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Volume 39, Number 3, June 2006

Molecular pattern and antimicrobial susceptibility of methicillin-resistant Staphylococcus aureus isolates at a teaching hospital in Northern Taiwan

Pei-Wen Tai, Cheng-Hua Huang, Qin-Dong Lin, Yang-Yang Huang
Division of Infectious Diseases, Department of Internal Medicine, Cathay-General Hospital, Taipei; Department of Medical Education and Research, Cathay-General Hospital, Shijin; and Department of Medical Laboratory, Cathay-General Hospital, Taipei, Taiwan

Received: July 5, 2005    Revised: August 29, 2005    Accepted: August 30, 2005   


Corresponding author:

Dr. Cheng-Hua Huang, Division of Infectious Diseases, Department of Internal Medicine, Cathay-General Hospital. No.280, Jen-Ai Road, Sec. 4, Taipei, Taiwan. E-mail: This e-mail address is being protected from spam bots, you need JavaScript enabled to view it



Background and purpose: 

Methicillin-resistant Staphylococcus aureus (MRSA) infection has progressively increased worldwide. Knowledge of the specific epidemiological pattern of isolates at individual hospitals is important.




MRSA bacteremia was diagnosed in a total of 68 patients from January 2002 through December 2003, stratified for drug susceptibility and molecular pattern (staphylococcal cassette chromosome mec element [SCCmec] typing and genotypes).




SCCmec-A-positive isolates were found on polymerase chain reaction in 58 patients. The most frequent SCCmec types were III (40 cases) of which less than 5% were susceptible to other beta-lactam antibiotics and most were health care-associated, followed by SCCmec type IV (15 cases), that were demonstrated to be community-acquired. SCCmec type IV MRSA isolates were more likely to be susceptible to ciprofloxacin (93.3%), gentamicin (46.7%) and trimethoprim-sulfamethoxazole (93.3%) than type III isolates. All MRSA isolates were susceptible to glycopeptides and vancomycin (minimum inhibitory concentrations <2 μg/mL). Pulsed-field gel electrophoresis with SmaI digestion was used to fingerprint these isolates. A total of 9 genotypes with 26 type-subtypes were identified. Genotype A was the most frequent (9 subtypes) indicating that it is epidemic in this hospital.




After analysis, SCCmec typing could be used to predict drug susceptibility. Specific clones of S. aureus are circulating in hospital and communities in Taiwan.



Key words:

Bacterial typing techniques, epidemiology, methicillin resistance, microbial sensitivity tests, Staphylococcus aureus



J Microbiol Immunol Infect 2006;39:225-230