Emergence of -Type Vancomycin-Resistant ST 78 Strain with a rep2-Type Plasmid Carrying a Tn1546-Like Element Isolated from a Urinary Tract Infection in China.

PURPOSE

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 -positive strains has not been well characterized in China. Here, we report the whole-genome sequence of a -type vancomycin-resistant belonging to sequence type (ST) 78 isolated from a urinary tract infection in China.

PATIENTS AND METHODS

A vancomycin-resistant 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 HiSeq 4000 platform and the MinION platform. Plasmid, genomic and phylogenetic relationship analysis were further performed.

RESULTS

VRE1 was resistant to all antimicrobials tested except for tetracyclines and oxazolidinones. The whole genome of 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 and ; and glycopeptide resistance gene , were located on a -type plasmid carrying a Tn-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 ST78 strain harboring a -carrying plasmid in China. The ST78 clonal group possessed the potential to emerge as a successful -carrying epidemic lineage in China.