Molecular epidemiology of community-acquired methicillin-resistant Staphylococcus aureus bacteremia in a teaching hospital.
OBJECTIVE
Methicillin-resistant Staphylococcus aureus (MRSA) is a key nosocomial pathogen globally. Community-acquired MRSA (CA-MRSA) infections have become a growing problem in recent years. The purpose of this 4-year retrospective study was to analyze the molecular epidemiology and susceptibility pattern of isolates from adults (> or =18 years of age) with CA-MRSA bacteremia in northern Taiwan.


METHODS
Molecular epidemiology of CA-MRSA isolates was analyzed by pulsed-field gel electrophoresis. Antimicrobial susceptibility was tested by the disk diffusion method and the minimal inhibitory concentration was determined by Etest.


RESULTS
Thirty eight patients with CA-MRSA bacteremia were enrolled. Thirty one CA-MRSA isolates were available for further molecular typing and susceptibility testing. A total of 13 distinct genotypes were identified and 48.4% (15/31) of the isolates were found to belong to genotype A. Genotype A CA-MRSA isolates were closely associated with the nosocomial strains. All CA-MRSA isolates were multidrug resistant (19.4% susceptible to clindamycin and 25.8% to trimethoprim-sulfamethoxazole) and consistent susceptibility was only observed to glycopeptides, rifampin, and linezolid.


CONCLUSIONS
This study demonstrated that although CA-MRSA genotypes were heterogeneous, the predominant genotype that was circulating in our community was genotype A. Also, the multidrug resistance of CA-MRSA might be connected to the spreading of nosocomial strains in the community.
Chi
Chih-Yu
CY
Section of Infectious Diseases, Department of Internal Medicine, China Medical University Hospital, North District, Taichung, Taiwan.
Ho
Mao-Wang
MW
Ho
Cheng-Mao
CM
Lin
Po-Chang
PC
Wang
Jen-Hsian
JH
Fung
Chang-Phone
CP
D000328:Adult; D016470:Bacteremia / Q000453:epidemiology* / Q000235:genetics / Q000382:microbiology; D017714:Community-Acquired Infections / Q000453:epidemiology / Q000382:microbiology; D024901:Drug Resistance, Multiple, Bacterial; D016521:Electrophoresis, Gel, Pulsed-Field; D005838:Genotype; D006784:Hospitals, Teaching; D006801:Humans; D016106:Methicillin Resistance / Q000235:genetics; D017720:Molecular Epidemiology; D013203:Staphylococcal Infections / Q000453:epidemiology* / Q000382:microbiology; D013211:Staphylococcus aureus / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D013624:Taiwan / Q000453:epidemiology