Analysis of molecular epidemiological characteristics and antimicrobial susceptibility of vancomycin-resistant and linezolid-resistant Enterococcus in China.

This study investigates the distribution and characteristics of linezolid and vancomycin susceptibilities among Enterococcus faecalis (E. faecalis) and Enterococcus faecium (E. faecium) and explores the underlying resistance mechanisms. A total of 2842 Enterococcus clinical isolates from patients were retrospectively collected, and their clinical data were further analyzed. The minimum inhibitory concentrations (MICs) of vancomycin and linezolid were validated by broth dilution method. The resistance genes optrA, cfr, vanA, vanB and vanM were investigated using polymerase chain reaction (PCR). Housekeeping genes and resistance genes were obtianed through whole-genome sequencing (WGS). Of the 2842 Enterococcus isolates, 88.5% (2516) originated from urine, with E. faecium accounted for 60.1% of these. The vanA gene was identified in 27/28 vancomycin resistant Enterococcus (VRE) isolates, 4 of which carried both vanA and vanM genes. The remaining strain was vanM positive. The optrA gene was identified in all E. faecalis isolates among linezolid resistant Enterococcus (LRE). E. faecium showed a higher multiple antibiotic resistance index (MAR index) compared to E. faecalis. The multi-locus sequence typing (MLST) showed the sequence type of E. faecium mainly belongs to clonal complex (CC) 17, nearly E. faecalis isolates analyzed were differentiated into 7 characteristics of sequence types (STs), among which ST16 of CC16 were the major lineage. Urine was the primary source of VRE and LRE isolates in this study. E. faecium showed higher levels of resistance compared to E. faecalis. OptrA gene was detected in 91.6% of LRE, which could explain linezolid resistance, and van genes were detected in all vancomycin resistant Enterococcus strains, while vanA was a key resistance mechanism in VRE identified in this study.

Pan P ，Sun L ，Shi X ，Huang X ，Yin Y ，Pan B ，Hu L ，Shen Q ... -  《BMC Medical Genomics》

Characterization of clinical enterococci isolates, focusing on the vancomycin-resistant enterococci in a tertiary hospital in China: based on the data from 2013 to 2018.

Zhou W ，Zhou H ，Sun Y ，Gao S ，Zhang Y ，Cao X ，Zhang Z ，Shen H ，Zhang C ... -  《BMC INFECTIOUS DISEASES》

Surveillance of vancomycin-resistant enterococci reveals shift in dominating clusters from vanA to vanB Enterococcus faecium clusters, Denmark, 2015 to 2022.

Hammerum AM ，Karstensen KT ，Roer L ，Kaya H ，Lindegaard M ，Porsbo LJ ，Kjerulf A ，Pinholt M ，Holzknecht BJ ，Worning P ，Nielsen KL ，Hansen SGK ，Clausen M ，Søndergaard TS ，Dzajic E ，Østergaard C ，Wang M ，Koch K ，Hasman H ... -  《Eurosurveillance》

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 ... -  《-》

Molecular Epidemiology of Vancomycin-Resistant Enterococcus faecalis and Enterococcus faecium Isolated from Clinical Specimens in the Northwest of Iran.

Jahansepas A ，Ahangarzadeh Rezaee M ，Hasani A ，Sharifi Y ，Rahnamaye Farzami M ，Dolatyar A ，Aghazadeh M ... -  《-》