title: Molecular Characteristics of Carbapenem-ResistantEnterobacter cloacaein Ningxia Province, China.
abstract: The emergence of carbapenem-resistantEnterobacteriaceae(CRE) has become a major public health concern worldwide and a new challenge in the treatment of infectious diseases. The molecular characteristics ofEnterobacter cloacaein Ningxia China are unknown. In this study, we reported 10 carbapenem-resistantE. cloacaeisolates from the General Hospital of Ningxia Medical University, the largest university hospital in Ningxia between January 2012 and December 2013. Bacteria isolates were identified by Vitek2 compact and the identity of non-duplicateE. cloacaeisolates was further confirmed by PCR and sequencing. The drug susceptibility and phenotype identification of these isolates were analyzed by agar dilution method, modified Hodge test (MHT), and EDTA synergy test. Beta-lactamase (bla) genesblaNDM-1was found in 8 out of 10 isolates. Most isolates harbored multiple resistance genes includingblaESBL,blaAmpC, quinolones, aminoglycosides, and disinfectant resistance genes. Pulsed field gel electrophoresis (PFGE) showed that theseE. cloacaeisolates were grouped into 6 clusters based on a cutoff of 80% genetic similarity. In conjugative assay, 9 out of 10 isolates transferred carbapenem-resistant genes toEscherichia coli. Our study has revealed that NDM-1-producing isolates are the most prevalent carbapenem-resistantE. cloacaein Ningxia. These isolates also carry several other carbapenem-resistant genes and can transfer these genes to other bacteria through conjugation. These findings highlight an urgent need to monitor these isolates to prevent their further spread in this region.
authors.affiliation: Medical Experimental Center, General Hospital of Ningxia Medical UniversityYinchuan, China; Key Laboratory of Ningxia Clinical Pathogenic MicroorganismsYinchuan, China.
authors.forename: Zhiyun
authors.initials: Z
authors.lastname: Shi
authors.affiliation: Department of Laboratory, Institute of Clinical Medicine, Ningxia Medical UniversityYinchuan, China; Hematology and Oncology Center, Yanda Hospital of Hebei ProvinceLangfang, China.
authors.forename: Huizheng
authors.initials: H
authors.lastname: Zhao
authors.affiliation: Medical Experimental Center, General Hospital of Ningxia Medical UniversityYinchuan, China; Key Laboratory of Ningxia Clinical Pathogenic MicroorganismsYinchuan, China.
authors.forename: Gang
authors.initials: G
authors.lastname: Li
authors.affiliation: Medical Experimental Center, General Hospital of Ningxia Medical UniversityYinchuan, China; Key Laboratory of Ningxia Clinical Pathogenic MicroorganismsYinchuan, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Jia
keywords: Enterobacteriaceae; New Delhi metallo-beta-lactamase-1; antibiotic susceptibility; carbapenem resistance; genetic homologeneity