Molecular characterization of vancomycin-resistant enterococci isolated from a hospital in Beijing, China.

To investigate the occurrence of vancomycin-resistant enterococci (VRE) isolated from patients in Peking Union Medical College Hospital, Beijing, China from 2011 to 2017, and to evaluate their resistance mechanisms and genetic relatedness. All isolates were identified using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF). Antibiotic susceptibility testing was performed using the broth microdilution method. Molecular characterization were detected by PCR and sequencing. Genotyping of VRE isolates was performed by multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE) analysis. Virulence genes were detected by multiplex PCR. A total of 87 consecutive VRE were collected, including 84 isolates of vancomycin resistant Enterococcus faecium (VREfm) and 3 isolates of Enterococcus faecalis (VREfs). Urine (40.2%, 35/87) and blood (17.2%, 15/87) were the most commonly specimens. All VREfm isolates were resistant to ampicillin, and were susceptible to daptomycin, linezolid and tigecycline. The resistant rate of teicoplanin was 47.6%. All of the VREfm isolates carried the vanA gene, no isolates carried vanB. 11.9% (10/84) VREfm isolates carried both vanA and vanM. Among them, 76.2% (64/84) and 66.7% (56/84) carried esp and hyl, respectively. The 3 vancomycin resistant E. faecalis (VREfs) isolates were varied, and only one carried vanB. A total of 3 and 18 STs were detected among VREfs and VREfm strains, respectively. PFGE results indicated a genetic diversity among VREfm isolates. This study confirms that VREfm isolates associated with ST78 were the main epidemic lineage responsible for nosocomial infections in China, as were also observed in other nations worldwide.

Sun HL ，Liu C ，Zhang JJ ，Zhou YM ，Xu YC ... -  《-》

Prevalence of Diverse Clones of Vancomycin-Resistant Enterococcus faecium ST78 in a Chinese Hospital.

Yang J ，Jiang Y ，Guo L ，Ye L ，Ma Y ，Luo Y ... -  《-》

Molecular characterization of vancomycin-resistant Enterococcus spp. clinical isolates recovered from hospitalized patients among several medical institutions in China.

The epidemiology and molecular characteristics of vancomycin-resistant enterococci (VRE) from China deserve further investigation. This study reports on the molecular characterization of 101 unique VRE (96 E. faecium and 5 E. faecalis strains) recovered from diverse samples of 12 hospitals in China. MIC results were obtained by reference broth microdilution methods, and vancomycin resistance and virulence genes were screened by polymerase chain reaction. All strains were subjected to pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing. E. faecalis exhibited vancomycin and teicoplanin MIC results at ≥256 μg/mL and harbored vanA, except for 1 vanB-carrying strain (MIC, 32 and 1 μg/mL, respectively). This strain had a unique PFGE pattern and was associated with ST410 (clonal complex [CC]4). E. faecium displayed vancomycin MIC values of ≥256 μg/mL with variable results for teicoplanin (1-256 μg/mL). One E. faecium had a teicoplanin MIC value of 1 μg/mL and carried a vanB, while the other 2 strains had teicoplanin MIC values of 4 and 8 μg/mL and harbored vanA. E. faecalis strains were susceptible to ampicillin, and all VRE displayed a susceptible phenotype to daptomycin, linezolid, and tigecycline. Four E. faecalis from a particular hospital were grouped within a single PFGE type and were associated with ST470 and ST471 (CC4), which are double- and triple-locus variants of ST410 and ST4, respectively. Overall, E. faecium displayed genetic variability, but clonal dissemination was noted within and among hospitals. All E. faecium belonged to STs associated with CC17, except for 1 strain (ST362; CC362). A total of 77.2% and 29.7% of all strains carried esp and hyl, respectively. In conclusion, these results show that vanA-carrying isolates predominated in strains from China, and E. faecium strains are usually associated with a common and human-adapted lineage (CC17). Unlike the majority of clinical E. faecalis (CC2 and CC9), strains included in this study showed ST profiles similar to ST4 (CC4), which has been associated with human infections in other Asia-Pacific countries.

Sun H ，Wang H ，Xu Y ，Jones RN ，Costello AJ ，Liu Y ，Li G ，Chen M ，Mendes RE ... -  《-》

Molecular characterization of resistance, virulence and clonality in vancomycin-resistant Enterococcus faecium and Enterococcus faecalis: A hospital-based study in Beijing, China.

The incidence of vancomycin-resistant enterococcus (VRE) in China is increasing, the molecular epidemiology of VRE in China is only partly known. This study was conducted to assess the molecular characterization of resistance, virulence and clonality of 69 vancomycin-resistant Enterococcus faecium (VREfm) and seven vancomycin-resistant Enterococcus faecalis (VREfs) isolates obtained from a Chinese hospital between July 2011 and July 2013. The glycopeptide resistance genes (VanA and VanB) were screened by multiplex PCR. The presence of five putative virulence genes (esp, gelE, asa1, hyl and cylA) were evaluated by another multiplex PCR. Multilocus sequence typing (MLST) scheme was used to assess the clonality. All 76 VRE isolates exhibited VanA phenotype and harbored VanA gene. Esp was the only gene detected both in VREfm and VREfs strains, accounting for 89.9% and 42.9%, respectively. The hyl gene was merely positive in 27.5% of VREfm strains. MLST analysis demonstrated three STs (ST6, ST4 and ST470) in VREfs and twelve STs (ST78, ST571, ST17, ST564, ST389, ST18, ST547, ST341, ST414, ST343, ST262 and ST203) in VREfm, which were all designated as CC17 by eBURST algorithm. An outbreak of VREfm belonging to ST571 was found to happen within the neurology ward in this hospital. To our knowledge, this is the first report of ST6 (CC2) VREfs strains in China and the first outbreak report of VREfm strains belonging to ST571 around the world. Our data could offer important information for understanding the molecular features of VRE in China.

Yang JX ，Li T ，Ning YZ ，Shao DH ，Liu J ，Wang SQ ，Liang GW ... -  《-》

Molecular characterization of vancomycin-resistant Enterococcus faecium strains isolated from carriage and clinical samples in a tertiary hospital, Turkey.

Gozalan A ，Coskun-Ari FF ，Ozdem B ，Unaldi O ，Celikbilek N ，Kirca F ，Aydogan S ，Muderris T ，Guven T ，Acikgoz ZC ，Durmaz R ... -  《-》