hospital, Shanghai Jiaotong University, No. 24, Lane 1400, West Beijing Road, Shanghai 200040, People’s Republic of ChinaTel/ Fax +86 21 6247 4880 Ext 82301Email schjyk2015@126.comPurpose: To determine the epidemiology characteristics of intestinal colonization of carbapenem-resistant Enterobacteriaceae (CRE) among inpatients in a pediatric hospital in China.Methods: A retrospective study was conducted from April to December 2019. Medical records were reviewed to extract the clinical information. Antimicrobial susceptibility was performed by broth microdilution method. Drug resistance determinants and plasmid types were analyzed using polymerase chain reaction (PCR) assays. Multilocus sequence typing (MLST) and Enterobacterial repetitive intergenic consensus sequences PCR (ERIC-PCR) were employed to determine the genetic relationships between strains.Results: A total of 90 CRE strains were isolated, with a fecal carriage rate of 8.6% (90/1052), and mainly distributed in E. aerogenes (n=30), K. pneumoniae (n=25) and E. coli (n=23). More than 50% of CRE colonizers had a history of invasive procedures and antibiotic exposures. As high as 91.1% (82/90) of CRE isolates carried carbapenemase genes, with blaNDM-5 (n=56) being the most common, and mainly found in E. aerogenes (51.8%, 29/56) and E. coli (32.1%, 18/56) isolates, which primarily belonged to ST4 (100%, 29/29) and ST692 (55.6%, 10/18), respectively. Followed by blaKPC-2 (n=12), and all found in K. pneumoniae ST11 isolates. Other carbapenemase genes including blaNDM-1, blaIMP-4 and blaIMP-26. Meanwhile, ESBL genes (blaCTX-M, blaTEM-1 and blaSHV) and AmpC genes (blaDHA-1 and blaEBC) were also detected. All CRE isolates showed high resistance to cephalosporins and carbapenemases (97.8%-100.0%) but remained susceptible to tigecycline (98.9%). IncX3 was a major plasmid type in NDM-containing strains (91.3%), and 91.7% of KPC-2-producing K. pneumoniae harboring IncFII and IncFIB plasmids. The ERIC-PCR revealed that several strains with identical STs were genetically similar.Conclusion: This study revealed a major intestinal colonization of ST4 NDM-5 E. aerogenes, ST11 KPC-2 K. pneumoniae and ST692 NDM-5 E. coli strains among inpatients in a pediatric hospital. Infection control measures should be implemented immediately to prevent the spread of these strains in clinical settings.Keywords: intestinal colonization, hospitalized children, ST4, E. aerogenes, NICU, ERIC-PCR