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Chunmei Jin,1 Rong Shi,1 Xue Jiang,1 Fuxian Zhou,1 Jixiang Qiang,1 Changshan An2 1Department of Clinical Laboratory, Yanbian University Hospital, Yanji, People’s Republic of China; 2Department of Respiratory Medicine, Yanbian University Hospital, Yanji, People’s Republic of ChinaCorrespondence: Changshan An Tel +86-433-2660064Email cs_an2003@aliyun.comIntroduction: Carbapenem-resistant Enterobacteriaceae (CRE) pose a serious threat to clinical patient management and public health, as they are generally resistant to most antibiotics and cause infections with high mortality rates. Klebsiella pneumoniae ranks second among Enterobacteriaceae species that cause nosocomial infections. In this study, we investigated the epidemic characteristics of carbapenem-resistant K. pneumoniae (CRKP) in the pediatric intensive care unit (PICU) of Yanbian University Hospital.Materials and Methods: A total of 14 non-duplicate CRKP strains, collected from March 2015 to November 2019, were subjected to automated microbial identification and antimicrobial susceptibility tests using the Phoenix-100 ID/AST system. The strains were also subjected to genotypic resistance testing, polymerase chain reaction assays to detect genes encoding carbapenemases and other β-lactamases, multi-locus sequence typing (MLST), and pulsed-field gel electrophoresis (PFGE)-based homology analysis.Results: Two carbapenemase genes, KPC-2 and NDM-1 (in eight and six strains, respectively), were detected. MLST enabled the division of the strains into two sequence types, ST11 and ST1224 (containing eight and six strains, respectively). PFGE results classified the 14 strains into clonotypes A–D, of which clonotypes A and B belonged to ST11, while clonotypes C and D belonged to ST1224.Conclusion: Our study reveals that epidemics of the KPC-2-ST11 and NDM-1-ST1224 strains occurred in the PICU of Yanbian University Hospital. Surveillance and strict implementation of prevention and control measures are crucial to prevent the occurrence and rapid spread of nosocomial infections.Keywords: Klebsiella pneumoniae, carbapenemase, sequence type 1224, pediatric intensive care unit

Chunmei Jin,1 Fuxian Zhou,1 Qingsong Cui,2 Jixiang Qiang,1 Changshan An3 1Department of Clinical Laboratory, Yanbian University Hospital, Yanji, People’s Republic of China; 2Department of Intensive Care Unit, Yanbian University Hospital, Yanji, People’s Republic of China; 3Department of Respiratory Medicine, Yanbian University Hospital, Yanji, People’s Republic of ChinaCorrespondence: Changshan An Tel +86-0433-2660064Email cs_an2003@aliyun.comBackground: Infections caused by the carbapenem-resistant Enterobacter cloacae (CREC) bring great challenges to the clinical treatment and pose a serious threat to public health. In this study, we investigated the molecular characteristics of CREC in a tertiary hospital.Materials and Methods: A total of 12 non-duplicate CREC strains isolated during the period of November 2016 to July 2019 were subjected to automated microbial identification and antimicrobial susceptibility testing (AST) using the BD Phoenix-100 identification and antimicrobial susceptibility testing (ID/AST) system. The strains were also subjected to phenotypic screening for the detection of antibiotic resistance genes such as the carbapenemase and other β-lactamase genes, with the use of the polymerase chain reaction assay (PCR). Finally, multi-locus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE)-based homology analysis were applied.Results: Four types of carbapenemases namely IMP-26, NDM-5, NDM-1, and KPC-2 were identified in 12 CREC strains. IMP-26 was the most prevalent type (6/12 strains, 50 %), followed by NDM-5 (3/12 strains, 25 %). The results of MLST revealed that these 12 strains could be divided into five sequence types (STs) among which ST544 was the dominant type (6/12 strains, 50 %). The PFGE results divided the 12 strains into four clusters.Conclusion: Our study indicated that the epidemics of the IMP-26-producing E. cloacae ST544 strain did occur in the intensive care unit (ICU) of a tertiary hospital. Therefore, early surveillance and strict implementation of control measures are crucial for the prevention of nosocomial infections and transmissions in hospitals.Keywords: Enterobacter cloacae, carbapenemase, IMP-26, ST544