Molecular Characteristics and Dissemination Mechanism of Vancomycin-Resistant Enterococci: A Tertiary vs. Non-Tertiary Health Care Hospitals

Vancomycin-resistant enterococci (VRE) have been endemic in Korea as a nosocomial pathogen. The aim of this study was to examine genetic relatedness and dissemination mechanism by comparative analysis of the antimicrobial and biomolecular characteristics of VRE isolates from tertiary and non-tertiary health care hospitals in Korea. We studied a total of 54 clinical vancocmycin-resistant Enterococcus faecium (VREF) isolates: 18 isolates collected from a tertiary health care hospital (Tertiary) (1,087 beds), and 36 isolates from 20 non-tertiary health care hospitals (Non-Tertiaries) (0-544 beds) in diverse geographical areas of Korea from October 2010 to April 2011. The mimimum inhibitory concentration (MIC)s of vancomycin and teicoplanin, multiplex PCR for resistance genotype, structural analysis of Tn1546, multilocus sequence typing (MLST), virulence factor (esp), and dendrogram of repetitive extragenic palindromic PCR (rep-PCR) were analyzed in all VREF isolates. All the isolates harboured the vanA gene. 15 isolates (41.7%) from Non-Tertiaries and 13 isolates (72.2%) from the Tertiary showed VanB phenotype (P < 0.05). All isolates were divided into 3 main types according to the distribution of IS elements (IS1542 and IS1216V) integrated into Tn1546. The major type of isolates from the Non-Tertiaries was type II (80.6%). Type III was the most prevalent among the isolates from the Tertiary (50.0%). IS1542 was inserted at position 3925 in the orf2-vanR intergenic region. The position of insertion site of IS1216V in the vanX-vanY intergenic region was variable in the Tertiary. All the isolates belonged to clonal complex 17 (CC17), associated with nosocomial infection worldwide. Sequence type (ST) 17 (38.9%) was predominant in Non-Tertiaries. There were 3 largest ST groups of ST18 (27.8%), ST192 (22.2%), and ST78 (22.2%) in the Tertiary. They are single or double locus variant of ST17. The Esp gene was found in 30 isolates (83.3%) from Non-Tertiaries and 12 isolates (66.7%) from the Tertiary (P > 0.05). The dendrogram created using rep-PCR results showed no genetic relatedness between the VREF isolates. These results suggest horizontal transmission of the vanA gene may have occurred among genetically diverse strains of E. faecium between Tertiaries and Non-Tertiaries in Korea.

Author dc:creator

• 정, 민권

Contributors dc:contributor

• 대학원 의학과
• 201024451

• Vancomycin-resistant Enterococcus faecium
• VRE
• vanA
• Tn1546
• Multilocus sequence typing
• MLST
• esp
• Rep-PCR

Language dc:language

ko

Identifier

http://dcoll.ajou.ac.kr:9080/dcollection/jsp/common/DcLoOrgPer.jsp?sItemId=000000012699
000000012699

OAI identifier oai:identifier

oai:repository.ajou.ac.kr:201003/7643