Infection and Drug Resistance (Apr 2020)
Emergence of vanA-Type Vancomycin-Resistant Enterococcus faecium ST 78 Strain with a rep2-Type Plasmid Carrying a Tn1546-Like Element Isolated from a Urinary Tract Infection in China
Abstract
Long Sun,1,* Juan Xu,2,* Weizhong Wang,3 Fang He3 1Department of Clinical Laboratory, Hangzhou Women’s Hospital, Hangzhou Maternity and Child Health Care Hospital, Hangzhou, Zhejiang 310008, People’s Republic of China; 2Institute of Hygiene, Zhejiang Academy of Medical Sciences, Hangzhou Medical College, Hangzhou, Zhejiang 310013, People’s Republic of China; 3Department of Clinical Laboratory, Zhejiang Provincial People’s Hospital, People’s Hospital of Hangzhou Medical College, Hangzhou, Zhejiang 310014, People’s Republic of China*These authors contributed equally to this workCorrespondence: Fang He Tel/Fax +86-571-8821-5596Email [email protected]: The emergence of vancomycin-resistant enterococci (VRE) dramatically narrows therapeutic options. Although the prevalence of VRE in China has maintained a low level, VRE outbreaks have been reported in some tertiary hospitals in the developed areas of China. The clonal background of vanA-positive Enterococcus faecium strains has not been well characterized in China. Here, we report the whole-genome sequence of a vanA-type vancomycin-resistant E. faecium belonging to sequence type (ST) 78 isolated from a urinary tract infection in China.Patients and Methods: A vancomycin-resistant E. faecium was isolated from a 66-year-old male patient diagnosed with brainstem hemorrhage. Antibiotic susceptibility assays were performed according to the guidelines of the Clinical and Laboratory Standards Institute (CLSI). Complete genome sequencing was performed using both the HiSeqTM 4000 platform and the MinION platform. Plasmid, genomic and phylogenetic relationship analysis were further performed.Results: E. faecium VRE1 was resistant to all antimicrobials tested except for tetracyclines and oxazolidinones. The whole genome of E. faecium VRE1 was composed of one chromosomal DNA and four plasmids. Two virulence genes and five antimicrobial resistance genes were identified. In silico multilocus sequence typing (MLST) showed that it belonged to ST78 (clonal complex CC17), a well-known epidemic clone that is widespread in Europe and the United States. Three antimicrobial resistance genes, including aminoglycoside resistance genes ant(6)-Ia and aph(3ʹ)-III; and glycopeptide resistance gene vanA, were located on a rep2-type plasmid carrying a Tn 1546-like element that has not been reported. The most closely related strain harboring a similar plasmid backbone was recovered from fodder sample in China that differed by 178 cgMLST loci.Conclusion: Our study characterizes the genomic feature of a vancomycin-resistant E. faecium ST78 strain harboring a vanA-carrying plasmid in China. The ST78 clonal group possessed the potential to emerge as a successful vanA-carrying epidemic lineage in China.Keywords: Enterococcus faecium, vancomycin-resistant enterococci, vanA, whole-genome sequencing, Tn 1546-like element
