title: Prevalence of the fosfomycin-resistance determinant, fosB3, in Enterococcus faecium clinical isolates from China.
abstract: In order to investigate the prevalence of fosfomycin-resistance (fos) determinants in Enterococcus faecium, clinical strains were collected from hospitals throughout China between January 2008 and December 2009. Antimicrobial susceptibility testing was performed, after which the fos genes in all isolates and van genes in vancomycin-resistant isolates were characterized by PCR and sequencing. Conjugation experiments were carried out with fosB-positive E. faecium, DNA fragments flanking the fosB3 gene were sequenced and the genetic environment of fosB3 was analysed. Fosfomycin-resistant E. faecium (FREF) strains were characterized further by multilocus sequence typing (MLST) and PFGE. Among 145 E. faecium clinical isolates, 10 were resistant to fosfomycin with MICs>1024 mg l(-1) including six vancomycin-resistant strains of which five were vanA-positive and the sixth vanM-positive. All ten FREF strains harboured the fosB3 gene. Fosfomycin resistance and fosB3 could be transferred by conjugation from nine isolates. The fosB3 and tnpA genes were located in a circular DNA intermediate in all FREF strains and reversely inserted into vanA transposon Tn1546 in four vanA-positive FREF isolates. Ten different PFGE types and seven MLST types were found among the ten fosB3-positive isolates, while all strains belonged to the common clonal complex CC17. In conclusion, the transferable fosfomycin-resistance determinant fosB3 plays an important role in E. faecium resistance to fosfomycin in China.
authors.affiliation: Institute of Antibiotics, Huashan Hospital, Fudan University, and Key Laboratory of Clinical Pharmacology of Antibiotics, National Health and Family Planning Commission, Shanghai 200040, PR China.
authors.forename: Chunhui
authors.initials: C
authors.lastname: Chen
authors.affiliation: Institute of Antibiotics, Huashan Hospital, Fudan University, and Key Laboratory of Clinical Pharmacology of Antibiotics, National Health and Family Planning Commission, Shanghai 200040, PR China.
authors.forename: Xiaogang
authors.initials: X
authors.lastname: Xu
authors.affiliation: First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 310016, PR China.
authors.forename: Tingting
authors.initials: T
authors.lastname: Qu
authors.affiliation: First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 310016, PR China.
authors.forename: Yunsong
authors.initials: Y
authors.lastname: Yu
authors.affiliation: Department of Clinical Laboratory, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200127, PR China.
authors.forename: Chunmei
authors.initials: C
authors.lastname: Ying
authors.affiliation: Department of Clinical Laboratory, Shanghai First People's Hospital, Shanghai Jiaotong University, Shanghai 200080, PR China.
authors.forename: Qinzhong
authors.initials: Q
authors.lastname: Liu
authors.affiliation: Institute of Antibiotics, Huashan Hospital, Fudan University, and Key Laboratory of Clinical Pharmacology of Antibiotics, National Health and Family Planning Commission, Shanghai 200040, PR China.
authors.forename: Qinglan
authors.initials: Q
authors.lastname: Guo
authors.affiliation: Institute of Antibiotics, Huashan Hospital, Fudan University, and Key Laboratory of Clinical Pharmacology of Antibiotics, National Health and Family Planning Commission, Shanghai 200040, PR China.
authors.forename: Fupin
authors.initials: F
authors.lastname: Hu
authors.affiliation: Institute of Antibiotics, Huashan Hospital, Fudan University, and Key Laboratory of Clinical Pharmacology of Antibiotics, National Health and Family Planning Commission, Shanghai 200040, PR China.
authors.forename: Demei
authors.initials: D
authors.lastname: Zhu
authors.affiliation: Institute of Antibiotics, Huashan Hospital, Fudan University, and Key Laboratory of Clinical Pharmacology of Antibiotics, National Health and Family Planning Commission, Shanghai 200040, PR China.
authors.forename: Guanghui
authors.initials: G
authors.lastname: Li
authors.affiliation: Institute of Antibiotics, Huashan Hospital, Fudan University, and Key Laboratory of Clinical Pharmacology of Antibiotics, National Health and Family Planning Commission, Shanghai 200040, PR China.
authors.forename: Minggui
authors.initials: M
authors.lastname: Wang
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002681:China / Q000453:epidemiology; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D016984:Enterococcus faecium / Q000235:genetics / Q000378:metabolism*; D005578:Fosfomycin / Q000494:pharmacology*; D016908:Gram-Positive Bacterial Infections / Q000453:epidemiology / Q000382:microbiology*; D006801:Humans; D014640:Vancomycin / Q000494:pharmacology
chemical_list: D001426:Bacterial Proteins; D005578:Fosfomycin; D014640:Vancomycin