title: Increasing resistance in multiresistant methicillin-resistant Staphylococcus aureus clones isolated from a Chinese hospital over a 5-year period.
abstract: BACKGROUND
  The aim was to study the changes in the antimicrobial resistance of methicillin-resistant Staphylococcus aureus (MRSA) clones over a 5-year period (from 2000 to 2005) at a representative hospital in Beijing, China.
  
  
  METHODS
  A total of 100 randomly selected MRSA strains were analyzed using antimicrobial susceptibility testing, pulsed-field gel electrophoresis, spa typing, multilocus sequence typing, SCCmec typing, and PCR for the Panton-Valentine leukocidin virulence factor.
  
  
  RESULTS
  Resistance to rifampin greatly increased from 32% (16/50) to 68% (34/50). High-level mupirocin-resistant isolates were found only in 2005, when four were identified. Intermediate susceptibly to quinupristin-dalfopristin increased from 22% (11/50) to 52% (26/50) between 2000 and 2005. The main antimicrobial resistance profiles changed from TC-GM-CI-EM-CM in 2000 to TC-GM-CI-EM-CM-RI in 2005. The main pulsed-field gel electrophoresis type changed from types C, L, and E in 2000 to types J, F, and N, respectively, in 2005. ST239-MRSA-III was the most predominant clone in 2000 and 2005, whereas ST5-MRSA-II was found only in 2005.
  
  
  CONCLUSIONS
  There were increasing levels of antimicrobial resistance and epidemiological changes in the hospital-associated MRSA strains isolated in this facility between 2000 and 2005.
authors.affiliation: National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.
authors.forename: Xiaomei
authors.initials: X
authors.lastname: Yan
authors.forename: Xiaoxia
authors.initials: X
authors.lastname: Tao
authors.forename: Lihua
authors.initials: L
authors.lastname: He
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Cui
authors.forename: Jianzhong
authors.initials: J
authors.lastname: Zhang
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001427:Bacterial Toxins / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D002681:China / Q000453:epidemiology; D002999:Clone Cells / Q000382:microbiology; D016521:Electrophoresis, Gel, Pulsed-Field; D005098:Exotoxins / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D006786:Hospitals, Urban; D006801:Humans; D007956:Leukocidins / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D016106:Methicillin Resistance / Q000187:drug effects / Q000235:genetics*; D055624:Methicillin-Resistant Staphylococcus aureus / Q000145:classification / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D008826:Microbial Sensitivity Tests; D058885:Multilocus Sequence Typing; D012137:Respiratory System / Q000382:microbiology*; D013203:Staphylococcal Infections / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology*; D013211:Staphylococcus aureus; D013997:Time Factors; D014769:Virginiamycin / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D001427:Bacterial Toxins; D005098:Exotoxins; D007956:Leukocidins; C078284:Panton-Valentine leukocidin; D014769:Virginiamycin; C062940:quinupristin-dalfopristin