1. Department of Microbiology, College of Basic Medical Science Dalian Medical University Dalian P.R. China
2. The Liaoning Province People's Hospital Shenyang P.R. China
3. Laboratory of Pathogenic Biology, College of Basic Medical Science Dalian Medical University Dalian P.R. China
4. Department of General Surgery, The First Affiliated Hospital Dalian Medical University Dalian P.R. China