title: Characteristic of Enterococcus faecium clinical isolates with quinupristin/dalfopristin resistance in China.
abstract: Quinupristin/dalfopristin (Q/D) is a valuable alternative antibiotic to vancomycin for the treatment of multi-drug resistant Enterococcus faecium infections. However, resistance to Q/D in E. faecium clinical isolates and nosocomial dissemination of Q/D-resistant E. faecium have been reported in several countries and should be of concern.
  
  
  
  From January 2012 to December 2015, 911 E. faecium clinical isolates were isolated from various specimens of inpatients at the first Affiliated Hospital of Wenzhou Medical University located in Wenzhou, east China. Of 911 E. faecium clinical isolates, 9 (1.0 %, 9/911) were resistant to Q/D, with the Q/D MIC values of 64 mg/L(1), 32 mg/L(1), 16 mg/L(3), 8 mg/L(1) and 4 mg/L(3) determined by broth microdilution. All Q/D-resistant isolates were susceptible to vancomycin, tigecycline and teicoplanin but resistant to penicillin, ampicillin and erythromycin. vatE was only found in one Q/D-resistant E. faecium isolate while vatD was not detected in any of the isolates tested. 8 of 9 Q/D-resistant E. faecium isolates were found be positive for both ermB and msrC. The combinations of Q/D resistance determinants were ermB-msrC (7 isolates) and ermB-msrC-vatE (one isolate). ST78, ST761, ST94, ST21 and ST323 accounted for 4, 2, 1, 1 and 1 isolate, respectively, among which ST78 was the prevalent ST.
  
  
  
  Q/D-resistant E. faecium clinical isolates were first described in China. Carriage of vatE, ermB and msrC was responsible for Q/D resistance.
authors: Department of Laboratory Medicine, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325000, China.
authors: Shanshan
authors: S
authors: Wang
authors: Department of Laboratory Medicine, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325000, China.
authors: Yinjuan
authors: Y
authors: Guo
authors: Department of Laboratory Medicine, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325000, China.
authors: Jingnan
authors: J
authors: Lv
authors: Department of Laboratory Medicine, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325000, China.
authors: Xiuqin
authors: X
authors: Qi
authors: Department of Laboratory Medicine, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325000, China.
authors: Dan
authors: D
authors: Li
authors: Department of Laboratory Medicine, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325000, China.
authors: Zengqiang
authors: Z
authors: Chen
authors: Department of Laboratory Medicine, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325000, China.
authors: Xueqing
authors: X
authors: Zhang
authors: Department of Respiratory Medicine, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325000, China. 38805@163.com.
authors: Liangxing
authors: L
authors: Wang
authors: Department of Laboratory Medicine, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325000, China. wzjxyfy@163.com.
authors: Fangyou
authors: F
authors: Yu
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics; D002681:China / Q000453:epidemiology; D003428:Cross Infection; D004269:DNA, Bacterial / Q000235:genetics; D024901:Drug Resistance, Multiple, Bacterial; D016984:Enterococcus faecium / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification*; D005798:Genes, Bacterial; D016908:Gram-Positive Bacterial Infections / Q000453:epidemiology / Q000382:microbiology*; D006801:Humans; D008826:Microbial Sensitivity Tests; D058885:Multilocus Sequence Typing / Q000379:methods; D015995:Prevalence; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D014640:Vancomycin / Q000494:pharmacology; D014769:Virginiamycin / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S; D014769:Virginiamycin; C062940:quinupristin-dalfopristin; D014640:Vancomycin
keywords: Enterococcus faecium; Quinupristin/dalfopristin; Resistance