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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: infection@cgh.org.tw 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.

 



 

Methods:

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).

 



 

Results:

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.

 



 

Conclusion:

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