Four novel sequence types in catheter-related MRSE isolates

Abstract

Objective To study the genotypic and biological characteristics of catheter-related MRSE isolates and to further provide information for the diagnosis and prevention of catheter-related bloodstream infection. Methods Thirty strains of catheter-related MRSE isolates were collected from venosus blood and whole blood of 30 inpatients including 20 males and 10 females from Beijing Tongren Hospital, Capital Medical University from January 2006 to December 2009. The genetic features of these strains were determined by MLST. PCR was used to detect the icoA gene (encoding the polysaccharide intercellular adhesion associated with pathogenicity), and the antimicrobial susceptibility test was detected by disc diffusion test. Results A total of 15 STs were obtained from 30 strains ST259, ST20, ST2 and ST235 were common clones obtained from 17 strains. Four novel STs were found and uploaded to the MLST database (http://www. mlst. net), including ST259 (6 strains), ST260 (1 strain), ST261 (1 strain) and ST262 (1 strain). The ST259 was the dominant clone of catheter-related MRSE isolates in this hospital, and 3 strains carrying icaA gene were detected in this study. Conclusion Some ST259 isolates express high pathogenesis among the four novel STs, which may make them as the pandemic strains in nosocomial infection, and this would increase the difficulty of the prevention and control of nosocomial infection. Key words: Methicillin resistance; Staphylococcus epidermidis; Bacterial typing techniques